How we deliver
ADU Design-Build
An ADU needs a designer, an engineer, a permit, trades and inspections. The question is who holds all of that together. In design-build, one team does, and cost is part of the design from the start.
Two ways to deliver an ADU
Both can produce a good building. They differ in who is responsible for what, and when you learn what it costs.
Design-bid-build
- You hire a designer, who draws the ADU.
- The finished drawings go out to contractors for bids.
- You pick a contractor and sign a second agreement.
- Real construction pricing arrives after design is done.
- Gaps between drawings and field conditions become your problem to referee.
Design-build
- One team is responsible for design and construction.
- Construction pricing informs the design as it develops.
- Engineering, permits and utilities are coordinated by the same team.
- You have one point of contact.
- You give up a competitive bid on the finished drawings.
Why design-build suits ADUs
ADUs are small buildings with an unusual number of constraints: city size and height limits, setbacks, parking, owner occupancy rules, utility capacity and a house and household right next to the work. Most of the budget risk sits in the site, not the finishes: a long sewer run, a panel upgrade, difficult access. A design drawn without that knowledge often has to be redrawn once someone prices it. Design-build puts the person who will price and build the ADU in the room while the design is still flexible.
Who it is for
- Homeowners who want one accountable team rather than managing a designer, engineer and contractor separately.
- Anyone whose property has real constraints, where early pricing and site knowledge change the design.
- Families with a firm budget who would rather design to it than cut back afterward.
If you already have a designer you trust and want competitive bids on finished drawings, design-bid-build may suit you better. We will tell you that honestly.
Property considerations come first
Our design-build process starts with the lot, not a floor plan. The feasibility review checks zoning, lot size, setbacks, existing coverage, parking, access and utilities against your city's current rules. Only when we know which ADU types the property can support does design start. That is the main difference between a design-build process built for ADUs and one that treats an ADU like any other remodel.
From property evaluation to finished construction
- Feasibility: which ADU types fit the lot, the main constraints and the likely cost drivers.
- Site evaluation: measurements, utility locations, access and anything the public records do not show.
- Design: layout, exterior and site plan, with construction pricing checked as decisions are made.
- Engineering where required: structural, and any civil or geotechnical work the site calls for, coordinated by us.
- Permitting: preparing the city's ADU application and building permit, answering review comments. See ADU permitting.
- Pre-construction planning: schedule, utility coordination, site protection and how the household lives through the work.
- Construction: managed day to day, with changes documented and priced before they happen.
- Inspections and completion: each stage inspected, then final inspection and the city's sign-off for occupancy.
The full process page explains what you decide at each step.
Design considerations in a design-build process
Because pricing and design move together, trade-offs are visible early. Moving a bathroom next to the kitchen to share a drain wall, choosing a simple roof form, or placing the unit to shorten the sewer run are all design choices with direct cost effects. We still design for light, privacy, storage and a good fit with the house. Read more on ADU design.
Construction considerations
One team means one schedule. The trades that affect each other, such as foundation, plumbing and electrical, are sequenced by the same team that coordinated the design, so questions in the field get answered quickly. It also means one party is responsible when something between the drawings and the field needs to be solved.
Cost factors and budget control
Design-build does not change what an ADU costs to build. It changes when you find out. The drivers are the same: ADU type, size, foundation, utility runs, access, finishes, engineering and fees. The difference is that they are priced as the design develops, with allowances and contingency set out clearly. See ADU budget planning and the ADU cost guide.
Contractor questions worth asking any team
Whoever you hire, ask how they handle changes, who is on site day to day, and how they coordinate utilities and inspections. Utah requires a contractor's license number on permit applications, contracts and bids when a license is required, so ask for it and check it with the state's Division of Professional Licensing. Some cities limit owner-building for ADUs: Murray does not allow it, and Millcreek says homes under LLC ownership or rental properties need a general contractor.
Related services
Design-build covers every ADU type we plan: detached, attached, garage conversions, basement and internal units. See all types on ADU construction.
Questions about ADU design-build
What is ADU design-build?
It is a way of delivering the project in which one team is responsible for both designing and building the ADU. The homeowner has one point of contact from the first property review to the final inspection, and the people pricing the construction are involved while the design is still being shaped.
Is design-build more expensive than hiring an architect and bidding it out?
Not inherently. Design-bid-build lets you compare contractor bids on a finished design, which can create price competition. Design-build gives up that bid comparison in exchange for pricing during design, which helps avoid designing something that later has to be cut back. The better value depends on how well either process is run.
Can I bring my own plans to a design-build team?
Often, yes. We review existing plans against the property and your city's current rules before pricing them. If the plans need changes to fit the lot or the code, we explain why and what it would take.
Who pulls the permits on a design-build ADU?
The builder usually applies for the building permit, and the homeowner signs the documents only an owner can sign, such as owner occupancy affidavits. Some cities restrict owner-building: Murray does not allow it for ADUs, and Millcreek says homes under LLC ownership or rental properties need a general contractor.
What do I still decide myself?
The things that are yours: the goals for the unit, the budget, the layout and finish choices, and approval at each stage before the next one starts. Design-build moves coordination off your plate, not the decisions.