#1 ADU Contractor in Santa Ana
Custom Builds by Horizon Remodeling
Horizon Construction & Remodeling Inc. builds accessory dwelling units for homeowners across Santa Ana, handling design coordination, permitting, material selection, and construction under one general contractor. Many of the city’s single-family lots in neighborhoods like Floral Park and French Park sit within designated historic districts, where any new structure may require a Certificate of Appropriateness before a building permit is issued through the City of Santa Ana Building Safety Division, and we walk you through that process from the start. Scope and site conditions determine how long a project takes and what it costs.
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.
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Working as an adu contractor in Santa Ana means navigating a set of rules that are both statewide and deeply local. California law, updated effective January 1, 2026, now measures square footage as interior livable space and requires the city to determine application completeness within 15 business days and issue an approval or denial within 60. That approval is ministerial, meaning no public hearing and no discretionary design review stands between a qualifying application and a permit decision. Those applications move through the City of Santa Ana Building Safety Division, part of the city’s Planning and Building Agency.
State law also sets a floor of protections that apply to every parcel. A local agency cannot cap an ADU below 850 square feet of interior livable space, or 1,000 square feet for a unit with more than one bedroom. Side and rear setbacks cannot exceed four feet, owner-occupancy cannot be required, and building the unit cannot trigger a fire sprinkler retrofit of the main house. Units of 750 square feet or less carry no impact fees.
Santa Ana’s housing stock adds its own layer of complexity. Downtown-adjacent tracts were largely built out before World War II, leaving a mix of Craftsman and Spanish Colonial Revival cottages, while postwar ranch homes filled the outlying neighborhoods through the 1950s and 1960s. That single-story pattern shapes setback calculations, utility routing, and whether a detached build or a garage conversion makes more sense on a given lot. We walk every parcel before drawing anything.
Historic districts in areas like Floral Park and French Park require a Certificate of Appropriateness reviewed against the Secretary of the Interior’s Standards before alterations can proceed. We account for that review in the project schedule from the start, so it does not become a surprise late in the process.
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 Santa Ana ?
ADU Contractor in Santa Ana
Horizon Construction and Remodeling is a licensed and bonded Class B general building contractor that has been building ADUs since 2009. Santa Ana’s older tracts, including the pre-war Craftsman and Spanish Colonial Revival cottages near downtown and the postwar ranch homes in areas like Washington Square and Heninger Park, present real site constraints, and we account for those from the first sketch forward. A detached ADU is a complete small house: foundation, framing, roof, electrical service, plumbing, kitchen, and bathroom, added to a lot that already carries a primary residence.
Permits in Santa Ana run through the City’s Building Safety Division, part of the Planning and Building Agency. In historic districts such as Floral Park and French Park, alterations also require a Certificate of Appropriateness reviewed against the Secretary of the Interior’s Standards, and we prepare that submittal alongside the building permit rather than treating it as an afterthought.
Because one team handles design, permitting, and construction, the decisions made on paper stay consistent through the build. Specialty trade work is performed by appropriately licensed subcontractors we coordinate directly.
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ADU Contractor Services in Santa Ana
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ADU Contractor in Santa Ana 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 backyard cottage, a converted garage, or an attached in-law suite. Working with Horizon Construction and Remodeling on an ADU in Santa Ana lets you add rental income, house extended family, or simply gain usable living space on a lot that is already yours.
How much does it cost to build an ADU in California?
What an ADU Actually Costs in Santa Ana
Pricing an ADU before anyone has walked your lot is guesswork, and we will not do it. The real number depends on whether you are converting an existing structure or building a detached unit from scratch, how much site work your parcel requires, how far utility runs need to travel, and the finish level you choose. What we can explain clearly is where state law draws the line on fees. A unit at or under 750 square feet of livable space is exempt from impact fees. School fees only apply once a unit exceeds 500 square feet. Connection fees for a garage conversion or a junior ADU are limited because state law does not treat those as a new residential use, and building an ADU cannot force a fire-sprinkler retrofit on your existing home.
Santa Ana’s permit process runs through the City of Santa Ana Building Safety Division, and for properties inside a designated historic district such as Floral Park or French Park, a Certificate of Appropriateness is required before construction begins. That review is measured against the Secretary of the Interior’s Standards, which means design choices matter in ways they do not on a standard postwar ranch lot. We confirm setbacks, utility conditions, and any historic overlay requirements before quoting a fixed scope and 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 has warned that anyone offering to help you obtain that grant is running a scam.
Do I need permits for an ADU in Santa Ana?
An ADU always requires a building permit, but state law makes approval ministerial rather than discretionary, meaning no hearing and no design review board. Applications in Santa Ana go to the City of Santa Ana Building Safety Division, part of the city’s Planning and Building Agency. Under state law the agency has 15 business days to confirm completeness and 60 days to approve or deny, and a pre-approved plan shortens that window to 30 days. Horizon prepares and submits the full package and follows it through every 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 Santa Ana?
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. handles ADU design, permitting, and construction as a single coordinated project, managing each phase so your build meets code requirements and stays within budget. In Santa Ana neighborhoods like Floral Park or French Park, that includes navigating historic district review alongside the City of Santa Ana Building Safety Division.
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 Santa Ana property, talk through your goals, and deliver a detailed estimate covering every phase of your ADU project.
Recent ADU and Garage Conversions
Three completed ADU and garage conversion projects from our Orange County portfolio. Every project below was built in San Clemente. Nothing loads from YouTube until you press play.
ADU project in San Clemente
ADU project in San Clemente
ADU project in San Clemente
Built by Horizon Construction & Remodeling, Inc. Licensed Class B general building contractor.
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Horizon is a licensed Class B general building contractor serving Santa Ana and the surrounding Orange County communities.
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