Built to Last
Additions That Look Like They Were Always There
A new addition isn't a bolt-on. It's structural work that has to tie into your home, carry real loads, and pass inspection. We bring commercial-grade engineering and discipline to every addition, garage, and second storey we build.
Back to Residential ServicesMore Than Four Walls
We Build Additions the Right Way — From the Foundation Up
Most additions fail in the parts you can't see. A footing that wasn't dug deep enough. A beam that wasn't sized for the load. A roofline that doesn't drain. A connection to the existing house that lets water in two winters later.
We come from a commercial and structural background, so we treat your addition like what it is: a permitted, engineered build that becomes part of your home forever. New foundations, engineered beams, proper rooflines, and a finished result that looks like it was always part of the house — not stuck on the side of it.
Second-Storey Addition
A Full Floor, Added On Top
A complete second storey framed over an existing main floor. Crane-set framing, engineered to carry the new load — doubling the home's living space without moving.
Rear Addition & New Roofline
Built Into the Existing Home
A rear addition integrated into the existing home, with a new roofline tied cleanly into the original structure. High-performance exterior sheathing and a poured foundation built for our climate.
Garage Build
Engineered, Not Just Assembled
A new garage built on a proper foundation with an engineered beam header. Framed, sheathed, and squared — built to the same standard as the house it sits beside.
Our Addition Services
From a Single Room to a Second Storey
Second-Storey Additions
Add a full floor of living space without giving up your lot or your location.
Rear & Side Additions
Extend your main floor for a bigger kitchen, family room, or primary suite.
In-Law & Family Suite Additions
Self-contained additions built for comfortable multi-generational living.
Attached & Detached Garages
Engineered, permitted garages built to match the look of your home.
Sunrooms & Bump-Outs
Smaller additions that add light and space exactly where you need it.
Foundation & Structural Work
New footings, foundations, and engineered beams to carry it all.
What It Costs
What Does an Addition Cost in Durham Region?
Every addition is different, but here are realistic starting ranges to help you plan. These are ballpark figures — your exact investment depends on size, foundation, finishes, and how the addition ties into your existing home. You get a fixed, locked price after a site diagnostic.
Detached Garage
Rear / Side Addition
Second-Storey Addition
In-Law / Family Suite
Why a range and not a number? Because a $300/day on-time guarantee and a Price Lock Guarantee only mean something if the price is built on a real plan. Once we've walked your home and scoped the work, your price is locked — no surprises. (Ranges shown before HST.)
The Cornerstone Difference
Engineered. Permitted. Built to the Commercial Standard.
Engineered Drawings & Permits
We handle the structural drawings and the permit process, so your addition is legal, safe, and inspection-ready.
Structural Discipline
A commercial and ICI background means we size beams, footings, and connections to last for decades — not just pass the first look.
The Certainty Stack
Price Lock Guarantee, $300/day on-time guarantee, a real-time client portal, daily cleanup, and a 5-year warranty on every build. Learn more →
A Seamless Tie-In
We match rooflines, brick, and finishes so your addition looks like it was always part of the home.
Thinking About Adding On?
Book a free project diagnostic. We'll walk your home, talk through what's possible, and show you exactly how we'd build it.
