10 Mistakes to Avoid When Buying Pre-Construction in Ontario

Updated October 17, 2026

Buying a pre-construction home can be an exciting opportunity.

You may get a brand-new property, modern floor plans, builder incentives, flexible deposits, warranty protection and, for qualifying buyers in 2026, potentially significant HST relief.

But buying pre-construction is also very different from buying a resale home.

You’re often committing hundreds of thousands—or more than a million dollars—to a property that may not be completed for several years.

And some of the most expensive mistakes happen before construction even begins.

A buyer may focus on the floor plan and purchase price while overlooking:

Here are 10 common pre-construction mistakes Ontario buyers should avoid in 2026.

Mistake #1: Buying Based Only on the Advertised Price

This is probably the most common mistake.

You see:

“Freehold Townhomes From $699,990”

and immediately start calculating whether you can afford $699,990.

But the advertised starting price may not represent the home you actually want.

Your final purchase could also include:

For example:

Advertised price:

$699,990

Lot premium:

$20,000

Structural upgrades:

$15,000

Décor upgrades:

$20,000

Your actual contract price could quickly approach:

$755,000

before closing costs.

Better approach

Before deciding whether a project fits your budget, determine:

Actual home price + likely upgrades + closing costs + financing requirement.

The starting price is useful for marketing.

Your final number is what matters financially.

Mistake #2: Not Having the Agreement Reviewed by a Real-Estate Lawyer

A builder Agreement of Purchase and Sale can be long and complicated.

It may contain provisions dealing with:

This isn’t paperwork you should simply sign and file away.

Condo buyers

Purchasers of new or pre-construction condominiums in Ontario generally have a statutory 10-day cooling-off period after receiving the required documents, giving them an important opportunity to obtain legal advice.

Freehold buyers

Do not automatically assume that every freehold purchase has exactly the same cancellation rights as a condominium purchase.

Different contractual and Tarion provisions may apply.

Your lawyer should determine what applies to your particular agreement.

Better approach

Ask your lawyer specifically:

Don’t simply ask:

“Is this contract okay?”

Ask:

“What could cost me additional money?”

Mistake #3: Confusing the Builder Deposit With Your Mortgage Down Payment

These are not necessarily the same thing.

Suppose you’re buying an:

$800,000 home.

The builder requires:

5% deposit = $40,000.

That does not automatically mean $40,000 is all the equity you’ll need.

Under current insured-mortgage rules, the minimum down payment on an eligible $800,000 purchase would generally be:

5% of first $500,000:

$25,000

plus 10% of remaining $300,000:

$30,000

Total:

$55,000.

So even after paying the builder $40,000, you could still need additional down-payment funds at closing—plus closing costs.

The opposite can also happen.

If the builder requires 10%:

$80,000

you’ve already contributed more than that theoretical insured-mortgage minimum.

Better approach

Calculate separately:

Builder deposit

What does the builder require and when?

Mortgage down payment

How much will your lender require?

Closing costs

How much additional cash will you need?

Emergency reserve

What will remain after closing?

Never stop the calculation at the first deposit cheque.

Mistake #4: Assuming Every HST Rebate Applies to You

This mistake could involve a very large amount of money in 2026.

Ontario and the federal government have introduced significant new-home HST relief.

Eligible first-time buyers may qualify for up to $50,000 under the federal First-Time Home Buyers’ GST/HST Rebate on qualifying new homes up to $1 million, with the benefit gradually reduced between $1 million and $1.5 million.

Ontario’s temporary Enhanced New Housing Rebate can provide eligible purchasers with up to $80,000 of provincial HST relief, with qualifying builder agreements generally entered into between April 1, 2026 and March 31, 2027.

But:

“Up to $130,000” does not mean every buyer automatically receives $130,000.

Eligibility depends on factors such as:

Another common mistake is seeing an advertised builder price and then mentally subtracting the rebate again.

The builder’s advertised price may already assume an applicable rebate.

Better approach

Ask:

Your lawyer and, where appropriate, tax professional should confirm the treatment.

Mistake #5: Ignoring Closing Costs

You save enough money for the deposit.

You secure financing.

Then closing arrives.

Suddenly you’re faced with:

This can create a serious cash-flow problem.

Tarion’s buyer guidance specifically warns purchasers to budget beyond the purchase price and deposits for closing and moving-related costs.

Better approach

Keep a dedicated:

Closing-cost reserve.

And have your lawyer estimate your potential financial exposure under the APS.

Particularly ask about:

Capped development charges

versus

Uncapped charges.

A slightly more expensive property with capped closing adjustments can sometimes provide better financial certainty than a cheaper property with broad uncapped clauses.

Mistake #6: Buying Because of the Incentives Instead of the Property

You’ve probably seen offers like:

“$100,000 in incentives!”

That sounds impressive.

But what’s actually included?

Maybe:

These may all be useful.

But their value to you may not equal the advertised promotional value.

Imagine:

Builder home:

$900,000

Advertised incentives:

$75,000

Comparable resale:

$800,000

Even after assigning the full $75,000 value to the incentives, the builder home effectively remains around:

$825,000

before considering other differences.

That doesn’t necessarily make it a bad purchase.

But the incentive headline shouldn’t make the decision for you.

Better approach

Calculate:

Builder price

minus

Genuine incentives you actually value

plus

Closing costs

and compare that result with:

Don’t buy the incentive.

Buy the home.

Mistake #7: Failing to Research the Builder

A beautiful model home doesn’t tell you everything about the company building your property.

Before committing, investigate:

Ontario requires new-home builders and sellers to be licensed by the Home Construction Regulatory Authority.

The Ontario Builder Directory lets buyers review information including licensing status, years of activity, homes built and certain regulatory actions.

Better approach

Research both:

The property

and

The company responsible for delivering it.

A floor plan can be excellent.

But execution matters.

Mistake #8: Assuming the Closing Date Is Guaranteed

Imagine purchasing in 2026 with an anticipated closing in:

September 2028.

You plan everything around that date.

You:

Then construction is delayed.

This is one of the realities buyers need to plan for.

Ontario’s Tarion framework includes delayed-closing and delayed-occupancy protections. For qualifying freehold homes, improper delays beyond applicable contractual dates can result in compensation of up to $7,500, subject to the warranty rules.

But compensation doesn’t necessarily eliminate the inconvenience of delayed possession.

Better approach

Understand:

And avoid making irreversible commitments too far ahead based solely on an initial tentative date.

Mistake #9: Assuming Your Mortgage Approval Today Guarantees Financing at Closing

This can be one of the most financially dangerous mistakes.

Suppose you sign today for a home closing in three years.

Your mortgage broker tells you that you qualify.

Excellent.

But three years later:

Your lender will assess the transaction again closer to closing.

Your original pre-approval isn’t necessarily a permanent guarantee.

Appraisal risk matters too

Suppose your contract price is:

$1,000,000.

At closing, your lender appraises the home at:

$900,000.

The lender may calculate financing based on the lower valuation.

You may need additional cash.

Better approach

During construction:

Do not spend the construction period assuming the mortgage is permanently solved.

Mistake #10: Assuming You Can Always Assign or Sell Before Closing

Some buyers enter pre-construction thinking:

“If my circumstances change, I’ll just assign it.”

That can be dangerous.

An assignment allows a purchaser to transfer their interest in the purchase contract to another buyer before final closing, subject to the agreement.

But the builder may:

Even when the builder advertises:

“Free Assignment”

there may still be conditions and legal expenses.

And assignment transactions can have tax consequences.

Better approach

Before purchasing, ask your lawyer:

Treat assignment as:

A possible option—not a guaranteed exit strategy.

Bonus Mistake: Not Registering Your Freehold Purchase With Tarion

This one is particularly important because the rules changed in 2026.

Effective April 1, 2026, purchasers of new freehold homes are required to register their purchase with Tarion within:

45 days of signing the Agreement of Purchase and Sale.

Tarion has implemented a transition period for changes tied to maximum deposit coverage, with those deposit-coverage consequences deferred until January 1, 2027.

Registration is therefore something buyers should now incorporate into their new-home purchasing checklist.

Don’t assume someone else has done it for you.

Bonus Mistake: Not Understanding Deposit Protection

A large builder deposit can represent a substantial portion of your savings.

For qualifying freehold homes, Tarion currently provides deposit protection based on purchase price.

For homes priced at $600,000 or less, coverage can reach:

$60,000.

For homes above $600,000, protection can equal 10% of the purchase price up to:

$100,000.

Condominium deposits operate under a different framework and are generally subject to statutory trust protections.

Better approach

Before paying substantial deposits, understand:

Bonus Mistake: Spending Too Much at the Décor Centre

You purchase:

$750,000 home.

Then visit the builder’s décor centre.

Suddenly:

Your $750,000 home becomes:

$807,000.

And depending on your financing, you may need additional funds.

Better approach

Prioritize structural improvements that are difficult to change after closing.

Examples might include:

Some cosmetic improvements can be completed more economically after possession.

Bonus Mistake: Forgetting That Your Lifestyle Can Change Before Closing

Three years is a long time.

Between purchasing and closing, you might:

This is why flexibility matters.

Before buying, ask yourself:

“Would this home still make sense if my life changes?”

A functional floor plan, reasonable price and desirable location provide more flexibility than buying something extremely specialized.

What Should You Do Before Buying Pre-Construction?

Use this simple checklist.

Before signing:

1. Establish a comfortable budget

Not your absolute maximum mortgage qualification.

2. Confirm your deposit capacity

Know every payment date.

3. Research the builder

Use official licensing information as part of your due diligence.

4. Compare with resale

Make sure the new-home premium makes sense.

5. Compare competing builders

Don’t assume the first project is the best one.

6. Understand incentives

Calculate their real value.

7. Review the HST treatment

Don’t assume every rebate applies.

8. Review closing costs

Especially uncapped adjustments.

9. Have the APS reviewed by a lawyer

Immediately.

10. Confirm financing

But maintain reserves because closing may be years away.

During Construction

Your work isn’t finished after signing.

Continue to:

Before Closing

Several months before closing:

The closer you get to closing, the less room you have to solve financial surprises.

The Biggest Pre-Construction Mistake of All

There is one mistake behind many of the others:

Assuming everything will work itself out by closing.

Pre-construction is a future financial commitment.

You aren’t simply buying today’s home at today’s price.

You’re committing your future finances to complete the transaction when the property is ready.

That requires planning.

The strongest buyers don’t only ask:

“Can I afford the deposit?”

They ask:

“Can I comfortably complete this purchase if market conditions aren’t perfect?”

That’s a much better question.

Frequently Asked Questions

Is buying pre-construction risky in Ontario?

Pre-construction has risks, including construction delays, financing changes, appraisal risk, project cancellation and unexpected closing costs. Proper due diligence can reduce—but not eliminate—those risks.

Should I have a lawyer review a builder agreement?

Yes. Builder Agreements of Purchase and Sale can contain significant legal and financial obligations. A lawyer experienced with new construction should review the agreement and explain your specific exposure.

Do pre-construction condos have a 10-day cooling-off period?

Generally, yes. Buyers of new or pre-construction condominiums from developers in Ontario have a statutory 10-day cooling-off period under the applicable condominium framework.

Can I automatically cancel a freehold purchase within 10 days?

Do not assume so. Freehold transactions operate under different contractual and Tarion rules, and any review or termination rights should be confirmed by your lawyer.

Can I lose my pre-construction deposit?

Deposit protection exists for qualifying new homes, but coverage limits and rules vary depending on the property type and circumstances. Understand the applicable protection before purchasing.

Can a builder delay my closing?

Yes, within the applicable contractual and warranty framework. Tarion provides delayed-closing and delayed-occupancy protections and establishes notice requirements and potential compensation in qualifying circumstances.

Can I assign my pre-construction home?

Only if permitted by the Agreement of Purchase and Sale and builder policies. Consent, fees, restrictions and tax considerations may apply.

Can I get up to $130,000 in HST relief?

Some qualifying Ontario new-home purchasers can potentially receive substantial combined HST relief under current federal and provincial programs. Eligibility is transaction-specific and should be confirmed rather than assumed.

Should I buy directly from the builder or use a Realtor?

Builders can sell directly to consumers, but an experienced Realtor can help compare builders, communities, pricing, incentives, deposit structures, inventory and resale alternatives. Representation should be established early because builder cooperation and registration policies can vary.

The Bottom Line

Pre-construction can provide excellent opportunities.

But the biggest financial mistakes often happen because buyers focus too heavily on:

Price + Floor Plan + Incentive

and not enough on:

Contract + Financing + Closing Costs + Risk.

Before committing to a new home, remember these ten rules:

A good pre-construction purchase shouldn’t depend on everything going perfectly.

It should still make financial sense if:

That financial cushion can make the difference between an exciting new-home purchase and a stressful one.

Thinking About Buying Pre-Construction in Ontario?

Before choosing a project, compare more than the advertised starting price.

At New Home Source, we can help you review current opportunities based on:

Tell us your:

Budget + Preferred Location + Home Type + Closing Timeline

and we can help you identify new-home opportunities that fit your needs—and point out the questions worth asking before you commit.

Contact New Home Source to explore current pre-construction and inventory-home opportunities across Ontario.

Disclaimer: This article is provided for general informational and real-estate marketing purposes only and does not constitute legal, tax, mortgage, financial or investment advice. Builder agreements, deposit protections, government programs, financing requirements and warranty rules can change and may vary by transaction. Buyers should obtain independent legal, mortgage and tax advice as appropriate before entering into an Agreement of Purchase and Sale.