ADUs & Additions in Glendora

City of Glendora Community Development Department, Building and Safety Division. Building permits are issued by the Building and Safety Division of the Community Development Department at 116 East Foothill Boulevard, and land use and permit applications are filed through the city's Civic Access portal. Under Municipal Code Section 21.04.030, parcels with an average slope of ten percent or more follow hillside development standards: where more than 150 cubic yards of grading is involved, a development plan must be approved before a grading or building permit is issued; grading is prohibited where natural slopes exceed 35 percent; lot coverage, which counts impervious surface, steps down from 25 percent to 5 percent as average slope rises, with pool and spa water surface excluded but pool decking counted; and retaining walls visible from a public right-of-way are limited to six feet. Alterations to buildings in the city's one designated historic district, a residential neighborhood near the Glendora Village, are reviewed by the Planning Commission and require a Certificate of Appropriateness. Ordinance 2099, adopted September 8, 2026, updated the city's accessory dwelling unit, junior ADU and SB 9 unit rules for consistency with state law. We prepare the drawings, make the submittal and handle plan-check corrections ourselves, so you are not the one chasing plan check.

Across most of the flat, non-hillside city, the Community Plan's Low/Medium Density designation describes typical lots of 7,500 to 8,500 square feet in the R-1 and E-3 zones. The Low Density areas that form the transition toward the hillsides allow lots of 10,500 to 30,000 square feet in the E-5, E-6 and E-7 estate zones, and the Hillside Very Low Residential designation, paired with the RHR zone and the largest estate zones, calls for lots of at least one acre. One local condition that shapes the work: CAL FIRE's local responsibility area map dated March 24, 2025 places the foothill streets along the city's northern edge, Easley Canyon Road among them, and parts of the South Hills in the Very High Fire Hazard Severity Zone, with High zone on some blocks just below the foothills. The municipal code describes the city's fire hazard zone as large natural growths of chaparral exposed to Santa Ana winds, with steep terrain that makes firefighting access difficult and generally lower water pressure.

All of it, including Glendora Village, Alosta, Glendora Foothills and Easley Canyon. Our crews run every job out of our Cahuenga Pass base in Los Angeles, with our own people on site.

Detached ADU: generally $150,000 to $400,000+ across Southern California. What moves it is square footage, finish level, utility runs, and site access; garage conversions typically run well below a ground-up detached build. We give line-item pricing after seeing the site rather than quoting a number over the phone.

Plan a realistic year. Design and engineering typically take one to three months, city plan check and corrections add several more, and construction usually runs four to eight months depending on size and site access.

Usually yes, and often substantially, because the foundation, walls and roof already exist. The trade-offs are that you lose the garage, and older slabs and framing sometimes need upgrading to meet current code.

California ADU law is designed to allow long-term rental, and an ADU is one of the few ways to add rentable square footage to a single-family lot. Short-term rental rules vary by city, so confirm your local ordinance before counting on that income.

Yes. Plans, engineering, Title 24 and the city submittal are all handled in-house, including responding to plan-check corrections. That is a service we sell on its own, so it is not something we hand off.