#1 ADU Contractor in Chino Hills
Custom Builds by Horizon Remodeling
Horizon Construction & Remodeling Inc. builds accessory dwelling units and room additions for homeowners across Chino Hills, handling design coordination, budgeting, permitting through the City of Chino Hills Building and Safety Division, and material selection under one general contracting agreement. Because CAL FIRE mapping places most of the city in a fire hazard severity zone, we factor ignition-resistant materials into every scope from the start. Projects range from detached backyard units to attached additions on the graded hillside pads common throughout neighborhoods like Butterfield Ranch and Los Serranos.
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 looking for an adu contractor in Chino Hills, understanding how state law and local rules interact is one of the first things we walk you through. California consolidated its ADU statutes into Government Code sections 66310 through 66342 in 2024, and those rules were updated again on January 1, 2026. Square footage is now calculated as interior livable space, and once you submit an application, the reviewing agency has 15 business days to confirm it is complete and 60 days to approve or deny it. Approval is ministerial, meaning no public hearing and no discretionary design review stands between a complete application and a decision.
For a Chino Hills property, that application goes to the City of Chino Hills Building and Safety Division. San Bernardino County adopted Development Code Chapter 84.36 at the Board of Supervisors on January 13, 2026, making it the most current county ADU ordinance among the four counties we serve. Published standards allow an ADU ranging from 200 to 1,200 square feet, a junior ADU up to 500 square feet, attached height up to 25 feet, and detached height up to 18 feet with two additional feet permitted to match a roof pitch. Side and rear setbacks are four feet, with five feet of separation required between detached structures.
Two provisions stand apart from what you find in the coastal counties. First, two ADUs are permitted per lot. Second, properties of five acres or more can accommodate three units. Sewer connection is required when a public line runs within 200 feet of the property line, with that distance increasing by 100 feet for each additional dwelling unit added. When sewer connection is not triggered, the project relies on septic or an advanced treatment system. We involve Environmental Health before a single plan is drawn.
CAL FIRE mapping places the great majority of Chino Hills acreage in fire hazard severity zones, much of it rated very high. That designation pushes ignition resistant materials and defensible space planning into the scope of nearly every project we manage here, and it is a factor we account for during the design phase rather than treating it as an afterthought.
The lot itself determines much of what is feasible. Chino Hills was incorporated in 1991 following rapid development in the late 1980s, and the median build year sits around 1990. Most homes are two story stucco tract or hillside houses set on graded pads with tile roofs, layouts where the kitchen already flows into the family room. That footprint shapes where a detached ADU can realistically land and how far utilities need to run to serve it, both of which affect budget and timeline in ways we identify early.
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 Chino Hills ?
Horizon Construction and Remodeling is a licensed Class B general building contractor, bonded, and in business since 2009. We handle ADU projects in Chino Hills from a single point of contact: one team draws the plans, submits them to the City of Chino Hills Building and Safety Division, and builds the unit. That structure keeps the process clear and avoids the gaps that open up when design and construction are split between separate companies.
Chino Hills presents specific considerations that shape every ADU scope before a line gets drawn. CAL FIRE maps place most of the city’s acreage in fire hazard severity zones, which means ignition resistant materials and defensible space requirements move from optional to essential on a large share of parcels. We address those factors early, alongside utility connections and site access, because the answers determine what can realistically be built and at what cost. The tract and hillside homes throughout areas like Los Serranos, Butterfield Ranch, and Carbon Canyon were largely built around 1990, so we also account for what an existing structure can accommodate before finalizing any addition.
California state law provides certain protections regardless of where your parcel sits: no owner-occupancy requirement applies to an ADU, adding one does not trigger a sprinkler retrofit of the main house, and units with 750 square feet or less of interior livable space are not subject to impact fees. These are starting points worth understanding before your consultation.
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ADU Contractor Services in Chino Hills
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ADU Contractor in Chino Hills 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 converted garage, a detached backyard structure, or an attached in-law suite. Working with Horizon Construction & Remodeling Inc. on an ADU in Chino Hills lets you add rental income, house extended family, or gain usable living space on lots where CAL FIRE hazard zone requirements already shape material choices.
How much does it cost to build an ADU in California?
What an ADU costs in Chino Hills depends on details no contractor can assess from a web page alone. The size of the unit matters, as does whether you are converting existing space or building a detached structure from scratch. Site conditions on a graded hillside pad, the length of utility runs, and the finish level you choose all move the number. Because so much of Chino Hills falls within a CAL FIRE-mapped fire hazard severity zone, ignition-resistant materials often become part of the scope and affect the budget. Anyone who quotes you a firm price before walking the property is working from a guess, not a plan. We visit the site, confirm setbacks and utility connections, and then give you a fixed scope and price you can hold us to.
State law does provide real cost protections worth understanding before you start. An ADU of 750 square feet of livable space or less is exempt from impact fees, and school fees apply only above 500 square feet. Connection fees for a conversion or junior ADU are limited because the state does not classify those as a new residential use. Permits in Chino Hills go through the City of Chino Hills Building and Safety Division, and adding an ADU cannot trigger a fire sprinkler retrofit of your main house. One warning worth repeating: the CalHFA ADU grant program is closed, its funding fully allocated, and anyone offering to help you obtain that grant is running a scam.
Do I need permits for an ADU in Chino Hills?
Yes, every ADU requires a building permit, and in Chino Hills that application goes through the City of Chino Hills Building and Safety Division. State law sets the review clock at 15 business days for a completeness determination and 60 days for an approval or denial, and the city’s process reflects those timelines. On properties served by a septic system or a private well, Environmental Health joins the review. A sewer connection is also required when a public line runs within 200 feet of the property line. Horizon manages the submittal, tracks correction responses, and coordinates every inspection through final sign-off.
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 Chino Hills?
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 contracting in Chino Hills from design through the City of Chino Hills Building and Safety Division permit process to final construction, coordinating every trade so your project meets code, fits your budget, and moves 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?
Ready to move forward? Contact Horizon Construction & Remodeling Inc. at (714) 449-9035 to schedule a free estimate. We will assess your Chino Hills property, talk through your goals, and walk you through every phase of your ADU project from design to final inspection.
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Horizon is a licensed Class B general building contractor serving Chino Hills and the surrounding Orange County communities.
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