You own a beautiful century-old house in Old Longueuil ? You admire its unique character, but you also know that it needs some serious work.
Renovating an old house is not the same as renovating a new one. You have to respect the heritage character while making the house comfortable and safe for today. It's a delicate balance.
In 2024, the Ville de Longueuil issued 245 permits in sectors protected by the Site Planning and Architectural Integration Program (SPAIP), an increase of 10% over the previous year. This shows that more and more homeowners are investing in their built heritage.
In this guide, we'll show you the best ways to renovate your old house without losing its soul. We'll also tell you about regulations, available subsidies, and mistakes to avoid.
Need a free estimate for your Longueuil heritage project? Contact Cartago Construction - we know the specifics of these homes inside out.
Understanding the distinctive features of old houses in Vieux-Longueuil
The houses in downtown Longueuil have a history. Some date back over 100 years. They were built using methods and materials different from those used today.
Understanding these characteristics is the first step in planning a successful renovation. You need to know what makes your home unique before deciding how to renovate it.
The charm and challenges of century-old houses
The old houses of Vieux-Longueuil have an undeniable charm. High ceilings, period woodwork, solid hardwood floors, original sash windows, hand-carved staircases. These are details no longer found in modern construction.
But they also come with their challenges. Stone foundations can crack or settle after a century of use. Floors often have slopes and hollows. Insulation is virtually non-existent in original walls. Electrical wiring can be outdated and dangerous.
Approximately 60% of permits issued in heritage sectors concern structural or exterior envelope work, mainly on homes built before 1920. This work is necessary to ensure long-term safety and durability.
We often see cracks in the stone foundations and moisture problems in the basement, walls that are not perfectly plumb, and heating systems that are inadequate for our Quebec winters.
But the good news is that these homes were built to last. With the right restoration work, they can easily last another 100 years.
Rules to know before you start
If your home is located in a heritage district of Vieux-Longueuil, you must obtain approval from the Comité consultatif d'urbanisme (CCU) before carrying out certain work.
The Site Planning and Architectural Integration Program (SPAIP) provides a framework for renovations in these areas. The aim is to preserve the architectural harmony of the neighborhood and the historic character of the buildings.
Ville de Longueuil By-law VL-2025-839 specifies the types of work requiring PIIA approval. Generally speaking, everything visible from the street requires approval: facades, roofs, windows, doors, galleries, balconies and exterior siding.
An important principle of the PIIA is the use of reversible materials. This means that modifications must be able to be removed in the future without damaging the original elements of the house.
Since 2025, the City has digitized the PIIA approval process. You can now submit your application online, along with photos and plans. This speeds up processing and facilitates exchanges with the CCU.
The Canadian National Ways Heritage Program (CNWHP) also offers advice and sometimes funding for properties of recognized historic importance.
Download our free checklist «Rénovations patrimoniales 2025 à Longueuil» to find out exactly what you need before you start.
The best ways to renovate without losing historic style
The aim is to modernize your home while preserving its original charm. It's possible, but it requires a thoughtful and respectful approach.
Here are Cartago Construction's best practices for heritage renovations.
Restore instead of replace
This is the golden rule of heritage renovations: restore what can be restored before thinking of replacing.
Period windows - Many homeowners think they have to replace their old windows with modern PVC models. Not so. According to the Association du patrimoine de Montréal et de l'arrondissement (APMAQ), well-maintained wooden windows can last over 150 years.
A complete restoration costs around 40 to 60% off the price of new windows of comparable quality. And you retain the authenticity and beauty of the original windows.
We can strip, repair seals, replace broken glass and add modern weatherstripping without altering the appearance. The result: windows that work well and respect the style of your home.
Woodwork and mouldings - Plaster moldings, cornices, carved doorframes: these are treasures. Instead of tearing them out, we can restore them. Our craftsmen can repair cracks, reconstitute missing parts and restore them to their original lustre.
Hardwood floors - Old maple or solid oak floors are often in much better condition than they look under their old coat of yellowed varnish. A good sanding and a new finish can completely transform them.
Contact our specialized craftsmen to restore your original woodwork and windows - we'll bring them back to life while preserving their authenticity.
Reversible modernization
For necessary additions, use methods that won't damage the original elements and that can be removed later if necessary.
Heritage insulation - Insulating an old house is tricky. You can't just fill the walls with foam insulation like you would in a modern house. That can trap moisture and cause more damage than anything else.
Modern approaches to heritage homes use materials that allow walls to breathe. Sheep's wool, cellulose, hemp: these are natural insulating materials that allow water vapour to migrate.
One trend we're seeing a lot of in 2025 is hybrid eco-heritage. This combines traditional techniques with modern ecological materials. For example, using lime mortar rather than cement mortar to join bricks or stones.
The data show a 15% increase in projects using this hybrid approach between 2024 and 2025. Homeowners understand that energy efficiency can be improved without sacrificing authenticity.
Discrete technologies - When it comes to plumbing and electricity, it's often possible to run wires and pipes through existing spaces without demolishing the original walls. Floors, crawl spaces, attics: there are usually ways to modernize systems while minimizing the impact on historic finishes.
A pilot project in Longueuil in 2025 used 3D scanning to plan renovation work. The result: a 15% reduction in design errors and less unnecessary demolition.
Preventing structural problems
Structural problems in older homes need to be treated before they get worse. Ignoring a cracked foundation or subsidence means risking much more costly damage in the long term.
Foundations and drainage - The stone foundations of century-old houses can crack over time. Soil moisture, freeze-thaw cycles and natural ground movements create stresses.
The Quebec government's Programme de réparation des maisons lézardées (PRQ) now provides funding for these repairs. In 2025, an envelope of $2 million has been allocated specifically for properties in core areas like Vieux-Longueuil, where around 40% of century-old homes show signs of cracking.
Modern methods can be used to stabilize foundations while preserving the environment. outward appearance. Epoxy resin injection, helical piles, improved French drainage: there are effective solutions.
Frame and roof - Solid timber frames in older homes are generally strong, but sometimes need strengthening. Supports can be added without altering the visible appearance of the structure.
When it comes to roofing, we prefer materials that respect the original style. If your house had a Canadian-style tin roof, we can reproduce it. If it was cedar shingles, you can find suppliers who still make this type of material.
Ask for a free inspection of your foundation and structure - we'll tell you exactly what needs to be done and whether you qualify for the QRP program.
Subsidies and assistance programs available in 2025
It's true that renovating a heritage home is expensive. But there are several programs that can help you financially.
The key is to know what programs exist and how to combine them to maximize your financial assistance.
Provincial and municipal programs
Here are the main programs available to homeowners in Vieux-Longueuil in 2025:
SHQ Heritage Program - The Société d'habitation du Québec (SHQ) offers subsidies of up to 5,000$ for the restoration of the exterior envelope of recognized heritage homes. This includes the façade, windows, doors and roof.
Rénoclimat program - This provincial program is designed to improve the energy efficiency of homes. You can receive up to 10,000$ for insulation, window and door replacement, and heating system upgrades.
For heritage homes, Rénoclimat now accepts adapted insulation methods that respect architectural integrity. This is an important change introduced in 2024.
Cracked Home Repair Program (PRQ) - For homeowners with cracked foundations, QRP offers financing in the form of a low-interest loan or grant, depending on your income. Amounts can cover up to 50% of the cost of repairs.
Longueuil municipal programs - The city sometimes offers tax incentives or property tax reductions for owners who restore their heritage homes to the standards approved by the PIIA.
By intelligently combining these programs, you can reduce the total cost of your renovations by between 30 and 50%. That's significant.
How to maximize your chances of eligibility
Grant applications have specific criteria. Here's how to increase your chances of approval:
Full documentation - Take detailed photos of your home's current condition before starting any work. Keep all quotes from RBQ-certified contractors. Prepare a clear project plan that explains what you want to do and why.
Respect heritage standards - For the SHQ Patrimoine program, your work must respect the principles of heritage restoration. Use appropriate materials, preserve original features and follow the recommendations of the PIIA.
Call on certified professionals - Most programs require that work be carried out by contractors holding a valid RBQ license. Keep all invoices and certificates of compliance.
Submit early - Budget envelopes for these programs are limited. The earlier in the year you submit your application, the better your chances of obtaining funding before funds run out.
The Direction de l'urbanisme de la Ville de Longueuil can help you navigate these programs. Their advisors are well versed in eligibility criteria.
Talk to a Cartago Construction expert to optimize your grant application - we've helped dozens of customers secure financing for their heritage projects.
Costs, profitability and mistakes to avoid
Let's talk money. How much does it really cost to renovate an old house, and is it worth it?
The short answer: yes, it's worth it. But you have to do it properly to reap the benefits.
Myth vs. reality - «Rebuilding is cheaper»
We often hear that it's cheaper to demolish and rebuild from scratch. In most cases, this is not true, especially for houses in Old Longueuil.
According to APMAQ data published in 2025, renovating a heritage home generally costs between 40 and 60% of the price of a complete rebuild.
For a typical house in Vieux-Longueuil, a well-planned major renovation costs between 25,000$ and 60,000$, depending on the scope of the work. Rebuilding from scratch on the same lot would easily cost more than 100,000$, not to mention demolition costs, approval delays, and the complete loss of heritage cachet.
And then there's the added value. A well-restored heritage home in Vieux-Longueuil often sells for more than a modern house in the same neighborhood. Buyers are actively looking for that unique cachet.
Not to mention the environmental impact. Reusing an existing structure is much more environmentally friendly than tearing it down and starting from scratch.
Common mistakes to avoid
We've seen owners lose a lot of money and time because of avoidable mistakes. Here are the most common:
Error #1: Using inappropriate modern materials - Installing vinyl on a brick façade, replacing wood windows with white PVC, using cement mortar on stone: these mistakes destroy the house's character and can cause structural problems.
The PPCMN reports that approximately 15% of applications for approval are refused because the proposed materials are not reversible or do not respect the heritage character.
Error #2: Insulating without understanding how the house breathes - Old houses were designed to handle moisture in a certain way. If you insulate with modern waterproof materials without taking this into account, you risk creating mold and rot problems.
Error #3: Start work without PIIA approval - Some homeowners do the work first and ask for forgiveness later. Not a good idea. If the CCU refuses your project after the fact, you could be forced to undo it all at your own expense. Fines can also be steep.
Error #4: Neglecting foundations - Focusing on aesthetics while ignoring structural problems is like putting a Band-Aid on an open wound. Cracked foundations will continue to worsen and eventually cause much more costly damage.
Mistake #5: Hiring a contractor who has no experience with heritage homes - Renovating an old house is not like renovating a modern house. It requires specific knowledge and techniques.
Have your plans validated by our experts before you start - they'll tell you whether your approach meets heritage standards and avoids costly pitfalls.
Why choose Cartago Construction for your heritage renovations?
When you entrust your century-old home to Cartago Construction, you're working with a team that truly understands the peculiarities of these buildings.
We don't apply the same methods we would to a newer home. We adapt our approach to respect the unique character of your property.
Local expertise and certification
Yassine Troudi, our founder, has over 10 years' experience in residential construction in France. Québec. He has worked on several heritage renovation projects in Longueuil and Montreal.
We know the PIIA regulations inside out. We've established a good relationship with the Comité consultatif d'urbanisme de Longueuil. When we submit a project, we know exactly what they're looking for and how to present things to maximize the chances of approval.
Our RBQ license is active and verifiable. We also hold all the necessary insurance. We work with a network of specialized craftsmen experienced in traditional restoration techniques.
Turnkey, human approach
Our turnkey service simplifies your life. You have a single point of contact from start to finish.
We really listen to what you want. Some owners want to preserve every original detail. Others want to modernize further while respecting the spirit of the house. We tailor our approach to your vision.
We're transparent about costs, deadlines and potential challenges. No surprises along the way. If we discover a hidden problem during the work, we explain the situation to you and together we find the best solution.
Our customers appreciate that we take the time to do things right. We don't cut corners to finish faster. A well-done heritage restoration is an investment for the next 100 years.
4-step process
Here's how we do it for your heritage renovations:
Step 1: Free inspection and assessment - We visit your property to understand its current condition. We identify elements to preserve, problems to correct, and opportunities for improvement. We give you an honest picture of the situation.
Step 2: Customized plan in compliance with the SPAIP - We prepare a detailed project plan that complies with PIIA requirements and municipal bylaws. We help you choose the right materials and prepare all the necessary documents for approval.
Stage 3: Work with certified craftsmen - Our team and specialized subcontractors carry out the work according to best restoration practices. Every step is supervised to ensure quality and compliance.
Step 4: Final verification and warranty - Before handing over the keys, we perform a complete inspection. We make sure everything meets standards and your expectations. We provide you with all the necessary documents and warranties.
Request your free estimate today - we'll show you how to transform your old house while respecting its soul.
Call us at 438-932-4326 or e-mail [email protected].
Take a look at our projects in Vieux-Longueuil on our website cartagoconstruction.ca - you'll see the quality of our work and our attention to detail.
Frequently asked questions (FAQ)
Do I need a special permit to renovate in Old Longueuil?
Yes, if your home is located in an area protected by the PIIA, you must obtain approval from the Comité consultatif d'urbanisme (CCU) before doing any work that is visible from the outside. This includes the façade, roof, windows, doors, galleries and siding. Interior work that does not alter the structure generally does not require PIIA approval, but may still require a standard renovation permit.
What materials should be used to respect the heritage style?
Choose traditional materials or their modern, high-quality equivalents. For facades: brick, stone, painted wood. Windows: wood with modern insulating glass. Roofing: Canadian-style sheet metal, cedar shingles or slate, depending on the original style. The important principle is to use reversible materials that can be removed without damaging the original elements.
Is it possible to insulate without losing character?
Absolutely. Modern methods of heritage insulation use materials that let walls breathe while improving energy efficiency. Sheep's wool, dense cellulose, hemp and thin interior insulation boards are all options that work well. The important thing is not to trap moisture in the walls. A heritage renovation expert can evaluate the best approach for your specific home.
What subsidies are available in 2025?
Several programs can help: the SHQ Patrimoine program (up to 5,000$), Rénoclimat (up to 10,000$), and the Programme de réparation des maisons lézardées (PRQ) for cracked foundations. You can often combine these programs to cover 30 to 50% of your renovation costs. The City of Longueuil also sometimes offers tax incentives for approved heritage restorations.
How do I know if my home is «heritage»?
Check the Ville de Longueuil website to see if your property is located in a PIIA sector. You can also check to see if it's listed in the Répertoire du patrimoine culturel du Québec. Even if your home has no official status, if it's over 50 years old and retains its original features, it deserves a respectful approach to renovation.
Should old windows be replaced?
Not necessarily. Well-built wooden windows can last over 150 years with proper maintenance. Restoration often costs 40 to 60% of the price of new windows of equivalent quality. We can strip, repair, replace glass with double-glazing, and add modern weatherstripping. The result: functional windows that preserve your home's authenticity and comply with PIIA requirements.
What can I do if my foundation is cracked?
Don't panic, but don't ignore the problem either. Have an expert assess the severity of the cracks first. Minor cracks can often be repaired by injection. More serious problems require stabilization work. The Cracked Home Repair Program (CHRP) offers funding specifically for these repairs. In 2025, 40% of century-old homes in the central areas of Longueuil are eligible for this program.
Does Cartago also do modern interior renovations?
Yes, absolutely. We can completely modernize your home's interior while preserving its heritage exterior. Contemporary kitchens, luxurious bathrooms, open spaces: anything is possible. The great thing about us is that we know how to integrate these modern elements without compromising the historic structure or important architectural details. We create the perfect balance between period charm and modern comfort.
More questions about your heritage renovation project? The Cartago Construction team is here to guide you - contact us at 438-932-4326 for free advice.
