Lic #1007864 · Contra Costa County · General Contracting
Custom ADU & Additions
Detached ADUs, room additions, garage conversions, and JADUs — permitted, engineered, and built to estate standards.
The East Bay's retail capital — Broadway Plaza-caliber tenant improvements, striping, and luxury home upgrades in the surrounding hills.
California's ADU laws have unlocked enormous property value, and JMG builds accessory dwelling units and home additions that match the main residence — not prefab afterthoughts. From Los Altos to San Ramon, our ADUs and additions command premium rents and appraisals.
In Walnut Creek and across Contra Costa County, JMG delivers adus & additions under California Contractor's License #1007864 — permitted, inspected, and personally overseen by owner Jerry Guinn. We manage the entire lifecycle: feasibility, design, permitting, utilities, and construction, delivering turnkey units and seamless additions ready for family or income.
Walnut Creek pairs a high-traffic downtown retail core with hillside neighborhoods in Saranap and Northgate. Retail refreshes downtown demand night work and zero downtime; hillside homes demand fire-safe materials and defensible-space detailing. JMG crews handle both on one schedule.
What's included in Walnut Creek
Recent adus & additions work
The process in Walnut Creek
Private Consultation
Walk the property with owner Jerry Guinn. Honest scope, realistic timeline, and a written line-item estimate — free.
Design & 3D Rendering
See the finished project in photorealistic 3D before a single wall comes down. Finishes get locked before demo day.
Permits, Handled
Plans, submittals, corrections, and city or county coordination under CA License #1007864. You sign — we run the process.
Build & Final Inspection
Sixteen in-house trades on one schedule, one accountable owner. Inspection passed, walkthrough done, keys in hand.
ADUs & Additions in Walnut Creek — FAQ
Feasibility check on your lot, design and 3D rendering, permit submittal, then construction. State law guarantees most ADUs a 60-day ministerial review — we prepare complete packages so that clock never stops.
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ADUs & Additions · Walnut Creek