What drives the cost of a custom home in the GTA?

Two lots of the same size can carry very different houses. A serviced infill lot in Toronto has water, sewer and hydro at the street and a zoning by-law that sets height, setbacks and floor area to the metre. A rural lot in Caledon or King has none of the services and needs a well, a septic system and a driveway before the house is a line on a drawing.

The lot also decides what happens before construction. A tear-down needs a demolition permit and utility disconnects. A sloping lot needs more excavation and a taller foundation on one side. A lot with a protected tree, a ravine edge or a floodplain has a review before the permit, and that review shapes the footprint.

A design inside the zoning envelope goes through as a building permit. A design outside it goes to the Committee of Adjustment first, and that hearing adds months and its own fees. Ravine, moraine, escarpment and waterfront lots add a conservation authority or commission review. Heritage districts add a design review of anything visible from the street.

None of those stop a house. They add time, and time on a build is carrying cost: the mortgage on the lot, the rent where you are living, the price movements in materials between the quote and the pour. That is why Savino Construction reads the zoning before a line is drawn.

Once the drawings are set, the building itself is priced from the outside in.

• Floor area and storeys. Square footage above and below grade sets the foundation, the framing and the hours.
• Foundation type. A full basement, a walk-out on a slope, or a slab, and what the soil and the water table allow.
• Structure. Long open spans mean steel; a conventional plan means lumber. Cantilevers, tall glazing and flat roofs each add engineering.
• Envelope. Brick, stone, stucco, fibre cement or wood, the count and size of the windows, the roof form and the insulation standard.
• Mechanical. Heating and cooling type, in-floor heat, a backup generator on a rural lot, and the electrical service size.

Kitchen, bathrooms, flooring, millwork, stone, fixtures and lighting are the lines you control most. That is why the quote comes with a catalogue: every material is named, every line has a number beside it, and you can move any of them before you sign. A quote that gives you an allowance instead of a line is asking you to trust a number nobody has priced.

Put any two custom home quotes side by side and look for these.

• Every line priced, with the material named, not an allowance.
• The approvals listed, with who applies and what each one adds to the schedule.
• A contract handover date, and what happens if it is missed.
• The warranty term in writing.
• The person who will run the job, by name.