Custom Home Builds
Built From
the Ground Up.
Your Vision. Our Craft.
Your land, your floor plan, your home, designed and built by one accountable team from first sketch to final walkthrough. Serving Cobourg, Port Hope, Peterborough and all of Northumberland County.
25+
Years Building
100+
Homes Completed
$750K+
Avg. Build Value
4.8★
Google Rating
What’s Included
Everything under one roof. One team accountable for all of it.
We handle the entire process in-house: no hand-offs, no gaps between design and build, no dealing with three different companies who don’t talk to each other. One contract, one point of contact, one team that carries the job from first conversation to the day you move in. The same applies to an ADU or garage conversion on the same property, which plenty of builds now include from the start.







What It Costs
From $300 a square foot, agreed before we start
That covers the build from foundation to finish. What moves the number is the site, the foundation type, and the level of finish you choose. The land, the services and the municipal development charges sit outside it and vary across the county.
$540k
1,800 sq ft
A three bedroom home on a straightforward lot. The most common size we build.
$750k
2,500 sq ft
Four bedrooms with a bonus room or a finished basement. Where most of our custom builds land.
$1.05m
3,500 sq ft
Larger footprint, more complex roof lines, higher finish level throughout.
Site
Varies
Slope, rock, high water table and servicing distance all change the number before the house starts. We look before we price.
The Process
How we build your home
01
Discovery Call
We learn about your land, your vision, your timeline, and your budget. No sales pressure, just an honest conversation about what you want to build.
02
Design & Plans
Custom floor plans and 3D visualizations produced so you can see your home before we break ground. Revisions until it’s right.
03
Permits & Approvals
We handle all permit applications and approvals with the municipality. You don’t chase paper. We do.
04
Build & Deliver
Construction begins. One point of contact throughout. We don’t hand over the keys until every detail is right.

Est. 1999
Family-Owned
Why Choose Us
25 years of building in Northumberland County
The Merson family started Cobourg Construction in 1999 with one goal: build homes the right way and stand behind the work. 25 years and 100+ projects later, that’s still exactly what we do.
We’re a design-build firm, meaning we handle design, drafting, permits, and construction under one roof. You deal with one team, one contract, and one phone number. No gaps, no finger-pointing, no surprises on your invoice.
We build across Cobourg, Port Hope, Brighton, Colborne and the surrounding townships, out to Peterborough and the Kawarthas, and west into Durham Region including Oshawa, Whitby and Clarington. If you are weighing a home addition instead of a new build, that work starts at a different number and has its own page.
Frequently Asked Questions
What does it cost to build a custom home in Northumberland County?
Custom home builds with Cobourg Construction start at $300 per square foot. A 2,000 square foot home therefore starts around $600,000. What moves the number is site conditions, foundation type, and the level of finish. Every quote is fixed before work begins.
Do I need to own the land before I start?
Yes. A custom home is built on your lot, so the land needs to be secured before design begins. We can look at a property with you before you buy and tell you what it will cost to build on, which is worth doing before you commit.
Who handles the drawings and the permits?
We do. Design, drafting, permit applications and construction are all handled in-house, so there is one contract and one accountable team rather than an architect, a designer and a builder pointing at each other.
What is not included in the per square foot price?
The land, servicing connections, and municipal development charges. Those vary between Cobourg, Port Hope, Hamilton Township and the rest of the county, and they can be significant, so we set them out separately rather than burying them in a square foot figure.
Can you work from drawings I already have?
Yes. If you have drawings from an architect or designer we will build from them. If you do not, we handle the design and drafting as part of the same contract, which is one less party for you to coordinate.
What happens if something is found once you start?
It comes to you before it is touched, with the cost attached. A fixed price only means something if the exceptions are handled in the open.
Do you build on rural lots with wells and septic?
Yes, and a lot of Northumberland is exactly that. Rural builds bring servicing, well and septic into the picture, and septic approvals are issued by Northumberland County rather than by your municipality, so that is a separate application to a separate office. We handle both.
Can you build a secondary suite or in-law unit into a new home?
Yes, and it is worth deciding early. A self-contained suite designed in from the start costs far less than one added later, and it changes the layout, the servicing and the permit application. If the suite is for a parent or grandparent, there is a federal tax credit that may apply, with conditions worth understanding before the build rather than after. Ask your accountant early and we will build to whatever the suite needs to qualify.
Ready to build your home?
Tell us about your land and your vision. We’ll give you an honest conversation and a clear path forward.