How to design a single-family house, the technical guide?
If your home is no longer large enough for your needs, expanding your current space could be an interesting solution. While adding habitable square meters to your home is an important and costly project, it can be worth investing to stay in a neighborhood you love.
There are several ways to increase the area of your home. You can build up, down or sideways. This means adding a floor to your house, digging a more functional and welcoming basement, or enlarging an existing level, either sideways, backwards or forward, what we call an extension or an annex. The type of construction you choose and the use you want to make of this additional space will affect the cost, timing and requirements of the construction.
For many owners, their home represents much more than four walls and a roof; it embodies precious memories, comfort and feelings of community. But as the family grows or needs change, it is not uncommon for our home to no longer meet our needs. We can choose to move or adapt our current home to our present and future lifestyle. In both cases, there will be temporary disruptions, so how to make the right choice ?
Expanding your home is probably the best option if you live in a sought-after neighborhood and want to stay there. Of course, you could sell your house quickly, but could you find and offer yourself a new house that meets all your requirements ?
On the other hand, if the idea of embarking on a large-scale renovation, like a house enlargement, anguishes you (you worry about the costs, process management and the search for reliable partners to make your dreams a reality and to live in a space under construction) a move could be more attractive.
The financial question must obviously be taken into account in your decision. Take into consideration the date of purchase of your home and its net worth. In many markets around the world, house prices are skyrocketing. If you bought your house several years ago, when prices were lower, and your mortgage is largely paid, you may be able to finance the expansion of your home without significantly increasing your monthly payments . In addition, a larger house involves more expenses and, if you buy a new house, you may want or may need to make changes, which will have to be budgeted for.
Any type of enlargement will require a building permit and architectural plans. Depending on the complexity of the work, the plan of a structural engineer could be sufficient. During your first meeting with Billdr, your project manager will guide you to the best professional for your project.
Before deciding on a type of enlargement, you should know what is allowed in your area. For example, there may be a height restriction in your neighborhood, which will prevent you from building a second floor. Or, if you live in a heritage area, you may be allowed to build a floor, but only if you keep the facade of the existing building. There may also be restrictions on the types of exterior coverings you can use, the number of windows you need to install, and evacuation requirements. If you are already working with an architect, it is up to him to collect this information from the City. But if you’re only in the exploration phase and wondering what you can do and what you can’t do, you should go to the building permit office in your area, where an agent can inform you about what is authorized by the municipal code according to your address.
If you want a type of enlargement that is not allowed by the code, you can normally request an exemption or a derogation, but be careful: this requires some research work and will have a considerable impact on the schedule of your project. . At this point, it may be useful to consider whether there is another way to expand your home that meets your objectives and that is consistent with building codes in your area.
As with any home renovation, the cost depends on a multitude of factors: the complexity, size, finishes and purpose of the new space. An enlargement without plumbing and with minimal ventilation and electricity facilities will be less costly than creating an annex for a new kitchen or bathroom. However, it is the type of construction that will have the most impact on the price. In the planning phase, it is important to think long term. The smaller the expansion, the higher the cost per square foot, both in terms of labor and building materials. Therefore, if you plan to need more space in the future, it is advisable to do all the work at once.
Build by digging: addition of a basement
Average price: $ 225 / pi² or $ 180,000 for 800 pi²
Adding a basement is a popular way to expand a house. This is a good option when you want to add a living room or entertainment space for your family, a few more rooms or an office space and a bathroom. But you can also dig your basement to create accessory housing for rental income or transform your home into a multigenerational home for a family member.
To add a basement, it is not enough to convert the existing space. This means digging to create larger windows, a higher ceiling and legal exits. Many old houses do not have a full-rise basement, which makes them less usable than basements with ceilings of 7 feet or more.
Digging a foundation involves important structural work. During the process, the house must be stabilized, and the foundations reinforced by the installation of supports. This is called the takeover. Once the excavation work is complete, your contractor will build a new foundation, walls and soles. This is a specialized profession and your general contractor should call on subcontractors who exclusively do this kind of work.
If you plan to add plumbing to your basement, you will also need a plumber who can check where the main water supply and the drain are. If the drain is above the newly dug basement floor, you will not be able to install a standard toilet and shower unless you bring the drain below ground level. There are options like toilets and showers that pump up wastewater, but it is best to discuss the implications of this solution with your contractor.
Build in height: addition of a floor
Average price: $ 200 / pi² or $ 160,000 for 800 pi²
If you own a single-family home, building a floor is often a much less difficult and less costly addition than digging a basement, especially if you choose to reproduce your existing floor plan on the new floor . This means that a new bathroom must be placed directly above the existing bathroom in order to share the piping, and align the radiators and the heating caps with those on the first floor.
That said, a number of factors affect the cost and complexity of this type of project. Is your roof flat or sloping ? Share a wall with a neighbor ? Is it a concrete wall ? Do you want to use the second floor for independent accommodation ? A structural engineer and an architect will be best able to assess your current situation and the possibilities available to you.
Since building in height means modifying the exterior of your home, you will also have to ensure visual harmony between the existing building and the addition. Again, this is an aspect that your architect or architecture technologist will take into account when designing your new space.
Build laterally: addition of an appendix
Garage: $ 135 / pi² or $ 108,000 for 800 pi²
With foundation: $ 195 / pi² or $ 156,000 for 800 pi².
On stilts: $ 160 / pi² or $ 128,000 for 800 pi².
If you have a backyard, good space on the side or in front of your house, an extension could be the right solution for you. There are many construction options in this category. You can build a garage-type unit with access from the main part of your home, but use it to house a family room, or even a bathroom. It is also possible to build a garage for a vehicle, then another unit over it.
When expanding your home backwards, forward or sideways, your engineer or architect will determine whether you need a concrete foundation or a pipe construction.
A concrete foundation is necessary if you want your enlargement to include the basement, or a basement and a ground floor. In the case of an annex on stilts, supports (or piles) are pressed into the ground to support the new area of your house. Although this is the most economical option, it is only possible if you want to enlarge on one floor. If you think that in the future you will also want to build high up, you will have to sink a foundation.
It is normal and important to think about the money you can get from your renovation when you decide to sell your house. A well-made enlargement will undoubtedly add value to your property. After all, it will be larger, more modern and, hopefully, more functional. For example, if adding a floor allows you to put your home on the market as a four bedroom property, it will immediately be more attractive to families, especially in urban areas or in old house areas, where two or three bedrooms are the norm. According to Opendoor, an American residential real estate platform, adding a full bathroom can increase the resale value by almost 6%. Depending on the market, the increase in off-ground living space can bring you an average of $ 20,000 more. However, it is practically impossible to quantify exactly the value of your enlargement due to the large number of variables. Remember that if you decide to expand your home, it’s probably because you want to live there. It is therefore just as important to consider the value that an enlargement brings to your lifestyle as that which it brings to your portfolio.
The expansion of your home is a big project, but it is actually a series of small projects all put together. With careful planning, clear vision, trusted partners like Billdr and patience, getting the house of your dreams into the space you need to be comfortable and happy is quite possible.
Ready to start expanding your home ? Tell us about your project ! Billdr can help you. Contact one of our experts today for a free presentation of our services and to obtain a budget estimate.
Ready to plan your house expansion?
This guide shows you all the stages, starting with the definition of your needs up to construction as well as renovation tips.