Construction Financing Ontario: How Draw Mortgages Work (And What Can Go Wrong)
Building your own home or a rental property in Ontario is one of the most rewarding — and financially complex — projects you can undertake. The financing works completely differently from a standard purchase mortgage, and misunderstanding how it works can cause serious cash flow problems mid-build.
Here's how construction financing actually works, what lenders require, and how to protect yourself.
What Is a Construction Mortgage (Draw Mortgage)?
A construction mortgage — also called a draw mortgage or progress advance mortgage — is a short-term loan that releases funds in stages as your build progresses. You don't receive the full loan amount upfront. Instead, funds are released at specific construction milestones after a lender-approved inspector confirms completion.
This protects the lender (and you) by ensuring money is only advanced for work that's actually been done.
Typical Draw Schedule in Ontario
| Draw # | Stage | Typical % Released | What's Inspected |
|---|---|---|---|
| Draw 1 | Foundation complete | 15% | Footings, foundation walls, waterproofing |
| Draw 2 | Framing complete | 25% | Structure, roof deck, windows/doors roughed |
| Draw 3 | Mechanical rough-in | 20% | Plumbing, electrical, HVAC roughed in |
| Draw 4 | Drywall complete | 20% | Insulation, drywall hung and taped |
| Draw 5 | Final completion | 20% | Occupancy permit issued, finishes complete |
⚠️ Each draw requires a lender-ordered inspection ($150–$300 per inspection). You pay for this. Budget 4–6 inspections into your total project cost.
The Interest Reserve: How You Pay During Construction
During construction, you only pay interest on the funds drawn — not the full loan amount. However, lenders typically hold back a portion of your loan as an interest reserve to cover these payments automatically. This prevents you from being required to make mortgage payments while also funding construction costs.
Example: On a $800,000 construction loan over 12 months at 7%, the interest reserve might be $28,000–$35,000 — set aside from your loan approval and drawn automatically each month.
What Lenders Require for a Construction Mortgage
- Fixed-price construction contract — open-ended contracts are declined. The lender needs a detailed scope and firm price
- Builder's qualifications — most lenders require a licensed contractor with $2M+ liability insurance and a track record
- Plans and permits — approved building permit, architectural drawings
- As-improved appraisal — an appraiser estimates the value of the finished home; the loan is based on the lower of cost or appraised value
- 20–25% equity/down payment — based on total project cost (land + construction)
- Construction timeline — typically funded for 12–18 months. Extensions are available but may require re-approval
Owner-Builder Construction Mortgages
If you plan to act as your own general contractor, financing becomes significantly more difficult. Most institutional lenders won't finance owner-builder projects due to completion risk. Private lenders and some specialty lenders will, but expect higher rates (10–14%) and more stringent draw release conditions.
💡 Hybrid approach: Hire a licensed GC but act as your own project manager. You get the financing of a standard construction mortgage with the cost savings of being hands-on.
Construction-to-Permanent Financing: The Cleaner Path
Rather than taking a construction mortgage and then refinancing into a regular mortgage at completion, some lenders offer a construction-to-permanent product — a single loan that converts from a draw mortgage to a conventional amortizing mortgage at completion with no new approval, no new appraisal, and no break fees.
This is the best structure when you can get it — it eliminates the risk of not qualifying for the take-out mortgage at completion (which can happen if rates have risen or your income situation has changed).
What Can Go Wrong (And How to Protect Yourself)
- Builder insolvency mid-project — use a lawyer to hold builder deposits in trust and use staged payments only
- Cost overruns beyond the loan amount — add a 15–20% contingency to your budget before applying
- Failing the final inspection — no occupancy permit = no final draw = you're funding gap out of pocket
- Rate risk at conversion — if you're in a construction mortgage and rates rise before you convert, your permanent mortgage will be at higher rates. Lock the take-out rate early if possible
- HST on new construction — new builds attract 13% HST. The new housing rebate covers some of this but budget carefully
Building in Ontario? Let's Structure This Right.
Paul places construction mortgages for ground-up builds, custom homes, and investor projects across the GTA. Get the right lender, the right draw structure, and no surprises.
Learn About Construction Financing →Frequently Asked Questions
What is a draw mortgage in Ontario?
A draw mortgage releases funds in stages as construction milestones are reached and inspected. Interest is only charged on funds drawn — not the full loan amount — which keeps costs down during the build phase.
How much down payment is needed for a construction mortgage?
Most lenders require 20–25% of the total project cost (land plus construction). Some lenders base the loan on the as-completed appraised value, so a well-designed project in a strong market can reduce your cash requirement.
What happens if my builder goes over budget?
Cost overruns beyond the approved loan amount are your responsibility. Most lenders include a 10% contingency in the approved budget. Anything beyond that, you fund from your own resources — which is why a detailed fixed-price contract with your builder is non-negotiable.
