
Our expertise
Design-build
One team from the first sketch to the keys: James runs construction, his wife runs design, and both work from the same plan.
Design-build means one firm designs your project and builds it. Here the two halves are a married couple: James Jarvis runs construction, and his wife runs design through her studio, Juliette Interiors. Greenwood in Toronto, a rear extension and a new top floor, went from the permit and the design through construction in 10 months that way.
What's included

Every job, start to finish
- Consultation and measurements
- Floor plans and a 3D model
- Selections with the designer
- Permit drawings, engineering and the permit
- Construction, inspections and handover
- One point of contact throughout
The kinds of job
- Additions and second storeys
- Whole-home and main-floor renovations
- Kitchens, bathrooms and basements
- Additional units
- Typical duration
- Greenwood, a rear extension and a new top floor in Toronto, took 10 months including the permit, the design and construction.
- Permits involved
- Whatever the project needs, applied for and managed by us
What it costs
Our 2026 ranges, not quotes. Every job is priced after a site visit, and the first estimate is free.
No single range for this work. Every job is priced after a site visit.
What moves the number
- The scope you choose
- The finishes you pick with the designer
- Structural work
- 13% HST on top
Finished jobs

Aurelia
Kitchen, refinished stair, fluted fireplace, levelled floors, rewiring and a bathroom added mid-job.
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Greenwood
Top floor replaced with a new storey, rear extension, basement enlarged, full interior design and build.
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Solace
Complete gut to the studs, load-bearing walls removed and reframed, spray foam throughout, new upstairs washroom, full interior design.
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Syncopa
Permits, steel beams, layout reworked, stone fireplace out, three new bathrooms, new doors, floors, trim and tile, attic insulation upgraded.
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Bellamy
Whole main floor: load-bearing walls out, steel beams in, new kitchen, mudroom, office, fireplace, floors, trim and doors.
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Orra
Two load-bearing walls out, kitchen and living room swapped, gas fireplace with built-ins, new floors, doors and trim, popcorn ceilings removed.
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Design-build
Design-build or a separate designer and contractor?
With separate firms, the plans are drawn first and priced later, by builders who didn't draw them. With design-build, the people who price the job are the people who draw it and build it. Our design-build vs general contractor guide sets out when each makes sense, and fixed price vs cost-plus covers how the contract is priced.
How does it work here?
You meet James first, and he prices the whole job before design starts. Our designer measures, draws the floor plans, builds a 3D model and presents the finishes in our office, and James's crew builds it. One client put it this way: they "bring the practical and the design together" (Tony O'Brien, Google review).
Real work
Greenwood took a Toronto house through the permit, interior design and construction in 10 months. At Bellamy, Juliette Interiors designed a modern organic main floor with the owners, and we built it around the steel beams that replaced the walls; both are in our projects.
Where we do this
In Ajax, Aurora, Brampton, Burlington, Caledon, Clarington, East Gwillimbury, Halton Hills, King, Markham, Milton, Mississauga, Newmarket, Oakville, Oshawa, Pickering, Richmond Hill, Scarborough, Scugog, Toronto, Uxbridge, Vaughan, Whitby and Whitchurch-Stouffville.
How the job runs
Meet James
James meets you at the house, hears what you want and gives you a rough estimate on the spot. The first estimate is free.
Proposal and contract
If the estimate works for you, James prepares a detailed proposal. The whole project is priced, and the contract signed with a 10% deposit, before any design work begins.
Design onboarding
Our designer sends you an onboarding email with some homework: your style, how your family uses the house, and what you need and want. You share Pinterest boards, then go through them together on a Zoom call: what you like in the pictures, and what you don't.
Measure and floor plans
The designer measures the house and draws the floor plan: which walls come out, where the stairs land, how new space joins the old. We go through it with you until it's confirmed.
Drawings and 3D rendering
With the plan confirmed, she draws the elevations and the millwork, then puts it all into a 3D rendering, so you see the rooms before anyone orders a cabinet.
Finishes presentation
We don't take you round the stores: there are too many options. Using what she learned in onboarding, the designer narrows the tile, flooring, quartz, plumbing fixtures and the rest to a few choices that suit your style, collects the samples and presents them to you in our office. If a selection changes the price, the change goes through a change order you sign.
Permits and engineering
We prepare the permit drawings, bring in the structural engineer wherever a beam or a load changes, and apply to the municipality. If the plan changes after the permit is issued, we file the amendment.
Construction
Our crew and trades build it, with one point of contact from demolition to the last coat of paint. Our site supervisors write a job log every day, which you can follow in our online app. When we open a wall and find a problem, you hear about it, and what it costs, before we fix it.
Inspections
The municipal building inspector checks the work at each stage the permit sets, before it gets covered up.
Handover
We walk the finished house with you and put right anything that isn't. On one job a stair stain didn't match the new floor, so we refinished the stairs.
Credentials
- Written warranty1 year workmanship and materials, 2 years plumbing, heating, electrical and building envelope, 7 years structural
- BBB Accredited BusinessAccredited by the Better Business Bureau since November 2025
- Durham Region Home Builders' AssociationMember, Renovators
- RenoMarkRenoMark renovator, through the DRHBA
Questions
What is design-build?
Who designs and who builds at Jarvis Contracting?
How long does a design-build project take?
Do I sign one contract or two?
Guides
- Design-build or architect plus contractor in Ontario?
- Fixed price vs cost-plus contracts for Ontario renovations
- How many units can I add to my lot in Ontario?
- How much does a home addition cost in Ontario in 2026?
- How much does a second-storey addition cost in Ontario in 2026?
- Ontario HST relief for owner-built homes and big renovations, 2026
- Questions to ask a contractor in Ontario before you sign
- Should we add on or move? Costs compared for 2026