Accessory Dwelling Units

ADU Builders in Tarzana

Permitted ADUs, garage conversions and junior ADUs. Detached or two-story, 400–1,200 sq ft designed and built across Tarzana and across the San Fernando Valley

ADU builders and garage-conversion specialists in Tarzana and the Los Angeles area. An accessory dwelling unit is one of the smartest ways to add space to your property — house a growing family, give aging parents their own place, generate rental income, or add long-term value without ever moving.

We design and permit every type of ADU (Accessory Dwelling Units), detached backyard cottages, garage conversions, junior ADUs and two-story units from 400 to 1,200 sq ft throughout Tarzana and the wider San Fernando Valley. Each one is fully permitted, structurally engineered, and finished to match your existing home so it looks like it was always part of the property.

One in-house team handles design, permits, structural, MEP rough-ins, framing, finishes and inspections — see our six-step process.

What it is

ADUs — Accessory Dwelling Units

Independent secondary living spaces on the same lot as a primary home — backyard cottages, garage conversions, in-law suites and detached studios — each with their own kitchen, bathroom and entry. California’s permissive ADU laws make these the fastest way to add usable square footage and long-term rental income on most residential lots.

Detached 1- or 2-bedroom backyard cottages, 400–1,200 sq ft
Garage-to-living-space conversions
Junior ADUs (JADU) carved out of the primary home
Two-story ADUs where lot coverage allows

What it is

Room Additions

Expansions of the existing home rather than separate units — bumping out a kitchen, adding a master suite, popping the roof for a second story, attaching a sunroom or family room. Footprint, structural work, MEP and finish carpentry are handled in-place so the new space flows naturally with what’s already there.

Primary-suite additions with walk-in closet + en-suite
Second-story builds over a single-story home
Family-room, sunroom and great-room bump-outs
Home-office and bonus-room expansions

Our process

We handle the full path end-to-end: design + structural engineering, City of LA / county permitting, foundation, framing, MEP rough-in, drywall, finish carpentry and final inspections. Typical timelines once permits issue: 12–20 weeks for a detached ADU, 8–14 weeks for a room addition, depending on scope, structural complexity and inspector schedule.

Independent units

ADUs — Accessory Dwelling Units

Detached cottages, garage conversions and JADUs — each with their own kitchen, bath and entry.

Modern Oak ADUDetached oak-clad backyard cottage with floor-to-ceiling glass and concrete patio

White Plaster Suite ADUDetached stucco ADU with sliding glass wall, bedroom suite and outdoor kitchenette

Garden Cottage ADUDetached stucco guest cottage with shed roof framed by drought-tolerant landscaping

Open-Plan ADU InteriorLight-oak kitchen island and living room under beamed ceiling with steel garden doors

In-place expansions

Room Additions

Master suites, family rooms, sunrooms and second-story builds attached to the existing home.

Second-Story AdditionSecond-story addition with vertical wood cladding and floor-to-ceiling upper windows

Primary Suite AdditionVaulted primary-bedroom addition with beamed ceiling, plaster fireplace and arched window seat

Formal Living AdditionFront sitting room with stone fireplace, window seat, crown molding and white boucle seating

Primary Bedroom AdditionCoffered-ceiling primary bedroom with plantation shutters and dark walnut furnishings

Family Room AdditionFamily room with custom walnut media wall, built-in shelving and tall flanking windows

Great Room Bump-OutVaulted living + dining great-room opening to kitchen with black-frame casement windows

Living Room Bump-OutTray ceiling, brass chandelier, window-seat bump-out, wall-mounted TV on walnut console

Sitting Room AdditionCozy addition with curved bay window, masonry fireplace and floating walnut reading shelf

Guest Bedroom AdditionGuest bedroom with black-frame windows over hillside, cube storage and accent seating

ADU FAQs

What homeowners ask before building an accessory dwelling unit in Tarzana and LA.

What's the difference between an ADU and a room addition?

An ADU (Accessory Dwelling Unit) is a permitted, self-contained living unit with its own kitchen, bath and entry — used for family, rental income, or a home office. A room addition expands the existing home (master suite, second story, bump-out). We build both.

How long does an ADU take in Los Angeles?

Most detached ADUs run 5–8 months from permit-ready to final inspection. Attached and garage-conversion ADUs can be faster (3–6 months). Site conditions and city plan-check times are the biggest variables.

What does an ADU cost in Tarzana?

Our ADUs typically run $75,000–$400,000 depending on square footage, finish level, foundation type and whether it's a garage conversion or new construction. We give a written line-item estimate after the design phase.

Do I need an architect?

For most ADUs we cover the design in-house and bring in a licensed architect / structural engineer where the city plan-check requires stamped drawings. Either way it's coordinated through us.

Can I rent out my ADU?

Yes — that's one of the most common reasons homeowners build one. Because an ADU is self-contained with its own kitchen, bath and private entry, it can be rented as a long-term unit, while local rules govern short-term rentals. We design the layout and utilities with rental use in mind from day one.

Recent Work

Built. Finished. Loved.

A look at recent kitchen, bathroom, room-addition and whole-home transformations from our Tarzana design-build team.

Open-plan whole-home remodel in modern California style — Master in Design, Tarzana CA

Designer Visualizations

Ready to start your project?

Tell us about it — no obligation, no pressure. We respond within one business day.

Every ADU we build is permitted through LADBS (or your local jurisdiction), with Master in Design managing the full process. Title 24, CALGreen, and structural plans are all in scope.