TMC Greater Simcoe

ADU Financing Calculator

How much can you actually borrow to build a secondary suite or garden suite? Compares the CMHC Refinance Program (90% as-complete LTV) and a standard refinance/HELOC, then shows the best combination against your build cost.

Illustrative borrowing capacity, not a pre-approval. Every program is subject to full lender underwriting, appraisal, and program rules at the time of application. Full disclaimer.
$
$
$

Home value once the ADU is built, not today's value

$

Use the Build Cost Calculator if you don't have a number yet

Illustrative rates (override if you have quotes)
%
%

Illustrative borrowing capacity only, not a pre-approval. Every program is subject to full lender underwriting, appraisal, and program rules at the time of application.

Best combined financing available

$285,000

That covers the full $285,000 build cost entered, combining every program you're eligible for.

How the combination breaks down

CMHC Refinance Program (90% as-complete LTV)$285,000.00

Every program, on its own

CMHC Refinance Program (90% as-complete LTV)
$506,000.00
Standard refinance / HELOC (80% current LTV)$205,000.00

CMHC mortgage insurance premium applies on the insured refinance portion. The exact premium depends on the LTV tier and CMHC's current rate card — confirm the precise figure with your mortgage professional before treating this as a final number.

Where to go next

Don't have a build cost yet? Start with the Build Cost Calculator. Already know your numbers and want the full multi-year picture of building vs. staying put? Run the Garden Suite Build vs. Status Quo calculator. For the full explanation of every program modelled here, read the Ontario ADU Financing Hub.