diff --git a/src/house.h b/src/house.h
index 512665ae71..0f362f83df 100644
--- a/src/house.h
+++ b/src/house.h
@@ -52,35 +52,40 @@ static constexpr BuildingFlags BUILDING_2_TILES_X   = {BuildingFlag::Size2x1, Bu
 static constexpr BuildingFlags BUILDING_2_TILES_Y   = {BuildingFlag::Size1x2, BuildingFlag::Size2x2};
 static constexpr BuildingFlags BUILDING_HAS_4_TILES = {BuildingFlag::Size2x2};
 
-enum HouseZonesBits : uint8_t {
-	HZB_BEGIN     = 0,
-	HZB_TOWN_EDGE = 0,
-	HZB_TOWN_OUTSKIRT,
-	HZB_TOWN_OUTER_SUBURB,
-	HZB_TOWN_INNER_SUBURB,
-	HZB_TOWN_CENTRE,
-	HZB_END,
-};
-static_assert(HZB_END == 5);
+enum class HouseZone : uint8_t {
+	TownEdge = 0,
+	TownOutskirt = 1,
+	TownOuterSuburb = 2,
+	TownInnerSuburb = 3,
+	TownCentre = 4,
+	TownEnd,
 
-DECLARE_INCREMENT_DECREMENT_OPERATORS(HouseZonesBits)
-
-enum HouseZones : uint16_t {
-	HZ_NOZNS             = 0x0000,  ///<       0          This is just to get rid of zeros, meaning none
-	HZ_ZON1              = 1U << HZB_TOWN_EDGE,    ///< 0..4 1,2,4,8,10  which town zones the building can be built in, Zone1 been the further suburb
-	HZ_ZON2              = 1U << HZB_TOWN_OUTSKIRT,
-	HZ_ZON3              = 1U << HZB_TOWN_OUTER_SUBURB,
-	HZ_ZON4              = 1U << HZB_TOWN_INNER_SUBURB,
-	HZ_ZON5              = 1U << HZB_TOWN_CENTRE,  ///<  center of town
-	HZ_ZONALL            = 0x001F,  ///<       1F         This is just to englobe all above types at once
-	HZ_SUBARTC_ABOVE     = 0x0800,  ///< 11    800        can appear in sub-arctic climate above the snow line
-	HZ_TEMP              = 0x1000,  ///< 12   1000        can appear in temperate climate
-	HZ_SUBARTC_BELOW     = 0x2000,  ///< 13   2000        can appear in sub-arctic climate below the snow line
-	HZ_SUBTROPIC         = 0x4000,  ///< 14   4000        can appear in subtropical climate
-	HZ_TOYLND            = 0x8000,  ///< 15   8000        can appear in toyland climate
-	HZ_CLIMALL           = 0xF800,  ///< Bitmask of all climate bits
+	ClimateSubarcticAboveSnow = 11, ///< Building can appear in sub-arctic climate above the snow line
+	ClimateTemperate = 12, ///< Building can appear in temperate climate
+	ClimateSubarcticBelowSnow = 13, ///< Building can appear in sub-arctic climate below the snow line
+	ClimateSubtropic = 14, ///< Building can appear in subtropical climate
+	ClimateToyland = 15, ///< Building can appear in toyland climate
+};
+using HouseZones = EnumBitSet<HouseZone, uint16_t>;
+
+static constexpr uint NUM_HOUSE_ZONES = to_underlying(HouseZone::TownEnd);
+static_assert(NUM_HOUSE_ZONES == 5);
+
+static constexpr HouseZones HZ_ZONE_ALL = {
+	HouseZone::TownEdge,
+	HouseZone::TownOutskirt,
+	HouseZone::TownOuterSuburb,
+	HouseZone::TownInnerSuburb,
+	HouseZone::TownCentre,
+};
+
+static constexpr HouseZones HZ_CLIMATE_ALL = {
+	HouseZone::ClimateSubarcticAboveSnow,
+	HouseZone::ClimateTemperate,
+	HouseZone::ClimateSubarcticBelowSnow,
+	HouseZone::ClimateSubtropic,
+	HouseZone::ClimateToyland,
 };
-DECLARE_ENUM_AS_BIT_SET(HouseZones)
 
 enum class HouseExtraFlag : uint8_t {
 	BuildingIsHistorical   = 0, ///< this house will only appear during town generation in random games, thus the historical
@@ -139,5 +144,6 @@ inline HouseID GetTranslatedHouseID(HouseID hid)
 }
 
 void ShowBuildHousePicker(struct Window *);
+HouseZones GetClimateMaskForLandscape();
 
 #endif /* HOUSE_H */
diff --git a/src/industry_gui.cpp b/src/industry_gui.cpp
index 6ef9c2cb5a..c3c664e4c4 100644
--- a/src/industry_gui.cpp
+++ b/src/industry_gui.cpp
@@ -2704,19 +2704,13 @@ struct IndustryCargoesWindow : public Window {
 	 */
 	static bool HousesCanAccept(const std::span<const CargoType> cargoes)
 	{
-		HouseZones climate_mask;
-		switch (_settings_game.game_creation.landscape) {
-			case LandscapeType::Temperate: climate_mask = HZ_TEMP; break;
-			case LandscapeType::Arctic:    climate_mask = HZ_SUBARTC_ABOVE | HZ_SUBARTC_BELOW; break;
-			case LandscapeType::Tropic:    climate_mask = HZ_SUBTROPIC; break;
-			case LandscapeType::Toyland:   climate_mask = HZ_TOYLND; break;
-			default: NOT_REACHED();
-		}
+		HouseZones climate_mask = GetClimateMaskForLandscape();
+
 		for (const CargoType cargo_type : cargoes) {
 			if (!IsValidCargoType(cargo_type)) continue;
 
 			for (const auto &hs : HouseSpec::Specs()) {
-				if (!hs.enabled || !(hs.building_availability & climate_mask)) continue;
+				if (!hs.enabled || !hs.building_availability.Any(climate_mask)) continue;
 
 				for (uint j = 0; j < lengthof(hs.accepts_cargo); j++) {
 					if (hs.cargo_acceptance[j] > 0 && cargo_type == hs.accepts_cargo[j]) return true;
diff --git a/src/newgrf.cpp b/src/newgrf.cpp
index 099f23a56d..b9534adfee 100644
--- a/src/newgrf.cpp
+++ b/src/newgrf.cpp
@@ -976,7 +976,7 @@ static bool IsHouseSpecValid(HouseSpec &hs, const HouseSpec *next1, const HouseS
 	}
 
 	/* Make sure that additional parts of multitile houses are not available. */
-	if (!hs.building_flags.Any(BUILDING_HAS_1_TILE) && (hs.building_availability & HZ_ZONALL) != 0 && (hs.building_availability & HZ_CLIMALL) != 0) {
+	if (!hs.building_flags.Any(BUILDING_HAS_1_TILE) && hs.building_availability.Any(HZ_ZONE_ALL) && hs.building_availability.Any(HZ_CLIMATE_ALL)) {
 		hs.enabled = false;
 		if (!filename.empty()) Debug(grf, 1, "FinaliseHouseArray: {} defines house {} without a size but marked it as available. Disabling house.", filename, hs.grf_prop.local_id);
 		return false;
@@ -997,7 +997,7 @@ static void EnsureEarlyHouse(HouseZones bitmask)
 
 	for (const auto &hs : HouseSpec::Specs()) {
 		if (!hs.enabled) continue;
-		if ((hs.building_availability & bitmask) != bitmask) continue;
+		if (!hs.building_availability.All(bitmask)) continue;
 		if (hs.min_year < min_year) min_year = hs.min_year;
 	}
 
@@ -1005,7 +1005,7 @@ static void EnsureEarlyHouse(HouseZones bitmask)
 
 	for (auto &hs : HouseSpec::Specs()) {
 		if (!hs.enabled) continue;
-		if ((hs.building_availability & bitmask) != bitmask) continue;
+		if (!hs.building_availability.All(bitmask)) continue;
 		if (hs.min_year == min_year) hs.min_year = CalendarTime::MIN_YEAR;
 	}
 }
@@ -1077,19 +1077,11 @@ static void FinaliseHouseArray()
 		}
 	}
 
-	HouseZones climate_mask = (HouseZones)(1 << (to_underlying(_settings_game.game_creation.landscape) + 12));
-	EnsureEarlyHouse(HZ_ZON1 | climate_mask);
-	EnsureEarlyHouse(HZ_ZON2 | climate_mask);
-	EnsureEarlyHouse(HZ_ZON3 | climate_mask);
-	EnsureEarlyHouse(HZ_ZON4 | climate_mask);
-	EnsureEarlyHouse(HZ_ZON5 | climate_mask);
-
-	if (_settings_game.game_creation.landscape == LandscapeType::Arctic) {
-		EnsureEarlyHouse(HZ_ZON1 | HZ_SUBARTC_ABOVE);
-		EnsureEarlyHouse(HZ_ZON2 | HZ_SUBARTC_ABOVE);
-		EnsureEarlyHouse(HZ_ZON3 | HZ_SUBARTC_ABOVE);
-		EnsureEarlyHouse(HZ_ZON4 | HZ_SUBARTC_ABOVE);
-		EnsureEarlyHouse(HZ_ZON5 | HZ_SUBARTC_ABOVE);
+	HouseZones climate_mask = GetClimateMaskForLandscape();
+	for (HouseZone climate : climate_mask) {
+		for (HouseZone zone : HZ_ZONE_ALL) {
+			EnsureEarlyHouse({climate, zone});
+		}
 	}
 }
 
diff --git a/src/newgrf_airporttiles.cpp b/src/newgrf_airporttiles.cpp
index a13482f155..f5815e3abf 100644
--- a/src/newgrf_airporttiles.cpp
+++ b/src/newgrf_airporttiles.cpp
@@ -170,7 +170,7 @@ static uint32_t GetAirportTileIDAtOffset(TileIndex tile, const Station *st, uint
 		case 0x41: return GetTerrainType(this->tile);
 
 		/* Current town zone of the tile in the nearest town */
-		case 0x42: return GetTownRadiusGroup(ClosestTownFromTile(this->tile, UINT_MAX), this->tile);
+		case 0x42: return to_underlying(GetTownRadiusGroup(ClosestTownFromTile(this->tile, UINT_MAX), this->tile));
 
 		/* Position relative to most northern airport tile. */
 		case 0x43: return GetRelativePosition(this->tile, this->st->airport.tile);
diff --git a/src/newgrf_house.cpp b/src/newgrf_house.cpp
index 3bcd644128..d7dc676715 100644
--- a/src/newgrf_house.cpp
+++ b/src/newgrf_house.cpp
@@ -345,7 +345,7 @@ static uint32_t GetDistanceFromNearbyHouse(uint8_t parameter, TileIndex start_ti
 		case 0x41: return IsTileType(this->tile, MP_HOUSE) ? GetHouseAge(this->tile).base() : 0;
 
 		/* Town zone */
-		case 0x42: return GetTownRadiusGroup(this->town, this->tile);
+		case 0x42: return to_underlying(GetTownRadiusGroup(this->town, this->tile));
 
 		/* Terrain type */
 		case 0x43: return GetTerrainType(this->tile);
diff --git a/src/newgrf_industries.cpp b/src/newgrf_industries.cpp
index b10c67fa79..9bf1b99ea7 100644
--- a/src/newgrf_industries.cpp
+++ b/src/newgrf_industries.cpp
@@ -185,7 +185,7 @@ static uint32_t GetCountAndDistanceOfClosestInstance(uint8_t param_set_id, uint8
 			case 0x87: return GetTerrainType(this->tile);
 
 			/* Town zone */
-			case 0x88: return GetTownRadiusGroup(this->industry->town, this->tile);
+			case 0x88: return to_underlying(GetTownRadiusGroup(this->industry->town, this->tile));
 
 			/* Manhattan distance of the closest town */
 			case 0x89: return ClampTo<uint8_t>(DistanceManhattan(this->industry->town->xy, this->tile));
@@ -295,7 +295,7 @@ static uint32_t GetCountAndDistanceOfClosestInstance(uint8_t param_set_id, uint8
 		case 0x65: {
 			if (this->tile == INVALID_TILE) break;
 			TileIndex tile = GetNearbyTile(parameter, this->tile, true);
-			return GetTownRadiusGroup(this->industry->town, tile) << 16 | ClampTo<uint16_t>(DistanceManhattan(tile, this->industry->town->xy));
+			return to_underlying(GetTownRadiusGroup(this->industry->town, tile)) << 16 | ClampTo<uint16_t>(DistanceManhattan(tile, this->industry->town->xy));
 		}
 		/* Get square of Euclidean distance of closest town */
 		case 0x66: {
diff --git a/src/newgrf_industrytiles.cpp b/src/newgrf_industrytiles.cpp
index 0e8c5ed695..ac5838e759 100644
--- a/src/newgrf_industrytiles.cpp
+++ b/src/newgrf_industrytiles.cpp
@@ -69,7 +69,7 @@ uint32_t GetRelativePosition(TileIndex tile, TileIndex ind_tile)
 		case 0x41: return GetTerrainType(this->tile);
 
 		/* Current town zone of the tile in the nearest town */
-		case 0x42: return GetTownRadiusGroup(ClosestTownFromTile(this->tile, UINT_MAX), this->tile);
+		case 0x42: return to_underlying(GetTownRadiusGroup(ClosestTownFromTile(this->tile, UINT_MAX), this->tile));
 
 		/* Relative position */
 		case 0x43: return GetRelativePosition(this->tile, this->industry->location.tile);
diff --git a/src/newgrf_object.cpp b/src/newgrf_object.cpp
index c853ebfff1..ff059e33fb 100644
--- a/src/newgrf_object.cpp
+++ b/src/newgrf_object.cpp
@@ -331,7 +331,7 @@ static uint32_t GetCountAndDistanceOfClosestInstance(uint8_t local_id, uint32_t
 		case 0x44: return GetTileOwner(this->tile).base();
 
 		/* Get town zone and Manhattan distance of closest town */
-		case 0x45: return GetTownRadiusGroup(t, this->tile) << 16 | ClampTo<uint16_t>(DistanceManhattan(this->tile, t->xy));
+		case 0x45: return to_underlying(GetTownRadiusGroup(t, this->tile)) << 16 | ClampTo<uint16_t>(DistanceManhattan(this->tile, t->xy));
 
 		/* Get square of Euclidean distance of closest town */
 		case 0x46: return DistanceSquare(this->tile, t->xy);
diff --git a/src/newgrf_railtype.cpp b/src/newgrf_railtype.cpp
index f455904506..89d06952ef 100644
--- a/src/newgrf_railtype.cpp
+++ b/src/newgrf_railtype.cpp
@@ -33,7 +33,7 @@
 			case 0x41: return 0;
 			case 0x42: return 0;
 			case 0x43: return TimerGameCalendar::date.base();
-			case 0x44: return HZB_TOWN_EDGE;
+			case 0x44: return to_underlying(HouseZone::TownEdge);
 			case 0x45: {
 				auto rt = GetRailTypeInfoIndex(this->rti);
 				uint8_t local = GetReverseRailTypeTranslation(rt, this->ro.grffile);
@@ -57,7 +57,7 @@
 			} else if (IsLevelCrossingTile(this->tile)) {
 				t = ClosestTownFromTile(this->tile, UINT_MAX);
 			}
-			return t != nullptr ? GetTownRadiusGroup(t, this->tile) : HZB_TOWN_EDGE;
+			return to_underlying(t != nullptr ? GetTownRadiusGroup(t, this->tile) : HouseZone::TownEdge);
 		}
 		case 0x45:
 			return GetTrackTypes(this->tile, ro.grffile);
diff --git a/src/newgrf_roadstop.cpp b/src/newgrf_roadstop.cpp
index d1e4aca577..ba98dc7691 100644
--- a/src/newgrf_roadstop.cpp
+++ b/src/newgrf_roadstop.cpp
@@ -106,9 +106,9 @@ uint32_t RoadStopScopeResolver::GetVariable(uint8_t variable, [[maybe_unused]] u
 
 		/* Town zone and Manhattan distance of closest town */
 		case 0x45: {
-			if (this->tile == INVALID_TILE) return HZB_TOWN_EDGE << 16;
+			if (this->tile == INVALID_TILE) return to_underlying(HouseZone::TownEdge) << 16;
 			const Town *t = (this->st == nullptr) ? ClosestTownFromTile(this->tile, UINT_MAX) : this->st->town;
-			return t != nullptr ? (GetTownRadiusGroup(t, this->tile) << 16 | ClampTo<uint16_t>(DistanceManhattan(this->tile, t->xy))) : HZB_TOWN_EDGE << 16;
+			return t != nullptr ? (to_underlying(GetTownRadiusGroup(t, this->tile)) << 16 | ClampTo<uint16_t>(DistanceManhattan(this->tile, t->xy))) : to_underlying(HouseZone::TownEdge) << 16;
 		}
 
 		/* Get square of Euclidean distance of closest town */
diff --git a/src/newgrf_roadtype.cpp b/src/newgrf_roadtype.cpp
index 4498cc0507..afd8fa05f3 100644
--- a/src/newgrf_roadtype.cpp
+++ b/src/newgrf_roadtype.cpp
@@ -67,7 +67,7 @@ uint32_t GetTrackTypes(TileIndex tile, const GRFFile *grffile)
 			case 0x41: return 0;
 			case 0x42: return 0;
 			case 0x43: return TimerGameCalendar::date.base();
-			case 0x44: return HZB_TOWN_EDGE;
+			case 0x44: return to_underlying(HouseZone::TownEdge);
 			case 0x45: {
 				auto rt = GetRoadTypeInfoIndex(this->rti);
 				uint8_t local = GetReverseRoadTypeTranslation(rt, this->ro.grffile);
@@ -95,7 +95,7 @@ uint32_t GetTrackTypes(TileIndex tile, const GRFFile *grffile)
 			} else {
 				t = ClosestTownFromTile(this->tile, UINT_MAX);
 			}
-			return t != nullptr ? GetTownRadiusGroup(t, this->tile) : HZB_TOWN_EDGE;
+			return to_underlying(t != nullptr ? GetTownRadiusGroup(t, this->tile) : HouseZone::TownEdge);
 		}
 		case 0x45:
 			return GetTrackTypes(this->tile, ro.grffile);
diff --git a/src/newgrf_town.cpp b/src/newgrf_town.cpp
index 74baa8e4c0..81a89f1e70 100644
--- a/src/newgrf_town.cpp
+++ b/src/newgrf_town.cpp
@@ -57,16 +57,16 @@
 		case 0x8A: return this->t->grow_counter / Ticks::TOWN_GROWTH_TICKS;
 		case 0x92: return this->t->flags;  // In original game, 0x92 and 0x93 are really one word. Since flags is a byte, this is to adjust
 		case 0x93: return 0;
-		case 0x94: return ClampTo<uint16_t>(this->t->cache.squared_town_zone_radius[HZB_TOWN_EDGE]);
-		case 0x95: return GB(ClampTo<uint16_t>(this->t->cache.squared_town_zone_radius[HZB_TOWN_EDGE]), 8, 8);
-		case 0x96: return ClampTo<uint16_t>(this->t->cache.squared_town_zone_radius[HZB_TOWN_OUTSKIRT]);
-		case 0x97: return GB(ClampTo<uint16_t>(this->t->cache.squared_town_zone_radius[HZB_TOWN_OUTSKIRT]), 8, 8);
-		case 0x98: return ClampTo<uint16_t>(this->t->cache.squared_town_zone_radius[HZB_TOWN_OUTER_SUBURB]);
-		case 0x99: return GB(ClampTo<uint16_t>(this->t->cache.squared_town_zone_radius[HZB_TOWN_OUTER_SUBURB]), 8, 8);
-		case 0x9A: return ClampTo<uint16_t>(this->t->cache.squared_town_zone_radius[HZB_TOWN_INNER_SUBURB]);
-		case 0x9B: return GB(ClampTo<uint16_t>(this->t->cache.squared_town_zone_radius[HZB_TOWN_INNER_SUBURB]), 8, 8);
-		case 0x9C: return ClampTo<uint16_t>(this->t->cache.squared_town_zone_radius[HZB_TOWN_CENTRE]);
-		case 0x9D: return GB(ClampTo<uint16_t>(this->t->cache.squared_town_zone_radius[HZB_TOWN_CENTRE]), 8, 8);
+		case 0x94: return ClampTo<uint16_t>(this->t->cache.squared_town_zone_radius[to_underlying(HouseZone::TownEdge)]);
+		case 0x95: return GB(ClampTo<uint16_t>(this->t->cache.squared_town_zone_radius[to_underlying(HouseZone::TownEdge)]), 8, 8);
+		case 0x96: return ClampTo<uint16_t>(this->t->cache.squared_town_zone_radius[to_underlying(HouseZone::TownOutskirt)]);
+		case 0x97: return GB(ClampTo<uint16_t>(this->t->cache.squared_town_zone_radius[to_underlying(HouseZone::TownOutskirt)]), 8, 8);
+		case 0x98: return ClampTo<uint16_t>(this->t->cache.squared_town_zone_radius[to_underlying(HouseZone::TownOuterSuburb)]);
+		case 0x99: return GB(ClampTo<uint16_t>(this->t->cache.squared_town_zone_radius[to_underlying(HouseZone::TownOuterSuburb)]), 8, 8);
+		case 0x9A: return ClampTo<uint16_t>(this->t->cache.squared_town_zone_radius[to_underlying(HouseZone::TownInnerSuburb)]);
+		case 0x9B: return GB(ClampTo<uint16_t>(this->t->cache.squared_town_zone_radius[to_underlying(HouseZone::TownInnerSuburb)]), 8, 8);
+		case 0x9C: return ClampTo<uint16_t>(this->t->cache.squared_town_zone_radius[to_underlying(HouseZone::TownCentre)]);
+		case 0x9D: return GB(ClampTo<uint16_t>(this->t->cache.squared_town_zone_radius[to_underlying(HouseZone::TownCentre)]), 8, 8);
 		case 0x9E: return this->t->ratings[0];
 		case 0x9F: return GB(this->t->ratings[0], 8, 8);
 		case 0xA0: return this->t->ratings[1];
diff --git a/src/road_cmd.cpp b/src/road_cmd.cpp
index 584730a101..b685e37ef0 100644
--- a/src/road_cmd.cpp
+++ b/src/road_cmd.cpp
@@ -621,7 +621,7 @@ CommandCost CmdBuildRoad(DoCommandFlags flags, TileIndex tile, RoadBits pieces,
 			company = OWNER_TOWN;
 
 			/* If we are not within a town, we are not owned by the town */
-			if (town == nullptr || DistanceSquare(tile, town->xy) > town->cache.squared_town_zone_radius[HZB_TOWN_EDGE]) {
+			if (town == nullptr || DistanceSquare(tile, town->xy) > town->cache.squared_town_zone_radius[to_underlying(HouseZone::TownEdge)]) {
 				company = OWNER_NONE;
 			}
 		}
@@ -1956,7 +1956,7 @@ static const Roadside _town_road_types[][2] = {
 	{ ROADSIDE_STREET_LIGHTS, ROADSIDE_PAVED }
 };
 
-static_assert(lengthof(_town_road_types) == HZB_END);
+static_assert(lengthof(_town_road_types) == NUM_HOUSE_ZONES);
 
 static const Roadside _town_road_types_2[][2] = {
 	{ ROADSIDE_GRASS,         ROADSIDE_GRASS },
@@ -1966,7 +1966,7 @@ static const Roadside _town_road_types_2[][2] = {
 	{ ROADSIDE_STREET_LIGHTS, ROADSIDE_PAVED }
 };
 
-static_assert(lengthof(_town_road_types_2) == HZB_END);
+static_assert(lengthof(_town_road_types_2) == NUM_HOUSE_ZONES);
 
 
 static void TileLoop_Road(TileIndex tile)
@@ -1997,14 +1997,14 @@ static void TileLoop_Road(TileIndex tile)
 
 	const Town *t = ClosestTownFromTile(tile, UINT_MAX);
 	if (!HasRoadWorks(tile)) {
-		HouseZonesBits grp = HZB_TOWN_EDGE;
+		HouseZone grp = HouseZone::TownEdge;
 
 		if (t != nullptr) {
 			grp = GetTownRadiusGroup(t, tile);
 
 			/* Show an animation to indicate road work */
 			if (t->road_build_months != 0 &&
-					(DistanceManhattan(t->xy, tile) < 8 || grp != HZB_TOWN_EDGE) &&
+					(DistanceManhattan(t->xy, tile) < 8 || grp != HouseZone::TownEdge) &&
 					IsNormalRoad(tile) && !HasAtMostOneBit(GetAllRoadBits(tile))) {
 				if (std::get<0>(GetFoundationSlope(tile)) == SLOPE_FLAT && EnsureNoVehicleOnGround(tile).Succeeded() && Chance16(1, 40)) {
 					StartRoadWorks(tile);
@@ -2023,7 +2023,7 @@ static void TileLoop_Road(TileIndex tile)
 
 		{
 			/* Adjust road ground type depending on 'grp' (grp is the distance to the center) */
-			const Roadside *new_rs = (_settings_game.game_creation.landscape == LandscapeType::Toyland) ? _town_road_types_2[grp] : _town_road_types[grp];
+			const Roadside *new_rs = (_settings_game.game_creation.landscape == LandscapeType::Toyland) ? _town_road_types_2[to_underlying(grp)] : _town_road_types[to_underlying(grp)];
 			Roadside cur_rs = GetRoadside(tile);
 
 			/* We have our desired type, do nothing */
diff --git a/src/script/api/script_town.cpp b/src/script/api/script_town.cpp
index e4e0c12623..730d1829ee 100644
--- a/src/script/api/script_town.cpp
+++ b/src/script/api/script_town.cpp
@@ -206,7 +206,7 @@
 	if (!IsValidTown(town_id)) return false;
 
 	const Town *t = ::Town::Get(town_id);
-	return ((uint32_t)GetDistanceSquareToTile(town_id, tile) <= t->cache.squared_town_zone_radius[HZB_TOWN_EDGE]);
+	return ((uint32_t)GetDistanceSquareToTile(town_id, tile) <= t->cache.squared_town_zone_radius[to_underlying(HouseZone::TownEdge)]);
 }
 
 /* static */ bool ScriptTown::HasStatue(TownID town_id)
diff --git a/src/station_cmd.cpp b/src/station_cmd.cpp
index 25e009e19f..0e93152019 100644
--- a/src/station_cmd.cpp
+++ b/src/station_cmd.cpp
@@ -3644,14 +3644,14 @@ static void TileLoop_Station(TileIndex tile)
 				default: break;
 			}
 
-			HouseZonesBits new_zone = HZB_TOWN_EDGE;
+			HouseZone new_zone = HouseZone::TownEdge;
 			const Town *t = ClosestTownFromTile(tile, UINT_MAX);
 			if (t != nullptr) {
 				new_zone = GetTownRadiusGroup(t, tile);
 			}
 
 			/* Adjust road ground type depending on 'new_zone' */
-			Roadside new_rs = new_zone > HZB_TOWN_EDGE ? ROADSIDE_PAVED : ROADSIDE_GRASS;
+			Roadside new_rs = new_zone != HouseZone::TownEdge ? ROADSIDE_PAVED : ROADSIDE_GRASS;
 			Roadside cur_rs = GetRoadWaypointRoadside(tile);
 
 			if (new_rs != cur_rs) {
diff --git a/src/table/town_land.h b/src/table/town_land.h
index 98f3c11b5f..12c9c0c1b5 100644
--- a/src/table/town_land.h
+++ b/src/table/town_land.h
@@ -1834,443 +1834,443 @@ extern const HouseSpec _original_house_specs[] = {
 	 */
 	MS(1963, CalendarTime::MAX_YEAR, 187, 150, STR_TOWN_BUILDING_NAME_TALL_OFFICE_BLOCK_1,      140,  70,   8,   3,   4,
 	   BuildingFlag::Size1x1,
-	   HZ_TEMP | HZ_ZON5,
+	   HouseZones({HouseZone::ClimateTemperate, HouseZone::TownCentre}),
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 00
 	MS(1957, CalendarTime::MAX_YEAR,  85, 140, STR_TOWN_BUILDING_NAME_OFFICE_BLOCK_1,           130,  55,   8,   3,   4,
 	   BuildingFlag::Size1x1,
-	   HZ_TEMP | HZ_ZON5 | HZ_ZON4,
+	   HouseZones({HouseZone::ClimateTemperate, HouseZone::TownCentre, HouseZone::TownInnerSuburb}),
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 01
 	MS(1968, CalendarTime::MAX_YEAR,  40, 100, STR_TOWN_BUILDING_NAME_SMALL_BLOCK_OF_FLATS_1,    90,  20,   8,   3,   1,
 	   BuildingFlag::Size1x1,
-	   HZ_TEMP | HZ_ZON4 | HZ_ZON3 | HZ_ZON2,
+	   HouseZones({HouseZone::ClimateTemperate, HouseZone::TownInnerSuburb, HouseZone::TownOuterSuburb, HouseZone::TownOutskirt}),
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 02
 	MS(   0, CalendarTime::MAX_YEAR,   5,  90, STR_TOWN_BUILDING_NAME_CHURCH_1,                 230,   2,   2,   0,   0,
 	   BuildingFlags({BuildingFlag::IsChurch, BuildingFlag::Size1x1}),
-	   HZ_TEMP | HZ_ZON4 | HZ_ZON3 | HZ_ZON2 | HZ_ZON1,
+	   HouseZones({HouseZone::ClimateTemperate, HouseZone::TownInnerSuburb, HouseZone::TownOuterSuburb, HouseZone::TownOutskirt, HouseZone::TownEdge}),
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 03
 	MS(1975, CalendarTime::MAX_YEAR, 220, 160, STR_TOWN_BUILDING_NAME_LARGE_OFFICE_BLOCK_1,     160,  85,  10,   4,   6,
 	   BuildingFlags({BuildingFlag::IsAnimated, BuildingFlag::Size1x1}),
-	   HZ_TEMP | HZ_SUBARTC_BELOW | HZ_SUBTROPIC | HZ_ZON5,
+	   HouseZones({HouseZone::ClimateTemperate, HouseZone::ClimateSubarcticBelowSnow, HouseZone::ClimateSubtropic, HouseZone::TownCentre}),
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 04
 	MS(1975, CalendarTime::MAX_YEAR, 220, 160, STR_TOWN_BUILDING_NAME_LARGE_OFFICE_BLOCK_1,     160,  85,  10,   4,   6,
 	   BuildingFlags({BuildingFlag::IsAnimated, BuildingFlag::Size1x1}),
-	   HZ_SUBARTC_ABOVE  | HZ_ZON5,
+	   HouseZones({HouseZone::ClimateSubarcticAboveSnow, HouseZone::TownCentre}),
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 05
 	MS(   0, CalendarTime::MAX_YEAR,  30,  80, STR_TOWN_BUILDING_NAME_TOWN_HOUSES_1,             80,  12,   4,   1,   0,
 	   BuildingFlag::Size1x1,
-	   HZ_TEMP | HZ_ZON4 | HZ_ZON3 | HZ_ZON2 | HZ_ZON1,
+	   HouseZones({HouseZone::ClimateTemperate, HouseZone::TownInnerSuburb, HouseZone::TownOuterSuburb, HouseZone::TownOutskirt, HouseZone::TownEdge}),
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 06
 	MS(1959, CalendarTime::MAX_YEAR, 140, 180, STR_TOWN_BUILDING_NAME_HOTEL_1,                  150,  22,   6,   1,   2,
 	   BuildingFlag::Size1x2,
-	   HZ_TEMP | HZ_ZON5 | HZ_ZON3,
+	   HouseZones({HouseZone::ClimateTemperate, HouseZone::TownCentre, HouseZone::TownOuterSuburb}),
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 07
 	MS(1959, CalendarTime::MAX_YEAR,   0, 180, STR_TOWN_BUILDING_NAME_HOTEL_1,                  150,  22,   6,   1,   2,
 	   {},
-	   HZ_NOZNS,
+	   {},
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 08
 	MS(1945, CalendarTime::MAX_YEAR,   0,  65, STR_TOWN_BUILDING_NAME_STATUE_1,                  40,   0,   2,   0,   0,
 	   BuildingFlag::Size1x1,
-	   HZ_TEMP | HZ_SUBARTC_BELOW | HZ_SUBTROPIC | HZ_ZON5 | HZ_ZON4,
+	   HouseZones({HouseZone::ClimateTemperate, HouseZone::ClimateSubarcticBelowSnow, HouseZone::ClimateSubtropic, HouseZone::TownCentre, HouseZone::TownInnerSuburb}),
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 09
 	MS(1945, CalendarTime::MAX_YEAR,   0,  65, STR_TOWN_BUILDING_NAME_FOUNTAIN_1,                40,   0,   2,   0,   0,
 	   BuildingFlag::Size1x1,
-	   HZ_TEMP | HZ_SUBARTC_BELOW | HZ_SUBTROPIC | HZ_ZON5,
+	   HouseZones({HouseZone::ClimateTemperate, HouseZone::ClimateSubarcticBelowSnow, HouseZone::ClimateSubtropic, HouseZone::TownCentre}),
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 0A
 	MS(   0, CalendarTime::MAX_YEAR,   0,  60, STR_TOWN_BUILDING_NAME_PARK_1,                    75,   0,   2,   0,   0,
 	   BuildingFlag::Size1x1,
-	   HZ_TEMP | HZ_ZON3,
+	   HouseZones({HouseZone::ClimateTemperate, HouseZone::TownOuterSuburb}),
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 0B
 	MS(1935, CalendarTime::MAX_YEAR,   0,  60, STR_TOWN_BUILDING_NAME_PARK_1,                    75,   0,   2,   0,   0,
 	   BuildingFlag::Size1x1,
-	   HZ_TEMP | HZ_ZON4,
+	   HouseZones({HouseZone::ClimateTemperate, HouseZone::TownInnerSuburb}),
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 0C
 	MS(1951, CalendarTime::MAX_YEAR, 150, 130, STR_TOWN_BUILDING_NAME_OFFICE_BLOCK_2,           110,  65,   8,   2,   4,
 	   BuildingFlag::Size1x1,
-	   HZ_TEMP | HZ_ZON5 | HZ_ZON4,
+	   HouseZones({HouseZone::ClimateTemperate, HouseZone::TownCentre, HouseZone::TownInnerSuburb}),
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 0D
 	MS(1930, 1960,      95, 110, STR_TOWN_BUILDING_NAME_SHOPS_AND_OFFICES_1,      100,  48,   6,   2,   3,
 	   BuildingFlag::Size1x1,
-	   HZ_TEMP | HZ_ZON5 | HZ_ZON4 | HZ_ZON3,
+	   HouseZones({HouseZone::ClimateTemperate, HouseZone::TownCentre, HouseZone::TownInnerSuburb, HouseZone::TownOuterSuburb}),
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 0E
 	MS(1930, 1960,      95, 105, STR_TOWN_BUILDING_NAME_SHOPS_AND_OFFICES_1,      100,  48,   6,   2,   3,
 	   BuildingFlag::Size1x1,
-	   HZ_TEMP | HZ_ZON5 | HZ_ZON4 | HZ_ZON3,
+	   HouseZones({HouseZone::ClimateTemperate, HouseZone::TownCentre, HouseZone::TownInnerSuburb, HouseZone::TownOuterSuburb}),
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 0F
 	MS(1930, 1960,      95, 107, STR_TOWN_BUILDING_NAME_SHOPS_AND_OFFICES_1,      100,  48,   6,   2,   3,
 	   BuildingFlag::Size1x1,
-	   HZ_TEMP | HZ_ZON5 | HZ_ZON4 | HZ_ZON3,
+	   HouseZones({HouseZone::ClimateTemperate, HouseZone::TownCentre, HouseZone::TownInnerSuburb, HouseZone::TownOuterSuburb}),
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 10
 	MS(1977, CalendarTime::MAX_YEAR, 130, 200, STR_TOWN_BUILDING_NAME_MODERN_OFFICE_BUILDING_1, 150,  50,  10,   3,   6,
 	   BuildingFlag::Size1x1,
-	   HZ_TEMP | HZ_SUBARTC_BELOW | HZ_SUBTROPIC | HZ_ZON5,
+	   HouseZones({HouseZone::ClimateTemperate, HouseZone::ClimateSubarcticBelowSnow, HouseZone::ClimateSubtropic, HouseZone::TownCentre}),
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 11
 	MS(1983, CalendarTime::MAX_YEAR,   6, 145, STR_TOWN_BUILDING_NAME_WAREHOUSE_1,              110,  10,   6,   3,   8,
 	   BuildingFlag::Size1x1,
-	   HZ_TEMP | HZ_ZON5,
+	   HouseZones({HouseZone::ClimateTemperate, HouseZone::TownCentre}),
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 12
 	MS(1985, CalendarTime::MAX_YEAR, 110, 155, STR_TOWN_BUILDING_NAME_OFFICE_BLOCK_3,           110,  55,   6,   2,   6,
 	   BuildingFlag::Size1x1,
-	   HZ_TEMP | HZ_ZON5,
+	   HouseZones({HouseZone::ClimateTemperate, HouseZone::TownCentre}),
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 13
 	MS(   0, CalendarTime::MAX_YEAR,  65, 250, STR_TOWN_BUILDING_NAME_STADIUM_1,                300,   5,   4,   0,   0,
 	   BuildingFlags({BuildingFlag::IsStadium, BuildingFlag::Size2x2}),
-	   HZ_TEMP | HZ_ZON4 | HZ_ZON3 | HZ_ZON2 | HZ_ZON1,
+	   HouseZones({HouseZone::ClimateTemperate, HouseZone::TownInnerSuburb, HouseZone::TownOuterSuburb, HouseZone::TownOutskirt, HouseZone::TownEdge}),
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 14
 	MS(   0, CalendarTime::MAX_YEAR,   0, 250, STR_TOWN_BUILDING_NAME_STADIUM_1,                300,   5,   4,   0,   0,
 	   {},
-	   HZ_NOZNS,
+	   {},
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 15
 	MS(   0, CalendarTime::MAX_YEAR,   0, 250, STR_TOWN_BUILDING_NAME_STADIUM_1,                300,   5,   4,   0,   0,
 	   {},
-	   HZ_NOZNS,
+	   {},
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 16
 	MS(   0, CalendarTime::MAX_YEAR,   0, 250, STR_TOWN_BUILDING_NAME_STADIUM_1,                300,   5,   4,   0,   0,
 	   {},
-	   HZ_NOZNS,
+	   {},
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 17
 	MS(   0, 1951,      15,  70, STR_TOWN_BUILDING_NAME_OLD_HOUSES_1,              75,   6,   3,   1,   0,
 	   BuildingFlag::Size1x1,
-	   HZ_TEMP | HZ_ZON2 | HZ_ZON1,
+	   HouseZones({HouseZone::ClimateTemperate, HouseZone::TownOutskirt, HouseZone::TownEdge}),
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 18
 	MS(   0, 1952,      12,  75, STR_TOWN_BUILDING_NAME_COTTAGES_1,                75,   7,   3,   1,   0,
 	   BuildingFlag::Size1x1,
-	   HZ_TEMP | HZ_ZON1,
+	   HouseZones({HouseZone::ClimateTemperate, HouseZone::TownEdge}),
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 19
 	MS(1931, CalendarTime::MAX_YEAR,  13,  71, STR_TOWN_BUILDING_NAME_HOUSES_1,                  75,   8,   3,   1,   0,
 	   BuildingFlag::Size1x1,
-	   HZ_TEMP | HZ_ZON4 | HZ_ZON3 | HZ_ZON2 | HZ_ZON1,
+	   HouseZones({HouseZone::ClimateTemperate, HouseZone::TownInnerSuburb, HouseZone::TownOuterSuburb, HouseZone::TownOutskirt, HouseZone::TownEdge}),
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 1A
 	MS(1935, CalendarTime::MAX_YEAR, 100, 135, STR_TOWN_BUILDING_NAME_FLATS_1,                  100,  35,   7,   2,   2,
 	   BuildingFlag::Size1x1,
-	   HZ_TEMP | HZ_ZON5 | HZ_ZON4 | HZ_ZON3,
+	   HouseZones({HouseZone::ClimateTemperate, HouseZone::TownCentre, HouseZone::TownInnerSuburb, HouseZone::TownOuterSuburb}),
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 1B
 	MS(1963, CalendarTime::MAX_YEAR, 170, 145, STR_TOWN_BUILDING_NAME_TALL_OFFICE_BLOCK_2,      170,  50,   8,   3,   3,
 	   BuildingFlag::Size1x1,
-	   HZ_TEMP | HZ_ZON5 | HZ_ZON4 | HZ_ZON3,
+	   HouseZones({HouseZone::ClimateTemperate, HouseZone::TownCentre, HouseZone::TownInnerSuburb, HouseZone::TownOuterSuburb}),
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 1C
 	MS(   0, 1955,     100, 132, STR_TOWN_BUILDING_NAME_SHOPS_AND_OFFICES_2,      135,  40,   6,   2,   3,
 	   BuildingFlag::Size1x1,
-	   HZ_TEMP | HZ_ZON5 | HZ_ZON4 | HZ_ZON3,
+	   HouseZones({HouseZone::ClimateTemperate, HouseZone::TownCentre, HouseZone::TownInnerSuburb, HouseZone::TownOuterSuburb}),
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 1D
 	MS(1973, CalendarTime::MAX_YEAR, 180, 155, STR_TOWN_BUILDING_NAME_SHOPS_AND_OFFICES_3,      180,  64,   8,   3,   3,
 	   BuildingFlag::Size1x1,
-	   HZ_TEMP | HZ_SUBTROPIC | HZ_ZON5 | HZ_ZON3,
+	   HouseZones({HouseZone::ClimateTemperate, HouseZone::ClimateSubtropic, HouseZone::TownCentre, HouseZone::TownOuterSuburb}),
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 1E
 	MS(   0, CalendarTime::MAX_YEAR,  35, 220, STR_TOWN_BUILDING_NAME_THEATER_1,                230,  23,   8,   2,   2,
 	   BuildingFlag::Size1x1,
-	   HZ_TEMP | HZ_ZON5 | HZ_ZON4,
+	   HouseZones({HouseZone::ClimateTemperate, HouseZone::TownCentre, HouseZone::TownInnerSuburb}),
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 1F
 	MS(1958, CalendarTime::MAX_YEAR,  65, 250, STR_TOWN_BUILDING_NAME_STADIUM_2,                300,   5,   4,   0,   0,
 	   BuildingFlags({BuildingFlag::IsStadium, BuildingFlag::Size2x2}),
-	   HZ_TEMP | HZ_SUBARTC_BELOW | HZ_SUBTROPIC | HZ_ZON4 | HZ_ZON3 | HZ_ZON2 | HZ_ZON1,
+	   HouseZones({HouseZone::ClimateTemperate, HouseZone::ClimateSubarcticBelowSnow, HouseZone::ClimateSubtropic, HouseZone::TownInnerSuburb, HouseZone::TownOuterSuburb, HouseZone::TownOutskirt, HouseZone::TownEdge}),
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 20
 	MS(1958, CalendarTime::MAX_YEAR,   0, 250, STR_TOWN_BUILDING_NAME_STADIUM_2,                300,   5,   4,   0,   0,
 	   {},
-	   HZ_NOZNS,
+	   {},
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 21
 	MS(1958, CalendarTime::MAX_YEAR,   0, 250, STR_TOWN_BUILDING_NAME_STADIUM_2,                300,   5,   4,   0,   0,
 	   {},
-	   HZ_NOZNS,
+	   {},
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 22
 	MS(1958, CalendarTime::MAX_YEAR,   0, 250, STR_TOWN_BUILDING_NAME_STADIUM_2,                300,   5,   4,   0,   0,
 	   {},
-	   HZ_NOZNS,
+	   {},
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 23
 	MS(2000, CalendarTime::MAX_YEAR, 140, 170, STR_TOWN_BUILDING_NAME_OFFICES_1,                250,  65,   8,   3,   2,
 	   BuildingFlag::Size1x1,
-	   HZ_TEMP | HZ_SUBARTC_BELOW | HZ_SUBTROPIC | HZ_ZON5 | HZ_ZON4,
+	   HouseZones({HouseZone::ClimateTemperate, HouseZone::ClimateSubarcticBelowSnow, HouseZone::ClimateSubtropic, HouseZone::TownCentre, HouseZone::TownInnerSuburb}),
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 24
 	MS(   0, 1960,      15,  70, STR_TOWN_BUILDING_NAME_HOUSES_2,                  75,   6,   3,   1,   1,
 	   BuildingFlag::Size1x1,
-	   HZ_SUBARTC_BELOW | HZ_ZON2 | HZ_ZON1,
+	   HouseZones({HouseZone::ClimateSubarcticBelowSnow, HouseZone::TownOutskirt, HouseZone::TownEdge}),
 	   CT_PASSENGERS, CT_MAIL, CT_FOOD), // 25
 	MS(   0, 1960,      15,  70, STR_TOWN_BUILDING_NAME_HOUSES_2,                  75,   6,   3,   1,   1,
 	   BuildingFlag::Size1x1,
-	   HZ_SUBARTC_ABOVE | HZ_ZON2 | HZ_ZON1,
+	   HouseZones({HouseZone::ClimateSubarcticAboveSnow, HouseZone::TownOutskirt, HouseZone::TownEdge}),
 	   CT_PASSENGERS, CT_MAIL, CT_FOOD), // 26
 	MS(1945, CalendarTime::MAX_YEAR,  35, 210, STR_TOWN_BUILDING_NAME_CINEMA_1,                 230,  23,   8,   2,   2,
 	   BuildingFlag::Size1x1,
-	   HZ_TEMP | HZ_ZON5 | HZ_ZON4 | HZ_ZON3,
+	   HouseZones({HouseZone::ClimateTemperate, HouseZone::TownCentre, HouseZone::TownInnerSuburb, HouseZone::TownOuterSuburb}),
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 27
 	MS(1983, CalendarTime::MAX_YEAR, 180, 250, STR_TOWN_BUILDING_NAME_SHOPPING_MALL_1,          300,   5,   8,   2,   3,
 	   BuildingFlag::Size2x2,
-	   HZ_TEMP | HZ_ZON5 | HZ_ZON4 | HZ_ZON3 |HZ_ZON2,
+	   HouseZones({HouseZone::ClimateTemperate, HouseZone::TownCentre, HouseZone::TownInnerSuburb, HouseZone::TownOuterSuburb,HouseZone::TownOutskirt}),
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 28
 	MS(1983, CalendarTime::MAX_YEAR,   0, 250, STR_TOWN_BUILDING_NAME_SHOPPING_MALL_1,          300,   5,   8,   2,   3,
 	   {},
-	   HZ_NOZNS,
+	   {},
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 29
 	MS(1983, CalendarTime::MAX_YEAR,   0, 250, STR_TOWN_BUILDING_NAME_SHOPPING_MALL_1,          300,   5,   8,   2,   3,
 	   {},
-	   HZ_NOZNS,
+	   {},
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 2A
 	MS(1983, CalendarTime::MAX_YEAR,   0, 250, STR_TOWN_BUILDING_NAME_SHOPPING_MALL_1,          300,   5,   8,   2,   3,
 	   {},
-	   HZ_NOZNS,
+	   {},
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 2B
 	MS(   0, CalendarTime::MAX_YEAR,  80, 100, STR_TOWN_BUILDING_NAME_FLATS_1,                   90,  20,   5,   2,   2,
 	   BuildingFlag::Size1x1,
-	   HZ_SUBARTC_BELOW | HZ_ZON5 | HZ_ZON4 | HZ_ZON3,
+	   HouseZones({HouseZone::ClimateSubarcticBelowSnow, HouseZone::TownCentre, HouseZone::TownInnerSuburb, HouseZone::TownOuterSuburb}),
 	   CT_PASSENGERS, CT_MAIL, CT_FOOD), // 2C
 	MS(   0, CalendarTime::MAX_YEAR,  80, 100, STR_TOWN_BUILDING_NAME_FLATS_1,                   90,  20,   5,   2,   2,
 	   BuildingFlag::Size1x1,
-	   HZ_SUBARTC_ABOVE  | HZ_ZON5 | HZ_ZON4 | HZ_ZON3,
+	   HouseZones({HouseZone::ClimateSubarcticAboveSnow, HouseZone::TownCentre, HouseZone::TownInnerSuburb, HouseZone::TownOuterSuburb}),
 	   CT_PASSENGERS, CT_MAIL, CT_FOOD), // 2D
 	MS(   0, CalendarTime::MAX_YEAR,  16,  70, STR_TOWN_BUILDING_NAME_HOUSES_2,                  70,   6,   3,   1,   2,
 	   BuildingFlag::Size1x1,
-	   HZ_SUBARTC_BELOW | HZ_ZON4 | HZ_ZON3 | HZ_ZON2 | HZ_ZON1,
+	   HouseZones({HouseZone::ClimateSubarcticBelowSnow, HouseZone::TownInnerSuburb, HouseZone::TownOuterSuburb, HouseZone::TownOutskirt, HouseZone::TownEdge}),
 	   CT_PASSENGERS, CT_MAIL, CT_FOOD), // 2E
 	MS(   0, CalendarTime::MAX_YEAR,  16,  70, STR_TOWN_BUILDING_NAME_HOUSES_2,                  70,   6,   3,   1,   2,
 	   BuildingFlag::Size1x1,
-	   HZ_SUBARTC_ABOVE | HZ_ZON4 | HZ_ZON3 | HZ_ZON2 | HZ_ZON1,
+	   HouseZones({HouseZone::ClimateSubarcticAboveSnow, HouseZone::TownInnerSuburb, HouseZone::TownOuterSuburb, HouseZone::TownOutskirt, HouseZone::TownEdge}),
 	   CT_PASSENGERS, CT_MAIL, CT_FOOD), // 2F
 	MS(   0, 1963,      14,  80, STR_TOWN_BUILDING_NAME_HOUSES_2,                  70,   6,   3,   1,   2,
 	   BuildingFlag::Size1x1,
-	   HZ_SUBARTC_BELOW | HZ_ZON3 | HZ_ZON2 | HZ_ZON1,
+	   HouseZones({HouseZone::ClimateSubarcticBelowSnow, HouseZone::TownOuterSuburb, HouseZone::TownOutskirt, HouseZone::TownEdge}),
 	   CT_PASSENGERS, CT_MAIL, CT_FOOD), // 30
 	MS(   0, 1963,      14,  80, STR_TOWN_BUILDING_NAME_HOUSES_2,                  70,   6,   3,   1,   2,
 	   BuildingFlag::Size1x1,
-	   HZ_SUBARTC_ABOVE | HZ_ZON3 | HZ_ZON2 | HZ_ZON1,
+	   HouseZones({HouseZone::ClimateSubarcticAboveSnow, HouseZone::TownOuterSuburb, HouseZone::TownOutskirt, HouseZone::TownEdge}),
 	   CT_PASSENGERS, CT_MAIL, CT_FOOD), // 31
 	MS(1966, CalendarTime::MAX_YEAR, 135, 150, STR_TOWN_BUILDING_NAME_TALL_OFFICE_BLOCK_1,      120,  60,   8,   3,   4,
 	   BuildingFlag::Size1x1,
-	   HZ_SUBARTC_BELOW | HZ_SUBTROPIC | HZ_ZON5 | HZ_ZON4,
+	   HouseZones({HouseZone::ClimateSubarcticBelowSnow, HouseZone::ClimateSubtropic, HouseZone::TownCentre, HouseZone::TownInnerSuburb}),
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 32
 	MS(1966, CalendarTime::MAX_YEAR, 135, 150, STR_TOWN_BUILDING_NAME_TALL_OFFICE_BLOCK_1,      120,  60,   8,   3,   4,
 	   BuildingFlag::Size1x1,
-	   HZ_SUBARTC_ABOVE | HZ_ZON5 | HZ_ZON4,
+	   HouseZones({HouseZone::ClimateSubarcticAboveSnow, HouseZone::TownCentre, HouseZone::TownInnerSuburb}),
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 33
 	MS(1970, CalendarTime::MAX_YEAR, 170, 170, STR_TOWN_BUILDING_NAME_TALL_OFFICE_BLOCK_1,      130,  70,   9,   3,   4,
 	   BuildingFlag::Size1x1,
-	   HZ_SUBARTC_BELOW | HZ_ZON5 | HZ_ZON4,
+	   HouseZones({HouseZone::ClimateSubarcticBelowSnow, HouseZone::TownCentre, HouseZone::TownInnerSuburb}),
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 34
 	MS(1970, CalendarTime::MAX_YEAR, 170, 170, STR_TOWN_BUILDING_NAME_TALL_OFFICE_BLOCK_1,      130,  70,   9,   3,   4,
 	   BuildingFlag::Size1x1,
-	   HZ_SUBARTC_ABOVE | HZ_ZON5 | HZ_ZON4,
+	   HouseZones({HouseZone::ClimateSubarcticAboveSnow, HouseZone::TownCentre, HouseZone::TownInnerSuburb}),
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 35
 	MS(1974, CalendarTime::MAX_YEAR, 210, 200, STR_TOWN_BUILDING_NAME_TALL_OFFICE_BLOCK_1,      140,  80,  10,   3,   5,
 	   BuildingFlag::Size1x1,
-	   HZ_SUBARTC_BELOW | HZ_SUBTROPIC | HZ_ZON5 | HZ_ZON4,
+	   HouseZones({HouseZone::ClimateSubarcticBelowSnow, HouseZone::ClimateSubtropic, HouseZone::TownCentre, HouseZone::TownInnerSuburb}),
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 36
 	MS(1974, CalendarTime::MAX_YEAR, 210, 200, STR_TOWN_BUILDING_NAME_TALL_OFFICE_BLOCK_1,      140,  80,  10,   3,   5,
 	   BuildingFlag::Size1x1,
-	   HZ_SUBARTC_ABOVE | HZ_ZON5 | HZ_ZON4,
+	   HouseZones({HouseZone::ClimateSubarcticAboveSnow, HouseZone::TownCentre, HouseZone::TownInnerSuburb}),
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 37
 	MS(   0, CalendarTime::MAX_YEAR,  10,  60, STR_TOWN_BUILDING_NAME_HOUSES_2,                  60,   5,   2,   1,   1,
 	   BuildingFlag::Size1x1,
-	   HZ_SUBARTC_BELOW | HZ_ZON1,
+	   HouseZones({HouseZone::ClimateSubarcticBelowSnow, HouseZone::TownEdge}),
 	   CT_PASSENGERS, CT_MAIL, CT_FOOD), // 38
 	MS(   0, CalendarTime::MAX_YEAR,  10,  60, STR_TOWN_BUILDING_NAME_HOUSES_2,                  60,   5,   2,   1,   1,
 	   BuildingFlag::Size1x1,
-	   HZ_SUBARTC_ABOVE | HZ_ZON1,
+	   HouseZones({HouseZone::ClimateSubarcticAboveSnow, HouseZone::TownEdge}),
 	   CT_PASSENGERS, CT_MAIL, CT_FOOD), // 39
 	MS(   0, CalendarTime::MAX_YEAR,  25, 100, STR_TOWN_BUILDING_NAME_SHOPS_AND_OFFICES_1,       80,  20,   3,   1,   1,
 	   BuildingFlag::Size1x1,
-	   HZ_SUBARTC_BELOW | HZ_ZON5 | HZ_ZON4 | HZ_ZON3 | HZ_ZON2,
+	   HouseZones({HouseZone::ClimateSubarcticBelowSnow, HouseZone::TownCentre, HouseZone::TownInnerSuburb, HouseZone::TownOuterSuburb, HouseZone::TownOutskirt}),
 	   CT_PASSENGERS, CT_MAIL, CT_FOOD), // 3A
 	MS(   0, CalendarTime::MAX_YEAR,  25, 100, STR_TOWN_BUILDING_NAME_SHOPS_AND_OFFICES_1,       80,  20,   3,   1,   1,
 	   BuildingFlag::Size1x1,
-	   HZ_SUBARTC_ABOVE | HZ_ZON5 | HZ_ZON4 | HZ_ZON3 | HZ_ZON2,
+	   HouseZones({HouseZone::ClimateSubarcticAboveSnow, HouseZone::TownCentre, HouseZone::TownInnerSuburb, HouseZone::TownOuterSuburb, HouseZone::TownOutskirt}),
 	   CT_PASSENGERS, CT_MAIL, CT_FOOD), // 3B
 	MS(   0, CalendarTime::MAX_YEAR,   6,  85, STR_TOWN_BUILDING_NAME_CHURCH_1,                 230,   2,   2,   0,   0,
 	   BuildingFlags({BuildingFlag::IsChurch, BuildingFlag::Size1x1}),
-	   HZ_SUBARTC_BELOW | HZ_ZON4 | HZ_ZON3 | HZ_ZON2 | HZ_ZON1,
+	   HouseZones({HouseZone::ClimateSubarcticBelowSnow, HouseZone::TownInnerSuburb, HouseZone::TownOuterSuburb, HouseZone::TownOutskirt, HouseZone::TownEdge}),
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 3C
 	MS(   0, CalendarTime::MAX_YEAR,   6,  85, STR_TOWN_BUILDING_NAME_CHURCH_1,                 230,   2,   2,   0,   0,
 	   BuildingFlags({BuildingFlag::IsChurch, BuildingFlag::Size1x1}),
-	   HZ_SUBARTC_ABOVE | HZ_ZON4 | HZ_ZON3 | HZ_ZON2 | HZ_ZON1,
+	   HouseZones({HouseZone::ClimateSubarcticAboveSnow, HouseZone::TownInnerSuburb, HouseZone::TownOuterSuburb, HouseZone::TownOutskirt, HouseZone::TownEdge}),
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 3D
 	MS(   0, CalendarTime::MAX_YEAR,  17,  80, STR_TOWN_BUILDING_NAME_HOUSES_2,                  80,   7,   3,   1,   1,
 	   BuildingFlag::Size1x1,
-	   HZ_SUBARTC_BELOW | HZ_ZON3 | HZ_ZON2 | HZ_ZON1,
+	   HouseZones({HouseZone::ClimateSubarcticBelowSnow, HouseZone::TownOuterSuburb, HouseZone::TownOutskirt, HouseZone::TownEdge}),
 	   CT_PASSENGERS, CT_MAIL, CT_FOOD), // 3E
 	MS(   0, CalendarTime::MAX_YEAR,  17,  80, STR_TOWN_BUILDING_NAME_HOUSES_2,                  80,   7,   3,   1,   1,
 	   BuildingFlag::Size1x1,
-	   HZ_SUBARTC_ABOVE | HZ_ZON3 | HZ_ZON2 | HZ_ZON1,
+	   HouseZones({HouseZone::ClimateSubarcticAboveSnow, HouseZone::TownOuterSuburb, HouseZone::TownOutskirt, HouseZone::TownEdge}),
 	   CT_PASSENGERS, CT_MAIL, CT_FOOD), // 3F
 	MS(   0, 1960,      90, 140, STR_TOWN_BUILDING_NAME_SHOPS_AND_OFFICES_1,      110,  45,   6,   2,   3,
 	   BuildingFlag::Size1x1,
-	   HZ_SUBARTC_BELOW| HZ_ZON5 | HZ_ZON4 | HZ_ZON3,
+	   HouseZones({HouseZone::ClimateSubarcticBelowSnow, HouseZone::TownCentre, HouseZone::TownInnerSuburb, HouseZone::TownOuterSuburb}),
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 40
 	MS(   0, 1960,      90, 140, STR_TOWN_BUILDING_NAME_SHOPS_AND_OFFICES_1,      110,  45,   6,   2,   3,
 	   BuildingFlag::Size1x1,
-	   HZ_SUBARTC_ABOVE| HZ_ZON5 | HZ_ZON4 | HZ_ZON3,
+	   HouseZones({HouseZone::ClimateSubarcticAboveSnow, HouseZone::TownCentre, HouseZone::TownInnerSuburb, HouseZone::TownOuterSuburb}),
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 41
 	MS(1972, CalendarTime::MAX_YEAR, 140, 160, STR_TOWN_BUILDING_NAME_HOTEL_1,                  160,  25,   6,   1,   3,
 	   BuildingFlag::Size1x2,
-	   HZ_SUBARTC_BELOW| HZ_ZON5 | HZ_ZON4 | HZ_ZON3,
+	   HouseZones({HouseZone::ClimateSubarcticBelowSnow, HouseZone::TownCentre, HouseZone::TownInnerSuburb, HouseZone::TownOuterSuburb}),
 	   CT_PASSENGERS, CT_MAIL, CT_FOOD), // 42
 	MS(1972, CalendarTime::MAX_YEAR,   0, 160, STR_TOWN_BUILDING_NAME_HOTEL_1,                  160,  25,   6,   1,   2,
 	   {},
-	   HZ_NOZNS,
+	   {},
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 43
 	MS(1972, CalendarTime::MAX_YEAR, 140, 160, STR_TOWN_BUILDING_NAME_HOTEL_1,                  160,  25,   6,   1,   3,
 	   BuildingFlag::Size1x2,
-	   HZ_SUBARTC_ABOVE| HZ_ZON5 | HZ_ZON4 | HZ_ZON3,
+	   HouseZones({HouseZone::ClimateSubarcticAboveSnow, HouseZone::TownCentre, HouseZone::TownInnerSuburb, HouseZone::TownOuterSuburb}),
 	   CT_PASSENGERS, CT_MAIL, CT_FOOD), // 44
 	MS(1972, CalendarTime::MAX_YEAR,   0, 160, STR_TOWN_BUILDING_NAME_HOTEL_1,                  160,  25,   6,   1,   2,
 	   {},
-	   HZ_NOZNS,
+	   {},
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 45
 	MS(1963, CalendarTime::MAX_YEAR, 105, 130, STR_TOWN_BUILDING_NAME_SHOPS_AND_OFFICES_1,      105,  50,   7,   2,   3,
 	   BuildingFlag::Size1x1,
-	   HZ_SUBARTC_BELOW | HZ_SUBTROPIC | HZ_ZON5 | HZ_ZON4 | HZ_ZON3,
+	   HouseZones({HouseZone::ClimateSubarcticBelowSnow, HouseZone::ClimateSubtropic, HouseZone::TownCentre, HouseZone::TownInnerSuburb, HouseZone::TownOuterSuburb}),
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 46
 	MS(1963, CalendarTime::MAX_YEAR, 105, 130, STR_TOWN_BUILDING_NAME_SHOPS_AND_OFFICES_1,      105,  50,   7,   2,   3,
 	   BuildingFlag::Size1x1,
-	   HZ_SUBARTC_ABOVE| HZ_ZON5 | HZ_ZON4 | HZ_ZON3,
+	   HouseZones({HouseZone::ClimateSubarcticAboveSnow, HouseZone::TownCentre, HouseZone::TownInnerSuburb, HouseZone::TownOuterSuburb}),
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 47
 	MS(1978, CalendarTime::MAX_YEAR, 190, 190, STR_TOWN_BUILDING_NAME_TALL_OFFICE_BLOCK_1,      135,  75,   9,   3,   4,
 	   BuildingFlag::Size1x1,
-	   HZ_SUBARTC_BELOW | HZ_ZON5 | HZ_ZON4,
+	   HouseZones({HouseZone::ClimateSubarcticBelowSnow, HouseZone::TownCentre, HouseZone::TownInnerSuburb}),
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 48
 	MS(1978, CalendarTime::MAX_YEAR, 190, 190, STR_TOWN_BUILDING_NAME_TALL_OFFICE_BLOCK_1,      135,  75,   9,   3,   4,
 	   BuildingFlag::Size1x1,
-	   HZ_SUBARTC_ABOVE | HZ_ZON5 | HZ_ZON4,
+	   HouseZones({HouseZone::ClimateSubarcticAboveSnow, HouseZone::TownCentre, HouseZone::TownInnerSuburb}),
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 49
 	MS(1967, CalendarTime::MAX_YEAR, 250, 140, STR_TOWN_BUILDING_NAME_TALL_OFFICE_BLOCK_1,      200,  60,   7,   2,   2,
 	   BuildingFlag::Size2x1,
-	   HZ_SUBARTC_BELOW| HZ_ZON5 | HZ_ZON4 | HZ_ZON3,
+	   HouseZones({HouseZone::ClimateSubarcticBelowSnow, HouseZone::TownCentre, HouseZone::TownInnerSuburb, HouseZone::TownOuterSuburb}),
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 4A
 	MS(1967, CalendarTime::MAX_YEAR,   0, 140, STR_TOWN_BUILDING_NAME_TALL_OFFICE_BLOCK_1,      200,  60,   7,   2,   2,
 	   {},
-	   HZ_NOZNS,
+	   {},
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 4B
 	MS(1967, CalendarTime::MAX_YEAR, 250, 140, STR_TOWN_BUILDING_NAME_TALL_OFFICE_BLOCK_1,      200,  60,   7,   2,   2,
 	   BuildingFlag::Size2x1,
-	   HZ_SUBARTC_ABOVE | HZ_ZON5 | HZ_ZON4 | HZ_ZON3,
+	   HouseZones({HouseZone::ClimateSubarcticAboveSnow, HouseZone::TownCentre, HouseZone::TownInnerSuburb, HouseZone::TownOuterSuburb}),
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 4C
 	MS(1967, CalendarTime::MAX_YEAR,   0, 140, STR_TOWN_BUILDING_NAME_TALL_OFFICE_BLOCK_1,      200,  60,   7,   2,   2,
 	   {},
-	   HZ_NOZNS,
+	   {},
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 4D
 	MS(   0, CalendarTime::MAX_YEAR,  16,  80, STR_TOWN_BUILDING_NAME_HOUSES_2,                  80,   6,   3,   1,   2,
 	   BuildingFlag::Size1x1,
-	   HZ_SUBTROPIC | HZ_ZON5 | HZ_ZON4 | HZ_ZON3 | HZ_ZON2,
+	   HouseZones({HouseZone::ClimateSubtropic, HouseZone::TownCentre, HouseZone::TownInnerSuburb, HouseZone::TownOuterSuburb, HouseZone::TownOutskirt}),
 	   CT_PASSENGERS, CT_MAIL, CT_FOOD), // 4E
 	MS(   0, CalendarTime::MAX_YEAR,  16,  80, STR_TOWN_BUILDING_NAME_HOUSES_2,                  80,   6,   3,   1,   2,
 	   BuildingFlag::Size1x1,
-	   HZ_SUBTROPIC | HZ_ZON5 | HZ_ZON4 | HZ_ZON3 | HZ_ZON2,
+	   HouseZones({HouseZone::ClimateSubtropic, HouseZone::TownCentre, HouseZone::TownInnerSuburb, HouseZone::TownOuterSuburb, HouseZone::TownOutskirt}),
 	   CT_PASSENGERS, CT_MAIL, CT_FOOD), // 4F
 	MS(   0, CalendarTime::MAX_YEAR,  16,  80, STR_TOWN_BUILDING_NAME_HOUSES_2,                  80,   5,   3,   1,   2,
 	   BuildingFlag::Size1x1,
-	   HZ_SUBTROPIC | HZ_ZON5 | HZ_ZON4 | HZ_ZON3 | HZ_ZON2,
+	   HouseZones({HouseZone::ClimateSubtropic, HouseZone::TownCentre, HouseZone::TownInnerSuburb, HouseZone::TownOuterSuburb, HouseZone::TownOutskirt}),
 	   CT_PASSENGERS, CT_MAIL, CT_FOOD), // 50
 	MS(   0, CalendarTime::MAX_YEAR,   7,  30, STR_TOWN_BUILDING_NAME_HOUSES_2,                  30,   4,   3,   1,   1,
 	   BuildingFlag::Size1x1,
-	   HZ_SUBTROPIC | HZ_ZON1,
+	   HouseZones({HouseZone::ClimateSubtropic, HouseZone::TownEdge}),
 	   CT_PASSENGERS, CT_MAIL, CT_FOOD), // 51
 	MS(   0, CalendarTime::MAX_YEAR,  45, 130, STR_TOWN_BUILDING_NAME_FLATS_1,                   95,  15,   6,   2,   1,
 	   BuildingFlag::Size1x1,
-	   HZ_SUBTROPIC | HZ_ZON5 | HZ_ZON4 | HZ_ZON3,
+	   HouseZones({HouseZone::ClimateSubtropic, HouseZone::TownCentre, HouseZone::TownInnerSuburb, HouseZone::TownOuterSuburb}),
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 52
 	MS(   0, CalendarTime::MAX_YEAR,   8,  90, STR_TOWN_BUILDING_NAME_CHURCH_1,                 200,   3,   2,   0,   0,
 	   BuildingFlags({BuildingFlag::IsChurch, BuildingFlag::Size1x1}),
-	   HZ_SUBTROPIC | HZ_ZON4 | HZ_ZON3 | HZ_ZON2,
+	   HouseZones({HouseZone::ClimateSubtropic, HouseZone::TownInnerSuburb, HouseZone::TownOuterSuburb, HouseZone::TownOutskirt}),
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 53
 	MS(   0, CalendarTime::MAX_YEAR,  18,  80, STR_TOWN_BUILDING_NAME_HOUSES_2,                  80,   7,   3,   1,   2,
 	   BuildingFlag::Size1x1,
-	   HZ_SUBTROPIC | HZ_ZON5 | HZ_ZON4 | HZ_ZON3 | HZ_ZON2,
+	   HouseZones({HouseZone::ClimateSubtropic, HouseZone::TownCentre, HouseZone::TownInnerSuburb, HouseZone::TownOuterSuburb, HouseZone::TownOutskirt}),
 	   CT_PASSENGERS, CT_MAIL, CT_FOOD), // 54
 	MS(1973, CalendarTime::MAX_YEAR,  90, 110, STR_TOWN_BUILDING_NAME_FLATS_1,                   95,  24,   6,   2,   1,
 	   BuildingFlag::Size1x1,
-	   HZ_SUBTROPIC | HZ_ZON5 | HZ_ZON4 | HZ_ZON3,
+	   HouseZones({HouseZone::ClimateSubtropic, HouseZone::TownCentre, HouseZone::TownInnerSuburb, HouseZone::TownOuterSuburb}),
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 55
 	MS(1962, CalendarTime::MAX_YEAR, 120, 120, STR_TOWN_BUILDING_NAME_FLATS_1,                   95,  25,   6,   2,   1,
 	   BuildingFlag::Size1x1,
-	   HZ_SUBTROPIC | HZ_ZON5 | HZ_ZON4 | HZ_ZON3,
+	   HouseZones({HouseZone::ClimateSubtropic, HouseZone::TownCentre, HouseZone::TownInnerSuburb, HouseZone::TownOuterSuburb}),
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 56
 	MS(1984, CalendarTime::MAX_YEAR, 250, 190, STR_TOWN_BUILDING_NAME_TALL_OFFICE_BLOCK_1,      140,  80,   8,   3,   4,
 	   BuildingFlag::Size2x1,
-	   HZ_SUBTROPIC | HZ_ZON5 | HZ_ZON4,
+	   HouseZones({HouseZone::ClimateSubtropic, HouseZone::TownCentre, HouseZone::TownInnerSuburb}),
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 57
 	MS(1984, CalendarTime::MAX_YEAR,   0, 190, STR_TOWN_BUILDING_NAME_TALL_OFFICE_BLOCK_1,      140,  80,   8,   3,   4,
 	   {},
-	   HZ_SUBTROPIC,
+	   HouseZones({HouseZone::ClimateSubtropic}),
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 58
 	MS(   0, CalendarTime::MAX_YEAR,  80, 110, STR_TOWN_BUILDING_NAME_FLATS_1,                   95,  23,   6,   2,   1,
 	   BuildingFlag::Size1x1,
-	   HZ_SUBTROPIC | HZ_ZON5 | HZ_ZON4 | HZ_ZON3,
+	   HouseZones({HouseZone::ClimateSubtropic, HouseZone::TownCentre, HouseZone::TownInnerSuburb, HouseZone::TownOuterSuburb}),
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 59
 	MS(1993, CalendarTime::MAX_YEAR, 180, 180, STR_TOWN_BUILDING_NAME_TALL_OFFICE_BLOCK_1,      150,  90,   8,   3,   4,
 	   BuildingFlag::Size1x1,
-	   HZ_SUBTROPIC | HZ_ZON5 | HZ_ZON4 | HZ_ZON3,
+	   HouseZones({HouseZone::ClimateSubtropic, HouseZone::TownCentre, HouseZone::TownInnerSuburb, HouseZone::TownOuterSuburb}),
 	   CT_PASSENGERS, CT_MAIL, CT_GOODS), // 5A
 	MS(   0, CalendarTime::MAX_YEAR,   8,  90, STR_TOWN_BUILDING_NAME_CHURCH_1,                 200,   3,   2,   0,   0,
 	   BuildingFlags({BuildingFlag::IsChurch, BuildingFlag::Size1x1}),
-	   HZ_TOYLND | HZ_ZON5 | HZ_ZON4 | HZ_ZON3 | HZ_ZON2 | HZ_ZON1,
+	   HouseZones({HouseZone::ClimateToyland, HouseZone::TownCentre, HouseZone::TownInnerSuburb, HouseZone::TownOuterSuburb, HouseZone::TownOutskirt, HouseZone::TownEdge}),
 	   CT_PASSENGERS, CT_MAIL, CT_CANDY), // 5B
 	MS(   0, CalendarTime::MAX_YEAR,  18,  90, STR_TOWN_BUILDING_NAME_HOUSES_2,                  90,   5,   6,   2,   2,
 	   BuildingFlag::Size1x1,
-	   HZ_TOYLND | HZ_ZON5 | HZ_ZON4 | HZ_ZON3 | HZ_ZON2 | HZ_ZON1,
+	   HouseZones({HouseZone::ClimateToyland, HouseZone::TownCentre, HouseZone::TownInnerSuburb, HouseZone::TownOuterSuburb, HouseZone::TownOutskirt, HouseZone::TownEdge}),
 	   CT_PASSENGERS, CT_MAIL, CT_CANDY), // 5C
 	MS(   0, CalendarTime::MAX_YEAR,   7,  70, STR_TOWN_BUILDING_NAME_HOUSES_2,                  50,   3,   3,   1,   1,
 	   BuildingFlag::Size1x1,
-	   HZ_TOYLND | HZ_ZON2 | HZ_ZON1,
+	   HouseZones({HouseZone::ClimateToyland, HouseZone::TownOutskirt, HouseZone::TownEdge}),
 	   CT_PASSENGERS, CT_MAIL, CT_CANDY), // 5D
 	MS(   0, CalendarTime::MAX_YEAR,  15,  80, STR_TOWN_BUILDING_NAME_HOUSES_2,                  75,   6,   3,   1,   2,
 	   BuildingFlag::Size1x1,
-	   HZ_TOYLND | HZ_ZON4 | HZ_ZON3 | HZ_ZON2 | HZ_ZON1,
+	   HouseZones({HouseZone::ClimateToyland, HouseZone::TownInnerSuburb, HouseZone::TownOuterSuburb, HouseZone::TownOutskirt, HouseZone::TownEdge}),
 	   CT_PASSENGERS, CT_MAIL, CT_CANDY), // 5E
 	MS(   0, CalendarTime::MAX_YEAR,  17,  80, STR_TOWN_BUILDING_NAME_HOUSES_2,                  75,   6,   3,   1,   2,
 	   BuildingFlag::Size1x1,
-	   HZ_TOYLND | HZ_ZON4 | HZ_ZON3 | HZ_ZON2 | HZ_ZON1,
+	   HouseZones({HouseZone::ClimateToyland, HouseZone::TownInnerSuburb, HouseZone::TownOuterSuburb, HouseZone::TownOutskirt, HouseZone::TownEdge}),
 	   CT_PASSENGERS, CT_MAIL, CT_CANDY), // 5F
 	MS(   0, CalendarTime::MAX_YEAR,  19,  80, STR_TOWN_BUILDING_NAME_HOUSES_2,                  75,   6,   3,   1,   2,
 	   BuildingFlag::Size1x1,
-	   HZ_TOYLND | HZ_ZON4 | HZ_ZON3 | HZ_ZON2 | HZ_ZON1,
+	   HouseZones({HouseZone::ClimateToyland, HouseZone::TownInnerSuburb, HouseZone::TownOuterSuburb, HouseZone::TownOutskirt, HouseZone::TownEdge}),
 	   CT_PASSENGERS, CT_MAIL, CT_CANDY), // 60
 	MS(   0, CalendarTime::MAX_YEAR,  21,  80, STR_TOWN_BUILDING_NAME_HOUSES_2,                  75,   6,   3,   1,   2,
 	   BuildingFlag::Size1x1,
-	   HZ_TOYLND | HZ_ZON4 | HZ_ZON3 | HZ_ZON2 | HZ_ZON1,
+	   HouseZones({HouseZone::ClimateToyland, HouseZone::TownInnerSuburb, HouseZone::TownOuterSuburb, HouseZone::TownOutskirt, HouseZone::TownEdge}),
 	   CT_PASSENGERS, CT_MAIL, CT_CANDY), // 61
 	MS(   0, CalendarTime::MAX_YEAR,  75, 160, STR_TOWN_BUILDING_NAME_TALL_OFFICE_BLOCK_1,      130,  20,   8,   4,   2,
 	   BuildingFlag::Size1x1,
-	   HZ_TOYLND | HZ_ZON5 | HZ_ZON4 | HZ_ZON3,
+	   HouseZones({HouseZone::ClimateToyland, HouseZone::TownCentre, HouseZone::TownInnerSuburb, HouseZone::TownOuterSuburb}),
 	   CT_PASSENGERS, CT_MAIL, CT_CANDY), // 62
 	MS(   0, CalendarTime::MAX_YEAR,  35,  90, STR_TOWN_BUILDING_NAME_HOUSES_2,                  80,   9,   4,   1,   2,
 	   BuildingFlag::Size1x2,
-	   HZ_TOYLND | HZ_ZON5 | HZ_ZON4 | HZ_ZON3 | HZ_ZON2 | HZ_ZON1,
+	   HouseZones({HouseZone::ClimateToyland, HouseZone::TownCentre, HouseZone::TownInnerSuburb, HouseZone::TownOuterSuburb, HouseZone::TownOutskirt, HouseZone::TownEdge}),
 	   CT_PASSENGERS, CT_MAIL, CT_CANDY), // 63
 	MS(   0, CalendarTime::MAX_YEAR,   0,  90, STR_TOWN_BUILDING_NAME_HOUSES_2,                  80,   0,   4,   1,   2,
 	   {},
-	   HZ_NOZNS,
+	   {},
 	   CT_PASSENGERS, CT_MAIL, CT_CANDY), // 64
 	MS(   0, CalendarTime::MAX_YEAR,  85, 150, STR_TOWN_BUILDING_NAME_TALL_OFFICE_BLOCK_1,      130,  18,   8,   4,   2,
 	   BuildingFlag::Size1x1,
-	   HZ_TOYLND | HZ_ZON5 | HZ_ZON4 | HZ_ZON3,
+	   HouseZones({HouseZone::ClimateToyland, HouseZone::TownCentre, HouseZone::TownInnerSuburb, HouseZone::TownOuterSuburb}),
 	   CT_PASSENGERS, CT_MAIL, CT_CANDY), // 65
 	MS(   0, CalendarTime::MAX_YEAR,  11,  60, STR_TOWN_BUILDING_NAME_IGLOO_1,                   45,   3,   3,   1,   1,
 	   BuildingFlag::Size1x1,
-	   HZ_TOYLND | HZ_ZON1,
+	   HouseZones({HouseZone::ClimateToyland, HouseZone::TownEdge}),
 	   CT_PASSENGERS, CT_MAIL, CT_CANDY), // 66
 	MS(   0, CalendarTime::MAX_YEAR,  10,  60, STR_TOWN_BUILDING_NAME_TEPEES_1,                  45,   3,   3,   1,   1,
 	   BuildingFlag::Size1x1,
-	   HZ_TOYLND | HZ_ZON1,
+	   HouseZones({HouseZone::ClimateToyland, HouseZone::TownEdge}),
 	   CT_PASSENGERS, CT_MAIL, CT_CANDY), // 67
 	MS(   0, CalendarTime::MAX_YEAR,  67, 140, STR_TOWN_BUILDING_NAME_SHOPS_AND_OFFICES_1,      130,  22,   8,   4,   4,
 	   BuildingFlag::Size1x1,
-	   HZ_TOYLND | HZ_ZON5 | HZ_ZON4 | HZ_ZON3,
+	   HouseZones({HouseZone::ClimateToyland, HouseZone::TownCentre, HouseZone::TownInnerSuburb, HouseZone::TownOuterSuburb}),
 	   CT_PASSENGERS, CT_MAIL, CT_FIZZY_DRINKS), // 68
 	MS(   0, CalendarTime::MAX_YEAR,  86, 145, STR_TOWN_BUILDING_NAME_SHOPS_AND_OFFICES_1,      130,  23,   8,   4,   4,
 	   BuildingFlag::Size1x1,
-	   HZ_TOYLND | HZ_ZON5 | HZ_ZON4 | HZ_ZON3,
+	   HouseZones({HouseZone::ClimateToyland, HouseZone::TownCentre, HouseZone::TownInnerSuburb, HouseZone::TownOuterSuburb}),
 	   CT_PASSENGERS, CT_MAIL, CT_FIZZY_DRINKS), // 69
 	MS(   0, CalendarTime::MAX_YEAR,  95, 165, STR_TOWN_BUILDING_NAME_TALL_OFFICE_BLOCK_1,      130,  28,   8,   4,   2,
 	   BuildingFlag::Size1x1,
-	   HZ_TOYLND | HZ_ZON5 | HZ_ZON4 | HZ_ZON3,
+	   HouseZones({HouseZone::ClimateToyland, HouseZone::TownCentre, HouseZone::TownInnerSuburb, HouseZone::TownOuterSuburb}),
 	   CT_PASSENGERS, CT_MAIL, CT_CANDY), // 6A
 	MS(   0, CalendarTime::MAX_YEAR,  30,  90, STR_TOWN_BUILDING_NAME_STATUE_1,                  70,  10,   4,   1,   2,
 	   BuildingFlag::Size1x1,
-	   HZ_TOYLND | HZ_ZON5 | HZ_ZON4 | HZ_ZON3,
+	   HouseZones({HouseZone::ClimateToyland, HouseZone::TownCentre, HouseZone::TownInnerSuburb, HouseZone::TownOuterSuburb}),
 	   CT_PASSENGERS, CT_MAIL, CT_CANDY), // 6B
 	MS(   0, CalendarTime::MAX_YEAR,  25,  75, STR_TOWN_BUILDING_NAME_TEAPOT_HOUSE_1,            65,   8,   3,   1,   2,
 	   BuildingFlag::Size1x1,
-	   HZ_TOYLND | HZ_ZON5 | HZ_ZON4 | HZ_ZON3 | HZ_ZON2 | HZ_ZON1,
+	   HouseZones({HouseZone::ClimateToyland, HouseZone::TownCentre, HouseZone::TownInnerSuburb, HouseZone::TownOuterSuburb, HouseZone::TownOutskirt, HouseZone::TownEdge}),
 	   CT_PASSENGERS, CT_MAIL, CT_CANDY), // 6C
 	MS(   0, CalendarTime::MAX_YEAR,  18,  85, STR_TOWN_BUILDING_NAME_PIGGY_BANK_1,              95,   7,   3,   2,   4,
 	   BuildingFlag::Size1x1,
-	   HZ_TOYLND | HZ_ZON5 | HZ_ZON4 | HZ_ZON3 | HZ_ZON2 | HZ_ZON1,
+	   HouseZones({HouseZone::ClimateToyland, HouseZone::TownCentre, HouseZone::TownInnerSuburb, HouseZone::TownOuterSuburb, HouseZone::TownOutskirt, HouseZone::TownEdge}),
 	   CT_PASSENGERS, CT_MAIL, CT_FIZZY_DRINKS), // 6D
 };
 #undef MS
diff --git a/src/town.h b/src/town.h
index 1c6e134db6..ba4310ad1f 100644
--- a/src/town.h
+++ b/src/town.h
@@ -42,7 +42,7 @@ struct TownCache {
 	uint32_t population = 0; ///< Current population of people
 	TrackedViewportSign sign{}; ///< Location of name sign, UpdateVirtCoord updates this
 	PartsOfSubsidy part_of_subsidy{}; ///< Is this town a source/destination of a subsidy?
-	std::array<uint32_t, HZB_END> squared_town_zone_radius{}; ///< UpdateTownRadius updates this given the house count
+	std::array<uint32_t, NUM_HOUSE_ZONES> squared_town_zone_radius{}; ///< UpdateTownRadius updates this given the house count
 	BuildingCounts<uint16_t> building_counts{}; ///< The number of each type of building in the town
 
 	auto operator<=>(const TownCache &) const = default;
@@ -228,7 +228,7 @@ void UpdateTownRadius(Town *t);
 CommandCost CheckIfAuthorityAllowsNewStation(TileIndex tile, DoCommandFlags flags);
 Town *ClosestTownFromTile(TileIndex tile, uint threshold);
 void ChangeTownRating(Town *t, int add, int max, DoCommandFlags flags);
-HouseZonesBits GetTownRadiusGroup(const Town *t, TileIndex tile);
+HouseZone GetTownRadiusGroup(const Town *t, TileIndex tile);
 void SetTownRatingTestMode(bool mode);
 TownActions GetMaskOfTownActions(CompanyID cid, const Town *t);
 bool GenerateTowns(TownLayout layout);
diff --git a/src/town_cmd.cpp b/src/town_cmd.cpp
index 2ccda65ba4..5f07725944 100644
--- a/src/town_cmd.cpp
+++ b/src/town_cmd.cpp
@@ -1943,7 +1943,7 @@ static bool GrowTown(Town *t)
  */
 void UpdateTownRadius(Town *t)
 {
-	static const std::array<std::array<uint32_t, HZB_END>, 23> _town_squared_town_zone_radius_data = {{
+	static const std::array<std::array<uint32_t, NUM_HOUSE_ZONES>, 23> _town_squared_town_zone_radius_data = {{
 		{  4,  0,  0,  0,  0}, // 0
 		{ 16,  0,  0,  0,  0},
 		{ 25,  0,  0,  0,  0},
@@ -1976,11 +1976,11 @@ void UpdateTownRadius(Town *t)
 		/* Actually we are proportional to sqrt() but that's right because we are covering an area.
 		 * The offsets are to make sure the radii do not decrease in size when going from the table
 		 * to the calculated value.*/
-		t->cache.squared_town_zone_radius[HZB_TOWN_EDGE] = mass * 15 - 40;
-		t->cache.squared_town_zone_radius[HZB_TOWN_OUTSKIRT] = mass * 9 - 15;
-		t->cache.squared_town_zone_radius[HZB_TOWN_OUTER_SUBURB] = 0;
-		t->cache.squared_town_zone_radius[HZB_TOWN_INNER_SUBURB] = mass * 5 - 5;
-		t->cache.squared_town_zone_radius[HZB_TOWN_CENTRE] = mass * 3 + 5;
+		t->cache.squared_town_zone_radius[to_underlying(HouseZone::TownEdge)] = mass * 15 - 40;
+		t->cache.squared_town_zone_radius[to_underlying(HouseZone::TownOutskirt)] = mass * 9 - 15;
+		t->cache.squared_town_zone_radius[to_underlying(HouseZone::TownOuterSuburb)] = 0;
+		t->cache.squared_town_zone_radius[to_underlying(HouseZone::TownInnerSuburb)] = mass * 5 - 5;
+		t->cache.squared_town_zone_radius[to_underlying(HouseZone::TownCentre)] = mass * 3 + 5;
 	}
 }
 
@@ -2304,6 +2304,21 @@ static TileIndex FindNearestGoodCoastalTownSpot(TileIndex tile, TownLayout layou
 	return INVALID_TILE;
 }
 
+/**
+ * Get the HouseZones climate mask for the current landscape type.
+ * @return HouseZones climate mask.
+ */
+HouseZones GetClimateMaskForLandscape()
+{
+	switch (_settings_game.game_creation.landscape) {
+		case LandscapeType::Temperate: return HouseZone::ClimateTemperate;
+		case LandscapeType::Arctic: return {HouseZone::ClimateSubarcticAboveSnow, HouseZone::ClimateSubarcticBelowSnow};
+		case LandscapeType::Tropic: return HouseZone::ClimateSubtropic;
+		case LandscapeType::Toyland: return HouseZone::ClimateToyland;
+		default: NOT_REACHED();
+	}
+}
+
 /**
  * Create a random town somewhere in the world.
  * @param attempts How many times should we try?
@@ -2426,15 +2441,15 @@ bool GenerateTowns(TownLayout layout)
  * @param tile TileIndex where town zone needs to be found.
  * @return the bit position of the given zone, as defined in HouseZones.
  */
-HouseZonesBits GetTownRadiusGroup(const Town *t, TileIndex tile)
+HouseZone GetTownRadiusGroup(const Town *t, TileIndex tile)
 {
 	uint dist = DistanceSquare(tile, t->xy);
 
-	if (t->fund_buildings_months && dist <= 25) return HZB_TOWN_CENTRE;
+	if (t->fund_buildings_months != 0 && dist <= 25) return HouseZone::TownCentre;
 
-	HouseZonesBits smallest = HZB_TOWN_EDGE;
-	for (HouseZonesBits i = HZB_BEGIN; i < HZB_END; i++) {
-		if (dist < t->cache.squared_town_zone_radius[i]) smallest = i;
+	HouseZone smallest = HouseZone::TownEdge;
+	for (HouseZone i : HZ_ZONE_ALL) {
+		if (dist < t->cache.squared_town_zone_radius[to_underlying(i)]) smallest = i;
 	}
 
 	return smallest;
@@ -2733,13 +2748,14 @@ static bool TryBuildTownHouse(Town *t, TileIndex tile)
 
 	/* Get the town zone type of the current tile, as well as the climate.
 	 * This will allow to easily compare with the specs of the new house to build */
-	HouseZonesBits rad = GetTownRadiusGroup(t, tile);
+	HouseZones zones = GetTownRadiusGroup(t, tile);
 
-	/* Above snow? */
-	int land = to_underlying(_settings_game.game_creation.landscape);
-	if (_settings_game.game_creation.landscape == LandscapeType::Arctic && maxz > HighestSnowLine()) land = -1;
-
-	uint bitmask = (1 << rad) + (1 << (land + 12));
+	switch (_settings_game.game_creation.landscape) {
+		case LandscapeType::Temperate: zones.Set(HouseZone::ClimateTemperate); break;
+		case LandscapeType::Arctic: zones.Set(maxz > HighestSnowLine() ? HouseZone::ClimateSubarcticAboveSnow : HouseZone::ClimateSubarcticBelowSnow); break;
+		case LandscapeType::Tropic: zones.Set(HouseZone::ClimateSubtropic); break;
+		case LandscapeType::Toyland: zones.Set(HouseZone::ClimateToyland); break;
+	}
 
 	/* bits 0-4 are used
 	 * bits 11-15 are used
@@ -2752,7 +2768,7 @@ static bool TryBuildTownHouse(Town *t, TileIndex tile)
 	/* Generate a list of all possible houses that can be built. */
 	for (const auto &hs : HouseSpec::Specs()) {
 		/* Verify that the candidate house spec matches the current tile status */
-		if ((~hs.building_availability & bitmask) != 0 || !hs.enabled || hs.grf_prop.override_id != INVALID_HOUSE_ID) continue;
+		if (!hs.building_availability.All(zones) || !hs.enabled || hs.grf_prop.override_id != INVALID_HOUSE_ID) continue;
 
 		/* Don't let these counters overflow. Global counters are 32bit, there will never be that many houses. */
 		if (hs.class_id != HOUSE_NO_CLASS) {
@@ -3651,9 +3667,9 @@ static void ForAllStationsNearTown(Town *t, Func func)
 	 * The true radius is not stored or calculated anywhere, only the squared radius. */
 	/* The efficiency of this search might be improved for large towns and many stations on the map,
 	 * by using an integer square root approximation giving a value not less than the true square root. */
-	uint search_radius = t->cache.squared_town_zone_radius[HZB_TOWN_EDGE] / 2;
+	uint search_radius = t->cache.squared_town_zone_radius[to_underlying(HouseZone::TownEdge)] / 2;
 	ForAllStationsRadius(t->xy, search_radius, [&](const Station * st) {
-		if (DistanceSquare(st->xy, t->xy) <= t->cache.squared_town_zone_radius[HZB_TOWN_EDGE]) {
+		if (DistanceSquare(st->xy, t->xy) <= t->cache.squared_town_zone_radius[to_underlying(HouseZone::TownEdge)]) {
 			func(st);
 		}
 	});
diff --git a/src/town_gui.cpp b/src/town_gui.cpp
index e0f5bea8ea..6f0ac5f9bf 100644
--- a/src/town_gui.cpp
+++ b/src/town_gui.cpp
@@ -1421,13 +1421,7 @@ public:
 	 */
 	void SetClimateMask()
 	{
-		switch (_settings_game.game_creation.landscape) {
-			case LandscapeType::Temperate: this->climate_mask = HZ_TEMP; break;
-			case LandscapeType::Arctic:    this->climate_mask = HZ_SUBARTC_ABOVE | HZ_SUBARTC_BELOW; break;
-			case LandscapeType::Tropic:    this->climate_mask = HZ_SUBTROPIC; break;
-			case LandscapeType::Toyland:   this->climate_mask = HZ_TOYLND; break;
-			default: NOT_REACHED();
-		}
+		this->climate_mask = GetClimateMaskForLandscape();
 
 		/* In some cases, not all 'classes' (house zones) have distinct houses, so we need to disable those.
 		 * As we need to check all types, and this cannot change with the picker window open, pre-calculate it.
@@ -1455,7 +1449,7 @@ public:
 
 	/* Houses do not have classes like NewGRFClass. We'll make up fake classes based on town zone
 	 * availability instead. */
-	static inline const std::array<StringID, HZB_END> zone_names = {
+	static inline const std::array<StringID, NUM_HOUSE_ZONES> zone_names = {
 		STR_HOUSE_PICKER_CLASS_ZONE1,
 		STR_HOUSE_PICKER_CLASS_ZONE2,
 		STR_HOUSE_PICKER_CLASS_ZONE3,
@@ -1500,16 +1494,19 @@ public:
 	int GetSelectedType() const override { return sel_type; }
 	void SetSelectedType(int id) const override { sel_type = id; }
 
+	static HouseZone GetHouseZoneFromClassId(int cls_id) { return static_cast<HouseZone>(to_underlying(HouseZone::TownEdge) + cls_id); }
+	static int GetClassIdFromHouseZone(HouseZones zones) { return FindFirstBit((zones & HZ_ZONE_ALL).base()) - to_underlying(HouseZone::TownEdge); }
+
 	StringID GetTypeName(int cls_id, int id) const override
 	{
 		const HouseSpec *spec = HouseSpec::Get(id);
 		if (spec == nullptr) return INVALID_STRING_ID;
 		if (!spec->enabled) return INVALID_STRING_ID;
-		if ((spec->building_availability & climate_mask) == 0) return INVALID_STRING_ID;
-		if (!HasBit(spec->building_availability, cls_id)) return INVALID_STRING_ID;
+		if (!spec->building_availability.Any(climate_mask)) return INVALID_STRING_ID;
+		if (!spec->building_availability.Test(GetHouseZoneFromClassId(cls_id))) return INVALID_STRING_ID;
 		for (int i = 0; i < cls_id; i++) {
 			/* Don't include if it's already included in an earlier zone. */
-			if (HasBit(spec->building_availability, i)) return INVALID_STRING_ID;
+			if (spec->building_availability.Test(GetHouseZoneFromClassId(i))) return INVALID_STRING_ID;
 		}
 
 		return GetHouseName(spec);
@@ -1520,11 +1517,11 @@ public:
 		const auto *spec = HouseSpec::Get(id);
 		if (spec == nullptr) return {};
 		if (!spec->enabled) return {};
-		if ((spec->building_availability & climate_mask) == 0) return {};
-		if (!HasBit(spec->building_availability, cls_id)) return {};
+		if (!spec->building_availability.Any(climate_mask)) return {};
+		if (!spec->building_availability.Test(GetHouseZoneFromClassId(cls_id))) return {};
 		for (int i = 0; i < cls_id; i++) {
 			/* Don't include if it's already included in an earlier zone. */
-			if (HasBit(spec->building_availability, i)) return {};
+			if (spec->building_availability.Test(GetHouseZoneFromClassId(i))) return {};
 		}
 
 		return spec->badges;
@@ -1548,7 +1545,7 @@ public:
 			if (*it == 0) continue;
 			HouseID house = static_cast<HouseID>(std::distance(id_count.begin(), it));
 			const HouseSpec *hs = HouseSpec::Get(house);
-			int class_index = FindFirstBit(hs->building_availability & HZ_ZONALL);
+			int class_index = GetClassIdFromHouseZone(hs->building_availability);
 			items.insert({0, house, class_index, house});
 		}
 	}
@@ -1569,7 +1566,7 @@ public:
 					/* Not preset, hide from UI. */
 					dst.insert({item.grfid, item.local_id, -1, -1});
 				} else {
-					int class_index = FindFirstBit(it->building_availability & HZ_ZONALL);
+					int class_index = GetClassIdFromHouseZone(it->building_availability);
 					dst.insert( {item.grfid, item.local_id, class_index, it->Index()});
 				}
 			}
diff --git a/src/tunnelbridge_cmd.cpp b/src/tunnelbridge_cmd.cpp
index 1188556463..458fa5b785 100644
--- a/src/tunnelbridge_cmd.cpp
+++ b/src/tunnelbridge_cmd.cpp
@@ -281,7 +281,7 @@ CommandCost CmdBuildBridge(DoCommandFlags flags, TileIndex tile_end, TileIndex t
 		company = OWNER_TOWN;
 
 		/* If we are not within a town, we are not owned by the town */
-		if (town == nullptr || DistanceSquare(tile_start, town->xy) > town->cache.squared_town_zone_radius[HZB_TOWN_EDGE]) {
+		if (town == nullptr || DistanceSquare(tile_start, town->xy) > town->cache.squared_town_zone_radius[to_underlying(HouseZone::TownEdge)]) {
 			company = OWNER_NONE;
 		}
 	}
@@ -635,7 +635,7 @@ CommandCost CmdBuildTunnel(DoCommandFlags flags, TileIndex start_tile, Transport
 		company = OWNER_TOWN;
 
 		/* If we are not within a town, we are not owned by the town */
-		if (town == nullptr || DistanceSquare(start_tile, town->xy) > town->cache.squared_town_zone_radius[HZB_TOWN_EDGE]) {
+		if (town == nullptr || DistanceSquare(start_tile, town->xy) > town->cache.squared_town_zone_radius[to_underlying(HouseZone::TownEdge)]) {
 			company = OWNER_NONE;
 		}
 	}