ADU Construction in Laguna Niguel
Serving 92677 and Dana Point, Laguna Beach, San Juan Capistrano
The ADU question in Laguna Niguel is answered by the shape of the lot more than by anything else. Terraced parcels give with one hand and take with the other: there is often a flat pad or an under-house volume nobody uses, and there is also a slope that makes a conventional detached building an engineering exercise. The most successful projects here start by finding the space the property already has before considering the space it would have to create.
Real projects. Real prices.
73 finished remodels published with their final price — nothing hidden.
What our finished LA work actually cost: 27 kitchens ran $23k–$84k, median $50k; 28 bathrooms $28k–$105k, median $38k; 17 whole-home remodels $36k–$440k, median $150k. Real final prices from our own job records, not estimates.
$30,000 A full-length double vanity under twin lit mirrors, with herringbone mosaic shower niches.
$34,800 White uppers over warm grey shaker lowers, white quartz, and a stainless chimney hood.
$72,000 White shaker cabinetry against a deep teal backsplash, with an island under a stainless hood.
$95,000 Two glazed-tile showers, one olive and one aqua, with brass fittings and taupe shaker vanities.
$150,000 A cobalt glass-tile backsplash with marble-look slab baths in brushed brass.
$440,000 Stone-look tile bathrooms with freestanding tubs, under an exposed beam ceiling.
Second units on a hillside master plan
Look inside the house before looking at the yard
Many of these plans contain a usable candidate already — a level with its own entry, a large downstairs room, an over-scaled garage. Converting existing volume avoids the foundation and retaining costs a hillside detached unit carries, and it is the first option worth pricing.
What a slope adds to a detached build
Where a freestanding unit is genuinely the right answer, the slope brings foundations, retaining and access into the budget in a way a flat lot never does. Those are knowable costs, and knowing them early is what keeps a good idea from becoming a disappointed one.
Privacy between two households on one terrace
On stepped lots, buildings look down on each other. Siting, window placement and landscape have to be designed so both dwellings have somewhere private to sit and neither is overlooked from above — which is a design problem the plan solves, not a fence.
Filing a complete package with the city
The Building & Safety Division reviews the application through the city's permit centre, and a second dwelling requires site, utility, structural and energy documentation that all agree. Preparing them as one coordinated set is the practical route to a short review.
Where the water goes on a stepped site
Adding a building to a terraced lot changes how rain moves across it, and on hillside parcels that is not a detail. Roof water, surface water from new hard landscape and anything shed by a retaining structure all have to be collected and taken somewhere deliberate rather than allowed to find its own way toward a neighbour or a slope. Designing the drainage at the same time as the building — rather than treating it as a groundworks afterthought — is both good engineering and good neighbourliness, and it is one of the things a careful reviewer will look for on a hillside application here.
Written by Onn Cohen-Meguri, founder and designer at Design Onn Point — 12+ years in business, 1,200+ finished Los Angeles projects. CSLB #1133368.
Pricing in Laguna Niguel
Market estimate, not our own project data.
Talk to Onn about your Laguna Niguel adu construction.
Free consult, no obligation. Onn reads every inquiry personally — and aims to reply within one business day.
From the blog
ADU vs Garage Conversion: Which Adds More Value in LA?
Side-by-side comparison of detached ADUs and garage conversions for LA homeowners — costs, timelines, ROI, rental income, and which one adds more value on resale.
LA County Kitchen Permits Explained (2026 Edition)
When you need a permit for an LA kitchen remodel, how LADBS plan-check works, typical timelines, and how to avoid the common mistakes.