How Much Do Home Additions Cost In Toronto?

In Toronto, the cost of a home addition can range from $300-$500 per square foot. Basic additions typically start at $300 per square foot for a basic ground-floor extension, with second-story additions ranging from $300 to $500 per square foot due to added structural complexity. Total costs vary based on size, location, materials, and labor. Smaller projects, like adding one or two rooms, can reach up to $100,000, while adding a full second story may exceed $250,000, especially with high-end finishes.

Cost Breakdown Of Home Additions In Toronto

Deck or Patio Addition

A deck or patio is one of the most cost-effective ways to expand usable living space and improve outdoor enjoyment. In Toronto, these additions typically range from $15,000 to $50,000, depending on size, materials, and design complexity.

Wood decks are generally more affordable upfront, while composite materials cost more initially but require less maintenance over time. Costs can increase if the project includes built-in seating, railings, lighting, privacy screens, or custom stairs. Permits may be required depending on height and structural attachment to the home.

Decks and patios are ideal for homeowners looking to enhance lifestyle value without major structural work.

Sunroom Addition

Sunrooms provide a bright, transitional space that blends indoor comfort with outdoor views. In Toronto, sunroom additions typically cost between $25,000 and $70,000.

Pricing depends heavily on whether the sunroom is:

• A three-season room (screens or basic glazing)
• A four-season room with insulation, heating, and energy-efficient windows

Four-season sunrooms are more expensive but can be used year-round and may count as conditioned living space. Structural integration, foundation requirements, and roof tie-ins all influence final cost.

Bathroom Addition

Adding a bathroom improves both convenience and resale value, especially in growing households. Bathroom additions in Toronto generally cost $30,000 to $75,000.

Costs are driven by fixture quality, tile selection, and whether plumbing needs to be extended or upgraded. Bathrooms located far from existing plumbing stacks tend to be more expensive due to additional labour and materials.

High-end finishes, heated floors, and custom showers can push costs toward the upper end of the range.

Single Garage Addition

A single-car garage addition typically costs $50,000 to $90,000 for a basic attached structure. Garages add storage, weather protection, and long-term value—especially in Toronto neighbourhoods where parking is limited.

Costs vary based on:

• Attached vs. detached construction
• Foundation requirements
• Electrical, insulation, and interior finishing

Detached garages or garages with loft storage will increase the overall budget.

Two-Car Garage Addition

A two-car garage addition is a larger investment, with typical costs ranging from $100,000 to $120,000 for a basic attached build.

These projects require more extensive foundations, wider structural spans, and additional roofing and exterior finishes. Zoning setbacks and lot coverage limits must be reviewed carefully, as garage size can be restricted by municipal bylaws.

Two-car garages are particularly appealing for families or homeowners with multiple vehicles and storage needs.

Single Room Addition

A single room addition—such as a bedroom, home office, or family room—typically costs $50,000 to $100,000 in Toronto.

Final pricing depends on room size, ceiling height, windows, and interior finishes. Rooms that require heating, cooling, and full insulation add more to the cost than basic three-season spaces.

This type of addition is popular for homeowners needing flexible space without committing to a full-scale expansion.

Attic Conversion

Attic conversions are an efficient way to gain living space without expanding a home’s footprint. Costs usually range from $50,000 to $120,000, depending on existing structure and intended use.

Key cost factors include:

• Structural reinforcement of floor joists
• Staircase installation
• Insulation and ventilation upgrades
• Dormers or roof modifications for headroom

Attics are commonly converted into bedrooms, offices, or guest suites, making them a strong value-add when zoning allows.

Kitchen Extension

Kitchen extensions are among the most expensive ground-floor additions, with costs typically ranging from $75,000 to $150,000.

The higher price reflects the complexity of kitchen builds, which often include:

• Custom cabinetry
• High-end appliances
• Plumbing and electrical upgrades
• Structural beam installations for open layouts

Kitchen extensions significantly improve functionality and resale appeal, especially when they create open-concept living areas.

Second Story Addition

Second-story additions represent the largest and most complex type of home expansion. In Toronto, costs typically range from $250,000 to $500,000 or more.

These projects require substantial structural work, including reinforcement of existing foundations and load-bearing walls. Roof removal, full system extensions (plumbing, electrical, HVAC), and extensive engineering are all part of the process.

While expensive, second-story additions can double a home’s living space without sacrificing yard area, making them ideal for homeowners planning long-term occupancy.

Benefits of a Home Addition

Adding an extension to your home is one of the smartest investments you can make—both financially and functionally. In a city like Toronto, where real estate values are high and space is at a premium, expanding your existing home can provide significant returns. By increasing your square footage, you’re not only creating more livable space but also boosting your home’s resale value. Well-executed additions, especially those that match the existing architecture and use high-quality materials, are known to deliver strong returns on investment. Whether you’re adding a new bedroom, bathroom, or even an entire floor, the added space makes your property more attractive to future buyers.

But the benefits go beyond market value. A home addition gives you the opportunity to design a space tailored to your specific needs and lifestyle. For growing families, adding a bedroom or bathroom can reduce crowding and make daily routines more manageable. Remote workers often benefit greatly from a quiet, purpose-built home office that promotes productivity and separates work from personal life. Home gyms, hobby rooms, or even in-law suites can improve convenience and quality of life without requiring daily travel or major compromises.

For homeowners who love their current neighborhood but need more space, a home addition is a great alternative to moving. The process of selling your home, finding a new one, and relocating can be expensive and disruptive—especially in competitive markets like Toronto. By investing in your current property, you maintain your location, community ties, and the comfort of a familiar environment while upgrading your home to better suit your long-term goals.

Whether your aim is to increase resale value, improve day-to-day living, or future-proof your space for changing family needs, a thoughtfully planned home addition offers both practical and financial advantages. With the right design and construction team, you can turn your existing home into your dream space—without ever needing to leave it.

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Is It Cheaper To Build Up Or Out In Toronto?

Whether it's cheaper to build up or out depends on several factors, including your lot size, existing structure, and local zoning rules. In general, building out—extending your home horizontally on the ground floor—is often less expensive per square foot because it typically involves simpler construction. These are projects like four seasons sunrooms or garage extensions. There's no need to remove the roof or reinforce the structure to support a second story, which keeps engineering and labor costs lower. However, building out does require sufficient yard space and may involve additional costs for excavation, foundation work, and landscaping. You might also need zoning variances or permits to extend beyond existing setbacks.

On the other hand, building up—adding a second story—is ideal for properties with limited land, especially in dense urban areas like Toronto. This approach preserves outdoor space but usually comes with higher costs. Your existing foundation may need to be reinforced, structural upgrades are often required, and the process is more invasive. In some cases, homeowners may need to temporarily relocate during construction. While building up can add significant value to your home, it typically ranges from $300 to $500 per square foot, compared to around $300+ per square foot for ground-level additions.

In short, if you have the lot space, building out is generally more straightforward and cost-effective. But if maximizing square footage without losing yard space is the priority, building up—despite the added cost—may be the better long-term investment.

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Budgeting a Home Addition

Budgeting for a home addition in Toronto can vary widely based on the scope and complexity of the project. As a starting point, you should expect to spend at least $300 per square foot for a basic single-story extension, including both materials and labor. If you're planning a second-story addition, the cost typically ranges from $300 to $500 per square foot, largely due to the extra structural work and engineering required.

Several other factors can significantly impact your budget. These include the condition and design of your existing structure, the need to relocate plumbing or electrical systems, and potential upgrades such as increasing your electrical service from 100 amps to 200 amps. Seasonal considerations, like winter construction handling fees, can also affect costs.

Additionally, permit fees in Toronto can be substantial and will vary depending on the size and scope of your addition. It's also important to account for neighborhood-specific restrictions, such as height limits or setback requirements, which may influence what you're allowed to build and how much it will cost. Planning ahead for these variables will help you set a more accurate and realistic budget.

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What Is The ROI of a Home Addition In Toront?

The ROI of a home addition in Toronto is around 45% to 60% of their cost upon resale. For example, a $300,000 addition in a high-end neighborhood may boost property value by just $175,000. Upscale features like luxury bedroom suites tend to offer even lower returns, averaging only 23 cents on the dollar. Additions that expand heated living space—such as family rooms or finished basements—tend to perform better than purely aesthetic or outdoor upgrades like decks, which recoup around 45% to 55%. In Toronto’s four-season climate, practical additions that enhance daily living tend to offer the most benefit. That’s why we guide homeowners to view additions not just as financial investments, but as lifestyle upgrades that balance comfort, sustainability, and smart design.

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How Much Are Permits For Home Additions In Toronto?

When planning a home addition in Toronto, the most important permit you'll need is a building permit. This is required for any structural expansion to your home, including modifications to the foundation, exterior walls, or roof. As of 2025, the base fee for a building permit starts at $198.59, plus $17.16 per square metre of new construction area. For example, a 200 sq. ft. addition may cost anywhere from $500 to $1,200 or more depending on the design and complexity.

In addition to the building permit, several other permits or approvals may be required depending on the scope of your project:

• Plumbing Permit: Required if the addition includes plumbing fixtures (e.g., a bathroom, wet bar, or laundry area). Typically costs $200–$300.
• Electrical Permit: Issued by the Electrical Safety Authority (ESA) for any new wiring, lighting, or HVAC electrical connections. Fees generally range from $79 to $400+ based on the work involved.
• HVAC/Mechanical Permit: Needed if you're extending heating or cooling systems into the new space. This permit usually starts at $250+.
• Zoning Review: All additions are reviewed for compliance with zoning bylaws, including setbacks, height, and lot coverage. If your design doesn’t comply, you'll need to apply to the Committee of Adjustment, which can add $1,000 or more to your costs and delay your project.
• Heritage Permit: If your home is located in a heritage conservation district or is heritage-designated, additional approvals are required before construction can proceed.

Proper planning and consultation with professionals can help ensure that all permits are accounted for and that the process runs smoothly from design through construction.

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TGC Can Help Plan Your New Home Addition

The cost of a home addition in Toronto varies widely depending on the size, scope, and complexity of the project. As a general guide, ground-floor extensions typically start at $300 per square foot, while second-story additions range from $300 to $500 per square foot due to the added structural and engineering work required. Smaller additions, such as a new bedroom or bathroom, can cost up to $100,000, while full second-story builds may exceed $250,000, particularly when using high-end materials and finishes.

With careful planning and budgeting, it’s possible to create a functional, beautiful space that enhances both your lifestyle and your home’s value. To make things easier, we’ve developed a Home Addition Cost Estimator—a simple online tool that calculates real-time estimates based on your desired square footage and project type. You can explore room options like garage conversions, master suites, or expanded living areas without waiting for an in-person consultation.

At Toronto General Contractors, we have years of experience helping homeowners bring their home addition projects to life. Whether you’re looking to create more space for your growing family or improve your home’s layout and functionality, our team is here to guide you every step of the way. Reach out today to get started on making your home more spacious, comfortable, and personalized.

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