New Detached ADU in West Hollywood - Design, Permits and Build Under One Contract

Fast, Reliable New Detached ADU Across West Hollywood

A new detached ADU in West Hollywood typically runs $220,000-$480,000 all-in, from permit set through final inspection, depending on whether you build custom, modular, or prefab. Most projects take 8-14 months in this market, with permitting through WeHo’s Building & Safety Division adding 3-5 months due to the city’s unique Rent Stabilization Ordinance review layer. Call (424) 325-4322 to schedule your free estimate - we’ll bring a written price, not a callback promise.

Call (424) 325-4322

We’re familiar with West Hollywood’s 1.9 square miles of pre-1978 multifamily housing, the dingbat buildings along Fountain Avenue and Sweetzer Avenue, and the courtyard apartments near Santa Monica Boulevard. Our dispatch and scheduling are coordinated from our Los Angeles office, but our crews serve West Hollywood locally and understand the sequencing rules that catch out-of-area contractors. When you’re carving a new dwelling unit out of a rent-stabilized parcel, local permit fluency isn’t a bonus - it’s the difference between a buildable project and a rejected application.

Why Ellery ADU Studio Glendale Is West Hollywood’s Preferred New Detached ADU Company

We’ve designed, permitted, and built over 900 ADUs since 2015, the year California’s ADU laws shifted, and a significant share of those have been in West Hollywood’s dense multifamily core. Our clients here are property owners on Hayworth Avenue, Flores Street, and the bungalow courts near Melrose who needed a New Detached ADU team that understood the RSO implications before the first drawing was drafted.

Our response time to West Hollywood is same-week for initial site visits, with permit sets typically delivered within 6-8 weeks of contract signing. We don’t quote over the phone - Haven Standard Clause 1 requires a written price before any work starts, so we walk the property, document existing conditions with photos you receive, and return a line-item scope. No “call for a quote.” The price is on the page, in writing, before you decide.

What builds trust here is specificity. We know that WeHo’s Building & Safety Division requires soft-story retrofit compliance orders to be closed or properly sequenced before ADU permits issue. We know that RSO relocation obligations can add $15,000-$30,000 to a project’s soft costs if triggered. And we know that the urban heat island effect along Santa Monica Boulevard means even a 400-square-foot studio ADU needs mechanical ventilation and a mini-split system, not just a window unit. That’s the local knowledge that shows up in our permit sets, not just our conversation.

Our New Detached ADU Services in West Hollywood

Custom Built ADU

Custom built ADUs in West Hollywood start around $280,000 and run to $480,000+ for larger 2-bed units with upgraded finishes. On a small lot off Hayworth Avenue, our crew took a detached 1960s dingbat-adjacent carport structure and converted it into a custom 1-bed detached ADU while the main building already had an open soft-story retrofit compliance order with WeHo Building & Safety - we sequenced the retrofit permit ahead of the ADU permit so the structural work wasn’t invalidated. We framed with James Hardie siding and a Mighty Buildings panelized shell, then added a mini-split and ERV mechanical ventilation because the urban heat island on that block keeps even a small footprint warm. The owner kept the builder-grade melamine cabinets as-is but upgraded the countertops and swapped to a heat-pump water heater to avoid voiding the main home’s warranty. Custom builds let you make these tradeoffs intentionally, with every choice documented in the permit set before construction starts.

Prefab ADU Installation

Prefab ADU installation in West Hollywood typically ranges $220,000-$350,000, with faster site construction but the same 3-5 month WeHo permitting timeline. We specify and coordinate Abodu and Cover systems within our single-contract model, meaning the prefab manufacturer’s drawings are integrated into our permit set, not handed off as a separate package. This matters in West Hollywood because the RSO review requires square footage, bedroom count, and utility metering details to be locked at permit submission - changes mid-process trigger re-review. Our prefab clients receive the same Haven Standard protections: written price before work starts, documented photo record on every visit, and the 365-Day Done Right Promise.

Modular ADU

Modular ADUs in West Hollywood run $240,000-$380,000, occupying the middle ground between site-built and prefab. We work with Dvele and Mighty Buildings systems, coordinating factory fabrication with WeHo’s inspection schedule. The critical local consideration: modular units arrive on a truck, and West Hollywood’s narrow streets - especially the residential blocks between Fairfax and La Cienega - require crane placement and street closure permits that must be sequenced with the building permit itself. Our permit sets include these logistics drawings from day one, not as afterthoughts. Under Haven Standard Clause 5 (No Surprises), the scope is locked at signing; no door-side upsells, no scope creep.

Studio ADU & 1-Bed & 2-Bed ADU

Studio ADUs in West Hollywood typically start at $220,000, with 1-bed units at $260,000-$340,000 and 2-bed configurations at $320,000-$480,000. The 1-bed and 2-bed ADU formats are what most WeHo property owners actually need - the city’s RSO covers virtually every multifamily building built before 1978, so a “detached ADU” here almost always means carving a new, potentially rent-stabilized unit out of a pre-1978 parcel, not building on open land, since the city is 1.9 square miles of mostly pre-1978 multifamily and true single-family lots are rare. Bedroom count affects RSO relocation obligations, utility metering requirements, and whether the unit qualifies as “affordable housing” under state density bonus rules. We model these scenarios in our preliminary feasibility study, which is included with every free estimate.

Trusted Brands We Service in West Hollywood

We specify and coordinate prefab and modular systems from Abodu, Cover, Mighty Buildings, and James Hardie within our single-contract design-build model. For West Hollywood projects, we stock James Hardie siding and trim locally to avoid supply-chain delays on the narrow streets where delivery windows are tight. Our crews are fluent in Mighty Buildings’ panelized shell system, which we’ve used on multiple WeHo dingbat-adjacent conversions where crane access was limited and factory precision reduced on-site cutting. Every brand we specify is backed by the same Haven Standard documentation: written price before work starts, permit set as core product, and 365-Day Done Right Promise.

Common New Detached ADU Problems We See in West Hollywood Homes

• Filing a detached ADU permit before checking whether the host dingbat building has an open soft-story retrofit order. WeHo’s Building & Safety Division will reject or unwind the sequence, creating structural liability. The retrofit permit must precede or properly sequence with the ADU permit, and a contractor who skips this check will cost you months.
• Assuming the new detached unit escapes West Hollywood’s RSO. Any pre-1978 multifamily parcel can trigger rent-stabilization status and relocation obligations during build-out, unlike City of LA or Beverly Hills rules. We evaluate RSO exposure before the first drawing.
• Treating a detached garage conversion as a cosmetic job and skipping mechanical ventilation and mini-split cooling. WeHo’s extreme urban density and canyon-adjacent heat island make passive comfort unreliable even in small units. We specify ERV and mini-split on every project under 800 square feet.
• Upgrading builder-grade finishes without checking the main home’s warranty terms. In West Hollywood’s newer pockets - the small condo developments near Doheny Drive - swapping to a heat-pump water heater or upgrading electrical service can void the host building’s warranty if not coordinated with the original builder’s approved scope.

Pricing for New Detached ADU in West Hollywood, CA

We Also Serve Cities Near West Hollywood

Our crews work throughout the central LA basin, including West Hollywood and the surrounding cities of Beverly Hills, Studio City, North Hollywood, and Sherman Oaks. Each city has its own ADU ordinance nuances - Beverly Hills’ stricter design review, Studio City’s hillside grading requirements - and our permit sets are tailored to each jurisdiction’s specific code layer. We don’t template across cities.

FAQs - New Detached ADU in West Hollywood