Learn About The Best Way to Unlock More Space on Your Second Floor
BVM Contracting breaks down the process of designing a second floor layout that allows you to maximize the floor space while keeping the existing walls on the main floor as-is. Many times the square footage of a main floor is just short of a client’s requirements on a second floor addition project (usually 3-4 bedrooms plus 1-2 bathrooms for Toronto Bungalows), which is why we recommend this one simple engineering principle to extend the square footage of your second floor with negligible cost repercussions.
CANTILEVERED FLOOR SYSTEMS
BVM Contracting has successfully completed many projects in Toronto that have utilized this engineering method to provide additional floor space on a second floor. The basic principle of a cantilevered floor system is there is a load bearing beam that allows perpendicular joists to extend outside of the existing solid bearing exterior walls that many Toronto Bungalows have. Due to the setback of the support beam into the existing home the extension out from the home can be suspended with no supports (see picture below). To understand the structural components of a cantilevered floor system you can refer to the attached a structural design that shows a 3-ply Laminated Vaneer Lumber (LVL) Beam connected to perpendicular joists that span ~ 4 feet out from the home’s existing bungalow wall. There are also 3-ply LVL’s at each end running parallel to the joists, and a 1-ply LVL beam at the end of the cantilever.
On the left side of this photo you can see the cantilever of the second floor system (located at one of our project sites in Toronto) out from the back wall of the bungalow. The joists are still exposed in this shot which gives a nice view of how the framing looks.
An example of a recent project that was engineered with a second floor cantilevered system. Note that this design is not representative of how all centilevered floor systems should be engineered and you should consult a licensed professional engineer for stamped designs.
WHAT IS THE BENEFIT OF CANTILEVERED FLOOR SYSTEMS IN TORONTO?
You get to maintain more of your back yard, especially with smaller lots this is a huge benefit
Additional Floor space (around 3-4 square feet for every foot of width for your rear wall). For a 20 ft wide house this amounts to an extra 60-80 square feet of floor space for a second floor, which allows for an additional bathroom, Walk-in Closet, or larger bedrooms for your children.
Protected Outdoor Space: You will have a space below the centilever to still enjoy your backyard even when the elements get the better of the day
For all of the benefits of this type of system there are also some things to consider:
The underside of the centilevered floor system will have to be insulated with sprayfoam.
As a result of the underside of the floor being exposed to the elements, the floor above the cantilevered system will feel colder during the winter months than the floor that isn’t exposed to the elements. Not a huge deal for many but something to keep in mind for room layouts
There is an additional cost associated to getting the LVL’s needed for this design. Budget around 12-15 dollars per linear foot of LVL needed to get a good gauge of how much additional money the lumber package will be for your home. Just for reference that equates to around $2000 for the above structural design shown (has ~160 linear feet of LVL).
HOW FAR CAN YOU EXTEND A CENTILEVERED FLOOR SYSTEM?
From our experience we have seen many all-lumber cantilevered floor systems span out around 3-4 feet. This is subject to structural design calculations from a licenses professional engineer but that is a safe amount to assume. If you want to go out any further you are looking at larger steel beams being incorporated, or posts being needed to support the span above.
DO YOU NEED TO CANTILEVER OFF THE BACK OF A HOUSE?
We get this question every so often and the answer is no, you can cantilever off any side of the house, pending structural work and local setback rules. It is most cost effective to cantilever off the side of the house with the least width (usually the front or back for a bungalow in Toronto), but there are ways to complete a cantilevered design on a longer side of the home. You will need to work with a structural engineer to come up with the engineering plans in any case, just make sure they aren’t blowing your budget out of the water to get it done.
CASE STUDY: CANTILEVERED VERSUS NON-CANTILEVERED SECOND FLOOR
Using the same project I showed the structural plans for above, you can see the outlined second floor with and without the cantilevered floor system. As you can see, the cantilvered floor was utilized in the master bedroom to allow for a larger space for a bed and also to enlarge the bathroom to include a double vanity and walk in shower system. It works out to an additional 65 square feet of floor space and was the precise solution for our home building client to justify the second level addition.
About BVM COntracting
BVM Contracting is a full-service General Contractor or Home Builder located in Toronto. We provide home renovation and building services for major home renovations and custom home builds (full interior renovations, home additions, lot severances, new home construction, and laneway suites). Our goal is to help guide our clients through the process of building their home, from concept to completion.
Further than providing General Contracting and Project Management for major home renovations, we also offer value-added services such as renovation financing, renovation rebate consultations and services, building permit and design services, smart home installation services, and real estate investor services.
To learn more about our offering by visiting our services page.