Temecula and Murrieta's Premier ADU Builder
Stephens Brothers Construction has been the leading ADU contractor in the Temecula and Murrieta area since 2011. With more guest houses, ADUs, and casitas completed than any other general contractor in the region, they have built a well-earned reputation as the go-to accessory dwelling unit builder for Southern California homeowners.
ADUs have grown increasingly popular across California, thanks to recent changes in housing regulations that have opened up new opportunities for homeowners. Whether the goal is generating passive rental income, increasing property value, housing elderly family members in a comfortable and private space, or providing a transitional living arrangement for adult children, Stephens Brothers Construction delivers tailored solutions for every need.
Their full range of services includes:
- Detached and attached ADUs
- Junior ADUs (JADUs)
- Guest homes and casitas
- Garage conversion contractor services
- In-law suite builder services
- Granny flat builder services
- Rental units
- Room additions and second story additions
They serve homeowners throughout Temecula, Murrieta, Menifee, Wildomar, Lake Elsinore, and surrounding areas in Riverside County.
A Complete, One-Stop ADU Building Process
Stephens Brothers Construction simplifies the entire ADU journey from start to finish. Their streamlined approach covers every phase: meet, plan, permit, build, and enjoy. They work with a dedicated architect and engineer on every project, offering both custom designs tailored to specific lots and needs, as well as pre-approved plan sets available through local cities and counties.
As an experienced detached ADU builder and JADU contractor, they are deeply familiar with the permitting requirements across multiple jurisdictions. The permit process involves numerous departments — including land use, building and safety, waste, health, and fire — and Stephens Brothers Construction navigates all of it on behalf of their clients. Permit timelines typically require at least five months to clear all departments involved.
Once permits are issued, smaller ADUs are generally completed in 10 to 12 weeks, while larger builds typically take 12 to 16 weeks. All exterior finishes are designed to match the existing home, including roofing, stucco, siding, paint, and windows. Interior finishes such as flooring, tile, and cabinetry are fully customizable to each client's preferences.
Key project details to be aware of include:
- Detached ADU build costs typically range from $300 to $350 per square foot
- Architectural plans, engineering, and Title 24 processing generally run $10,000 to $15,000
- City and county fees vary by project size and jurisdiction, starting around $6,000 and up
- School impact fees apply to new construction over 500 sq. ft.
- Development Impact Fees apply to units over 750 sq. ft.
- All ADUs require a solar system to offset energy usage for the new square footage
- No deposit is required — payment schedules are milestone-based on completed work
Licensed, On-Site, and Hands-On Every Day
Stephens Brothers Construction holds General Contractor License #964759 and takes a genuinely hands-on approach to every project. The owners are on-site daily from the first estimate through final inspection. They complete the majority of work in-house and directly oversee specialty subcontractors for trades such as plumbing, electrical, HVAC, and roofing.
They are also an approved contractor with Cross Country Mortgage, offering clients access to multiple financing options for ADU construction, including FHA 203(k) Rehabilitation Loans, conventional construction loans, and cash-out refinance or HELOC options.
For homeowners in the Temecula Valley and surrounding Riverside County communities looking for a trusted backyard cottage builder or casita specialist, Stephens Brothers Construction offers the experience, local knowledge, and dedicated service to bring any ADU project to life.