#1 ADU Contractor in Running Springs
Custom Builds by Horizon Remodeling
Horizon Construction & Remodeling Inc. handles ADU projects in Running Springs from initial design through final inspection, coordinating every trade involved so you have one point of contact for the entire build. Because Running Springs sits in unincorporated San Bernardino County territory, permits run through County Land Use Services, Building and Safety, and mountain-region requirements shape the work from the start: foundations here typically call for an 18-inch frost line depth, roof and deck framing is sized for snow load, and any exit under a downslope eave steeper than 4:12 needs protection from sliding snow and ice. We manage design, budgeting, permitting, and material selection with all of that in mind.
Services We Offer
How Our ADU Process Works
When it comes to enhancing your living space, room additions combined with Accessory Dwelling Unit (ADU) construction offer unparalleled versatility and value. These projects not only increase square footage but also provide additional living accommodations, whether for extended family, rental income, or work-from-home setups, making them a popular choice for homeowners seeking to maximize their property’s potential. According to California’s Department of Housing and Community Development, ADUs are a key solution to expanding housing options in urban and suburban neighborhoods.
Read More →
Working with an adu contractor in Running Springs means navigating a permit process that runs through San Bernardino County Land Use Services, Building and Safety, because Running Springs is unincorporated county territory rather than an incorporated city. The governing ADU law sits in California Government Code sections 66310 through 66342, updated in 2024 and again on January 1, 2026. Under that framework, square footage is now measured as interior livable space, an agency has 15 business days to determine whether an application is complete, and 60 days to approve or deny it. Approval is ministerial, meaning no public hearing and no discretionary design review.
San Bernardino County adopted Development Code Chapter 84.36 at the Board of Supervisors on January 13, 2026, making it the most current county ADU ordinance among the areas we serve. The published standards permit an ADU between 200 and 1,200 square feet, a junior ADU up to 500 square feet, 25 feet of height for an attached unit and 18 feet for a detached one with two additional feet allowed to match an existing roof pitch, and four-foot side and rear setbacks with five feet of separation between detached structures. Two provisions stand apart from coastal county rules: two ADUs are allowed per lot, and properties of five acres or more may add three units total.
Sewer access determines feasibility on many parcels before anything else is decided. Connection is required when a sewer line runs within 200 feet of the property line, with that distance increasing by 100 feet for each additional dwelling unit. Where that threshold is not met, the project goes on septic or advanced treatment. We bring Environmental Health into the conversation before a plan is drawn.
The mountain setting adds structural requirements that do not apply in the valley. At roughly 6,080 feet, Running Springs falls within the county Mountain Region, so foundations are built to an 18-inch frost line depth, roofs and decks are engineered for snow load, and any exit positioned under a downslope eave steeper than 4:12 must be protected from sliding snow and ice. These are not optional upgrades; they are baseline design conditions for any new structure here.
The character of the existing housing stock shapes where a detached unit can realistically sit. Running Springs grew lot by lot from the 1920s onward, when highway access opened the old Hunsaker Flats logging country to cabin development, and the homes that followed across Smiley Park, Fredalba, and the Snow Valley area tend to be compact one- or two-story cabins on sloping lots, with steep roofs, galley kitchens, and entry and parking arranged around the grade. That topography determines not only placement but how far utilities have to run, which directly affects project cost and timeline.
Other Remodeling Services We Offer
A modern kitchen adds functionality, comfort, and lasting value to your home. At Horizon Construction & Remodeling, our kitchen remodeling experts bring fresh ideas and professional project management tailored to your unique needs. From layout design to material selection, we prioritize delivering a high-standard kitchen that’s both beautiful and energy-efficient — enhancing the way you cook, gather, and live every day.
Whether you envision a classic Southern California pool or a fully customized backyard oasis, Horizon Construction & Remodeling delivers the highest level of quality and service. Our comprehensive pool design and remodeling services cover everything from layout and decking to built-in BBQs and final touches like landscaping. Let Horizon be your trusted partner in transforming your backyard into the perfect outdoor retreat.
If you are planning a complete bathroom remodel or simply want to change your tub, shower, update your plumbing fixtures, or make the space more efficient, our team at Horizon will help you through the process with expert advice, professional craftsmanship, and affordable options with beautiful results. Learn more about our bathroom remodeling services.
Transform your space with our expert interior work services. We offer a comprehensive range of solutions — from space planning and custom design to the selection of high-quality finishes and materials. Our team of experienced professionals works closely with you to create a space that’s both functional and stylish, tailored to your unique needs, goals, and budget. Whether you’re updating a single room or overhauling your entire interior, we bring precision, creativity, and craftsmanship to every project.
At Horizon, we believe your home is more than just four walls — it’s where life happens. It’s the place you relax, gather with family and friends, and create lasting memories. That’s why we offer a full range of exterior work services designed to elevate your outdoor living space. From patios and hardscaping to custom decks and exterior renovations, we help turn your vision into a dream yard that complements your lifestyle and enhances curb appeal.
At Horizon Construction & Remodeling, our expert team includes a dedicated design and planning division that works hand-in-hand with licensed architects and structural engineers. We take care of everything — from detailed plans and blueprints to securing city permits — so you don’t have to deal with delays or red tape. Our goal is to streamline the process and provide a fully approved set of documents that aligns with both your vision and city regulations, saving you time and stress.
Why Choose Horizon Remodeling As Your ADU Contractor in Running Springs ?
Horizon Construction and Remodeling is a licensed Class B general building contractor, bonded, with more than 15 years of design-build work behind us. We handle ADU projects in Running Springs from initial planning through the final county inspection, keeping the plan, the permit process, and the construction under one roof. Because Running Springs sits in unincorporated San Bernardino County territory, permits run through San Bernardino County Land Use Services, Building and Safety rather than a city hall, and the feasibility questions come first: sewer or septic, percolation, well access, fire hazard zone classification, and which county region the parcel falls in.
Running Springs sits in the county Mountain Region at roughly 6,080 feet, and that elevation shapes every part of the structural work. Foundations are built to an 18-inch frost depth, roofs and decks are sized for snow load, and any exit under a downslope eave steeper than 4:12 needs protection from sliding snow and ice. Those requirements apply equally to an ADU added beside one of the compact cabins that have filled in areas like Smiley Park, Fredalba, Hunsaker Flats, and the Snow Valley area since the highway improvements of the 1920s first opened this mountain community to development.
California state law also provides certain protections that follow the parcel regardless of location: no owner-occupancy requirement applies to an ADU, building one does not trigger a sprinkler retrofit of the main house, and there are no impact fees on a unit with 750 square feet or less of interior livable space. We answer all of these questions early so the design work that follows reflects what the site, the county, and the state actually require.
Schedule a Consultation
ADU Contractor Services in Running Springs
View Our ADU Contractor Areas of Service
ADU Contractor in Running Springs FAQ
What is an ADU and why should I build one?
An accessory dwelling unit is a self-contained secondary home on your existing property, built as a detached cottage, a garage conversion, or an attached in-law suite. In Running Springs, where compact mountain cabins on sloping lots have defined the housing stock since the highway era opened Hunsaker Flats to development, an ADU lets you add rental income, house a family member, or simply gain more usable space without leaving the property.
How much does it cost to build an ADU in California?
What an ADU costs in Running Springs depends on details no contractor can assess from a distance: whether you are converting existing square footage or building a detached unit from scratch, how much site work a sloping mountain lot requires, how far utility runs need to travel, and what finish level you choose. What the law does make predictable is where certain costs are capped. A unit at or under 750 square feet of livable interior space is exempt from impact fees. School fees apply only when the unit exceeds 500 square feet. Connection fees for a junior ADU or a garage conversion are limited because state law does not treat those as a new residential use, and adding an ADU cannot force a fire sprinkler retrofit of your existing cabin.
Permitting in Running Springs goes through San Bernardino County Land Use Services, Building and Safety, since this is unincorporated county territory. That process takes time, and any contractor quoting a firm number before walking your parcel and confirming setbacks, utility access, and the frost line and snow load requirements the county Mountain Region enforces is working from guesswork, not a real scope. We visit the site, work through those details, and give you a fixed price you can hold us to. One point worth stating plainly: the CalHFA ADU grant program is closed and fully allocated, and the agency itself warns that anyone claiming they can obtain that grant money for you is running a scam.
Do I need permits for an ADU in Running Springs?
Yes, every ADU requires a building permit. Because Running Springs is unincorporated county territory rather than an incorporated city, applications go to San Bernardino County Land Use Services, Building and Safety, and the county’s own process already reflects state timelines of 15 business days for a completeness determination and 60 days to approve or deny. On properties served by a septic system or a private well, Environmental Health joins the review, and the sewer proximity rule applies wherever a sewer line falls within 200 feet of the property line, making connection mandatory. Horizon manages the submittal, the corrections, and the inspections from start to finish.
How long does ADU construction take with Horizon Remodeling?
Most ADU construction projects take between 4 to 8 months from design to completion, depending on scope and permit approvals. Horizon Remodeling prioritizes efficient timelines while maintaining quality workmanship.
What types of ADUs can Horizon Remodeling build?
We specialize in building detached ADUs, attached ADUs, garage conversions, backyard cottages, and junior ADUs (JADUs). Our team can help you choose the right ADU style for your property and goals.
Can I build a detached ADU on my property in Running Springs?
Yes, if your property meets California zoning and space requirements. Horizon Remodeling will assess your site, secure the necessary permits, and build a fully detached ADU tailored to your preferences.
Is Horizon Remodeling licensed to build ADUs in my area?
Yes, Horizon Remodeling is fully licensed, bonded, and insured to build ADUs throughout Orange County and surrounding areas. We have over 18 years of experience delivering high-quality ADU projects.
What are the benefits of hiring Horizon Remodeling for my ADU project?
Horizon Construction & Remodeling Inc. manages every phase of your ADU project, from design and permitting through finished construction, coordinating each trade so the work meets building codes, fits the budget, and stays on schedule. In Running Springs, where permits run through San Bernardino County Land Use Services rather than a city hall, that coordination matters from the first submittal.
Does Horizon Remodeling handle ADU design and permitting?
Absolutely! Horizon Remodeling provides complete ADU design services, including architectural plans and 3D renderings. We also handle city permits and inspections, streamlining your project and reducing stress.
How do I get started on an ADU with Horizon Remodeling?
Reach out to Horizon Construction & Remodeling Inc. to schedule a free consultation, where we assess your Running Springs property, talk through your goals, share design recommendations suited to mountain conditions like snow load and frost depth, and deliver a detailed estimate covering every phase of your ADU project.
Explore More in Running Springs
Horizon is a licensed Class B general building contractor serving Running Springs and the surrounding Orange County communities.
Other Services in Running Springs
ADU Contractors Nearby
Related Posts About ADU
