Six-Storey Infill Housing on a 9 m Tehran Lot
An infill lot at the edge of Tehran's District 7 measures 9.0 m wide by 21.0 m deep, with its only street frontage on the south. The zoning envelope permits six storeys above grade and 18.6 m to the parapet. To the west, a five-storey apartment block stands 1.5 m from the boundary and has habitable windows facing the site; to the east, a two-storey house sits directly on the boundary. The client wants six apartments of about 110 m², one per floor, plus one parking space per unit. The municipality requires the parking to be inside the lot, a maximum ramp grade of 15%, and a 2.1 m clear headroom. The site is 21 m deep, so a conventional two-way ramp and six standard stalls cannot be accommodated without consuming most of the ground floor. The client also insists that every living room face south, and that bedrooms not look directly into the west neighbour's windows. The architect must decide the section, core position, and parking strategy before applying for permit.
1. Given the 9 m width and the requirement that every living room face south, evaluate whether one apartment per floor can achieve both south daylight and cross-ventilation. What plan configuration do you propose, and what do you sacrifice?
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A single 9 m-wide apartment per floor can achieve south daylight for the living space, but not full cross-ventilation through the 18 m depth unless a lightwell is introduced. I would place the living/dining zone in a 5.0 m deep band on the south facade, with a 1.5 m deep balcony or overhang for summer shade. The middle band contains kitchen, dining, and a 3.0 m × 3.0 m lightwell on the west side; bathrooms and the stair core sit against the west party wall. Bedrooms go to the east and north, where the two-storey neighbour allows morning light and air. The sacrifice is that the west facade becomes mostly service and screen, so no habitable room relies on it; the north bedrooms become single-aspect. Cross-ventilation works south-to-north through the living room, lightwell, and a north operable window, with the lightwell acting as a stack. A double-loaded corridor would waste the 9 m width; one apartment per floor is the only way to give each unit a south living room. Net area falls because the lightwell and core consume about 12 m², but 110 m² remains feasible if the gross floor plate is 150–160 m².
2. Recommend a parking and core strategy that meets the 15% ramp and 2.1 m headroom constraints. Explain the trade-offs among a basement ramp, a car lift, and stacked parking.
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At 9 m width, a conventional two-way ramp plus a 6 m aisle and a 2.5 m stall cannot fit; a basement ramp would consume the whole ground floor and still yield only three or four stalls. I would use a three-level puzzle stacker in a 7.5 m × 5.0 m bay at the rear, served by a 3.2 m wide one-way ramp along the east boundary with a 15% grade and 2.1 m clear headroom. The stacker yields six stalls in the footprint of about two surface stalls. The stair and elevator core go at the northeast corner of the lobby, not on the south facade; a 1.5 m wide ventilated lobby separates parking from the residential entry. Trade-offs: a ramp to a true basement is cheaper per stall and easier to ventilate, but it eats the entire 9 m width and needs a 21 m long ramp; a car lift is compact but has maintenance and single-point failure; stacked parking needs mechanical ventilation and fire suppression. I would choose the stacker only if the municipality accepts mechanical parking; otherwise reduce to four units or lease off-site parking, because six conventional stalls cannot be compliantly fitted.
3. How should the west facade be composed to protect the neighbour's privacy without turning the apartments into closed boxes? Give specific architectural moves.
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Treat the west party wall as a thick, layered edge rather than a window wall. Put bathrooms, kitchen, storage, and the stair against it; where a room needs light, use a 1.2 m deep lightwell or a high-level clerestory at 2.2 m, above the neighbour's sightline. For the living room's west side, use a fixed screen of vertical brick fins at 300 mm centres, rotated 30–45 degrees, set 400 mm off the glass; this admits north and west sky light but cuts direct views. Add a 1.5 m high masonry spandrel at the balcony and a 3 m high deciduous tree in the 1.5 m setback, but keep the screen non-combustible and maintain fire separation. Avoid frosted glass everywhere, because it makes the facade blank; instead compose a rhythm of solid brick, a narrow vertical slot at the stair, and one screened opening per floor. The east facade, facing the low house, can carry the bedrooms and larger windows. This gives privacy without turning the apartments into closed boxes, and it produces a facade that reads as a deliberate urban edge.