Adding extra space to your home is one of the smartest investments a Montreal homeowner can make. Whether your family is growing or you simply want more comfort, a home addition can significantly increase your living space and your property value.
But the biggest question homeowners ask is: “What is the home addition cost in Montreal?”
In this guide, we break down real pricing, cost factors, types of additions, and what you can expect when planning a room extension in Montreal.
Average Home Addition Cost in Montreal
While every project is unique, these are the average 2025 home addition prices in Montreal:
| Type of Addition | Average Cost (Montreal) |
|---|---|
| Small room addition (bedroom/office) | $40,000 – $75,000 |
| Second-floor addition | $180,000 – $350,000+ |
| Kitchen extension | $70,000 – $140,000 |
| Bathroom addition | $45,000 – $90,000 |
| Sunroom / 4-season room | $30,000 – $90,000 |
| Garage addition | $35,000 – $120,000 |
Your final house addition estimate depends on size, materials, structure, and the complexity of electrical, plumbing, and HVAC work.
Main Factors That Affect Home Addition Costs
1. Size & Structure
The bigger the addition, the higher the price—especially if structural changes are needed.
Second-story additions usually cost more because engineers must reinforce existing foundations.
2. Plumbing, Electrical & HVAC
If your addition includes a kitchen or bathroom, the cost increases because new water lines, drains, and ventilation systems are required.
3. Material Selection
Premium windows, high-end flooring, and custom cabinetry will increase the budget. Basic finishes help reduce your room extension cost in Montreal.
4. Permits & Engineering
Montreal requires permits for structural additions. Expect up to $2,000 – $8,000 for architectural drawings, permits, and engineering.
5. Labor Costs
Skilled trades—carpenters, plumbers, electricians—affect the budget. Choosing a professional contractor ensures safety and durability.
Most Popular Home Addition Types in Montreal
Bedroom or Office Addition
Perfect for families who need an extra room without moving.
Cost-effective, fast, and high-ROI.
Kitchen Expansion
Montreal homeowners often open their kitchens into the backyard or dining area.
Increases home value significantly.
Second-Floor Addition
Ideal for smaller lots.
More costly, but adds major square footage.
Bathroom Addition
Adds convenience and increases resale value, especially in older Montreal homes.
Sunrooms / 4-Season Rooms
Bring natural light into your home and create a relaxing living space year-round.
Ways to Reduce Your Home Addition Cost in Montreal
-
Choose standard materials instead of premium finishes
-
Keep plumbing in the same area
-
Use an open-concept design to reduce walls and structural changes
-
Work with a contractor who offers turnkey service
-
Request a detailed estimate to avoid hidden costs
Revohouse helps homeowners plan efficiently and avoid unnecessary expenses.
How Long Does a Home Addition Take?
| Project Type | Timeline |
|---|---|
| Small room | 6–10 weeks |
| Kitchen extension | 10–14 weeks |
| Bathroom addition | 8–12 weeks |
| Second-story addition | 4–7 months |
Keep in mind: permitting in Montreal can add a few weeks to the timeline.
FAQ – Home Addition Cost in Montreal
1. What is the cheapest home addition?
A simple bedroom or office extension—starting around $40,000.
2. Does a home addition require a permit in Montreal?
Yes. Any expansion of square footage requires city approval.
3. Does a home addition increase home value?
Absolutely. Most additions offer 60–80% return on investment or more.
4. Can I live in my home during construction?
For small additions, yes. For major structural work, temporary relocation may be recommended.
Ready to Start Your Home Addition in Montreal?
Whether you’re planning a small room extension or a full second-floor build, Revohouse delivers high-quality design, construction, and project management from start to finish.
📞 Get your FREE home addition estimate:
https://revohouse.ca/
