Design-Build vs General
Contractor. How to choose
the right delivery model.
A plain-language guide for Ontario owners. How each model handles responsibility, cost certainty, speed, and risk, and when to choose which on commercial, office, and multi-residential work.
Answer
The core difference in design build vs general contractor is who holds responsibility for design. In design-build, one firm is contracted for both the design and the construction, giving you a single point of accountability from concept to completion. With a traditional general contractor, the design-bid-build model, you hire a designer first, then bid the completed drawings to a builder responsible only for construction. Design-build typically delivers faster with earlier cost certainty; design-bid-build gives you more design control and competitive price tension, but splits responsibility between two parties.
Choosing how to deliver a project is one of the first, and most consequential, decisions an owner makes. It shapes your budget, your schedule, and who's on the hook when something goes wrong. The design build vs general contractor question comes up on almost every commercial renovation, office fit-out, and multi-residential build in the GTA. This guide explains both models in plain terms, the contracts behind them, and how to decide which fits your project.
What is design-build?
Design-build is a single-contract delivery model: one firm, or a tightly integrated team, is responsible for both designing and constructing your project. You sign one agreement, deal with one point of contact, and that party owns the outcome end to end. Because design and construction sit under the same roof, the two phases can overlap (often called fast-tracking), which compresses the schedule. This is the heart of true design-build delivery, integration, not coordination after the fact.
In Canada, design-build projects are commonly delivered under CCDC 14, the standard Design-Build Stipulated Price Contract. It defines the single-point relationship between the owner and the design-builder, and it's the document most experienced GTA builders will reach for on this kind of work. The Canadian Construction Documents Committee maintains the full family of standard forms.
What is a general contractor (design-bid-build)?
The general contractor model, more precisely, design-bid-build, separates design from construction. You engage an architect or engineer to produce a complete set of drawings, then put those drawings out to tender. General contractors bid, and you award the work, usually to a competitive price. The general contractor is responsible for means, methods, and delivering the building to the drawings, but not for the design itself.
This is the most familiar model in the industry, typically delivered under CCDC 2, the Stipulated Price Contract. It gives the owner a fixed contract price once the design is finalized and tendered. Owners who go this route usually engage an architectural design team early to produce approvable permit drawings before construction is priced.
The differences that actually matter.
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Single point of responsibility
This is the headline difference. In design-build, one party owns design and construction, so if a detail doesn't work, there's no finger-pointing between designer and builder. In design-bid-build, the owner sits between two contracts and often has to mediate when a design issue surfaces during construction.
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Cost certainty, and when you get it
Both models can give you a firm price; the difference is timing. Design-build can lock a price (or a guaranteed maximum) earlier, before the design is fully detailed, because the builder is at the table from the start. Design-bid-build gives you a hard, competitively tendered number, but only after the design is complete, which means you commit design dollars before you know the construction cost.
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Speed and schedule
Design-build overlaps design and construction, so site work can begin while later-stage design is still being finalized. Design-bid-build is sequential, design, then tender, then build, which is more predictable but generally slower.
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Design control and competition
Design-bid-build gives the owner maximum control over the design and the leverage of competitive bidding. Design-build trades some of that direct control for integration and speed, you're buying an outcome, not directing every detail.
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Change orders and risk
In design-build, the builder carries design risk: if the design is wrong, fixing it is largely their problem. In design-bid-build, design errors and omissions can become the owner's problem, and a source of change orders, because the builder only priced what was drawn.
Choose the contract structure before the design starts. By the time drawings are finished, the trade-off has already been made, quietly, and in your name.
Where construction management fits in.
There's a third model worth knowing. In construction management, the owner engages a construction manager to run the project for a fee, with subtrades contracted transparently. It comes in two flavours, CM-as-agent (advisory) and CM-at-risk (the CM guarantees the price). These are delivered under CCDC 5A and CCDC 5B respectively.
CM is common on large, complex, or phased work where the owner wants open-book transparency and early builder involvement without a single lump-sum design-build commitment. For owners who want the schedule benefit of early builder engagement but need to retain full visibility into subtrade pricing, it's often the right answer.
The contracts behind each model
| Delivery Model | Standard CCDC Contract | Who Carries Design Responsibility |
|---|---|---|
| General Contractor (Design-Bid-Build) | CCDC 2 Stipulated Price Contract | Owner's designer |
| Design-Build | CCDC 14 Design-Build Stipulated Price | The design-builder |
| Construction Management | CCDC 5A / CCDC 5B | Owner's designer (CM coordinates) |
These are standard, industry-recognized Canadian Construction Documents Committee (CCDC) forms. Using a recognized contract for your chosen model protects both sides and sets clear expectations on price, risk, and responsibility. The Canadian Construction Association and the Ontario Construction Act provide the broader regulatory framework these contracts sit within.
When to choose which (GTA context).
There's no universally "better" model, only the right fit for the project. A practical example: a tenant fitting out 8,000 sq ft of downtown office space with a hard lease-commencement date is usually best served by design-build, one team, overlapping phases, one deadline to hit. A multi-residential project with fully engineered, permit-issued drawings in hand is a natural candidate to tender to general contractors for the sharpest price.
Choose by what the project most needs.
Speed and single-point accountability matter most.
Office fit-outs and tenant improvements on tight occupancy deadlines, or owners who simply want one team to own the outcome end to end.
Design is complete and you want competitive bids.
Drawings are stamped and ready to tender. You want tight control over every design decision and the leverage of multiple qualified contractors pricing the same scope.
Large, complex, or phased work needing transparency.
Open-book subtrade pricing, early builder input, and the flexibility to phase scope. Worth more than a single fixed contract on big or evolving projects.
What design-build means for an office fit-out timeline.
Office fit-outs are where the design-build advantage is easiest to see, because tenants are almost always racing a lease clock. In a traditional design-bid-build sequence, you design the space, finalize drawings, tender to contractors, evaluate bids, and only then start construction, and every handoff is a place the schedule can slip. If the low bid comes in over budget, you're back to redesigning, which pushes occupancy further out.
Design-build collapses that timeline. Because the builder is engaged alongside the designer, pricing feedback happens during design rather than after it, long-lead items (mechanical equipment, custom millwork, specialty glazing) can be ordered before the drawings are 100% complete, and demolition or base-building work can begin while finishes are still being detailed. For a tenant who needs to be operational by a fixed date, that overlap is often worth more than the competitive tension of a hard bid, a fit-out delivered two months sooner can mean two months less paying rent on two spaces at once.
For tenants planning their move, we cover the broader process in our notes on commercial interior construction, and the upstream piece, getting approvable permit drawings through the city in time to actually build, is handled by our design partner 6ixDesign.
Frequently asked questions
Is design-build cheaper than a general contractor?+
Not automatically. Design-build often lowers total cost by reducing change orders, rework, and schedule overruns, but design-bid-build's competitive tender can produce a lower headline construction price. The cheaper route depends on how complete your design is and how much schedule risk you're carrying.
Who is liable for design errors in design-build?+
The design-builder. Because one party is responsible for both design and construction, design errors are generally theirs to fix, which is a major reason owners value the single-point model.
What is CCDC 14?+
CCDC 14 is the standard Canadian Design-Build Stipulated Price Contract. It governs the relationship between the owner and a single design-builder responsible for both design and construction. The full standard is published by the Canadian Construction Documents Committee.
Can a general contractor also offer design-build?+
Yes. Many contractors deliver projects under both models. The distinction is contractual: under design-build they take on design responsibility; under a traditional general-contracting arrangement they build to the owner's drawings.
Which is faster, design-build or design-bid-build?+
Design-build is usually faster, because design and construction overlap. Design-bid-build runs design, tender, and construction in sequence, which is more predictable but takes longer overall.
Choosing the right model for your build.
The design build vs general contractor decision comes down to a trade-off between speed and single-point accountability on one side, and design control and competitive pricing on the other. 6ixBuild delivers commercial and multi-residential projects across the GTA under all three models, design-build construction, general contracting, and CCDC 5B delivery, and can help you pick the structure that fits your budget, schedule, and risk tolerance before a contract is signed.
Planning a commercial build or office fit-out?
Talk to 6ixBuild about the right delivery model, design-build, general contracting, or construction management. We'll help you choose the structure before the contract is signed.
