How much does it cost to build a custom home?

So, how much does it cost to build a custom home? This is one of the most common questions we get asked. Another variation of this question is “How much per square foot does it cost to build a custom home?”

Below is a list of costs for budgetary purposes only and is for the Ottawa area. Please remember that every homeowner, home design and building site is different (hence the word “custom”) so there will be many factors at play for every project. Also, as we have experienced with the pandemic, material costs can fluctuate significantly.

There’s no way to answer this question with an exact number, nor is there a way to give you a per-square-foot number. That’s because there are millions of variations and thousands of factors at play. Here are some examples of things that will drastically change the price without changing the total square footage of a home.


Site work

One lot could have perfect native soil and another lot could have three feet of rock that needs to be blasted or chipped away. Or, as in the case of my home, we had six feet of peat moss that had to be removed and replaced with blasted rock and an engineered pad.

Access could also affect the price significantly. Digging a small hole on a tight lot could be more expensive than digging a large hole on a wide open lot.

The Conscious Builder cost of a custom home
Beautiful design details and thoughtful planning from the start mean efficient homes can be healthy and luxuriously comfortable.


Pads, piers, garages, foundation type and height, slab thicknesses, structural requirements, basement or no basement: These and other factors all affect the foundation price.


Overall design

You could have a 2,500-square-foot box with a gable roof or you could have a 2,500-square-foot architectural dream design with overhangs, large windows, a flat roof and a two-car garage. Same size, completely different price.

Smaller homes will cost more per square foot as well because there is a start-up cost. Economies of scale come into play and larger homes usually have more of the “cheap” space, which is any floor area that does not have plumbing, cabinetry or fixtures associated with them (i.e. bathrooms, kitchens, bars).

The Conscious Builder cost of a custom home
Benches custom made with recycled materials are the perfect addition to this beautiful, bright Passive House kitchen.

Bathrooms & kitchens

​Your 2,500-square-foot custom home could have an Ikea kitchen with laminate tops and 1.5 bathrooms or it could have a $100,000 kitchen with 3.5 bathrooms. Bathrooms and kitchens are the most expensive rooms in homes.


Exterior finishes

You could have vinyl siding on the exterior, high-end wood siding, masonry veneer or stone. These all vary significantly in price and will affect structural requirements.

Windows & doors

You could spend $30,000 on cheap double-glazed vinyl windows or you could go for Passive House certified triple-glazed windows with wood frames and aluminum cladding, which could run you $100,000+. It’s not one or the other, but this shows the significant price range.

cost of a custom home The Conscious Builder
This heartwarming home surpasses Passive House standards and is the architect’s residence: A basecamp while they work and play, surrounded by nature.

Interior finishes

Do you want cheap vinyl flooring and carpet or do you want reclaimed hardwood floors and porcelain tile? Carpet stairs or hardwood stairs? Wood railing or glass railing? Finished basement or unfinished basement?


These are just some of the factors that will affect pricing of your custom home. I’m not saying you have to go to one extreme or the other, my point is that you can build a 2,500-square-foot custom home on the perfect site with cheap finishes, 1.5 bathrooms and an Ikea kitchen OR you could build a 2,500-square-foot custom home with reclaimed high-end products, quality windows, a garage, 3.5 bathrooms and Passive House certification. Both have the same square footage but they will be in completely different price ranges.


Now that I’ve laid the ground work and hopefully clarified where some of the costs may go, here are some numbers to keep in mind when planning your custom home project:

  • Planning and architectural design will be somewhere between $12 and $20 per square foot. Alternatively, drafting and builder code review only would be around $4 to $5 per square foot.
    • We recommend going for the planning and architectural design option if you’re building a custom home. This home is going to be yours for many years to come so you want to do it right.
  • Additional fees that may be applicable to your project:
    • Development approvals: $2,000 – $6,000
    • Surveying: $4,000 – $6,500
    • Structural engineering: $1,000 – $5,000
    • Geotechnical engineering: $1,800 – $2,700
    • Septic system engineering: $2,000 – $2,500
    • Mechanical engineering: $1,000
    • Heat loss/heat gain calculation: $500
    • Mechanical ventilation design summary: $250
  • Construction permit will vary (Ottawa fees here)
  • City development charges (if not paid yet): $26,000 – $40,000 (more information)
  • Additional fees are required for projects involving third-party verification and certification of their performance. The minimum additional fee for projects involving third-party verification are typically as follows:
    • Passive House (PHI or PHIUS): $8,000
    • NetZero Energy: $1,600
    • LEED for Homes (CaGBC): $3,000
    • R-2000: $1,200
    • Energy Star: $1,000
    • Energuide: $850
  • Construction costs will really vary from project to project, however, we generally fall in the $300 to $400 per square foot range for the projects we have done in the past.
    • IMPORTANT: Smaller homes will cost more per square foot and there is a minimum that is hard to break. You will want to budget at least $500,000 for construction costs to build a custom home in Ottawa.
  • Landscaping costs are NOT included in the per-square-foot price as homeowners often take care of this after their builder is done, however, ask if your builder is willing to assist with this as well.

The goal here is to help educate and inform you of what is realistic for your custom home so that you can make conscious decisions.


About the Author

Casey Grey

The Conscious Builder is an award-winning sustainable building company. Founder Casey Grey also hosts The Conscious Builder Podcast and The Conscious Builder on YouTube. He has written almost 400 blog posts on topics such as marketing, branding, entrepreneurship, personal development, sustainability and more.



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