How to build a wooden house extension
Are you thinking of adding a wooden extension to your house? What a great idea! Construction projects that use timber frames are often faster, less expensive and more eco-friendly.
To help you plan this ambitious project, our prefabricated wood structure specialists have prepared a handy guide that includes all the steps you’ll need to take.
Let’s get started!
1 – Design your wooden house extension
Before you can start building your wooden home extension, you’ll need to design it. For a precise, accurate design, you may want to enlist the help of an architect or contractor who has experience with this type of home improvement project. A professional will be able to tell you how feasible your project is and how much it’s likely to cost.
This step involves developing a plan that takes various constraints into account:
- Your budget
- The space available
- The climate (temperature, snowfall, wind)
- Applicable regulations
- The design of the existing building
The more carefully you plan, the less likely you are to encounter obstacles once you get started.
During the first step, you can also choose the doors and windows, wall coverings and roofing materials, flooring, light fixtures and other aesthetic components that will add to the overall look of your extension. It’s best to plan ahead, as some products may be difficult to get your hands on.
2 – Obtain a permit
Most areas require homeowners to get a permit from the municipal government for home expansion projects.
You’ll need to submit your project to your local urban planning department for approval. You’ll also need to pay for your construction permit. The price is usually based on the total cost of the construction work.
If your project isn’t approved, you’ll need to go back to the drawing board to make sure that you comply with local regulations to the letter.
3 – Procure the timber frame components
Once your plans have been approved by your local government, you can send them to a timber frame product manufacturer. For a home extension project, you will definitely need roof trusses and wall panels, and you may need floor systems as well.
We recommend working with a company that designs and manufactures custom timber frame components that will be ready to install as soon as you receive them. It may be worth finding out if you can get wall panels that come with insulation, a vapour barrier and waterproofing membrane already added. Make sure you choose a prefabricated wood structure manufacturer whose products meet National Building Code requirements.
Once the company has verified your plans, it will be able to manufacture the components needed for your project with great attention to detail.
4 – Lay the foundation
While your timber frame components are manufactured, you’ll need to create a foundation for them. Without a solid foundation, even the best materials cannot guarantee a sturdy and durable structure.
For a strong foundation that won’t shift over time, you’ll need to carry out excavation work to prepare the ground. After that, you can start building the foundation itself.
Reinforced concrete and screw piles are currently the two most popular types of foundation for a wooden house extension. It’s up to you to determine which one best suits your situation.
5 – Get your timber frame components delivered
This step should be very simple if you have chosen the right timber frame product manufacturer. Generally, your roof trusses, wall panels and floor systems should be delivered directly to your construction site at a time that is convenient for you. That way, you’ll be able to coordinate the workers you need to assemble them easily.
6 – Assemble your timber frame components
This step can be a breeze or a real headache, depending on the level of precision your prefabricated structure manufacturer has put into their work. If they have followed the given dimensions of the trusses, walls and joists to the letter, the timber frame components will fit together perfectly, making the assembly process very straightforward. All you’ll need to do is use the right connectors and fasteners and follow the instructions provided by the manufacturer.
If the dimensions of the prefabricated wood structure products are off, however, they will need to be adjusted on-site, which may require several more hours and additional workers.
Regardless of the dimensions of the timber frame components, any extension that is added to an existing building will require an expansion joint to compensate for any movement caused by shrinkage, temperature or moisture.
7 – Install doors and windows
The seventh step in a wooden house extension project is installing the doors and windows. This step must be done meticulously, because you need to make sure that the edges of each window are well sealed and structurally sound. That being said, it shouldn’t be too complicated if the openings the manufacturers made in your wall panels are the correct dimensions.
Seal the perimeter of the doors and windows in your home extension with a sealant to prevent water and cold air from getting in. You can also fill any larger spaces with polyurethane insulating foam to maximize energy efficiency.
8 – Install exterior coverings
After installing the doors and windows, you can proceed with the exterior coverings. After this step, the extension will be properly sealed, and you can continue working on the interior without having to worry about the weather.
For the roof, you can select asphalt shingles or other materials, depending on the type of truss you chose.
For the exterior walls, you can go with masonry, vinyl, wooden planks, or any other material that lends itself well to this type of use.
When selecting your materials, try to make sure that their style will blend well with the rest of your home.
9 – Make a hole in the connecting wall
To make the most of the extra space your house extension will provide, you’ll need to carefully consider how you will access it.
You’ll need to make a hole in the load-bearing wall to create a passage between the extension and the main part of your home. Take care not to weaken the structure of your house in the process. You may need to shore up the frame and install a new support beam.
10 – Work on the interior
The final step of your wooden house extension project is finishing the interior of your new living area.
Start with the mechanical elements of the building—plumbing, electricity and heating. While the walls are still open, you can also perfect your wood-frame wall and roof insulation.
Then you can install the partitions and flooring and start focusing on more stylistic elements such as light fixtures, mouldings and painting.
Building a wooden house extension? UsiHome can help!
Building a wooden house extension is a project that requires experience in several different areas of construction: design, administration, foundation, structure, insulation, finishing, etc.
If you are considering embarking on an expansion project, UsiHome can give you advice on timber framing and provide you with high-quality roof trusses, wall panels and floor systems made entirely in Quebec.