Part of Brick by Brick – Extra Buildings, an unofficial fan mod, not made by the game's developers.
In building order. A click shows the build up to that section: the section itself in color, everything before it paler.
Simplified model, about 1:3.3 of the original (128 m long, towers 69 m), drawn with the game's real brick shapes. Walls are 0.21 m thick and laid in running bond with 2×1 blocks. Roof tiles lie flat in rows that step in by one cell per layer (45°), like the game's own roofs. Doors and windows are framed like the house in the game: upright "2×1×2 Blocks" as jambs, the same block lying flat above them, "2×2 Window" pieces as sills or as drip caps over the doors. Windows close in a stepped point (one cell per row), in the round choir too; the belfry openings have the same frames with louvers. The portals are open passages with a lintel, a stepped tympanum and an archivolt. The round choir, its roof and the spire are laid in true rings: blocks at slight angles that overlap a little (the game checks no overlap when a brick is set), every other ring tile 5 mm higher against flickering. This was tried out in the game with a round test tower. The drum under the spire uses the curved wedge blocks of the library's round tower (18 per ring). Nothing hangs in the air: arcades of pointed arches on piers carry the upper walls of nave, transept and choir (a ring of arches in the round choir), and arches open the towers to the aisles and to the hall between them. Where two walls meet in an inner corner they share a corner block, so the corners interlock. Scaffold: the game's scaffold lift goes up to 17.05 m and a brick can be set from up to 5 m away. On top of that the mod adds a walkable scaffold (aluminium tubes and wooden planks, no bricks): a facade scaffold in front of the west front with a stair tower at each bell tower up to its platform, decks every 5 m and a cross bridge between the two tower tops, a stair tower in front of the north transept with a bridge at ridge height to a stair round the drum up to the spire, and lanes at 9.45 m along the upper walls of nave, transept and choir. Every stair turns on a square landing, and two ramps lead the game's mobile scaffold up onto the plinth. All 73 uprights stand on the plinth, stair flights rest on stringers, braces stiffen the frames, and no two parts share a face where they overlap (no flickering). In the game the cathedral is built as five construction sites (the game allows 8,192 brick slots per site): west front, bell towers, nave, transept and choir, drum and spire. It loads in the game, and a showcase mode shows it finished: screenshots from the game.