Alhambra ADU Builder

Thinking about an ADU in Alhambra? Yellow River Construction Inc designs and builds detached ADUs, attached ADUs, garage conversions and JADUs, and manages the Alhambra permit from submittal to final. CSLB #1161539 (B — General Building, C-10 — Electrical). 中文服务。

Alhambra’s permit process: building permit only

Alhambra keeps the ADU process simple: an ADU requires a building permit, obtained by submitting for plan check with the Building Division through the city’s online Permit Portal. The Building Division routes the plans to each department that needs to review them, and the permit is issued once all approvals are in. The city’s zoning code (§23.22.040) also provides a 30-day review track for detached ADUs that use qualifying pre-approved plans, consistent with AB 1332.

Alhambra ADU standards (single-family lots)

  • Number: one ADU and one JADU on a lot with one existing or proposed single-family home.
  • Detached ADU: up to two stories and 25 feet tall, at least 5 feet eave-to-eave from other buildings, and no more than 1,200 sq ft.
  • Attached ADU: up to two stories and 25 feet; floor area up to 50% of the main house, or 850 sq ft (one bedroom or less) / 1,000 sq ft (more than one bedroom), whichever is greater.
  • Setbacks: at least 4 feet from side and rear property lines; exterior mechanical equipment (like a heat-pump condenser) at least 3 feet from any property line.
  • Design: on single-family lots the ADU must match the main house — same exterior materials, roof covering, colors and architectural details.
  • Parking: one space for a new ADU unless the lot is within one-half mile of public transit (bus stops included) — which covers much of Alhambra. Conversions need no added parking, and parking lost to a garage demolition does not have to be replaced.
  • Small-ADU exception: ADUs of 800 sq ft or less with 4-foot setbacks are exempt from the zone’s floor-area, lot-coverage and open-space limits.

The two-story allowance is a real opportunity in Alhambra: on a narrow lot, a compact two-story ADU can leave more yard than a sprawling single-story unit.

Matching the main house — what that means in practice

Because Alhambra requires the ADU to match the existing home on single-family lots, we start by documenting your house: roof pitch and material, stucco or siding texture, window style and trim. Our drawings call out matching materials so plan check doesn’t come back with design corrections. (On multifamily lots, the matching requirement does not apply when a city-preapproved plan is used.)

Multifamily lots

If you own a duplex or apartment building, Alhambra allows up to two detached ADUs with a proposed multi-unit building, or up to eight detached ADUs with an existing one (not exceeding the number of existing units), plus conversions of non-livable space in up to 25% of existing units. Detached ADUs on multifamily lots are capped at 850 sq ft (one bedroom or less) or 1,000 sq ft (more than one bedroom). These projects benefit most from a contractor who handles both building and electrical work, because the electrical service is often the limiting factor.

Pre-approved plans in Alhambra

Alhambra is a member of the San Gabriel Valley Council of Governments, whose regional pre-approved ADU plans program gives member cities access to a curated set of vendor-owned designs. YRC’s own designs are currently pending pre-approval in Rosemead and Monterey Park; any of them can be adapted and permitted in Alhambra as a regular ADU. Browse YRC plan designs.

Our Alhambra ADU process

  1. Lot check: zoning, setbacks, transit distance (parking), utilities and electrical capacity.
  2. Design to Alhambra’s standards, including matching materials.
  3. Permit Portal submittal and correction responses.
  4. Construction, inspections and final.

Timeline and free quote

State law requires a decision on a complete ADU application within 60 days. For permit fees, check with the City of Alhambra Building Division when you apply. Every lot is different, so we quote each project after a free lot check.

Free quote — send us your address and we’ll call you back within 24 hours. 免费报价。

Official Alhambra resources

Building in Alhambra?

Call (626) 556-3606 or request a free lot check. ← All ADU services

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