Common Hearth No. 4
A freestanding Soviet Martian cooperative residence on flat ground. In plan, a three-storey long north wing and a two-storey shorter west wing meet at a right angle; a single-storey sealed winter-garden hall fills the inside southwest-facing elbow without closing the entire forecourt. Both residential wings step back at their upper floors, with closed deep glazed loggias rather than outdoor balconies. The garden hall has small rectangular panes under a low opaque roof, with restrained amber light and vegetation only behind sealed glazing. A blunt square stair tower at the elbow rises just above the taller wing.
Steel pressure cells are protected by massive cream-coated sulfur-concrete panels. Deep, narrow horizontal window bands have black mullions and red aggregate sills. A tall red enamel numeral 4 marks the front face of the stair tower above a recessed rectangular airlock. Low parapets conceal most of the regolith-covered shallow vaults, whose axes follow their respective wings; two short ribbed service drums have maroon caps. The east end has a tapering buttress and small maintenance hatch; the north and west rear elevations have sparse small windows, exposed panel straps, numbered service covers and substantial concrete buttresses. Preserve an inhabited, repaired finish with limited maroon replacement panels. Keep every roof and façade structurally resolved; no open air gardens, broad glass domes or exposed balconies.