# ADU Builder & Home Additions in Hidden Hills, CA [Browser-friendly HTML version](https://www.remodelyourvibe.com/website-guide/pages/services/adus-additions/hidden-hills/index) Source: https://www.remodelyourvibe.com/services/adus-additions/hidden-hills Last modified: 2026-09-24T00:00:00.000Z Text part: 1 of 1 [Full website text index](https://www.remodelyourvibe.com/llms-full.txt) | [Services by city](https://www.remodelyourvibe.com/llms/services-by-city-006.txt) | [Previous page](https://www.remodelyourvibe.com/llms/pages/services/adus-additions/agoura-hills/index.txt) | [Next page](https://www.remodelyourvibe.com/llms/pages/services/adus-additions/thousand-oaks/index.txt) --- Image: Open-plan living room and kitchen with polished concrete floors 1. [Home](https://www.remodelyourvibe.com/) 1. [Services](https://www.remodelyourvibe.com/services) 1. [ADUs & Additions](https://www.remodelyourvibe.com/services/adus-additions) 1. Hidden Hills Design · Permit · Build ### ADUs & Additions in Hidden Hills Detached ADUs, garage conversions and additions, from plans to move-in. [Book a Consultation](https://www.remodelyourvibe.com/contact-us) [Call 818-300-2393](tel:+18183002393) #### Built for Hidden Hills Homes Two approvals govern every project inside the gates: the City's and the Hidden Hills Community Association's. The Architectural Committee reviews exterior work, and the City will not issue a permit without that sign-off. We build the design package to satisfy both at once, and we plan logistics around gate access, the bridle trails and neighbors who live very close to the work. One-acre minimum building sites, mostly flat to gently rolling, with barns, arenas and long private driveways and enough rear yard to plan a pool, guest structure and equestrian improvements as one project. We are a design-build team, which means the people who draw your project are the people who build it. Design, engineering, permits and construction run through one project manager and our own crews, so nothing gets lost in a handoff between a salesperson and a subcontractor. We are licensed, bonded and insured, [CSLB license #1119054](https://www.cslb.ca.gov/OnlineServices/CheckLicenseII/LicenseDetail.aspx?LicNum=1119054) . Permits in Hidden Hills: Permits come from the City of Hidden Hills Building and Safety Department, whose plan check, permit issuance and inspection services are provided under contract by Transtech. The City does not issue a building permit until the Hidden Hills Community Association Architectural Committee has approved the exterior design. HHCA oversees architectural standards for exterior work, and the municipal code specifically requires perimeter fences to meet HHCA approval. The one-acre minimum building site rule constrains where structures can go, and bridle trails run through the community, with the zoning code restricting fencing along them. Most of the city is mapped Very High Fire Hazard Severity Zone under CAL FIRE's 2025 Local Responsibility Area maps, and the rest is mostly High or Moderate. Permit details checked September 2026 against [City of Hidden Hills](https://hiddenhills.gov/city-departments/building-and-safety-planning/information/) , [Hidden Hills Municipal Code](https://library.municode.com/ca/hidden_hills/codes/code_of_ordinances?nodeId=TIT5LAUSDE_CH2ZO_ARTCZO_5-2C-2LOSICO) and [LA County](https://file.lacounty.gov/SDSInter/bos/supdocs/204888.pdf) . Rules change, so we confirm them again for your parcel. What We Build - HHCA Architectural Committee submittals - Gate and private-road logistics planning - Bridle-trail-aware site planning - Detached ADUs, ground-up - Garage conversions to living space - Junior ADUs within the main house - Room additions and bump-outs - Second-story additions - Full kitchens and bathrooms in the ADU - Separate utility metering where required - Private entries, patios and landscaping - Plans, engineering and city submittals - Title 24 energy compliance Local Conditions #### What to Know in Hidden Hills These local conditions change the scope, the schedule and the budget. 01 Bridle trails run through the community and can affect where a pool, guest house or perimeter fence is placed. 02 Construction access runs through staffed gates on privately maintained roads, so deliveries, crane picks and haul-off have to be scheduled and staged rather than improvised. 03 Rolling terrain and expansive clay soils mean pool shells, sport courts and detached structures often need deepened footings and engineered subsurface drainage. 04 Wildland-adjacent frontage brings defensible-space obligations that influence exterior materials and the planting plan around outdoor living areas. Areas we serve in Hidden Hills:Ashley Ridge RoadLong Valley RoadRound Meadow RoadJed Smith RoadSpring Valley Road Investment #### What It Costs in Hidden Hills Real Southern California price ranges, not teaser numbers. ##### Detached ADU $150,000 to $400,000+ What moves it: square footage, finish level, utility runs, and site access; garage conversions typically run well below a ground-up detached build ##### Garage conversion ADU $80,000 to $180,000 What moves it: whether the existing slab and framing meet current code, how far utilities have to run, and the finish level of the kitchen and bathroom ##### Plans, drawings and permit management $4,500 to $25,000+ What moves it: project type and size, whether structural engineering, Title 24 or a soils report is required, and how many jurisdictions or review bodies are involved Your lot, access and finishes set the price. We walk the site, then show you where every dollar goes. [Get a line-item price for your Hidden Hills property](https://www.remodelyourvibe.com/contact-us) The Process #### How We Work in Hidden Hills 01 ##### Feasibility We check lot size, setbacks, utilities and access to confirm what your property will actually support. 02 ##### Design & 3D Layout, elevations and finishes, modeled in 3D so you approve the unit before submittal. 03 ##### Plans & Permits We prepare the full drawing set, handle engineering and Title 24, and manage the city submittal and corrections. In Hidden Hills that submittal goes to City of Hidden Hills Building and Safety Department. 04 ##### Foundation & Framing Site prep, foundation, framing and dry-in by our own crews. 05 ##### Systems & Finishes Electrical, plumbing, HVAC, insulation, then kitchen, bath and interior finishes. 06 ##### Final Inspection We pass final inspection, walk the unit with you and hand over the keys. Questions #### What Hidden Hills Homeowners Ask Who issues the permits for this work in Hidden Hills? City of Hidden Hills Building and Safety Department. Permits come from the City of Hidden Hills Building and Safety Department, whose plan check, permit issuance and inspection services are provided under contract by Transtech. The City does not issue a building permit until the Hidden Hills Community Association Architectural Committee has approved the exterior design. HHCA oversees architectural standards for exterior work, and the municipal code specifically requires perimeter fences to meet HHCA approval. The one-acre minimum building site rule constrains where structures can go, and bridle trails run through the community, with the zoning code restricting fencing along them. Most of the city is mapped Very High Fire Hazard Severity Zone under CAL FIRE's 2025 Local Responsibility Area maps, and the rest is mostly High or Moderate. We prepare the drawings, make the submittal and handle plan-check corrections ourselves, so you are not the one chasing plan check. What makes building in Hidden Hills different? One-acre minimum building sites, mostly flat to gently rolling, with barns, arenas and long private driveways and enough rear yard to plan a pool, guest structure and equestrian improvements as one project. One local condition that shapes the work: Bridle trails run through the community and can affect where a pool, guest house or perimeter fence is placed. Which parts of Hidden Hills do you work in? All of it, including Ashley Ridge Road, Long Valley Road, Round Meadow Road and Jed Smith Road. Our crews run every job out of our Cahuenga Pass base in Los Angeles, with our own people on site. What does an ADU or addition cost in Hidden Hills? Detached ADU: generally $150,000 to $400,000+ across Southern California. What moves it is square footage, finish level, utility runs, and site access; garage conversions typically run well below a ground-up detached build. We give line-item pricing after seeing the site rather than quoting a number over the phone. How long does an ADU take start to finish? Plan a realistic year. Design and engineering typically take one to three months, city plan check and corrections add several more, and construction usually runs four to eight months depending on size and site access. Is a garage conversion cheaper than a detached ADU? Usually yes, and often substantially, because the foundation, walls and roof already exist. The trade-offs are that you lose the garage, and older slabs and framing sometimes need upgrading to meet current code. Can I rent the ADU out? California ADU law is designed to allow long-term rental, and an ADU is one of the few ways to add rentable square footage to a single-family lot. Short-term rental rules vary by city, so confirm your local ordinance before counting on that income. Do you handle the permits? Yes. Plans, engineering, Title 24 and the city submittal are all handled in-house, including responding to plan-check corrections. That is a service we sell on its own, so it is not something we hand off. #### More Services in Hidden Hills [Pool & Spa Remodeling in Hidden Hills](https://www.remodelyourvibe.com/services/swimming-pool-spa/hidden-hills) [Backyard & Outdoor Living in Hidden Hills](https://www.remodelyourvibe.com/services/exterior-remodeling/hidden-hills) [Kitchen, Bath & Interior Remodeling in Hidden Hills](https://www.remodelyourvibe.com/services/interior-remodeling/hidden-hills) [Plans, Permits & Design in Hidden Hills](https://www.remodelyourvibe.com/services/plans-permits/hidden-hills) [Everything we build in Hidden Hills](https://www.remodelyourvibe.com/service-areas/hidden-hills) #### ADUs & Additions Nearby [ADUs & Additions in Calabasas](https://www.remodelyourvibe.com/services/adus-additions/calabasas) [ADUs & Additions in Agoura Hills](https://www.remodelyourvibe.com/services/adus-additions/agoura-hills) [ADUs & Additions in Woodland Hills](https://www.remodelyourvibe.com/services/adus-additions/woodland-hills) [ADUs & Additions in West Hills](https://www.remodelyourvibe.com/services/adus-additions/west-hills) [ADUs & Additions in Canoga Park](https://www.remodelyourvibe.com/services/adus-additions/canoga-park) Planning Guides #### Before You Build in Hidden Hills Costs, materials and process notes from our own projects. [Luxury Landscaping Ideas for Calabasas Homes Calabasas and Hidden Hills properties demand exceptional landscaping. Explore design ideas that match the area's luxury standards and create private estate environments. Read guide](https://www.remodelyourvibe.com/articles/luxury-landscaping-calabasas) [ADU Cost Breakdown by Size in Los Angeles A detached ADU in Los Angeles runs $150,000 to $400,000-plus. Here is the real cost broken down by unit size, with the soft costs, utility work and finish decisions that move the number. Read guide](https://www.remodelyourvibe.com/articles/adu-cost-breakdown-by-size-los-angeles) [Garage Conversion to ADU: The Step-by-Step Build A garage conversion runs $80,000 to $180,000 in Southern California. Here is the real sequence, from slab testing and plan check to the raised floor, the mini-split and final sign-off. Read guide](https://www.remodelyourvibe.com/articles/garage-conversion-adu-step-by-step) [ADU Rental Income Math in the San Fernando Valley A one-bedroom ADU in the San Fernando Valley rents for roughly $2,100 to $2,900 a month. Here is the honest arithmetic on payback, carrying costs and what the unit adds to the property. Read guide](https://www.remodelyourvibe.com/articles/adu-rental-income-san-fernando-valley) #### Planning an ADU in Hidden Hills? Sit down with your project manager and get an accurate estimate. We call you back within one business day. [Book a Consultation](https://www.remodelyourvibe.com/contact-us) [818-300-2393](tel:+18183002393) Licensed, bonded & insured · [CSLB license #1119054](https://www.cslb.ca.gov/OnlineServices/CheckLicenseII/LicenseDetail.aspx?LicNum=1119054) --- End of text part 1 of 1. This page is complete.