Detached ADU Construction
New freestanding units in the backyard or side yard, sited to respect oak root zones, slopes and four-foot setbacks. Suited to wider Westlake lots and estate parcels where privacy between households matters.
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Westlake Village ADU services
One team for the whole project: choosing the right unit type for your lot, drawing it, getting it approved by the agency that governs your parcel, and building it through final inspection.
All ADU services
New freestanding units in the backyard or side yard, sited to respect oak root zones, slopes and four-foot setbacks. Suited to wider Westlake lots and estate parcels where privacy between households matters.
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Additions that share a wall with your home but function independently, with a separate entrance, kitchen and bath. A strong fit where the backyard slopes or holds a pool or protected oak.
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Attached or detached garages turned into legal living units, reusing the slab and roof. City of Westlake Village homes may start from the County's pre-approved conversion plan when the garage fits.
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Units of up to 500 square feet created inside the existing house, with an efficiency kitchen and outside door. Usually the least construction of any ADU, and no impact fees apply.
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Second-story units built over a garage, keeping the yard intact on small or hillside lots. Requires structural engineering for the garage below and careful attention to height rules.
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Site preparation, permits, delivery planning and utility hookups for factory-built units. We look closely at crane access and gate logistics, which often decide whether prefab is practical.
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Added detached units, plus converted storage rooms and garages, on apartment and condo properties under current state law, phased so existing residents stay housed while work goes on.
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Site analysis, floor plans, HOA-ready elevations and full permit drawings, coordinated with structural, soils and energy consultants and drawn for the agency that governs your parcel.
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Jurisdiction checks, complete submittals and correction responses for the City of Westlake Village, Los Angeles County, Thousand Oaks or Ventura County, tracked against state review deadlines.
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Foundations, grading, retaining walls, sewer laterals, water lines, electrical service upgrades, wells, septic and fire sprinklers when the unit requires them.
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Compact kitchens and accessible bathrooms laid out for small floor plans, with plumbing runs, ventilation and electrical load planned before framing begins.
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The right ADU depends mostly on what the lot gives you. A flat tract lot with a two-car garage points toward a conversion. A hillside home on a tight pad points toward an addition or a unit over the garage. A large North Ranch, Lake Sherwood or Hidden Valley parcel opens the door to a detached guest house. A spare bedroom wing makes a junior ADU the quickest win.
We start every project by walking the property and asking who will live in the unit. Step-free living for a parent, durable finishes for a long-term tenant and a flexible plan for an adult child each lead to different layouts. Matching the unit type to both the site and the use is the most important decision in the project, and it is made before any drawings.

Splitting design, permitting and construction among different firms is common, and it is where many ADU projects lose time. Plans get drawn without a builder's input on cost, plan check comments go back and forth between parties, and the contractor inherits decisions it did not make. We keep the stages together so the people drawing the unit also know what it will take to build it.
That matters more in Westlake than in many places, because the permitting path changes by parcel. A home inside the City of Westlake Village goes through a City Zoning Clearance and then Los Angeles County plan check. Thousand Oaks and Ventura County parcels follow their own procedures. We handle whichever applies.
Below-grade and behind-the-wall work often decides the budget. Foundations on slopes, sewer lateral repairs, electrical service upgrades with Southern California Edison, water connections through the Las Virgenes Municipal Water District inside City limits, and wells and septic on rural parcels are all part of our scope.
Inside the unit, the kitchen and bathroom take the most planning. We size them to the occupant, keep plumbing walls shared where possible and plan electrical capacity for all-electric appliances. The result is a unit that works for its first occupant and adapts to the next.
We work across the Westlake area, not just inside one city's limits. That includes First Neighborhood, Three Springs and Lakeshore in the City of Westlake Village; Westlake Island, where parcels split between two cities; Southshore Hills and North Ranch in Thousand Oaks; and Lake Sherwood and Hidden Valley in unincorporated Ventura County. The services below apply in all of them, adjusted for each agency's rules.
FAQs
Both. We handle design, permits and construction as one project, so cost and buildability are considered from the first sketch.
Junior ADUs and garage conversions usually cost the least because they reuse existing structure. Detached and above-garage units cost more, and site conditions like slope and utility distance can shift the comparison.
Yes. We can review existing plans, adapt them for your parcel's rules, handle permits and build. For prefab units, we manage the site work, permits and installation.
Yes. North Ranch, Southshore Hills and other Ventura County parts of Westlake are permitted by the City of Thousand Oaks, and we prepare plans and submittals for that city's process.

ADU consultation
Tell us about your property and which ADU type interests you. We reply to every request by phone or email within 24 hours and help you narrow the options.