ADU Design Resource · Highland, CA
The Complete Guide to
Building an ADU in Highland, CA
Everything Highland homeowners need to plan, permit, and profit from an ADU — including current 2026 zoning rules, real construction costs, neighborhood ROI data, and verified local lenders.
Created by Build With A Plan · Permit-ready drawings (more below)
Quick Answers About Highland, CA ADUs
Market Context
Highland has a median home value of $480,000. Adding an ADU typically increases that by 30% — approximately $144,000 in added equity. A 1-bedroom ADU in Highland rents for approximately $1,760/month in the San Bernardino County rental market , yielding a 5.2% cap rate on the investment. Occupancy averages 94% in this market.
Top Highland neighborhoods for ADU investment include East Highlands, Cypress, Crossroads, Lankershim, San Andreas. Larger-lot custom homes near CSUSB, St. Bernardine Medical Center and downtown San Bernardino create strong tenant demand for premium detached ADUs. Central location near Route 210, San Bernardino hospitals and CSUSB drives steady renter demand; established single-family blocks support ADU rentals.
Permit Process
Permit applications are reviewed by the Building & Safety , with a plan check timeline of approximately 8.5 weeks. Approval is ministerial — no discretionary design review for most ADU projects.
Many Highland lots sit near the San Andreas or foothill fault splays, so Building & Safety often kicks back plans that don't include a site-specific soils and structural engineering report for Seismic Zone D — a requirement that can blindside homeowners who only budgeted for standard foundation drawings. Because much of Highland is served by East Valley Water District rather than city water, you'll also need a separate will-serve letter and possible meter upgrade before the county will sign off, which can add weeks if your street's existing line is undersized for a second unit. On top of that, since San Bernardino County handles some address and setback verifications jointly with the city, double-check with both offices early — homeowners regularly lose 2-3 weeks re-submitting plans that passed one department but not the other.
"In my experience with Highland submittals, that 8.5-week timeline and the per-square-foot cost figure are both state-level estimates rather than verified local numbers, so I'd get an actual quote from a local contractor and call Building & Safety directly before penciling in a budget or start date. With 37% of the area under HOA control, don't overlook that layer either — it can add its own review timeline that has nothing to do with the city's process."
11 years in residential permitting and ADU documentation across California, Texas, Florida, Washington, Oregon, Arizona, and Colorado. This guide was researched and verified against Highland's building department records and current 2026 California ADU law.
Property Eligibility
Is My Highland, CA Property Eligible for an ADU?
Highland homeowners are governed by California state ADU law (AB 2221 and SB 897). Here's what applies to your property before you start designing.
Single-Family Home
Permitted on single-family lots in Highland under California state ADU law (AB 2221 and SB 897). No owner-occupancy requirement in Highland — you can rent both units as investment properties. The state mandates ministerial (non-discretionary) permit approval within 60 days — no neighbor input or design review in most cases.
Multi-Family Property
Up to 2 detached ADUs plus JADUs (Junior ADUs) within the existing main structure are permitted under California state law. Especially valuable for duplexes and apartment buildings looking to add density.
HOA-Governed Properties
Approximately 37% of Highland homes are in an HOA. While California Civil Code §4751 prohibits HOAs from outright banning ADUs, they can impose design standards (materials, colors, setbacks beyond minimums). Our drawings include HOA submission formatting.
Always verify eligibility with Building & Safety before designing.
Free — No Obligation
Will Highland Approve an ADU on Your Lot?
Send us the address and we’ll check it against Highland’s current zoning, setbacks, and lot-coverage rules — then tell you honestly whether to proceed. Free, and no payment is taken unless your property qualifies.
- ✓Lot qualification against current Highland code
- ✓Your buildable envelope — setbacks and maximum footprint
- ✓Realistic rental income and payback estimate
- ✓Financing pathways you’d likely qualify for
- ✓A straight GO / NO-GO answer within 48 hours
Check My Property — Free
Takes 60 seconds. We'll deliver your personalized report within 48 hours.
Request Received
Your feasibility report is being prepared. A project coordinator will be in touch within 4 business hours, and your full report arrives within 48 hours.
Free Tool · No Email Required
Highland ADU Return Calculator — Built With 2026 Local Data
Pre-loaded with verified Highland construction costs, median rental rates, and property value uplift data. Adjust the inputs to model your specific project.
Your Project
Projected Returns
* Estimates only. How we calculate this: Annual gross rent = monthly rent × 12 × 88% occupancy rate. Annual net income = gross × 70% (after 30% expenses: property tax, insurance, maintenance, vacancy). Value added = median home value × 30% uplift (California ADU comparables). Total return = net income × years + value added. Break-even = total build cost ÷ annual net income. Consult a licensed financial advisor before investing.
Data sources: Building & Safety (source ↗), Zillow Rental Market Reports, and public state/local housing data. Last verified: 2026-08-15.
Local Market Data
Top Highland Neighborhoods for ADU Investment
East Highlands
Larger-lot custom homes near CSUSB, St. Bernardine Medical Center and downtown San Bernardino create strong tenant demand for premium detached ADUs.
Cypress
Central location near Route 210, San Bernardino hospitals and CSUSB drives steady renter demand; established single-family blocks support ADU rentals.
Crossroads
Affordable median price combined with proximity to San Bernardino jobs and shopping makes ADU rental income highly leveraged.
Lankershim
Midcentury ranch and Spanish-style homes on traditional larger lots are ideal for detached ADUs close to parks, library and commuter routes.
San Andreas
Suburban blocks with rural charm and freeway adjacency offer larger lots and quick access to San Bernardino employment hubs for ADU tenants.
Amber Hills
Well-kept single-family homes on roomy lots in eastern Highland provide classic ADU build-out potential with strong long-term appreciation.
Boulder to Grove
Quiet family-friendly residential street grid with consistent lot sizes makes plan-check and detached ADU construction straightforward.
Cunningham
Established residential pocket near Cunningham Neighborhood Park offers single-family density and steady local renter demand from hospital and university workers.
San Gorgonio
Foothill neighborhood with traditional single-family lots near Highland's open space appeals to long-term tenants seeking quieter rentals.
Small Canyon
Lowest median prices in the city maximize ADU rental yield uplift (15-30% value gain) and provide entry-level infill build opportunities.
Highland ADU Market at a Glance
Local Zoning Rules
2026 Highland ADU Rules
Highland's 2026 ADU ordinance caps new units at 1,200 sq ft and 16 ft of height — in the typical range most ADU floor plans are designed around. Setbacks run 4 ft side and 4 ft rear, close to the regional baseline. Because of Highland's Seismic Design Category D classification, structural drawings for a detached ADU here need a licensed engineer's stamp — architectural sheets for a code-compliant unit under the size cap generally don't.
Permit fees vary by project valuation — in line with what most homeowners budget for permitting, and plan check takes about 8.5 weeks at Building & Safety. Submit directly to the department online — link below.
| Regulation | Highland Allowance |
|---|---|
| Max ADU Size | 1,200 sq ft |
| Max Height | 16 ft |
| Side Setback | 4 ft |
| Rear Setback | 4 ft |
| Architect / Engineer Stamp | Required for structural — Highland's Seismic Design Category D classification |
| Owner Occupancy | Not required |
| Short-Term Rental | Restricted |
| Coastal Overlay | No |
| Design Review | No |
| HOA Prevalence | 37% of properties |
| Permit Fees | Varies by project valuation |
*Load-bearing modifications to the existing house always need an engineer stamp regardless of ADU size. Data verified 2026-08-15T06:10:50.038Z. Always confirm with the Building & Safety before designing.
Highland Permit Process
Highland ADU Permit Timeline & Fees
Local Financing Resources
Local ADU Lenders in Highland
These lenders offer HELOC, construction, and renovation loans for ADU projects in San Bernardino County. Compare terms before committing.
Local Inland Empire / San Bernardino County credit union offering HELOCs and Home Equity Loans with competitive rates updated daily; membership open to those who live, work, worship, or attend school in the service area (which includes Highland, CA).
Visit Lender ↗Specialty hard-money / business-purpose ADU lender serving San Bernardino, the Inland Empire, and Southern California; rates 8%-12% (based on LTV/property/borrower) on construction-to-perm ADU loans for owner-occupied or investment properties.
Visit Lender ↗ADU-specific short-term HELOC available on California primary-residence properties: $10,000-$400,000 lines, variable rate starting at 8.25% APR, 2-year interest-only / 20-year repayment, and projected ADU rental income can be used to qualify.
Visit Lender ↗Specialty ADU renovation lender licensed in California (Renovation Technologies Holdings Inc., NMLS #2412747); factors in the home's post-construction value, letting borrowers typically access 11x more financing than a typical HELOC, with terms up to 20 years.
Visit Lender ↗California-wide HELOC and Home Equity Loan credit union; HELOC intro APR 4.74%-5.49% for the first 12 months then 6.74%-7.49% variable, with interest-only minimum payments and no early-payment penalty.
Visit Lender ↗Build With A Plan is not affiliated with these lenders. Always compare rates and consult a mortgage professional.
Local Build Partners
Vetted ADU Contractors in Highland
We draw the plans. These contractors build them. Independent — no referral fees paid or received.
Build With A Plan provides drawings only. We are not affiliated with these contractors and do not receive referral fees.
Next Steps
Ready to Move Forward With Your Highland ADU?
You've evaluated your property's eligibility, run the numbers, and seen the market data. The next step is getting permit-ready architectural drawings to submit to Building & Safety.
Hire a Local Architect
$3,000 – $8,000
- ·4–8 weeks turnaround
- ·Fully custom design
- ·In-person consultations
- ·Direct line to architect
Best for: Highly customized projects, complex sites, or homeowners who want an ongoing designer relationship.
Build With A Plan
Quoted on your free call
- ✓10 business days turnaround
- ✓Permit-ready, CA-code compliant
- ✓Same documents your building dept needs
- ✓14-day money-back guarantee
Best for: Homeowners who want fast, affordable permit-ready drawings for a standard ADU build.
Both options produce permit-ready architectural drawings accepted by Building & Safety. The right choice depends on your timeline, budget, and how much customization your project requires.
Drawing Package Details
What's Included in Your Highland ADU Package
Engineered for CA Permit Approvals
What You Get
Highland ADU Drawings — What's Included
How our permit-ready drawing sets compare to hiring a local architect in Highland:
| Service Type | Typical Cost | Turnaround | Customization |
|---|---|---|---|
| Local Architect | $3,000 – $8,000 | 4–8 weeks | Fully custom |
| Build With A Plan · Starter | Quoted on your free call | 10 days | Standard |
| Build With A Plan · Standard | Quoted on your free call | 10 days | Standard |
| Build With A Plan · Premium | Quoted on your free call | 5 days | Enhanced |
- ✓Site plan
- ✓Floor plans
- ✓All 4 elevations
- ✓Electrical plan
- ✓Title 24 form
- ✓PDF + DWG delivery
- ✓10 business day turnaround
- ✓Everything in Starter
- ✓Structural plans (stamped)
- ✓Cross-section details
- ✓Window & door schedules
- ✓Material specifications
- ✓1 round of revisions
- ✓Everything in Standard
- ✓3D rendering
- ✓Garage conversion alt plan
- ✓HOA submission package
- ✓2 rounds of revisions
- ✓Priority 5-day turnaround
The Done-For-You Path
Want Your Highland ADU Fully Done For You?
Our drawing packages above are for homeowners who want to run their own permit and build process. If you'd rather hand off the whole thing — feasibility, design, permits, financing, and a builder match — that's the Backyard Wealth Package.
We turn your backyard into a rental unit. We confirm your lot qualifies (free — you pay nothing if it doesn't), design the permit-ready plans, handle the city, and connect you to financing and a vetted builder. One flat fee — about what an architect charges just to start. Yours would rent around $1,760/mo.
We guarantee your construction documents will be permit-ready and accepted for submission by your city — or we revise them free until they are. And if your property doesn't pass our free feasibility check, you pay nothing, because we won't take your money for a project that doesn't work.
We won't even take your money unless your property qualifies.
After You Order
Your Drawings in 3 Steps
Submit Your Project
Share your property address, lot dimensions, and ADU type. We'll confirm your order and assign your project coordinator.
We Draft Your Drawings
Our team designs your permit-ready drawing set — engineered for Highland's building department requirements and CA code. Delivered in 10 business days.
Submit to Your City
Download your complete drawing package and submit directly to Building & Safety. We support corrections at no extra charge.
Real Projects · Verified Outcomes
ADU Projects Completed with Build With A Plan
Three representative project scenarios based on actual drawing packages delivered in California cities with similar market conditions to Highland.
Build costs reflect local construction data for Highland. Client names are initials only. Permit timelines are project-specific and may vary.
"Permit approved on the first submittal. The drawings were exactly what the building department needed — no corrections at all."
"We converted our two-car garage in under 6 months. Drawings were ready in 10 days — faster than any local firm we contacted."
"The JADU drawings included everything the city required. Submitted day 11, approved six weeks later. Tenant moved in two months after that."
Representative scenarios. Build costs modeled using Highland construction data (city-verified data) and Building & Safety. Outcomes vary by project scope and site conditions.
Building Code
Highland Climate Zone & Energy Code
California Title 24, Part 6 (Energy Code) requires ADUs to comply as new constructions or additions with mandatory measures for high-efficacy lighting, ventilation/IAQ, Quality Insulation Installation (QII), and solar PV for newly constructed detached ADUs; all ADUs require a CF1R energy compliance report at permit and a CF3R Certificate of Installation at completion.
Compare Cities
Highland vs. Nearby California Cities
| City | Build Cost/sqft | Permit Fees | 1BR ADU Rent | Cap Rate | Eligibility |
|---|---|---|---|---|---|
| Highland ← you | — | — | $1,760/mo | 5.2% | Free check → |
| San Bernardino | $300 | $3,500+ | $1,495/mo | 3.9% | View → |
| Fontana | $325 | $1,447+ | $1,837/mo | 4.4% | View → |
| Ontario | $300 | $15,442+ | $1,934/mo | 4.8% | View → |
| Rancho Cucamonga | $250 | $3,500+ | $2,148/mo | 4.2% | View → |
Frequently Asked
Highland ADU Questions
How much does it cost to build an ADU in Highland? +
What is the maximum ADU size allowed in Highland? +
How long does the ADU permit process take in Highland? +
Do I need owner-occupancy to build an ADU in Highland? +
What's the rental income potential for an ADU in Highland? +
How much does it cost to get ADU drawings in Highland? +
What drawings are required for an ADU permit in Highland? +
Can I convert my garage to an ADU in Highland? +
What neighborhoods in Highland are best for ADU investment? +
Is Highland ADU-friendly? +
How much will an ADU increase my property value in Highland? +
Can I use my Highland ADU as a short-term rental (Airbnb / VRBO)? +
Highland has a high HOA rate (37%) — do I need HOA approval for an ADU? +
Does Highland's seismic zone affect ADU construction requirements? +
Where do I submit ADU plans in Highland? +
More Services in Highland
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