How Much Does a Second-Story Addition Cost in Toronto?

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tgcadmin

Published on

April 21, 2025

How Much Does a Second-Story Addition Cost in Toronto?

Adding a second story to your home can dramatically increase living space and property value—especially in a city like Toronto, where lot sizes are tight and vertical expansion is often the only viable option. But how much does a second-story addition really cost in the GTA?

Let’s break it down.

Why Add a Second Story?

Homeowners in Toronto neighbourhoods Oakville, Burlington, Etobicoke and similar areas are increasingly choosing to build up rather than out. With the price of land at a premium and zoning bylaws limiting lot coverage, a second-story addition is often the smartest way to expand.

Common reasons include:

Needing more bedrooms for a growing family
Adding a home office or rental unit
Maximizing resale value in a competitive market

Average Cost of a Second-Story Addition in Toronto

Addition Type	Estimated Cost Range	Description
Deck or Patio	$12,000 - $40,000	Depends on size, materials (wood vs. composite), and additional features like built-in seating.
Sunroom	$20,000 - $50,000	Costs depend on size, materials (glass vs. screens), and whether it's a four-season room.
Bathroom Addition	$15,000 - $50,000	Depends on fixtures, materials, and whether plumbing needs to be extended.
Single Garage Addition	$40,000 - $80,000	For a basic attached single-car garage. Costs increase for larger or detached garages.
Two Car Garage Addition	$80,000 - $110,000	For a basic attached two car garage addition.
Single Room Addition	$55,000 - $110,000	Costs vary based on size and luxury level. Could be a bedroom, home office, or family room.
Attic Conversion	$55,000 - $120,000	Costs vary based on existing structure and intended use (bedroom, office, etc.).
Kitchen Extension	$50,000 - $150,000	Varies based on size, appliances, and finishes. Often one of the more expensive additions.
Second Story Addition	$220,000 - $500,000+	Significant structural work required. Costs vary widely based on home size and design complexity.

In 2025, the average cost of a second-story addition in Toronto ranges between $275 and $375 per square foot, depending on the complexity of the project and the quality of finishes. For a typical 800 sq. ft. second-floor addition, you’re looking at a total cost between $220,000 and $300,000+.

Here’s what affects the price:

Structural engineering and reinforcement
Staircase installation
HVAC and electrical reconfiguration
Roofing and siding work
Finishing materials and layout

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Permit & Zoning Considerations in Toronto

Before building, it’s important to verify your property’s zoning regulations. Toronto’s Zoning By-law 569-2013 outlines the rules for height, setbacks, and lot coverage. In some areas, you may also need a Committee of Adjustment hearing if your addition doesn't meet existing bylaw standards.

At Toronto General Contractors, we handle this entire process—from zoning reviews to permit applications—so you don’t have to worry about the red tape.

Timelines: How Long Does It Take?

A second-story addition in Toronto generally takes 4 to 6 months, depending on:

Design and permitting duration
Structural scope
Seasonal weather conditions
Availability of materials and trades

We aim to minimize disruption to your household, and in some cases, temporary relocation may not be necessary.

Is It Worth It?

Absolutely—especially in high-demand Toronto neighbourhoods where detached homes are valued at over $1.5M. Adding a second floor significantly boosts your square footage, often increasing home value by 30–50% depending on finishes and market trends.

Ready to Expand?

If you’re considering a second-story addition in Toronto, Toronto General Contractors has the experience, design team, and construction crew to bring your vision to life. We’ll guide you through budgeting, permits, and the build—from start to finish.

Get in touch with us today for a free consultation and discover what’s possible on your lot.

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