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.

More 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 framed over an existing home in Durham Region

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 home addition with a new roofline tied into the existing house

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.

New garage build with engineered beam in Durham Region

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

$55,000 – $90,000Starting Range

Rear / Side Addition

$300 – $450Per Sq. Ft.

Second-Storey Addition

$350 – $500Per Sq. Ft.

In-Law / Family Suite

From $200,000Starting Range

Why a range and not a number? Because a $300/day on-time penalty 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 penalty, real-time JobTread portal, daily cleanup, and a 5-year warranty on every build.

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.