A Corner Lot That Cannot Hold Its Own Parking
A 60 m by 80 m corner lot fronts a 15 m right-of-way. It is zoned C-2. The owner proposes a six-storey building, 60% commercial and 40% residential by floor area, at the maximum lot occupancy. The zoning ordinance provides: maximum lot occupancy 70%; front setback 4.5 m on both street frontages; side and rear setbacks 3.0 m and 5.0 m; maximum building height 24.0 m; parking at 1 slot per 100 m2 of commercial GFA and 1 slot per 5 dwelling units; 1 loading bay per 3,000 m2 of commercial GFA; 10% of the lot as open space. Average dwelling unit is 56 m2; a parking slot with aisles needs about 25 m2.
1. Determine the buildable floor area and the parking demand, and state whether the scheme as proposed is feasible.
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GFA. Lot = 60 x 80 = 4,800 m2. Seventy percent occupancy gives a footprint of 3,360 m2. Check the setback envelope: (60 - 4.5 - 3.0) x (80 - 4.5 - 5.0) = 52.5 x 70.5 = 3,701 m2. The envelope is bigger than the occupancy cap, so 70% governs: footprint 3,360 m2, six storeys, total GFA 20,160 m2.
Programme split. Commercial 60% = 12,096 m2; residential 40% = 8,064 m2.
Parking.
- Commercial: 12,096 / 100 = 121 slots.
- Residential: 8,064 / 56 = 144 units; 144 / 5 = 29 slots.
- Total 150 slots, needing about 150 x 25 = 3,750 m2.
Loading: 12,096 / 3,000 = 4 bays.
Verdict: not feasible as proposed. The parking requirement alone (3,750 m2) is larger than an entire floor plate (3,360 m2). If you add a dedicated parking level you have seven levels, and at a realistic 3.6 m floor-to-floor that is 25.2 m plus parapet and mechanical space - over the 24.0 m height cap. The scheme is caught between the parking requirement and the height limit.
2. The client refuses to reduce the programme. Present the realistic options and recommend one, with reasoning.
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The options are reductions somewhere. Name them all, cost them, and recommend.
- Basement parking. Fits 3,750 m2 under the building in two levels of about 1,900 m2. Costs jump: excavation, waterproofing, mechanical ventilation, sump pumps, and the ramp eats ground-floor area. On a site with unknown groundwater this is the highest-risk option - and it does not solve the loading bays, which need height.
- Mechanical parking (stackers or puzzle systems). Two to three cars per footprint slot cuts the area to roughly 1,300–1,900 m2. Valid where the ordinance counts slots rather than area - confirm the ordinance text permits it, many do not yet. Adds maintenance cost and a single point of failure.
- Reduce commercial GFA. Dropping commercial to 45% removes ~3,000 m2 of GFA and ~30 slots, and buys back a floor of parking. The cheapest option technically, and the client will resist it.
- Variance. Argue the site is a corner lot on a 15 m ROW with mass transit within walking distance, and offer a shared-parking agreement with the adjacent mall. Variances are discretionary and slow; do not let the client sign leases on the assumption it will be granted.
Recommendation: present 3 as the base case, with 2 as the value-engineered alternative if the ordinance allows mechanical slots, and 4 only as a parallel track. Regardless of the option chosen, re-check the 10% open space (480 m2) and the two front setbacks after any reconfiguration - a corner lot has two front yards, and a designer who treats one as a side yard gets a permit rejection.
3. Neighbours object that the building will overload the street and block their light. How should the architect respond at the public consultation?
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Answer with the envelope, not with assurances. Bring the drawings that show what the code already does:
- The building is set back 4.5 m on two frontages, 3.0 m at the side and 5.0 m at the rear, so the neighbours' light and view are already partly protected by the bulk controls; show a shadow study at 8 a.m., noon and 4 p.m. rather than claiming it will be fine.
- Show the traffic numbers honestly: 150 parking slots means roughly 150 ingress and 150 egress trips at peak plus 4 loading bays. If the access is on the minor street, say so, and show the turn paths for a delivery truck.
- Distinguish what the zoning allows from what you are proposing. If you are asking for a variance, say that plainly - a consultation where the architect pretends no relief is being sought is the one that ends up in court.
What not to do: do not promise amenities you cannot deliver, and do not argue that objectors 'don't understand zoning'. The hearing record becomes part of the variance file. Concede the two or three points that cost the scheme little (a landscape buffer, restricted loading hours, a service access relocated to the minor street) and defend the one that matters.