Lic #1007864 · Santa Clara County · General Contracting
Custom ADU & Additions
Detached ADUs, room additions, garage conversions, and JADUs — permitted, engineered, and built to estate standards.
Luxury remodels and custom ADUs in one of Silicon Valley's wealthiest family communities — where lot values reward estate-level craftsmanship.
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 Los Altos and across Santa Clara 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.
Los Altos Community Development guides projects through planning and building review with close attention to lot coverage and neighborhood scale. We remodel the city's classic ranch homes, build ADUs that respect its single-story streetscapes, and deliver downtown-adjacent commercial work without disrupting neighboring businesses.
What's included in Los Altos
Recent adus & additions work



The process in Los Altos
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 Los Altos — 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 · Los Altos
