Zoning a narrow infill house on a south-facing plot
A young family owns an infill plot 8.50 m wide and 24.00 m deep. The street is on the south; a neighbour’s two-storey wall runs along the west boundary, and the east boundary opens to a low garden. Planning allows a two-storey house with maximum coverage of 60% and a plot ratio of 0.8. Front setback is 3.00 m, rear setback 3.00 m and side setbacks 1.50 m. The brief is for three bedrooms, an open living/dining/kitchen, a guest WC, a utility room and a covered veranda. The family wants living areas opening to a private garden and not overlooked from the street. Prevailing summer wind is from the west; winter sun comes from the south.
1. Propose a ground-floor zoning strategy. State where you would place the entry, living, kitchen, utility, WC, stair and veranda, with reasons linked to orientation and privacy.
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Put the entry on the east side, not facing the street directly, with a screen or recess so the living room is not exposed. Use the west party wall as a service buffer: utility, guest WC and stair can sit there, gaining space from the blank neighbour wall and reducing the need for west windows. The stair should be central enough to serve upstairs without a long corridor.
Place the kitchen toward the east or north-east, with a short link to the utility and a service door. Put living and dining across the south and east, opening to the rear garden and a covered veranda at the garden end. That gives winter sun from the south, cross-ventilation from the west breeze through east openings, and privacy because the main sitting area is behind the front setback and screened from the street. The veranda should be a genuine outdoor room, not a leftover strip.
2. Check the massing against the coverage and plot ratio limits. Show the arithmetic and explain what drawing checks you would make.
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Plot area = 8.50 × 24.00 = 204.0 m². Maximum coverage = 0.60 × 204.0 = 122.4 m². Maximum total floor area from plot ratio = 0.80 × 204.0 = 163.2 m². A two-storey house using the full plot ratio therefore has an average footprint of 163.2 ÷ 2 = 81.6 m². Plot ratio, not coverage, governs here.
The buildable rectangle after setbacks is (8.50 − 1.50 − 1.50) = 5.50 m wide and (24.00 − 3.00 − 3.00) = 18.00 m deep, or 99.0 m² per floor, so the setbacks are not the binding constraint. On the drawings, check the site plan area calculation, the covered veranda treatment, the roof overhang and any covered parking. These often change the measured area. Do not assume that a two-storey house can occupy the full 122.4 m² footprint.
3. Describe how you would use a freehand diagram to test two layout options and present the chosen scheme to the client.
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Start with a bubble diagram: entry, living, kitchen, service, stair and garden as circles, with arrows for the main routes. Test option A with the stair on the west service wall and option B with a central stair and a side courtyard. Overlay the sun path and the west breeze. The diagram should expose the trade-off: the central stair gives better upstairs access but eats living space and may block cross-ventilation; the west stair is efficient but darker.
Then redraw the chosen option as a single-line 1:100 sketch, with furniture blocks in the living room and a table in the kitchen. Add simple notes rather than full construction information. Present the diagram and the sketch together, because the client is judging the logic, not the line quality. Only after that should you produce the measured 1:50 plan with dimensions and wall thicknesses.