#1 ADU Contractor in Tustin
Custom Builds by Horizon Remodeling
Horizon Construction & Remodeling Inc. builds accessory dwelling units and home additions across Tustin, managing design, budgeting, permits, and material selection from the first meeting through final walkthrough. Tustin’s housing ranges from pre-war Old Town bungalows on modest lots to 1960s ranch-style tracts and larger two-story Tustin Ranch homes, and each property type comes with its own site and structural considerations. Projects in the Old Town Cultural Resources District typically require design review and a certificate of appropriateness before the City of Tustin Building Division issues permits, and we coordinate that process on your behalf.
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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If you are planning to add a rental unit or extra living space to your property, working with an experienced adu contractor in Tustin means navigating a process shaped by both state law and local conditions that vary widely from one neighborhood to the next. California Government Code sections 66310 through 66342 govern ADUs statewide, and as of January 1, 2026, square footage is measured as interior livable space. Once you submit an application to the City of Tustin Building Division, the agency has 15 business days to determine whether it is complete and 60 days to approve or deny it.
State approval is ministerial, meaning no public hearing and no discretionary design review are required. That protection holds across most of Tustin, though Old Town is a meaningful exception. Properties there fall inside the Cultural Resources District overlay established in 1988, which adds a design review step and requires a certificate of appropriateness before work can proceed.
Outside Old Town, your lot and its history do much of the deciding. Tustin housing spans roughly a century, from pre-war bungalows on modest Old Town lots to single-story 1960s ranch plans in Tustin Meadows to larger two-story homes in Tustin Ranch. That range shapes setbacks, utility runs, and whether a detached build or a garage conversion fits better. We walk the parcel first, checking grade, equipment access, and utility routes before anything gets drawn.
State law sets firm minimums that apply everywhere: 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. Building an ADU cannot trigger a fire sprinkler retrofit on the main house. And there are no impact fees on any unit 750 square feet or smaller.
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 Tustin ?
Horizon Construction and Remodeling is a licensed Class B general building contractor, bonded, with over 15 years of design-build work. Our Fullerton office puts Tustin well within our regular working area, not a distant job. A detached ADU is a complete small house placed on a lot where a primary residence already stands, covering foundation, framing, roof, envelope, plumbing, electrical service, a kitchen, and a bathroom. Because design decisions and construction constraints are inseparable on a new structure, having one company draw, permit, and build the project keeps the process coherent.
Tustin’s housing ranges from pre-war Old Town bungalows on modest lots to 1960s single-story ranch homes in areas like Tustin Meadows and larger two-story houses in Tustin Ranch. Lot size and existing structure both shape what an ADU can realistically be, and we work through those constraints during design.
Permits go through the City of Tustin Building Division. Properties inside Old Town’s Cultural Resources District overlay face additional design review and require a certificate of appropriateness, so we prepare that submittal alongside the building permit from the start. We work throughout Old Town Tustin, Tustin Meadows, Tustin Ranch, and Tustin Legacy.
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ADU Contractor Services in Tustin
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ADU Contractor in Tustin FAQ
What is an ADU and why should I build one?
An accessory dwelling unit is a self-contained secondary home built on your existing property, taking the form of a garage conversion, a backyard cottage, or an attached in-law suite. Building an ADU in Tustin with Horizon Construction and Remodeling can generate rental income, house extended family, or add usable living space to your lot.
How much does it cost to build an ADU in California?
ADU costs in Tustin depend on details no contractor can assess from a distance: the size and type of unit you want, whether you are converting an existing structure or building a detached unit from the ground up, what site work and utility connections your particular lot requires, and the finish level you choose. What we can tell you is how the law shapes what you pay. A unit at or under 750 square feet of livable space is exempt from impact fees. School fees only apply once the unit exceeds 500 square feet. Connection fees for a garage conversion or a junior ADU are limited because state law does not classify those as a new residential use, and adding an ADU cannot force a fire sprinkler retrofit on your existing home.
Permit applications go through the City of Tustin Building Division, and if your property sits within the Old Town Cultural Resources District overlay, design review and a certificate of appropriateness are part of the process before a building permit is issued. That is exactly why anyone quoting a firm price before visiting your property is guessing. We walk the parcel, confirm setbacks, utility runs, and any overlay requirements, then provide a fixed scope and price. One more thing worth stating plainly: the CalHFA ADU grant program is closed, its funding fully allocated, and the agency itself warns that offers to help secure an ADU grant are scams.
Do I need permits for an ADU in Tustin?
Yes, an ADU always requires a building permit, though approval is ministerial rather than discretionary, meaning no hearing and no design review board. In Tustin, that application goes to the City of Tustin Building Division, which has 15 business days under state law to determine completeness and 60 days to approve or deny the permit. A pre-approved plan shortens that review window to 30 days. One exception worth noting: properties in Old Town Tustin fall under the Cultural Resources District overlay, where changes may trigger additional design review. We prepare and submit the full permit package and carry 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 Tustin?
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 ADU projects in Tustin from initial design through final inspection, coordinating permitting with the City of Tustin Building Division and handling every trade involved, so your project meets code and stays on budget.
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 property, talk through your goals, and deliver a detailed estimate covering every phase of your Tustin ADU project, including design recommendations to get you started on the right foot.
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 Tustin and the surrounding Orange County communities.
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