ADUs & Additions in Monrovia

City of Monrovia Community Development Department, Building Division. Building permits, plan check and inspections run through the Building Division of the Community Development Department. In the Residential Foothill, Residential Estate and Residential Low-Density zones, a Hillside Development Permit is also required for a new house, or for earth movement with a footprint over 500 square feet, whenever the work involves five feet or more of cut or fill or a retaining wall six feet or taller, with swimming pools and basements excluded. New homes and two-story additions that are not already under a Hillside Development Permit go through neighborhood compatibility design review before the Development Review Committee, while single-story second units and single-story accessory structures in side or rear yards are exempt. Alterations to a designated landmark or a contributing property in the Wild Rose Tract or North Encinitas historic districts need a Certificate of Appropriateness from the Historic Preservation Commission, which must hold its public meeting no later than 50 days after a completed application is received. We prepare the drawings, make the submittal and handle plan-check corrections ourselves, so you are not the one chasing plan check.

Minimum lot size follows the zone: 7,500 square feet in Residential Low-Density, 20,000 in Residential Estate, and 15,000 in Residential Foothill, where lots in a development must also average more than an acre. On every residential lot a pool stays out of the front yard and at least five feet from the side and rear property lines. One local condition that shapes the work: In the Residential Foothill zone, where a pad sits beside a slope of three feet or more, structures must be set back from the side and rear pad edge by one third of the slope height, up to 15 feet for the single-story portion, and a second story sits a full 15 feet back. A retaining wall that extends the pad is limited to three feet unless a house, garage or other permitted structure screens it from the street and neighboring parcels.

All of it, including Old Town, Wild Rose Tract and North Encinitas. 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.