Design-Build vs Design-Bid-Build: Which Fits a Whidbey Island Home?
Design-build puts the design and the construction of your house under one contract with one company. Design-bid-build splits them in two. You hire a designer to draw the plans. Builders then bid on the finished set, and you sign a second contract with one of them.
Design-build suits owners who want the price worked out alongside the design and one team to answer for the result. Design-bid-build suits owners who already have an architect they trust, or who want several builders to price the same plans. Either method can build a new house or rework an old one on Whidbey Island. As a design-build contractor based in Langley, we also build from an architect’s finished set.
What is the difference between design-build and design-bid-build?
The national design-build association calls the single contract for design and construction the fundamental difference. In every other delivery method, it says, design and construction sit under separate contracts.
Federal contracting rules define design-build as design and construction combined in a single contract with one contractor. Washington’s own public works law defines it the same way. The federal rules call design-bid-build the traditional method, where design and construction are sequential and contracted for separately.
For a house, that changes who answers to you for what. Under one contract, the company that drew the plans also builds them. Under two, your designer and your builder each hold a separate contract with you.
How does design-bid-build work for a house in Island County?
Design-bid-build runs one phase after the other. You hire an architect or a home designer to draw the house. Your designer’s drawings then form the core of the permit set.
Builders bid once the plans are done, and the bids set the construction price. If the bids come in over your budget, you can add money or cut scope. Cutting scope sends the plans back to the designer, and then builders price the new set.
Once you pick a builder, construction follows the drawings. If the site and the plans disagree, the builder goes back to the designer. A fix that changes the work comes to you as a change order to approve. You sit between two contracts while the answer gets worked out.
How does design-build work for a house in Island County?
With design-build, one company carries the job from the first visit to the finished house. We design in-house, or we work from your architect’s set. A licensed engineer stamps what the plans require, and we coordinate that work. On a custom home on raw land, we also do the site work with our own equipment.
Pricing runs alongside the design. Our estimating study prices a full materials list with local vendors, then adds labor and work orders. You see a clear bottom line before construction starts. The national design-build association lists earlier knowledge of firm costs among the method’s benefits.
We plan the energy code package as we design and prepare the permit set. During construction, the team that drew the plans builds them, and we schedule the licensed trades. We build one home at a time, so the same design-builder stays with your project through every phase.
Do you need an architect to design a house in Washington?
Not for a single-family home. Under Washington’s architect licensing law, anyone may draw the plans for a residential building of up to four dwelling units. Hiring an architect is your call. The same law does not affect construction by contractors registered with the state.
Engineering still applies. A licensed engineer stamps whatever the plans require. Island County’s design table also flags topographic effects, so wind speed-up over hills, bluffs and ridges becomes a design factor. Confirm with the county what your design needs.
What does Island County want in the permit set either way?
Before Island County accepts a permit submittal, it wants a site registration and septic design, plus an approved access permit. It also wants an address and a water availability verification. Without them, the county will not accept the submittal.
A qualified septic designer completes the septic design, and the Health department reviews it. With us, you hire the septic designer, and we plan the site work around the design. State law also makes a permit applicant for a house show an adequate water supply for its intended use. The submittal needs a completed Washington State Energy Code worksheet too.
In design-build, we submit the permit set, and the county reviews it. In design-bid-build, agree up front on who gathers each piece.
Our Island County building permit guide covers each item. If you are starting from raw land, see how we build on your land.
How do the two methods compare side by side?
| Question | Design-build | Design-bid-build |
|---|---|---|
| How many contracts? | One, for design and construction | Two: one for design, one for construction |
| Who designs the house? | The design-builder | Your architect or designer, hired first |
| When do you pick the builder? | At the start, before design | After the plans are finished and bid |
| When do you learn the price? | As the design develops | When the bids come in |
| Who prices changes and drawing gaps? | The team that drew the plans | The builder, with the designer on a separate contract |
| Who do you call about a problem? | The design-builder | The builder for the work, the designer for the drawings |
The house and its lot drive the price under either method. The method changes when you learn it and who answers for the plans. Our guide to custom home costs on Whidbey Island covers market numbers.
When does design-bid-build or your own architect make sense?
Design-bid-build is a sound choice when you already have an architect you trust or a design you love. It also fits when you want several builders to price one finished set side by side. Some owners also like a designer who works only for them. That designer can check the builder’s work against the drawings.
With design-build, the designer and the builder sit on one team. If you want a separate voice checking the builder, hire your own architect. We build from an architect’s finished set too, and we coordinate the engineering it needs.
How do you choose between design-build and design-bid-build?
- You already have plans or an architect. Bid the set, or bring it to one builder to price and build.
- You want one contract and one call. Design-build fits that.
- You want several bids on the same plans. Design-bid-build fits that.
- You own raw land. The septic design and water verification come before the permit submittal. One team for design and site work can plan around both.
- You are adding on. For a home addition, the tie-in to the old house is the hard part. Design-build lets the people who price that tie-in draw it too.
- You are remodeling an older house. On a remodel of an older island home, we start with as-built drawings of the house as it stands.
Whichever method you pick, ask each builder how they price a plan. Ask what happens when the drawings and the site disagree.
Is design-build the right fit for your island project?
Culver Built is a design-build contractor based in Langley on South Whidbey Island. We design in-house or build from your architect’s set, with more than 30 years of building experience behind the work. See how our design-build process runs, or call or text (360) 544-9027 for a free estimate.