Lumber prices are rising fast - what GTA homeowners need to know before signing a reno contract

Lumber is up 17% year-over-year as of early 2026, and some forecasts are calling for another 25% spike by mid-summer. If you are planning a renovation this spring or summer in the GTA, this is the most important cost factor you need to understand before you sign anything.

What is driving the price increases?

A few things are happening at once. US tariffs on Canadian softwood lumber have been a persistent pressure point for years, but the current wave of tariffs — stacked on top of mill closures across BC and Ontario — has tightened supply faster than the market expected. When mills reduce production, the remaining inventory gets absorbed quickly, and spot prices climb.

On top of that, steel and aluminum — both heavily used in framing, brackets, lintels, and structural connectors — are also under tariff pressure. Your contractor’s material quote from three months ago is already out of date.

What this means for your project

If you are in the design phase, lock in your material quotes now in writing with an expiry date. Most suppliers will honour a quote for 30 days. Push your contractor to order structural lumber as soon as your permit is submitted — not after it is approved.

If you are framing this spring, talk to your GC about whether engineered lumber (LVL beams, I-joists, glulam) makes sense for your project. Engineered products have had more stable pricing than dimensional lumber and often have better moisture and warp resistance anyway.

If you are still in the planning stage and your project involves significant framing — an addition, a second-floor build-up, a full gut renovation — add a 10–15% materials contingency on top of whatever quote you receive today. That is not pessimism, that is 2026 budgeting reality in the GTA.

What about contractors who quote fixed-price?

Ask them specifically what their lumber escalation clause is. Many GTA contractors are now including a clause that allows them to adjust the materials portion of the contract if lumber prices move more than a set percentage between signing and framing day. Understand that clause before you sign.

Products least affected

Concrete, drywall, and most interior finishes have held relatively stable. If your project is primarily a kitchen or bathroom renovation without structural work, you are less exposed to lumber volatility. Plumbing rough-in and electrical rough-in materials costs are also comparatively stable right now.

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One contract detail worth flagging specifically in a lumber-volatile market: the material allowance clause.

Some renovation contracts - particularly from smaller or less formal contractors - will include a line like “materials subject to market pricing at time of purchase.” That sounds reasonable on its face, but in a tariff-driven spike environment it can create a situation where you signed on for a $60K budget and find yourself $10K over by framing stage because the contractor didn’t order structural lumber until three weeks after permit approval.

Before you sign, ask specifically:

  • Is lumber priced at a fixed unit rate in this contract, or at market at time of purchase?
  • When in the schedule does the contractor plan to order structural materials?
  • Is there a price escalation cap, and what triggers it?

Worth noting: the homeowner isn’t always better off with a fully fixed-price contract in a volatile market either. If a contractor is building in a 20-25% lumber cushion to protect their margin, you may end up paying for a spike that never materialises. The better middle ground is a contract that specifies lumber quantity and species clearly, with a documented price-at-signing and a cap on any escalation - typically 5-10% is reasonable.

If your contractor hasn’t voluntarily raised how they’re handling material pricing in current contracts, that’s the conversation to start before you hand over a deposit.