Home Addition in Montreal: Prices, Permits and Options

Is your family growing or do you need more space? A home addition is often more advantageous than moving. Here’s everything you need to know.

Types of additions

1. Horizontal addition

Adding a room on the ground floor:

• Expanded kitchen
• Family room
• Additional bedroom
• Attached garage

Price: $200 - $400 per sq. ft.

2. Vertical addition (floor addition)

Very popular in Montreal for duplexes and triplexes:

• Adding a 2nd or 3rd floor
• Attic conversion
• Complete elevation

Price: $250 - $500 per sq. ft.

3. Basement addition

Excavation and development:

• Height increase
• Complete finishing
• Adding windows (window wells)

Price: $150 - $300 per sq. ft.

Detailed prices by project

Addition Type	Area	Total Cost
Kitchen extension	200 sq. ft.	$40,000 - $80,000
Family room	300 sq. ft.	$60,000 - $120,000
Complete floor addition	800 sq. ft.	$200,000 - $400,000
Double garage	400 sq. ft.	$50,000 - $100,000

What’s included in the price

• Plans and permits
• Foundation and structure
• Roofing and exterior siding
• Electrical and plumbing
• Insulation and interior finishes
• Harmonization with existing

Required permits in Montreal

Necessary documents

1. Building permit (mandatory)

   • Plans signed by a technologist
   • Certificate of location
   • Application form

2. PIIA approval (if applicable)

   • Site and architectural integration plan
   • Required in certain boroughs

3. Minor variance (if necessary)

   • For insufficient setbacks
   • Height exceeding regulations

Approval timelines

• Standard permit: 4-8 weeks
• With variance: 3-6 months
• Heritage sector: 6-12 months

Steps of an addition project

Phase 1: Design (1-2 months)

1. Meeting with contractor/architect
2. Feasibility assessment
3. Preliminary plans
4. Detailed quote

Phase 2: Permits (1-3 months)

1. Document preparation
2. Application submission
3. Revisions if necessary
4. Permit approval

Phase 3: Construction (3-6 months)

1. Site preparation
2. Foundation work
3. Structure and roofing
4. Mechanical systems
5. Interior finishes

Factors that influence cost

1. Complexity

• Simple addition: Rectangular, single level
• Complex addition: Multiple levels, custom design
• Integration: Matching existing architecture

2. Foundation type

• Slab on grade: Most economical
• Crawl space: Medium cost
• Full basement: Most expensive

3. Finishes

• Standard: Builder-grade materials
• Mid-range: Quality materials
• High-end: Premium finishes

Addition vs Moving

Criteria	Addition	Moving
Cost	$100,000 - $400,000	$50,000+ (fees + moving)
Timeline	6-12 months	3-6 months
Location	Preserved	New neighborhood
Disruption	Moderate	High
ROI	50-80%	Variable

Financing options

1. Home equity line of credit (HELOC)

• Interest rates: Prime + 0.5-1%
• Flexible repayment
• Interest only payments possible

2. Refinancing

• Access to equity
• Lower rates than HELOC
• Fixed monthly payments

3. Personal loan

• No collateral required
• Higher interest rates
• Faster approval

Common mistakes to avoid

1. Skipping the permit

Consequences:

• Fines up to $50,000
• Forced demolition
• Resale complications
• Insurance issues

2. Underestimating costs

Always budget for:

• 15-20% contingency
• Temporary living arrangements
• Storage costs
• Landscaping restoration

3. Poor planning

Ensure:

• Adequate access during construction
• Proper drainage
• Future maintenance
• Resale value

Why choose Imperiales Industries?

We specialize in home additions in Montreal:

• ✅ RBQ certified general contractor
• ✅ Complete service from design to completion
• ✅ Permit management included
• ✅ Quality workmanship guaranteed
• ✅ Transparent pricing no surprises

Our expertise

• Horizontal additions
• Floor additions (vertical)
• Basement expansions
• Garage additions
• Complete renovations

Start your addition project

Ready to expand your home? Contact us for a free consultation and detailed quote.

Call 438-770-2904 - Serving Montreal, Laval, South Shore and Laurentians.