Which Contract Is Best for Homeowners
When you are planning a custom home or major renovation, one of the most important decisions you will make, often before design is even complete, is how you contract with your builder.
Most residential projects fall into three common contract types: Cost Plus, Fixed Price (Stipulated Sum), and Construction Management (CCDC 5B).
These contracts do far more than affect price. They shape risk, flexibility, transparency, and your overall experience throughout the project.
Quick answer
If your design is still evolving, Cost Plus can work, but the final cost is open ended unless you negotiate a cap.
If your drawings and specifications are fully complete and you want one firm number, Fixed Price can be a fit, but changes tend to be expensive.
For most custom homes and major renovations in Vancouver, Construction Management (CCDC 5B) offers the best balance: start flexible, then optionally add a Guaranteed Maximum Price (GMP) or converting to a Fixed Price once scope and pricing are clear.
The three core contract types
1. Cost-Plus
We’ll build it, you pay the actual cost, plus our fee.
Under a Cost Plus contract, you reimburse the builder for all actual construction costs, including labour, materials, trades, permits, and equipment. In addition to these costs, the builder charges an agreed fee, either as a percentage or a fixed amount.
Homeowners often appreciate Cost Plus because it allows projects to start before design is fully finished. It provides flexibility for changes and upgrades and offers transparent, open book invoicing.
However, there are important considerations. There is no hard cap on the final cost unless one is specifically negotiated. If the builder fee is percentage based, higher costs result in a higher fee. Budget control relies heavily on ongoing owner involvement and decision making.
Cost Plus is a good fit if you want to start while design is still evolving, value maximum flexibility, and are comfortable staying actively involved in budget decisions. It may not be the right choice if you need a firm total cost early, want minimal budget conversations, or prefer lower financial uncertainty.
2. Fixed Price
We agree on the price up front, and that’s what you pay.
With a Fixed Price contract, the builder commits to delivering a clearly defined scope of work for a single agreed amount. This structure offers strong cost certainty and is easy to understand, with most cost risk shifted to the builder.
What is often less visible is that Fixed Price contracts require very complete drawings and specifications. Builders typically include contingency and risk premiums, and changes after signing are usually expensive and can become contentious.
Allowances play a significant role. Many Fixed Price contracts include allowances for items such as cabinetry, plumbing fixtures, tile, and lighting. If your selections exceed the allowance, you pay the difference. Exclusions and assumptions can also affect the true cost. Items like site conditions, engineering, permits, utility upgrades, hazardous materials, or specialty finishes may be excluded or assumed and later appear as additional costs.
A Fixed Price contract is only as fixed as the scope. Incomplete drawings increase reliance on allowances, assumptions, and change orders.
This contract type works best when your drawings and specifications are complete, you want minimal cost variability, and you are unlikely to change scope once construction starts. It is less suitable if design decisions are still in progress or if you want full transparency into trade pricing and cost build-up.
3. Construction Management
Let’s plan it together first, then build it with options to lock in price later.
This is where CCDC 5B stands apart. CCDC 5B is a widely used, industry standard contract form developed by the Canadian Construction Documents Committee to clearly define roles, responsibilities, and risk in construction management projects.
Under this structure, the builder acts as the Construction Manager and holds the trade contracts (you still have one main point of accountability). Under CCDC 5B (as VPCM uses it), you still deal with one accountable lead for budget, schedule, quality, and coordination. The project begins on an actual cost plus fee basis.
Critically, CCDC 5B includes built in options to add a Guaranteed Maximum Price or convert to a Fixed Price once the scope is defined.
This approach is a strong fit if you want flexibility early, value collaboration and transparency, and want one accountable lead managing the budget, schedule and trades. It is less suitable if you want a single fixed number at contract signing, if you are not willing to invest time in pre-construction decisions and alignment or prefer to avoid any “open book” period, even early on.
How each works in practice (homeowner view)
With Cost Plus, you have one contract with the builder, the builder holds all trade contracts, monthly billing for actual costs plus a fee, and flexibility for scope changes. The cost risk remains largely with the owner.
With Fixed Price, you have one contract and one number. The builder controls trades and pricing, offering fewer financial surprises but less flexibility. Changes typically lead to change orders and price increases.
With Construction Management (CCDC 5B), you have one contract with the Construction Manager, who holds the trade contracts. A strong pre construction phase focuses on budgeting, scheduling, constructibility review, and value engineering. You start flexible and can later lock in pricing with a GMP or Fixed Price.
Why the GMP / Fixed Price option matters so much
This is the key homeowner advantage of CCDC 5B.
A Guaranteed Maximum Price is a cost cap with defined rules. If project costs exceed the GMP outside of approved changes, the Construction Manager absorbs the overage. If costs come in below, the treatment of savings depends on the contract. A GMP is optional and only applies if it’s added to the agreement.
Most Cost Plus contracts remain open ended for the entire project. CCDC 5B allows you to wait until drawings are 80-90% complete, major trades are priced, and unknowns are reduced before deciding whether to cap or fix the price.
This flexibility is especially valuable in custom homes and major renovations.
Risk, control, and certainty comparison
Which contract should you choose?
If you’re building a custom home or doing a major renovation, the “best” contract usually depends on one thing: how complete your design and selections are today.
Our general recommendation at VPCM is Construction Management (CCDC 5B), start with flexibility while design and selections are still evolving, use pre-construction to reduce unknowns with real pricing and planning, and add certainty later by capping cost with a GMP or converting to a fixed price when the scope is actually defined.
As a simple guideline, Fixed Price works best when drawings are complete and you want one number with minimal change. Cost Plus suits if you want to start fast and stay flexible, and you’re comfortable with more budget responsibility. CCDC 5B is ideal if you want collaboration and transparency now, with the option to lock in cost once the project is ready.
When each contract truly makes sense
Cost-Plus
Highly custom, fast-start projects
Owners comfortable with open-ended cost risk
Fixed Price
Well-defined scope
Minimal unknowns
Limited appetite for changes
CM 5B
Custom homes, major renovations
Owners who want collaboration, transparency, and optional cost caps
Projects where “lock it in later” makes more sense than “guess early”
The VPCM approach (why we prefer CM 5B)
At VPCM, we lead a structured pre construction phase that pressure tests budgets with real trade input, sequences schedules, reviews constructibility, and clarifies selections and assumptions. This allows homeowners to make informed decision about staying open-book or adding a GMP/fixed price.
We use CCDC 5B because it keeps everyone on the same side of the table, allows strong pre-construction leadership, avoids premature fixed pricing, and gives homeowners real options rather than false certainty. Under this contract, VPCM manages and holds the trade contracts.
Questions to ask before you sign
What’s included vs excluded in the price (and where are the assumptions listed)?
What allowances are included, and what happens if selections exceed them?
How are change orders priced and approved?
Who holds the trade contracts, and who is accountable for schedule and quality?
If there’s a GMP, what is included, and how are savings/overages handled?
Every project is different, so the best approach depends on your scope, timeline, and risk tolerance.
If you’re early in design, this decision is worth making now, before drawings are finalized and pricing hardens.
Next step
If you are planning a custom home or major renovation in Metro Vancouver, ask us for a contract fit walkthrough. We will help you choose the best structure based on your design maturity, risk tolerance, and timeline before you commit.
Schedule a free consultation to determine the best contract type for your project.