Hermosa Beach ADU contractor.

It's the question everyone asks first, and the honest answer is: it depends on what you build. A garage-conversion ADU, a detached new-build ADU, and a junior ADU are different projects with different price tags — and on a thirty-foot-wide lot, staging, access, and site logistics move the number in ways an inland quote never captures. We don't quote a figure before we've walked the lot. On the free consult you get an honest range, and we design backward from your real budget.

Two layers of rules shape every Hermosa ADU. The first is small-lot geometry: height is capped at thirty feet in the zones where it applies, and lots of 2,100 square feet or less are allowed 70% lot coverage — the provision that keeps the city's smallest parcels buildable. The second is the Coastal Zone: much of Hermosa sits inside it, and a Coastal Development Permit may be required — including where a project increases height by more than 10% or affects coastal resources. The CDP is not a stricter building permit; it's a separate approval with its own criteria, and treating it as a formality at the end of design is how a Hermosa project loses a season. There's no city-wide architectural review board — the binding constraints are the zoning code, the Local Coastal Program, and the lot itself.

Hermosa runs concurrent plan review — Planning, Building, and Public Works examine a submittal at the same time rather than passing it down a line. That's genuinely faster when the package is complete, and unforgiving when it isn't, because every department raises its corrections at once. The Building Division is at 1315 Valley Drive, first floor, and the permit counter runs 7:00–8:30am and 4:30–6:00pm, Monday to Thursday — two narrow windows, not a full day, and planning submittals around them is part of running the job. The city doesn't publish a standard plan-check turnaround, so we get the current answer from the department directly and schedule honestly. Building is (310) 318-0235; Planning is (310) 318-0242.

Hermosa is barely a mile deep, so effectively the whole city carries full coastal exposure. We specify stainless and marine-grade hardware on anything exposed as a default, not an upgrade. On Valley and Hills lots, excavation or new foundations warrant a geotechnical report, and the May–June marine layer narrows the window for exterior coatings — a scheduling fact we build into the calendar rather than discover in it. On walk-street lots, staging and deliveries need a plan of their own; most walk-street builds need a parking plan filed with the city, and we handle it.

The expensive ADU failures happen in the handoff — a designer draws a unit the coverage math or the Coastal Zone can't carry, and the owner pays to find out. Because the people who draw your ADU are the people who build it, that gap doesn't exist: one contract, one schedule, one point of accountability. Our published Hermosa project is the Raymond Estate, and the same team serves the rest of Hermosa Beach and the South Bay — Manhattan Beach, Redondo Beach, and beyond — under one CSLB Class A/B license, since 1978.

Start with a free consultation — and bring the survey, because on a thirty-foot lot it decides more than the wish list does.