How United Build Partners helps Chino Hills homeowners
We're not a construction company. United Build Partners is an ADU advisory and contractor-matching service: we start with a free review of your property and goals, help you understand what's realistic for your lot under Chino Hills's rules, and — when it's a good fit — connect you with up to three contractors in our network suited to your project type and neighborhood. From there, you compare proposals and decide who to work with; the licensed contractor you choose handles the actual design and construction.
ADU rules and permitting in Chino Hills
Every ADU in California starts from the same statewide floor: ministerial (by-right) approval, at least 16–18 feet of height, 4-foot side and rear setbacks, and size minimums the city can't undercut. Chino Hills layers fire-overlay and eligibility rules on top that matter more here than in flatter cities. Here's what stands out locally.
What's specific to Chino Hills
- Some properties fall in an ADU Ineligibility District. Chino Hills designates an ADU Ineligibility District (CHMC §16.10.140(H)) where the usual single-family ADU eligibility doesn't apply. State law still limits how far a city can restrict ADUs, but this is the first thing to check for your specific parcel — confirm your address isn't in it before you plan.
- The Fire Hazard Overlay triples building separation. Standard separation between the ADU and main house is 10 feet — but in the Fire Hazard Overlay it jumps to 30 feet. There's an important out: separation isn't required at all if the ADU is built of 100% non-combustible materials. Given Chino Hills' wildland edges, this single rule shapes a lot of site plans.
- Detached ADUs need their own meters. A detached ADU requires fully independent water, gas, and electric lines with separate connections and meters, plus washer and dryer hook-ups; an attached ADU may share utilities with the main house. Separate service connections are a real cost and planning item for a detached build here.
- One ADU and one JADU per property. Chino Hills allows a maximum of one ADU and one JADU per property — consistent with the common state-law pattern for single-family lots.
- No Conditional Use Permit required. ADUs don't require a Conditional Use Permit; they're reviewed against Development Code Chapters 16.02 and 16.10, with the ADU standards in §16.10.140. That keeps approval ministerial rather than discretionary.
- Impact fees only at 750 sq ft and up. Development impact fees apply to ADUs of 750 square feet or larger and don't apply to JADUs — so a smaller ADU or a junior ADU avoids them, one concrete lever on the budget.
Property and lot considerations
Chino Hills is a hillside community bordering open space, so many lots are larger but carry wildland-fire considerations. The Fire Hazard Overlay's 30-foot separation — and the non-combustible-materials exception that removes it — often drive where and how a detached ADU can sit. A free property review is the fastest way to see what your specific parcel, its overlay status, and its eligibility will realistically support; our size & setback calculator is a good first check.
Common ADU types for Chino Hills homeowners
Detached, attached, and junior ADUs (JADUs) are all recognized in Chino Hills. The practical difference here is utilities: a detached ADU needs its own metered water, gas, and electric service, while an attached ADU can share with the main house — which can tilt the math toward an attached unit or conversion on some lots. Our which-ADU quiz helps narrow the choice to your lot and goals.
Cost factors in Chino Hills
Two Chino Hills-specific factors touch cost: a detached ADU's separate utility meters and service connections, and — in the Fire Hazard Overlay — either the 30-foot separation or the non-combustible-materials build that waives it. Development impact fees apply at 750 square feet and up. Our cost guide and soft-costs guide frame the full budget beyond construction.
Financing your Chino Hills ADU
Most homeowners fund ADU construction through a HELOC, cash-out refinance, a construction loan, or some combination — see our ADU financing overview and loan payment calculator for how each works. Financing options aren't generally city-specific, but a lender may consider your neighborhood and local rents when evaluating projected rental income as qualifying income.
How our process works
Frequently asked questions
Most single-family properties can, but Chino Hills has an ADU Ineligibility District (CHMC §16.10.140(H)) where the usual eligibility doesn't apply, so confirm your specific parcel first. State law limits how far a city can restrict ADUs, but checking your address against the Ineligibility District and the Fire Hazard Overlay is the right first step.
Normally 10 feet between the ADU and the main house, but 30 feet if your property is in the Fire Hazard Overlay. There's a key exception: the separation isn't required if the ADU is built entirely of non-combustible materials. Because Chino Hills borders wildland areas, this rule often drives design decisions.
Yes. A detached ADU requires fully independent water, gas, and electric lines with separate connections and meters, plus washer and dryer hook-ups. An attached ADU may share utilities with the main house, so budget for the separate service connections on a detached build.