basement module 3d model

Create only the BASEMENT (UG) module of a modern minimalist single-family house as pure geometry (no textures/materials/colors). Use a rectangular footprint that will be reused by the upper floors; keep the same XY footprint for all later modules. All meshes must be STL-printable, manifold, watertight, closed, with outward normals and no internal faces or overlaps. Wall thickness: all walls 4–5 mm (target 5 mm for exterior, 4–5 mm for interior). Floor/ceiling slab thickness: 3.5–4 mm. Units in millimeters, Z up, origin centered under the footprint. No exterior openings at all (no windows, no outside doors) in the basement exterior walls. Interior plan exactly as follows (use right/left as seen when facing the FRONT side that will later hold terrace and balcony): a central corridor surrounding a U-shaped (gegenläufige) staircase going up to the ground floor; top-left = storage room 1, top-right = storage room 2, bottom-left = wash room, bottom-right = technical room. Provide rectangular interior door cutouts b