#1 ADU Contractor in North Tustin
Custom Builds by Horizon Remodeling
Horizon Construction & Remodeling Inc. builds ADUs and home additions throughout North Tustin, handling design, budgeting, permits, and material selection from the first conversation through final inspection. Because North Tustin is unincorporated county territory, permits run through OC Development Services at OC Public Works rather than a city building department, and the area’s genuinely hilly terrain affects site access, staging, and structural planning on every project. The large lots common across Cowan Heights, Lemon Heights, and the surrounding foothills typically give us the room to build detached units, backyard cottages, or additional bedrooms without compromising your existing footprint.
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 →
Finding the right adu contractor in North Tustin means working with a team that understands both state law and the specific permit path this area requires. Because North Tustin is unincorporated county territory, your application goes to OC Development Services at OC Public Works rather than a city building department, and the county’s North Tustin Specific Plan governs land use districts and height limits on top of that. We walk every parcel before drawing anything, checking setbacks, grade, equipment access and utility routes, because the hilly terrain here directly affects site staging and any structural work involved.
California ADU law, codified in Government Code sections 66310 through 66342, was updated effective January 1, 2026. Square footage is now measured as interior livable space. Once you submit, the reviewing agency has 15 business days to determine whether your application is complete and 60 days to approve or deny it. Approval is ministerial, meaning no public hearing and no discretionary design review.
State law also sets protections that apply regardless of where your parcel sits. 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 of the main house, and there are no impact fees on units of 750 square feet or less.
North Tustin’s housing stock grew gradually on former citrus and lemon ranch land between the 1940s and the 1990s, producing large single-family homes on generous hillside lots. That history works in your favor. The unusually high share of four and five bedroom floor plans means there is typically room to work with, and lot depth often determines whether a detached build or a garage conversion is the more practical path. We assess all of that before any plans are drawn.
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 North Tustin ?
Horizon Construction and Remodeling is a licensed Class B general building contractor, bonded, and in business since 2009. Our office in Fullerton puts North Tustin well within our regular working area, and we are familiar with the unincorporated county territory that makes up this part of the foothills. Because North Tustin falls outside city limits, permits are handled through OC Development Services at OC Public Works rather than a municipal building department, and the North Tustin Specific Plan governs land use districts and height limits on every project we submit there.
A detached ADU is essentially a small standalone house added to a lot that already has a primary residence on it. It requires a foundation, framing, a roof, exterior envelope, and full utility connections, with specialty trade portions coordinated through appropriately licensed subcontractors. The hilly terrain across areas like Cowan Heights, Lemon Heights, Panorama Heights, and Red Hill affects site access, equipment staging, and structural decisions from the earliest design stage.
Keeping design and construction under one general contractor matters on sites like these, where slope conditions and county-specific plan requirements shape the drawings before a permit application is ever filed. We coordinate the full process from design through final inspection so nothing falls between two separate companies.
Schedule a Consultation
ADU Contractor Services in North Tustin
View Our ADU Contractor Areas of Service
ADU Contractor in North 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 backyard cottage, a converted garage, or an in-law suite. Building an ADU in North Tustin lets you put those generously sized hillside lots to work, whether the goal is added rental income or independent living space for family members.
How much does it cost to build an ADU in California?
ADU costs in North Tustin vary based on factors no contractor can assess from a website alone. The size and type of unit matter, as does whether you are converting an existing structure or building a new detached ADU on your lot. Site work plays a significant role here, because the genuinely hilly terrain in areas like Cowan Heights and Lemon Heights often means more involved grading, staging, and utility runs than a flat suburban parcel would require. Finish level is another variable. What we can tell you is where the money goes and what state law limits. Any ADU at or under 750 square feet of livable space is exempt from impact fees. School fees apply only above 500 square feet. Connection fees for a conversion or junior ADU are capped because state law does not classify those as a new residential use, and adding an ADU cannot force a fire sprinkler retrofit of your existing home.
Because North Tustin is unincorporated county territory, permits run through OC Development Services at OC Public Works rather than a city building department, and the North Tustin Specific Plan governs height limits and land use districts that affect what you can build and where. Any contractor quoting a firm number before walking your specific parcel is guessing. We visit the property, confirm setbacks, utility connections, and site access conditions, then provide a fixed scope and price you can hold us to. One point worth stating plainly: the CalHFA ADU grant program is closed, its funding fully allocated, and the agency itself warns that anyone offering to help you secure an ADU grant is running a scam.
Do I need permits for an ADU in North Tustin?
An ADU in North Tustin always requires a building permit, though approval is ministerial rather than discretionary, meaning there is no hearing and no design review board to satisfy. Because North Tustin is unincorporated county territory and not part of the City of Tustin, your application goes to OC Development Services at OC Public Works. State law allows the agency 15 business days to confirm completeness and 60 days to approve or deny, and a pre-approved plan shortens that review to 30 days. We prepare and submit the full package and carry it through every inspection, so the process never lands back in your lap.
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 North 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 North Tustin from design through final inspection, coordinating permitting with OC Development Services and keeping the work aligned with building codes, budget, and schedule. On the hilly lots common to areas like Cowan Heights and Lemon Heights, that full-process oversight matters.
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?
Ready to move forward? Contact Horizon Construction & Remodeling Inc. to schedule a free consultation, where we assess your North Tustin property, talk through your goals, share design recommendations, and put together 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.
Explore More in North Tustin
Horizon is a licensed Class B general building contractor serving North Tustin and the surrounding Orange County communities.
Other Services in North Tustin
ADU Contractors Nearby
Related Posts About ADU
