#1 ADU Contractor in West Covina
Custom Builds by Horizon Remodeling
Need more space or searching for an ADU contractor near West Covina? Horizon specializes in seamless home additions and custom ADU construction in West Covina, from extra bedrooms to backyard cottages and detached units. As your trusted ADU contractor near West Covina, 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
about the process
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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California moved its ADU law into Government Code sections 66310 through 66342 in 2024, and it changed again on January 1, 2026: square footage is now measured as interior livable space, and an agency has 15 business days to determine whether an application is complete and 60 days to approve or deny it. Approval is ministerial — no hearing, no discretionary design review.
For a property in West Covina, that application goes to the City of West Covina, which issues building permits for work inside city limits. One local factor worth knowing: no unusual local overlay applies, so the building code and the age of the house are what govern. Los Angeles County has 88 incorporated cities, so the agency and the counter change from one city to the next even where the state rules do not.
One county-level point is worth knowing. The county’s own ADU ordinance, amended in July 2025, was found non-compliant with state law by the California Department of Housing and Community Development in December 2025 — among other findings, it caps detached ADUs on a multifamily lot at two where state law allows up to eight. That ordinance governs unincorporated territory rather than the cities, but it is a useful reminder that a local handout is not always current with the statute.
The lot decides most of the rest. Housing here was overwhelmingly a product of the 1950s, when the city grew more than tenfold in a single decade after its 1923 incorporation, and the typical home is a single-story postwar tract house on a suburban lot, typically built with the kitchen walled off from the living and dining rooms, which shapes where a detached unit can sit, how far the utilities have to run, and whether a garage conversion or a new detached build is the better answer. We walk the parcel and check setbacks, grade, equipment access and utility routes before drawing anything.
What state law protects wherever the parcel sits: a local agency cannot cap an ADU below 850 square feet of interior livable space, or 1,000 square feet with more than one bedroom; side and rear setbacks cannot exceed four feet; owner-occupancy cannot be required for an ADU; building one cannot trigger a fire sprinkler retrofit of the main house; and there are no impact fees on a unit of 750 square feet or less.
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 West Covina ?
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. One company draws the plan, runs it through the agency, and builds it.
On a Los Angeles County ADU the hard part is usually the site rather than the structure — grade, equipment access, where the utilities run, and whether the parcel sits in a very high fire hazard severity zone. We work that out before drawings, because a plan that ignores it becomes a redesign. Where a local ordinance and state law disagree, we know which one governs and we cite it in the submittal.
We also build ADUs in Baldwin Park, Covina and La Puente. Landmarks and neighborhoods we work around in West Covina include the South Hills area, Cortez Park, the Eastland Center district, the Plaza West Covina area.
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Clients Love
EXCELLENT
Based on 98 reviews
Posted on Google![]()
conchita leslieTrustindex verifies that the original source of the review is Google.
We recently had our roof remodeled by Horizon Construction and Remodeling, and we couldn't be more pleased with the outcome. David, our project manager, was exceptional—he kept us updated throughout the process and ensured everything went smoothly. The entire experience was amazing, and we truly enjoyed working with the team. We're already planning painting and insulation work in the near future and will definitely be reaching out to David and Horizon Construction and Remodeling againPosted on Google![]()
Sirous RouhiTrustindex verifies that the original source of the review is Google.
Mason was very polite , professional and knowledgeable. This was our 2nd with horizon homes renovation. Mason did an excellent job. The work was done in timely and professional manner. Thanks Mason I will definitely recommend you to friends and family.Posted on Google![]()
Wesley BrownTrustindex verifies that the original source of the review is Google.
Horizon has done 4 projects for us and each was completed very well, on schedule, and within budget.Posted on Google![]()
W Peter VosTrustindex verifies that the original source of the review is Google.
There are so many positive things to list and describe, it is far better to wrap them all up into a single simple statement. Horizon Construction and Remodeling is a joy to work with, from planning to finish, from personnel to cost. Across the board, Horizon is excellent and we feel lucky to have found them.Posted on Google![]()
Jie HuTrustindex verifies that the original source of the review is Google.
Great work! All individual workers (demo, shower prep, tile, electrician, plumber, wall, and shower door) worked with details, very responsible, and on time. The project management communicated with us well and did a wonderful job in organizing the work and inspections. The guest bathroom remodel took less than four weeks.Posted on Google![]()
Jeanne McEntireTrustindex verifies that the original source of the review is Google.
After two years in my home in Dana Point, I was finally ready to remodel my kitchen. I knew what worked and didn’t work for me and my family. I chose Horizon to do my project, and am so pleased with the results! David was always available, was very detail oriented, and made amazing suggestions along the way. His crew were hard working and took good care of my home. My single story home is now fully open concept with new floors, fireplace, paint and of course the star of the home- the kitchen with the huge porcelain topped island, and top of the line finishings. Thank you, Horizon! I whole heartedly recommend you for anyone looking to remodel their home!Posted on Google![]()
Marlene BakerTrustindex verifies that the original source of the review is Google.
Mark was here this morning to check out our Bathroom and we are sad we missed him! We wanted to give him a great big thank you and a hug! Please tell him thanks from us! Thanks to you too Enna, Caroline, Anna, Sam and your whole crew! You all have made this experience very pleasant! All of you have been kind, considerate and made us feel like we mattered! We appreciate you! We absolutely love our bathroom! It's beautiful and works so much better for us! I have been posting pictures and telling friends and family about the whole experience! I have one lady who may redo her bathrooms and another today that asked for your name to give to her daughter! We will continue to brag about you and our bathroom Thank you again! Marlene and DennisPosted on Google![]()
Eva ATrustindex verifies that the original source of the review is Google.
There is some hiccups but overall I am satisfied with the quality of work. Just make sure that you include absolutely everything in the contract.
ADU Contractor Services In West Covina
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ADU Contractor in West Covina 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 West Covina?
Yes — an ADU always requires a building permit, but approval is ministerial rather than discretionary, so there is no hearing and no design review. For a property in West Covina the application goes to the City of West Covina, which issues building permits for work inside city limits. State law gives the agency 15 business days to determine completeness and 60 days to approve or deny, and a denial has to identify the specific deficiencies and how to cure them; a pre-approved plan cuts that review to 30 days. Horizon prepares and submits the package and carries it through inspections rather than handing it back to the homeowner.
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 West Covina?
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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Horizon is a licensed Class B general building contractor serving West Covina and the surrounding Orange County communities. CSLB #938230.








