ADU Construction & Home Additions in Concord, California
DevCo Building Enterprises is a licensed general contractor serving homeowners and property investors in Concord, California, specializing in ADU construction, home additions, ADU garage conversions, and seismic retrofitting. ADU projects in Concord typically range from $150,000 to $350,000 for detached builds, and from $80,000 to $180,000 for garage conversions, with most projects taking 6 to 12 months from permit to completion. Owner Devin Grimes leads every project personally. Call (925) 448-2123 for a free Concord estimate.
Services We Provide in Concord
ADU Construction
Detached cottages, backyard ADUs, new ground-up builds
ADU Additions
Garage conversions, above-garage additions, existing structure conversions
Seismic Retrofitting
EBB, ESS, and EMR state program certified
Home Additions
Room additions, master suites, second-story additions
Why Concord, CA Homeowners Choose DevCo
DevCo is not a franchise or a national ADU company operating in Concord remotely. We are a Pacheco-based contractor - 15 minutes from most Concord neighborhoods - with owner Devin Grimes on every project. We know Contra Costa County permit departments, city setback rules, and local subcontractor relationships because we have been working in this area, not calling into it.
Concord is the largest city in Contra Costa County with approximately 129,000 residents. DevCo is based in Pacheco - on the border of Concord - giving us the fastest response times of any contractor in this market. We know Concord's building department, the Ygnacio Valley corridor neighborhoods, and the soil conditions around the Clayton Valley foothills where foundation considerations differ from flat areas near the waterfront.
Featured Projects
A look at recent ADU builds, additions, and retrofits completed across Concord, CA.
Real Projects. Real Results.
Frequently Asked Questions
ADU construction in Concord typically ranges from $150,000 to $350,000 for detached builds depending on size, site conditions, and finish level. Garage conversion ADUs are typically 30 to 50 percent less expensive. Concord Building Division processes ADU applications. DevCo provides free on-site estimates with detailed line-item breakdowns.
Yes. All ADU construction in Concord requires a building permit. California state law requires the city to process complete applications within 60 days. Concord Building Division processes ADU applications. Plan check typically 6 to 10 weeks. Concord adopted pre-approved ADU plan program in 2022 to speed approvals. City of Concord, 1950 Parkside Drive.. DevCo handles all permit applications, plan submissions, and city coordination on every project.
DevCo Building Enterprises is a licensed general contractor based in Pacheco, CA, serving Concord and surrounding Contra Costa communities. Owner Devin Grimes leads every project from permit to final walkthrough. DevCo is also an approved contractor for California's EBB, ESS, and EMR seismic programs.
From permit submittal to final inspection, most ADU projects in Concord take 6 to 12 months. Permitting adds 6 to 16 weeks depending on plan complexity. DevCo manages the full permit process and provides milestone updates throughout the build.
Yes. The City of Concord launched a pre-approved ADU plan program in 2022 that allows homeowners to use city-approved plan sets for common ADU types, significantly reducing plan check time. DevCo is familiar with this program and can discuss whether your project qualifies during your free estimate.
Get a Free Concord Estimate
Call (925) 448-2123 or fill out the estimate form at devco.llc/contact. We respond within one business day and schedule on-site consultations within 48 to 72 hours for Concord and surrounding Contra Costa communities.