What you need to know
Adding a floor to a building is an effective way of maximizing living space while increasing the value of your property. This option is particularly advantageous in areas where floor space is limited or expensive. However, this type of project requires careful planning and a thorough analysis of the existing structure.
Key steps to a successful floor addition
- Check local regulations. Before getting started, it’s imperative to check local bylaws on zoning, maximum height and urban planning. Some municipalities impose strict restrictions that could affect the feasibility of the project.
- Consult a structural engineer
A story addition imposes additional loads on existing foundations, load-bearing walls and beams. To ensure the safety of the building, it is essential to call in a structural engineer.
He or she will carry out a complete assessment of the existing structure: Checking the soundness of foundations, wall framing and beams.
He or she will provide customized recommendations, for example if reinforcements are required, such as the addition of steel beams or columns to support additional loads. - Exploratory openings. In some cases, openings in walls, ceilings or floors will need to be made to inspect hidden structural elements. This work is generally entrusted to a qualified contractor under the engineer’s supervision.
Technical challenges of adding a story
Adding a floor is not without its challenges. Here are a few to consider:
- Foundation reinforcement: If the existing foundation is not designed to support an additional load, it will have to be reinforced or widened.
- Redistribution of loads: Adding a story can lead to additional stresses on load-bearing walls and columns. Analysis is therefore required to avoid sagging or cracking of structural elements or architectural claddings.
- Managing snow accumulation: An additional floor can alter the dynamics of snow loads on the roof. The addition of a floor can create snow accumulations on a section of the building that is not designed to support these loads. Unreinforced roof sections could be subjected to a new load, necessitating validation and roof reinforcement work.