Top 5 Home Renovation Challenges Montreal Homeowners Face (and How to Solve Them)

Planning a home renovation project in Montreal can feel overwhelming—especially with older buildings, strict city rules, and weather conditions that often affect timelines and materials.

To make things easier, MTL Contractors, a trusted general contractor in Montreal, put together this local guide to help homeowners understand the most common renovation challenges and how to avoid them from the start.

Whether you’re updating an older duplex, improving a basement, or reworking the layout of a main floor, knowing these challenges in advance can help you plan more confidently, reduce surprises, and set a smoother path for your renovation.

Here are the 5 renovation challenges Montreal homeowners run into most often—and what to expect with each one.

1. Navigating Montreal’s Permit System & Local Regulations

Many home renovation and demolition projects in Montreal require permits, especially anything involving walls, structural changes, basement finishing, or major mechanical work.

Heritage zones add another layer of rules because the city protects the architectural character of these neighborhoods.

This means homeowners often need additional drawings, material samples, or façade details, and certain exterior changes—like windows, masonry, or siding—must match the original style. These requirements increase the documentation needed and can lead to longer review times.

For many homeowners, the permit process feels complicated because each borough has slightly different requirements. A home improvement project that’s allowed in Rosemont may need extra documentation in Plateau or Outremont.

Timelines also vary: simple permits may take a few weeks, while structural or heritage-related approvals can take significantly longer.

Common points of confusion:

• Not knowing which type of renovation requires a permit

• Submitting drawings that aren’t complete

• Forgetting heritage-area restrictions

• Beginning demolition before approval

• Missing required inspections

  
  

Tips to make the process easier:

• Get professional floor plans made for both your current layout and your new design. Montreal requires these for most permits, especially when moving walls or changing plumbing.

  
  

• Check if structural changes require engineering reports. It’s the only way to ensure the renovation is safe, legal, insurable, and approved by the city.

  
  

• Confirm if your home is in a heritage zone. If you’re in a heritage zone, your renovation becomes more regulated and needs extra steps — and knowing this early keeps your project on schedule.

  
  

• Submit all forms and fees accurately. The city of Montreal will immediately put your application on hold if anything is missing, incorrect, or unpaid.

  
  

• Plan project timelines around inspection availability. Montreal requires scheduled inspections at different stages, and city inspectors often aren’t available immediately—especially in peak construction months.
  

Understanding the city’s expectations early helps prevent delays and costly rework. MTL Contractors helps homeowners prepare and submit renovation permits, ensuring projects stay compliant and on track.

2. Hidden Defects in Older Montreal Homes

Montreal’s older housing stock often hides issues that only show up once demolition or exploratory work begins. These defects can quickly affect project scope and cost.

Many of these homes were built decades before today’s insulation standards, electrical capacity, or moisture-control methods existed.

Even if a home appears well-maintained, age-related deterioration can remain hidden behind walls, floors, or outdated materials.

Common hidden defects include:

• Basement moisture and water infiltration

• Failed French drains

• Mold inside wall cavities

• Structural cracks or sagging floors

• Old aluminum or knob-and-tube wiring

• Asbestos in older materials

  
  

Early signs to watch for:

• Damp or musty areas

• White powder (efflorescence) on concrete

• Uneven or sloping floors

• Frequent breaker trips

These issues often require structural repairs once uncovered, and addressing them correctly ensures long-term durability and safety. If you want a deeper look at the specific issues that typically show up inside Montreal’s older homes, read our full guide on the most common hidden defects in Montreal homes. It breaks down each defect in more detail and explains what homeowners should check before starting a renovation.

3. Budget Overruns From Unexpected Repairs & Scope Changes

Budgets in home renovations often shift once demolition begins—especially in older homes where structural or moisture-related issues appear.

Even with a detailed estimate, it’s difficult to predict what will be found behind old plaster, tile, or flooring. Hidden defects can require additional trades, new materials, and revised drawings. Each of these elements affects both cost and timeline.

Main reasons for cost increases:

• Hidden defects uncovered during demolition

• Structural repairs requiring engineering

• Heritage requirements affecting material choices

• Permit delays that pause work

• Late design changes

  
  

How to keep your renovation on budget:

• Request detailed estimates based on trade and scope of work

• Reserve an additional 10–20% of your total budget (contingency) for unforeseen repairs or changes that often appear once demolition begins

• Finalize key materials before demolition

• Ask your contractor to explain their process for handling project changes

• Avoid adjusting the scope mid-project

Good communication and planning make a significant difference.

The best renovation contractors provide clear estimates and explanations at each step of the renovation, helping homeowners understand expected costs and lower the chances of costly surprises.

If you want a clearer picture of typical renovation pricing in the city, you can also read our full Home Renovation Cost Montreal guide for detailed cost ranges and planning tips.

4. Choosing a Licensed, Insured, RBQ-Certified Contractor

Hiring the right contractor is one of the most important steps in a successful renovation.

A licensed, insured contractor ensures the work meets provincial building codes and passes required inspections.

Beyond compliance, having the right team also influences project communication, timeline management, and overall quality. Renovations often involve several trades, and coordinating them properly requires experience and organization.

Mistakes homeowners often make:

• Choosing the lowest estimate without reviewing scope of work

• Forgetting to verify RBQ licence and insurance

• Working without a written contract

• Not reviewing recent projects

• Overlooking warranty details

Before hiring, make sure you:

• Verify the contractor’s RBQ licence

• Request proof of liability insurance

• Review past Montreal renovations

• Ask for milestone-based payment schedules

• Confirm who handles permits and inspections

At MTL Contractors, we are fully licensed general contractors (RBQ 5767-5480-01), insured, and experienced with Montreal’s building types.

5. Montreal’s Climate: Freeze–Thaw, Moisture, and Material Durability

Montreal’s weather can be harsh on homes. Freeze–thaw cycles, moisture, and temperature swings can damage the wrong materials.

Homes built before modern insulation and building standards often experience drafts, condensation, and premature wear on exterior surfaces.

Without proper upgrades during renovation, these issues can return year after year, leading to higher energy bills and ongoing maintenance.

Common issues include:

• Cracked exterior finishes

• Basement moisture

• Window condensation

• Heat loss due to poor insulation

• Rotting exterior wood

Materials that perform best in Montreal:

• Moisture-resistant boards in bathrooms

• High-performance insulated windows

• Durable siding (brick, fiber cement, engineered)

• Proper insulation + ventilation

• Quality roofing materials

• Functional drainage systems

Choosing the right materials and construction methods protects your investment. The best renovation contractors help homeowners evaluate long-term performance, ensuring renovations stand up to Montreal’s climate and reduce future repair needs.

Choose the Right Contractor to Help You Navigate Home Renovation Challenges in Montreal

Renovating in Montreal comes with unique challenges, but the right preparation—understanding permits, budgeting realistically, choosing durable materials, and working with the right licensed contractor—makes the process smoother and more predictable.

MTL Contractors supports homeowners through every step of a renovation, including permit guidance, planning, repairs, and full project management.

Have a renovation project in mind or want to understand what your next steps should look like?

👉 Explore our Home Renovation Montreal page to see our completed renovation projects and learn how we plan and execute renovation work across Montreal.

👉 You can also book your free consultation to discuss your renovation goals.