Goto main content

Our service now covers areas all across Canada

Table of contents
Obtain 3 free quotes for your home addition
Attach a file

By submitting your project, you agree to our Terms of Use

The average costs to build a home addition

Last modified: 2023-01-20 | Approximate reading time 5 mins

When you first move into your home, it could be the ideal size and shape for the number of people as well as everything you own. Of course, as time goes by, you may accumulate more and more stuff and your family may grow in numbers. This could give the impression that your home is getting smaller and smaller and thus, you need to expand. Of course, a home extension or addition is generally possible, but what are the costs involved in such a large scale of project?

If your home is no longer meeting your needs for space, it's time to think about how to take on a home extension project as well as the obvious costs involved. Luckily, we’re here to lay down the average prices and important information on the subject!

The average costs for a home addition

home addition

source: unsplash

What are the factors that influence the price of a home extension project?

It’s difficult to pin down specific prices when it comes to a home addition project, and that’s because many factors will influence the cost. It’s important to take into account that each quote could greatly vary as well as the several factors which can influence the price.

First off, the level of complexity of the work will have a major influence on the price overall and can increase or decrease overall cost. The number of scaffolds, proximity to busy streets and commercial districts are other examples of factors that will likely influence the costs of construction. The types of materials you’ll be using as well as the type of materials already in place will also contribute to increased costs.

Planning to build a home addition?

Fill out the form so that we can put you in contact with certified contractors from our network

Home addition considerations

Of course, before you grab a hammer there are a few steps you’ll need to think about taking. First, have you considered hiring an architect? It may be an important step to ensure that the room you’re adding matches the rest of your home. Another consideration is hiring a structural engineer so that the addition will happen without compromising the form of your home. If you don’t already know about load bearing walls, well now is the time to get to know them! Hiring an architect, contractor or structural engineer is crucial to making sure any home addition happens in the safest manner possible.

The addition of a room

source: unsplash

One of the most common types of home extension is the addition of an extra room. This could mean an extra bedroom on an additional floor, a living or dining room extended out of the side of your home. With an extra room addition, it is only possible to build up or build out. Building out will involve adding a room to the ground floor, and this is generally the preferred mode of construction for smaller or older homes which may not be able to take the structural weight of a second addition.  As may be obvious, building out will increase the footprint of your home.

You may not have the ground support or foundation to take on this job, and thus it could be quite expensive to construct a new foundation as well as the licenses that you’ll need to expand. In contrast, building up does not involve increasing the footprint of the home. However, this project may require a professional hand as there could be a necessity to strengthen the foundation in order to support the additional weight. Adding an extra room to your home can average anywhere between $95-$360 per square foot.


Sunrooms are another common addition, often built-out and adding to the side of a home. Again, the cost of a sunroom will vary depending on the amount of space you intend on covering and if you’ll be including electricity and heating in the room. Make sure to get multiple estimates for this project and look for the best prices possible, especially because the materials involved when building this type of addition. A sunroom will average between $18,000 and $95,000 with the cost of hiring an electrician included.

Detached additions

This is an option for homeowners who don’t have the structural integrity or space directly beside their home for the other additions mentioned. This will be a shed-like structure or something similar. Rooting heating and electricity may be tricky depending on your property, so do take these costs into consideration. Your detached addition will average between $19,000 and $30,000.

The best calculation method to get an idea of the cost of a home addition project

source: unsplash

For the majority of the work, the best method consists of a simple calculation; the price of materials added to the price of labour according to the number of hours it will take to complete the work. As we mentioned earlier, in the case of a house extension, the price is difficult to estimate because of the intricacy of the work. As a result, it’s best to ask for a quote from a certified contractor.

Professionals are well-suited and skilled enough to give you a fixed price without risking leaving out aspects that will increase the cost. Of course, after receiving an estimation, do make sure to leave some space in your budget for any issues or problems, a common occurrence with large renovation projects.

Cost of a home addition project

For the addition of a floor, prices may range between $180-$300 per square foot. When it comes to work done on one floor only or a basement that hasn’t been finished and is only to be enlarged in terms of width, costs will be roughly between $360-$480 a square foot. If it’s a basement you’re working on, the finish will add about $90 per square foot. Something to bear in mind is that the greater the size of the work, the lower the price will be per square foot!

For an expansion spanning two floors, the first floor will cost between $360 and $480 per square foot but the second floor will cost between $210 and $240 per square foot. Regardless of the size of the work area, it is important to have a minimum budget of roughly $72 000 for a proper extension on your home (most likely between $120 000 and $240 000. Take note that these prices are a rough indication and do not take into account the particular characteristics of each room (plumbing, heating, windows, etc.)­.

We have formulated a small price guide that, depending on the nature of the work, could give you the cost of a home extension by the square foot. 

Here is an overview of the average costs for home addition project elements

Type of project or material Average price

Installing a new floor on a house

approx. $180 to $300 per square foot

Transforming a floor

approx. $360 to $480 per square foot

2 floor home addition (1st floor)


approx. $360 to $480 per square foot

2 floor home addition (2nd floor)

approx. $210 to $240 per square foot

Minimum budget for a home extension project

$72 000 (in general, $120 000 to $240 000)


For more information about home extensions, check out "The cost of a home addition project"

To learn more about the average prices of home renovation projects, consult our "Home renovation price guide". 

Get 3 renovation quotes for your home addition project can help you get quotes for your home extension project. If you submit your project to us, we’ll put you in contact with top-rated contractors. Fill in the form on the homepage (it only takes a few minutes), and you will get estimates from trusted professionals. 


Looking for something else? Search here!



You have a project? let us help you.

Fill out this form to receive quotes from 3 certified contractors
Optional: It seems the postal code is missing. Your postal code helps us refer local contractors.

By submitting your project, you agree to our Terms of Use


You tell us about your project


We put you in contact with 3 certified contractors within 48 hours


You compare the different quotes and you save time and money

Number of projects submitted since 2014
Number of contractors in our network
Average time for an answer
One hour
*During business hours

Toronto - Calgary - Edmonton - Montreal - Ottawa - Vancouver - Halifax - Winnipeg - Windsor

© 2019


Follow us:


Partner sites: