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.
Version 1.0 of a simplified Taj Mahal, about 1:3 of the original, drawn with the game's real brick shapes. Download (Extra Buildings 1.2.0). Played in world slot 3 (the Notre-Dame is slot 4), in a new save there.
Platform of 4×2×2 blocks in terracotta (red sandstone), so the light placement holograms of the first bricks stand out; grey in the mod's settings (Platform), any colour in the game's Settings > Accessibility > Custom brick colors (Factory · Terracotta). A 20° ramp in front for the game's mobile scaffold.
In the game the platform is a finished mesh made of the game's own blocks, like the Notre-Dame's plinth: the building starts on top of it.
Seven construction sites (the game takes at most 8,192 brick slots per site): ground floor walls, ground floor inside with the floor,
upper floor walls, upper floor inside with the inner dome, roof, dome, minarets. A block can only be set once every block it rests on is in place.
Mausoleum as in the original: a square with cut corners, on each side a high arched portal (pishtaq) with a deep recess, a door and a lattice window,
framed by a plum band (the calligraphy) with dots of blue and turquoise in the spandrels (the stone inlays), and two storeys of smaller arched niches beside it;
the cut corners carry blind niches. Walls are one 2×1 block thick, laid in running bond; the roof is one row of 2×1 blocks with merlons along the edge.
Inside a round central hall under a low inner dome, and two storeys round it: a square ring of pointed arcades on each storey carries the floor between them and the roof.
The outer onion dome stands on a drum that continues the hall wall, and a ring of blocks round its foot closes the roof. Nothing hangs in the air: every block rests on one below or on a supported neighbour in its row (checked by script).
Corners interlock: the 2×1 at a corner reaches into one wall and, one row up, into the other. The button "2×1 red · 1×1 blue" shows the bond.
Domes and minarets are laid in true rings: blocks at slight angles that overlap a little, as tried out in the game with the Notre-Dame's apse and spire.
Where a dome draws in faster than one block per row, extra inner rings fill the row below, so every block rests on one below.
Roof: four chhatris (small domes on eight columns), slim pinnacles at the portal frames and the corners, brass finials with a crescent.
Minarets at the corners of the platform with three balconies and a chhatri on top.
Scaffold (orange here, aluminium in the game; part of the mod, not bricks) stands only while the building is being built:
it goes once every construction site is complete, only the ramp stays. The game's mobile scaffold reaches the outer walls, the minarets and the chhatris from the platform.
A stair tower behind the building climbs from the platform onto the roof, with a bridge over the parapet; on the roof a stair winds round drum and dome
up to a platform with a bridge reaching in over the narrowing dome, from which the finial is within reach.
Inside, 1 m narrow: a stair tower in the hall, turned so its corners face the hall's arches, up to the inner dome; walkways round the hall on both storeys
in both corridors, joined by bridges through the arches. The upper storey is reached only this way, through the hall, because its niches outside are blind.
Drag the build progress back to see it.