You cannot legally close a home purchase in Ontario without a lawyer. That part isn’t optional. What is optional, and what most first-time buyers get wrong, is when you bring one in and how much they actually get to do for you once you have.

Here’s the short version. Hire a lawyer who specifically handles new-construction files, not just resale. The agreement is written entirely in the builder’s favour, and a general-practice review can miss the clauses that matter most. Get them the full agreement, not just the signature page, as early as possible. For a condo, that means the moment you sign, inside your 10-day cooling-off window. For freehold, it means before you sign, since there’s no automatic cooling-off right to fall back on. Expect to pay somewhat more than a resale legal fee, commonly $1,300 to $3,000 all-in for a pre-construction file. And expect them to catch things you’d never think to ask about — material change clauses, assignment restrictions, and how your deposit is actually protected.

A lawyer who mainly handles resale closings can still get you through a pre-construction deal, but it’s not the same job. Builder agreements run 40 to 80 pages, drafted by the builder’s own counsel. They include mechanisms resale contracts simply don’t have. The Tarion Addendum, development charge provisions, assignment clauses, and often a right for the builder to change square footage, layout, or finishes before the home is finished. A lawyer who reviews these regularly recognizes which of those clauses are standard and which ones are worth pushing back on. Ask directly, when you’re hiring: how many pre-construction closings have you done this year? A vague answer is itself useful information.

Timing is the one mistake that’s genuinely hard to undo. Once your agreement is firm, your options shrink fast. For a condo, Ontario gives you a statutory 10-day cooling-off period after signing. It’s a hard deadline, not a suggestion — the window to have a lawyer review everything and walk away cleanly if something’s wrong. For a freehold townhome or detached home, that automatic right doesn’t currently exist. The safer move is booking your legal review before you sign anything, not after. Once you’ve committed, a lawyer can still represent you through closing. Their ability to renegotiate a clause you didn’t like is far more limited than it was the day before you signed.

Verbal promises made in a sales centre are worth checking against this list too, in a roundabout way. If a sales consultant told you an upgrade was included or a deadline was flexible, your lawyer can only protect what’s actually written into the signed agreement. If it isn’t there, it isn’t real, no matter how confident the conversation felt.

Assignment clauses deserve a closer look than most buyers give them at signing, since plans change over a two-to-four-year build. An assignment lets you sell your contract to another buyer before closing, without ever taking title yourself. It’s useful if your circumstances shift, or if you bought partly as an investment. Builders typically charge an assignment fee, often a flat amount or a percentage of the price. Some restrict when an assignment can happen at all, sometimes blocking it entirely until a certain construction milestone. A lawyer reviewing your agreement should flag exactly what that fee is and when the right kicks in, before you need it rather than after you’re trying to use it.

On cost: a standard resale legal fee in Ontario commonly runs $900 to $2,500. Pre-construction and new-build files typically add another $400 to $700 on top of that. That’s because the builder’s closing package is longer and there’s more adjustment work to review. All-in, expect somewhere around $1,300 to $3,000 for legal fees alone on a pre-construction purchase. That’s before disbursements like title search, registration, and title insurance, which commonly add another few hundred dollars. Condo buyers should also ask whether their lawyer bills interim occupancy and final closing separately. Some firms quote them as two distinct fees rather than one, since they’re legally two separate events.

Your lawyer also handles a cost that’s easy to overlook: the Tarion enrolment fee. Every new home in Ontario must be enrolled in the Tarion warranty program. The fee is technically charged to the builder, but it’s commonly passed to the buyer as a line item on your closing adjustments. It scales with the price of the home, so budget a few hundred to a couple of thousand dollars for it. Have your lawyer confirm the exact number before closing day, rather than after. On HST: for a home you’re buying to live in yourself, the builder typically bakes the new housing rebate into the advertised price. You generally don’t pay it separately at closing. That picture changes if you’re buying on assignment or planning to rent the property out. It’s worth flagging to your lawyer early, since the rules around this shifted in 2026 and your specific situation determines how it applies to you.

When you’re actually interviewing lawyers, a few direct questions tell you more than a website ever will. Ask how many pre-construction files they’ve closed in the past year. Ask for a flat-fee quote in writing, not a verbal estimate, so you can compare firms on the same basis. Ask whether they’ll be personally available if something comes up on closing day itself, rather than handing you off to whoever’s on the file that week. And ask what their review actually includes — a thorough line-by-line pass with a written summary is a very different service than a same-day skim.

A few patterns are worth treating as flags rather than just preferences. A firm that can’t say how many new-construction files they’ve handled recently. A quote that comes only verbally, with no written breakdown of fee versus disbursements. A lawyer who seems unfamiliar with the Tarion Addendum when you ask about it directly. None of these are disqualifying on their own, but together they’re a reasonable signal to keep looking.

Closing day itself is mostly your lawyer’s work, not yours, but it helps to know what’s actually happening. Days before closing, your lawyer receives the builder’s final Statement of Adjustments — the document reconciling every credit, levy, and prorated cost into one final number. They review it against the agreement, flag anything that doesn’t match what was disclosed earlier, and confirm the figure with you before any money moves. On closing day, they coordinate the transfer of funds with your lender and register the transfer of title. They handle the builder’s lawyer directly so you don’t have to. For a freehold purchase, this is also the day your mortgage officially begins. For a condo reaching final closing after interim occupancy, it’s the day you go from occupying the unit to actually owning it. Either way, once registration is confirmed, your lawyer sends you the keys, or in practice, confirms you can pick them up. Your Tarion warranty clock starts running from that date.

The legal review is where your protection on paper turns into protection you can actually use. We covered the closing costs your lawyer will walk you through in our full cost guide for pre-construction purchases. Where this appointment fits into the broader process, we covered in our pre-construction timeline article. If you’re still earlier than that, deciding whether pre-construction is right for you at all, start with the first article in this series. And for the rest of what we’ve covered on this topic, browse our full pre-construction coverage.