#1 ADU Contractor in Riverside County
Custom Builds by Horizon Remodeling
Need more space or searching for an ADU contractor near Riverside County? Horizon specializes in seamless home additions and custom ADU construction in Riverside County, from extra bedrooms to backyard cottages and detached units. As your trusted ADU contractor near Riverside County, we manage design, budgeting, permits, and material selection—ensuring every project meets city codes and your vision. Our promise: safety, satisfaction, and a smooth build from start to finish. Let’s turn your ADU and home expansion dreams into reality.
SERVICES WE OFFER
Room Additions
Sunroom Additions
Garages & Conversions
Extensions
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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.
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Riverside County’s ADU ordinance is the oldest of the four we serve — Ordinance 348, articles 19.802 through 19.808, adopted in 2023 — and in May 2025 the California Department of Housing and Community Development issued formal findings identifying eighteen provisions that do not comply with state law. Those include a height cap of one story or 16 feet, a junior ADU capped at 50 percent of the primary dwelling, a parking requirement for interior ADUs, and an owner-occupancy provision. State law preempts all of them.
This matters in a very practical way: a homeowner reading the county’s published ordinance would conclude they can build less than the law actually allows. Under current state law an agency cannot cap an ADU below 850 square feet of interior livable space, or 1,000 with more than one bedroom; detached height starts at 16 feet and rises to 18 within half a mile of qualifying transit, plus two feet to match a roof pitch; and owner-occupancy cannot be required for an ADU at all.
Riverside does run a strong pre-approved plan program. Its Permit Ready ADU set offers four free plans, from a 499 square foot studio to a 909 square foot two-bedroom, three of which fall under 750 square feet and therefore below the state impact fee threshold. The program excludes parcels in flood hazard or environmental constraint areas, so the first question on any site here is which map it sits on.
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 Riverside County ?
Horizon Construction & Remodeling builds ADUs as a licensed Class B general building contractor, CSLB #938230, bonded and insured, with more than 15 years of design-build work behind us.
Riverside County is the clearest example we work in of why it pays to have someone who reads the statute rather than the handout. The county’s published ordinance is out of date, the state has said so in writing, and a homeowner who takes the county document at face value will design a smaller unit than the law entitles them to. We design to state law and cite it, and we plan around the constraints that are real here — summer heat, wind design in the desert communities, and whether the parcel falls in a flood hazard or environmental constraint area that removes the pre-approved plan option.
The protections you keep either way: no owner-occupancy requirement for an ADU, no sprinkler retrofit triggered on the main house, and no impact fees on a unit of 750 square feet or less of interior livable space.
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ADU Contractor Services In Riverside County
ADU cities we serve in Riverside County
ADU Contractor in Riverside County FAQ
What is an ADU and why should I build one?
An ADU, or Accessory Dwelling Unit, is a secondary housing unit built on your property—like a backyard cottage, garage conversion, or in-law suite. Building an ADU with Horizon Remodeling allows you to expand your living space, create a rental income opportunity, or provide independent living space for family members.
How much does it cost to build an ADU in California?
The honest answer is that it depends on things we cannot know from a web page: the size and type of unit, whether it is a conversion or new detached construction, the site work and utility runs your lot needs, and the finish level you choose. What we can tell you is where the money goes and what the law protects you from. An ADU of 750 square feet or less of interior livable space is exempt from impact fees; school fees apply only above 500 square feet; and connection fees for a conversion or a junior ADU are limited, because the state does not treat those as a new residential use. Building an ADU also cannot trigger a fire sprinkler retrofit of your main house. Anyone quoting a firm price before seeing the parcel is guessing — we walk the property, confirm the utility and setback situation, and then give you a fixed scope and price you can hold us to.
One warning worth repeating: the CalHFA ADU grant program is closed, its funding fully allocated, and the agency itself warns that anyone offering to help you obtain an ADU grant is running a scam.
Do I need permits for an ADU in Riverside County?
Yes. An ADU always requires a building permit, filed with the Riverside County Department of Building and Safety through rivcoplus.org for unincorporated parcels, or with the city for a property inside a city. Approval is ministerial: 15 business days for a completeness determination, 60 days to approve or deny, no hearing. Be aware that the county’s published ADU ordinance has been formally identified by the state as containing provisions that conflict with current law, so what a handout says you may build and what the statute entitles you to build are not always the same. Horizon prepares the submittal to state standards and carries it through inspection.
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 Riverside County?
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 15 years of experience delivering high-quality ADU projects.
What are the benefits of hiring Horizon Remodeling for my ADU project?
By choosing Horizon Remodeling, you gain a partner with expertise in ADU design, permitting, and construction. We manage the entire process from start to finish, ensuring your ADU meets building codes, stays within budget, and is completed on schedule.
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?
Contact Horizon Remodeling to schedule a free consultation. We’ll assess your property, discuss your goals, provide design recommendations, and deliver a detailed estimate. From there, our team guides you step-by-step through every phase of your ADU project.
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