Home Remodeling, ADUs & Additions in San Martin
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Our Services in San Martin
Backyard ADUs, garage conversions and junior ADUsBathroom Remodeling in San Martin
Primary suites, hall baths and accessible bathroomsKitchen Remodeling in San Martin
Open layouts, islands, structural and system upgradesHome Additions in San Martin
Single-story additions and second storiesNew Home Construction in San Martin
Custom homes and teardown rebuilds
San Martin General Contractor for ADUs, Additions and Remodels
Axiom Renovation (CA Lic. #1105006) builds ADUs, additions, remodels, pools and outdoor projects in San Martin, the rural unincorporated community between Morgan Hill and Gilroy. Santa Clara County handles planning and building permits here.
Most San Martin lots are rural residential, often on septic and wells, so utilities and County Environmental Health clearance are a big part of planning an ADU or addition.
What We Build in San Martin
- ADUs: detached, attached and junior ADUs, plus garage conversions
- Home additions and second story additions
- New custom homes, including tear-down and rebuild
- Kitchen and bathroom remodels and whole-home renovations
- Outdoor living: pools and spas, outdoor kitchens, pavers and hardscape, and artificial turf, lawns and landscaping
See finished work in our portfolio.
San Martin ADU Rules at a Glance
- Under current County rules, a legal lot can have an ADU and a JADU. The County is updating its ADU ordinance in late 2026 and early 2027, and state law applies where the two conflict.
- Detached ADUs can be up to 1,200 sq ft, plus an attached garage or carport up to 400 sq ft. Attached ADU size depends on the main home’s size. JADUs can be up to 500 sq ft.
- Side and rear setbacks are 4 ft, and a detached ADU must be at least 6 ft from the main home.
- One parking space is generally required for an ADU, with exemptions, and none for a JADU.
- The main home must already have building site approval before an ADU permit is submitted.
- The County offers free pre-approved plans: an 800 sq ft two-bedroom and a 1,200 sq ft three-bedroom, outside the Wildland-Urban Interface and hazard zones.
Sources: Santa Clara County ADU and pre-approved ADU pages; County Zoning Ordinance 4.10.015.
Rules change often, so we confirm the current standards for your parcel during the site assessment.
Other San Martin Rules That Affect Your Project
- Septic and wells: an ADU on septic needs Environmental Health clearance before the building permit, including a recent septic pumper report and a site plan showing the system and water supply.
- Fences: in rural districts, fences can be up to 6 ft within 20 ft of a street and up to 8 ft elsewhere.
- Wildfire: the County enforces the 2025 California Wildland-Urban Interface Code.
- Permits: normal County building permit processing takes about 4 to 6 weeks.
Getting Permits in San Martin
Santa Clara County accepts applications through its Public Permit Portal. The San Martin Planning Advisory Committee advises the County on major projects.
We Also Work Near San Martin
We also build in nearby Morgan Hill, Gilroy, San Jose, and across the Bay Area. See all of our service areas.
Frequently Asked Questions
Who issues permits in San Martin?
San Martin is unincorporated, so Santa Clara County handles planning and building permits.
Can I build an ADU on a septic lot in San Martin?
Often yes, but you need County Environmental Health clearance for the septic system before the building permit.
How big can a detached ADU be in San Martin?
Under current County rules, a detached ADU can be up to 1,200 sq ft, plus an attached garage or carport up to 400 sq ft.
Does Santa Clara County offer free ADU plans?
Yes. The County offers free pre-approved plans for an 800 sq ft two-bedroom and a 1,200 sq ft three-bedroom ADU.