Auditing an Over-Built Proposal Against FAR, Coverage and Height
A developer submits a proposal for a 3000 m² plot, 60 m × 50 m, abutting a 12 m wide road. Zoning allows FAR 2.0, ground coverage up to 40%, front setback 6 m, rear setback 3 m, side setbacks 3 m each, floor height 3.2 m and a maximum height of 1.5 times the abutting road width for fire-fighting access. Parking is one equivalent car space (ECS) per 100 m² of built-up area, each ECS 2.5 m × 5.0 m with 30% extra for circulation, and landscaped open space must be at least 15% of the plot.
The proposal shows a footprint of 40 m × 36 m, eight floors of 3.2 m, plus a 1.2 m parapet and tank, giving 11,520 m² of built-up area. The developer argues that the setbacks are respected, so 'the rest is design freedom'. A planner must decide what can legally be approved, what the maximum envelope really is, and whether the parking can be met on the surface.
1. Audit the submitted proposal against coverage, FAR, height and setbacks. Which of the developer's claims survives?
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Setbacks. Buildable rectangle = (60 − 6 − 3) × (50 − 3 − 3) = 51 × 44 = 2244 m². The 40 × 36 = 1440 m² footprint sits inside it, so this single claim is true - and it is the only one.
Coverage. 1440/3000 = 48% against a 40% cap. Non-compliant by 8 percentage points; permissible footprint is 1200 m², so the proposal is 240 m² over on every floor.
FAR. 11,520/3000 = 3.84 against 2.0. Permissible built-up area is 6000 m², so the proposal exceeds it by 5520 m² - nearly double.
Height. 8 × 3.2 = 25.6 m, plus 1.2 m = 26.8 m. Cap = 1.5 × 12 = 18.0 m. Over by 8.8 m, i.e. three storeys too tall.
Conclusion. Respecting setbacks is a necessary condition, not a sufficient one; it constrains where you build, while coverage, FAR and height constrain how much and how high. Three independent limits are breached, so the scheme cannot be approved with conditions - it needs redesign. The planner should also record that the setbacks being met means the failure cannot be cured by trimming the plan edges; only reducing floors and footprint will do it.
2. Derive the maximum permissible building envelope. Show which bylaw governs the outcome and check whether the limits bind together or separately.
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Storeys from height. (18.0 − 1.2)/3.2 = 5.25 → 5 floors, total 5 × 3.2 + 1.2 = 17.2 m ≤ 18.0 m. Six floors would be 20.4 m and fail.
Footprint from coverage. 0.40 × 3000 = 1200 m², comfortably inside the 2244 m² buildable rectangle.
Built-up area from FAR. 2.0 × 3000 = 6000 m².
Do they bind together? Yes - and that is the interesting part. Five floors at the maximum footprint give 5 × 1200 = 6000 m², exactly the FAR ceiling. So the height cap, the coverage cap and the FAR cap all converge on the same envelope, with zero slack on any of them: 6000 m² of built-up area is achievable only at exactly 1200 m² footprint and exactly 5 floors, and even 1 m² of lift machine room or staircase headroom above the fifth slab consumes FAR headroom that does not exist.
Practical recommendation. Design at 1150 m² footprint × 5 floors = 5750 m² (coverage 38.3%, FAR 1.92), which leaves about 250 m² of FAR for the stilt/lift overrun and a small terrace enclosure, and still leaves the plan within setbacks. Advise the developer that any request for more built-up area requires either a wider abutting road (raising the height cap) or a zoning relaxation - not a cleverer plan form. Quote the numbers in the approval note so the next submission is tested against the same three checks.
3. Test the parking and open-space requirements for the maximum compliant scheme. Can 60 ECS be provided on the surface, and what would you recommend?
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Parking demand. One ECS per 100 m² of built-up area: 6000/100 = 60 ECS. Area = 60 × (2.5 × 5.0) = 60 × 12.5 = 750 m²; with 30% circulation, 975 m² of parking ground is needed.
Open space available. 3000 − 1200 = 1800 m² is unbuilt. Landscaping must be at least 15% of the plot = 450 m². So 1800 − 975 − 450 = 375 m² is left for the entry drive, the ramp or gatehouse, refuse storage, fire-tender turning and pedestrian circulation.
Does it work? Only on paper. A 375 m² residue is roughly 12.5% of the plot for all movement and service functions, and the car park itself must sit outside the setback landscaping if the 450 m² is genuinely to be green - so the 975 m² of hardstanding competes with the very setback strip that is supposed to absorb it. In practice the layout would either eat the landscape requirement or block the fire access. The scheme is compliant in arithmetic and non-compliant in function.
Recommendation. Put part of the requirement below grade - for example a single basement level for 30 ECS (about 490 m² including circulation) and 30 ECS on surface (about 490 m²), which frees roughly 485 m² of ground for landscaping, driveway and turning. Check that the basement ramp does not cross the 6 m front setback and that the landscape stays at or above 450 m² after the ramp. State the parking calculation in ECS, not in 'cars', on the drawing, because stacking systems and compact spaces change the count and the planner must approve the method, not just the total.