Harmonie Construction

8 key factors influencing the cost of a new house foundation

a small house on top of a pile of rocks

A house foundation is the fundamental element of any new construction. It ensures the stability, durability and security of your home. In Canada, where climatic conditions are particularly harsh, foundations are mainly built in concrete for their strength and longevity.

At Harmonie Construction, we understand the importance of a well-designed house foundation and are dedicated to building your new home that precisely meet our customers’ needs while adapting to the specifics of their terrain.


Main functions of a house foundation

Structural support

Your home foundation acts as the main support for the entire structure, distributing its weight over a wide area of the ground. This distribution prevents uneven settlement, which can lead to cracks in walls, doors that don’t close properly, or even serious structural failure. A well-designed house foundation ensures that the house’s load is evenly supported, reducing the risk of problems associated with subsidence or ground movement.

Protection against water and humidity

Water is one of the greatest enemies of a residential structure, capable of causing considerable damage both immediately and in the long term. An effective home foundation is designed to prevent water and soil moisture from infiltrating the house.

This is achieved through a combination of proper drainage around the foundation, impermeable materials and specific construction techniques that direct water away from the house. These measures protect moisture-sensitive building materials and prevent the growth of mold and mildew, contributing to a healthier indoor environment.

Cold insulation

In regions like Quebec, where temperatures can drop considerably, foundation insulation is essential to maintain a comfortable indoor temperature and reduce heating costs. A well-insulated house foundation acts as a barrier against the cold outside, minimizing heat loss through the floor and basement walls. It contributes to the improved energy efficiency of new buildings and enhanced comfort for occupants, while reducing environmental impact and energy costs.


New home foundation types

As we have already mentioned, the foundation of your new build plays a decisive role not only in ensuring the stability of the structure, but also in influencing the functional and energy aspects of your home. But what are the main types of houses foundations used in Quebec? Here’s a quick overview:

Foundation for Sous-Sol

Full basement: Ideal for those looking to maximize their living space, the full basement extends over the entire surface area of the house and can be converted into additional rooms, such as bedrooms, playrooms, or even independent apartments. This option also offers excellent insulation and storage potential. We also use it to integrate the mechanics of the house.

Half basement

With a larger portion of the basement above ground level, you can benefit from more windows and more light. Direct access to the outside may be easier to arrange (outside entrance, sunken terrace…). Also advantageous where there are constraints related to excavation depth (water table, presence of rock, etc.).

Floor tile

The ” slab on grade ” simultaneously acts as a foundation wall and footing. More economical, comfortable and environmentally friendly than building a basement, a slab-on-grade construction avoids the problem of frost thanks to good insulation. In addition to providing a more pleasant living environment, this option will cost you less to build and minimize the risk of moisture and infiltration problems.

It helps maintain healthy indoor air by reducing the potential problems associated with humidity, a source of mold and toxins. Building a house with an ecological slab-on-grade reduces your GHG emissions by 3.9 tonnes compared to building with a basement. And it avoids upsetting the subsoil and the biodiversity that goes with it.

What’s more, slab-on-grade offers many advantages:

  • Can be designed to integrate underfloor water heating;
  • Avoid rooms with no natural lighting. Building an extra storey in wood will cost less, be more environmentally friendly and offer more pleasant rooms to live in. Concrete has a heavier toll, mainly because of its cement content, which has a strong impact on climate change, and the need for synthetic insulation, which is polluting and bad for health;
  • Improved energy efficiency;
  • Offers performance comparable to that of a house with foundation walls;
  • Can be used in locations with problematic or unstable soils;
  • Floating slabs are less expensive than basements;
  • The slab reduces the risk of flooding, and this is welcomed by insurance companies.
Monolithic slab

In comparison, the monolithic slab is poured in a single operation, integrating the base and floor of the house. Although it is less insulating than a floating slab, it may be preferred for its simplicity of construction and its cost, which can sometimes be lower.

Pile foundation (or Pilotis)

A pile foundation, also known as a piling foundation, is a construction technique used to raise the structure of a house above the ground. This method is particularly useful in areas where the soil is unstable, wet or prone to flooding, as well as in regions where freezing and thawing can compromise the integrity of a traditional foundation.

In Quebec, although pile foundations are less common than traditional concrete foundations (such as slabs-on-grade or basements), they are used in certain specific circumstances, such as flood zones, on land with unstable soil and for frost protection.

While pile foundations can offer advantages in terms of protection from the elements and stability, they can also present additional challenges and costs associated with specialized engineering, construction and thermal insulation of the space beneath the house. At Harmonie Construction, we use the piling technique mainly for outdoor landscaping and patios, and we always entrust the installation of the piles to our partners specialized in this field of construction.


Installing the house foundation forms for a new home is an important step


8 factors influencing the cost of a new house foundation


1. Square Feet and new homes

The total surface area and type of dwelling (single-family home, semi-detached, cottage, etc.) are determining factors in calculating the cost of a house foundation. The larger the floor area of the house, the greater the quantity of materials (concrete, steel for reinforcement, etc.) required. Similarly, the type of dwelling influences the complexity of the foundation. For example, a house with several storeys or a finished basement will require a sturdier foundation than a single-storey home.


2. Home Foundation types and climate

Quebec’s climate, with its harsh winters and freeze-thaw phenomenon, demands foundations that are adapted to withstand these extreme conditions. The type of house foundation chosen depends on its ability to cope with these climatic constraints. A new home foundation must be designed to avoid ground movement caused by freezing and thawing, which can increase their cost depending on the depth required and the insulating materials used.


3. Depth and use of house foundation

The depth at which a building’s foundation is poured plays a key role in its ability to withstand frost. A deeper house foundation may be required to reach a zone in the ground where the temperature remains stable throughout the year, thus increasing construction costs. In addition, the intended use of the foundation (for example, a habitable basement with sanitary facilities) will require additional features that may influence the cost.


4. Cost of concrete and transport

The cost of concrete varies according to market fluctuations and the specific composition required for the project. Winter concrete, which is used in cold weather, can also drive up costs. Transporting concrete to the construction site can also represent a significant proportion of the budget, especially if the site is remote or difficult to access, sometimes requiring the use of special concrete pumps.


5. Terrain and features

The topography of the site (flat, sloping, rocky) and its accessibility have a direct impact on the cost of a new house foundation. Terrain that is difficult to access or that requires major excavation work to prepare the site (such as rock clearing or filling) will increase labor and material costs.


Read this article to know more about findint a lot : 5 steps to finding the perfect lot for sale for your new homebuilding in the Outaouais region


6. Soil composition and expertise required

The composition of the soil determines the type of foundation to be built. Unstable soil or a high water table require in-depth geotechnical studies and the intervention of specialists (such as a soil scientist), adding to the overall cost of the house foundation. The need for special reinforcement or insulation techniques can also increase the budget.


7. Labour and weather conditions

Labour costs vary according to the complexity of the project, the duration of the work and weather conditions. Bad weather can delay the project, increasing labor and equipment rental costs.


8. Protection against water and soil vapors

Installing waterproofing, drainage and radon mitigation systems to protect the foundation from soil moisture and vapors like radon is a smart investment in the structure’s durability. These preventive systems represent an additional cost, but are essential to avoid future problems such as water infiltration and structural damage.


In the end, how do you estimate the price of your house foundation?

Estimating the cost of a home foundation requires careful consideration of several factors, such as the size of the house, the type and depth of the foundation, and the unique characteristics of your lot. As a general rule, in Quebec, the cost of excavating and building a house foundation can vary from $20,000 to over $50,000, depending on the complexity and specifications of each project.

At Harmonie Construction, we’re committed to providing accurate, personalized estimates, guiding you through every step to ensure your home foundation meets all your expectations in terms of strength, durability, and budget.

We invite you to contact us to discuss the specifics of your project and offer you an estimate tailored to your specific needs.


The main stages in the process of building a house foundation

We don’t always think about the implications of a house foundation in a new-build project. However, your building contractor and his subcontractor must follow a rigorous process, detailed in the specifications, to ensure that your foundation is solid, durable and in line with the specific needs of your residential project.

Here’s an overview of the main stages in a process:

  1. House layout by a surveyor;
  2. Excavation and compaction of foundation hole ;
  3. Formwork and pouring of foundation footings ;
  4. Formwork for foundation walls ;
  5. Casting the floor in the formwork ;
  6. Foundation stripping ;
  7. Foundation insulation ;
  8. Waterproofing walls ;
  9. Installing the drain pipe (French drain) ;
  10. Backfilling the floor.

NOTE: These are the steps for a conventional concrete foundation.

Resources: Association Béton Québec


To work with an experienced general contractor, consult the following article: A guide to selecting your new home builder


The importance of house foundations in new construction


Maintenance recommendations and annual checks

A well-maintained home foundation is crucial to the durability and safety of your home. Here’s a simple guide for homeowners to carry out annual checks and keep your home’s foundation in top condition.

Inspection for cracks and movement
  • Cracks: Check foundation walls regularly for cracks. While some small cracks may be normal, larger or progressing cracks may indicate serious problems.
  • Movement: Look out for any signs of movement in the foundation, such as shifting walls or changes in the alignment of doors and windows.
Drainage control and monitoring
  • Water: Make sure that water runs away from the foundation without stagnating around the house. Check gutters, downspouts and ground to ensure proper drainage.
Floor maintenance around the house foundation
  • Soil: The soil around the foundation must be properly maintained to avoid excess moisture. The ground should slope slightly away from the foundation of your house to facilitate water drainage.
Checking protection systems
  • Waterproofing: Inspect waterproofing and drainage systems to ensure that they are working properly and that there are no obstructions.
  • Insulation: Check the condition of your home’s foundation insulation to prevent heat loss and water infiltration.
Preventing frost damage
  • Frost protection: Make sure your foundation is protected against the effects of frost, by ensuring that spaces such as crawl spaces and basements are properly insulated and ventilated.

Regular maintenance and monitoring of your home’s foundation will always be important to preserve the structural integrity and value of your home. By following this annual checklist, homeowners can proactively identify and address potential problems, ensuring the safety and comfort of their home for years to come.

The role of your general contractor in building the foundation for your new home

As a general contractor specializing in the construction of new homes in the Gatineau – Ottawa region and custom homes in CantlyOur mission is to ensure that every home foundation we build is not only strong and durable, but also perfectly adapted to the needs of each customer and the specific characteristics of the project.


To find out more about building a custom home, read the following article : Everything you need to know to build your custom home


Coordination and supervision

Our expertise enables us to efficiently coordinate all stages of home foundation construction, from initial design to final completion. We supervise the work of all the professionals involved, including engineers, geotechnicians and construction crews, to ensure that every phase of the project is carried out with precision and to the highest quality standards, following precise specifications.

Advice and customization

We understand that every project is unique. That’s why we work closely with our customers to identify their specific needs and propose customized solutions. Whether it’s choosing the most suitable type of fhouse foundation, adjusting the depth according to soil conditions or integrating specific features such as a radiant heating system, our role is to guide you through every decision to ensure the best possible performance and satisfaction.

Quality and cost management

We optimize the quality of your home’s foundation while managing and controlling costs. This includes selecting high-quality materials at the best price, accurately planning the work to avoid costly delays, and implementing construction practices that maximize the efficiency and durability of your foundation.

Compliance with standards and regulations

As a general contractor, we make sure your new home foundation complies with all applicable standards and regulations. This includes compliance with building codes, frost and moisture protection measures, and the integration of insulation and waterproofing best practices.


A solid foundation with Harmonie Construction

At Harmonie Construction, we’re more than a general contractor; we’re the pillar you can count on to make your new home project a reality. Our promise? Full support right from our first project planning meeting, ensuring that every step thereafter runs smoothly.

Building a solid home foundation is the first step towards realizing your dream home. With the right partner at your side, it’s the first concrete step towards making your construction project a reality.

Each member of our team and each of our partners are carefully selected with the sole aim of exceeding your expectations. Contact our team to find out how we can work together to build your new home in one of our projects, starting with a durable, solid home foundation.