Comparing renovation quotes: anything not written down will cost extra

Three quotes for the same bathroom can differ by thousands of dollars, and the cheapest often looks like the obvious choice. CMHC's guide to hiring a contractor points to why that goes wrong: quotes are only comparable when they describe the same job, and anything missing from an estimate tends to come back as an extra.

Ask for the same thing from everyone

CMHC says to be specific about finishes, materials and lifespan when asking for estimates. If one contractor prices a mid-range tile and another a premium one, or one includes removing the old tub and another does not, the totals are not comparable. Write a short list of what you want, the rooms, the fixtures, the finish level, and give the same list to each contractor.

What each estimate should contain

CMHC says roughly three detailed estimates are usually enough, and that each should include a description of the work, the project duration and the total cost. Check that everything you asked for is included. CMHC's warning is worth repeating: assume that anything not specifically listed in the estimate will involve extra costs and possibly extra time. A one-line quote, such as 'bathroom renovation, $18,000', gives you nothing to hold the contractor to.

Compare line by line

Put the quotes side by side and go through them item by item: demolition and disposal, permits, rough plumbing and electrical, materials and who supplies them, finishes, cleanup, and the schedule. Where one quote lists an item and another is silent, ask the silent contractor whether it is included. CMHC advises not to choose based on the lowest price alone; a gap in scope is not a saving.

Questions that reveal the difference

CMHC lists interview questions that help explain price differences: whether the contractor uses their own crew or subcontractors, what work they or their subcontractors are licensed to do, whether they carry workers' compensation and liability insurance, whether they will get the required permits and which ones, what warranty they give and what it covers, how they handle cleanup and fine dust, and whether they provide a written contract. A contractor who cannot or will not answer may not be the right one, and CMHC advises not to sign or pay anything until you have decided.

From the chosen quote to the contract

Once you choose, CMHC says to get a written contract with a start and end date, a payment schedule showing how much you pay at each stage, a precise description of the work and everything promised for the price. Even if the contractor offers a discount for cash, CMHC says it is critical to still have a written contract. Check references too: ask past clients whether the job finished on schedule and within the quoted budget.

Prevention Checklist

• Give every contractor the same written list of what you want.
• Get about three detailed estimates with scope, duration and total.
• Compare quotes item by item and ask about anything missing.
• Ask about subcontractors, licences, insurance, permits and warranty.
• Do not choose on price alone, and do not pay before you decide.
• Turn the chosen quote into a written contract with a payment schedule.

References

1. Canada Mortgage and Housing Corporation. Hiring a contractor, Web page, Steps 2-5: interviews, references, detailed estimates, written contract. Accessed 2026-11-03.

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