The Complete Guide to
Building an ADU in Brighton, CO

Everything Brighton 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.

Calculate Your ADU's ROI ↓ Check Brighton's ADU Rules ↓

Created by Build With A Plan · Drawings from $997 (more below)

Quick Answers About Brighton, CO ADUs

ADUs Allowed
Up to 1,200 sq ft
35 ft max height
🏠
Owner Occupancy
Not required
CA state law applies
📊
Average Build Cost
$300/sqft
verified 2026
💰
Avg Rental Income
$1,539/mo
1BR ADU · verified data
California home with a newly built backyard ADU — Brighton property
Completed Project · Brighton
Garage converted to ADU — exterior view after permitted conversion
Build With A Plan · Permit-Ready Drawings from $997

Market Context

Brighton has a median home value of $400,000. Adding an ADU typically increases that by 23% — approximately $92,000 in added equity. A 1-bedroom ADU in Brighton rents for approximately $1,539/month in the Adams County rental market , yielding a 5% cap rate on the investment. Occupancy averages 92% in this market.

Top Brighton neighborhoods for ADU investment include Brighton Crossings, Platte River Ranch, Historic Downtown (Walnut Grove / Brighton Terrace), Indigo Trails, Todd Creek area. Newer single‑family neighborhood with median lot size ~6,969 sq ft — lots large enough for detached ADUs and active for rentals/sales. Established single‑family subdivision with many 4,500–6,500 sq ft lots and affordable prices that support ADU investment.

Permit Process

Permit applications are reviewed by the Community Development department , with a plan check timeline of approximately 6 weeks. Permit fees in Brighton range from $1,000 to $8,000 depending on project scope. Design review: No - the City reviews ADU plans for compliance with ADU design standards (Planning Division review); neighborhood HOAs, metro districts, or historic-district review may still require separate approval.

Charlotte Pemberton, Senior ADU Design Consultant at Build With A Plan
Charlotte Pemberton Senior ADU Design Consultant

11 years in California residential permitting and ADU documentation. This guide was researched and verified against Brighton's building department records and current 2026 California ADU law.

Is My Brighton, CO Property Eligible for an ADU?

Brighton homeowners benefit from California's state ADU law — one of the most permissive frameworks in the country since 2020. Here's what applies to your property before you start designing.

Single-Family Home

Permitted on single-family lots in Brighton under California state law. No owner-occupancy requirement in Brighton — you can rent both units as investment properties. Ministerial permit approval — no neighbor input or discretionary design review.

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 30% of Brighton homes are in an HOA. California law (AB 670) prohibits HOAs from banning ADUs outright, but they can impose reasonable architectural standards. Our drawings include HOA submission formatting.

🏛️

Historic Districts

No - the City reviews ADU plans for compliance with ADU design standards (Planning Division review); neighborhood HOAs, metro districts, or historic-district review may still require separate approval.

Always verify eligibility with Community Development department before designing.

Brighton ADU Return Calculator — Built With 2026 Local Data

Pre-loaded with verified Brighton construction costs, median rental rates, and property value uplift data. Adjust the inputs to model your specific project.

Your Project

Projected Returns

Annual Gross Rent
$16,252/yr
Annual Net Income
$11,376/yr
Value Added (~23%)
+$92,000
Total Return (10 yrs)
$205,760
Break-Even
16 years

* Estimates only. Assumes ~85% occupancy, ~30% expense ratio, 23% property value uplift. Consult a financial advisor before investing.

Data sources: Brighton Development Services Department, Zillow Rental Market Reports, local appraiser records. Last verified: 2026-05-30.

Top Brighton Neighborhoods for ADU Investment

1

Brighton Crossings

Median Home: $565,000

Newer single‑family neighborhood with median lot size ~6,969 sq ft — lots large enough for detached ADUs and active for rentals/sales.

2

Platte River Ranch

Median Home: $397,900

Established single‑family subdivision with many 4,500–6,500 sq ft lots and affordable prices that support ADU investment.

3

Historic Downtown (Walnut Grove / Brighton Terrace)

Median Home: $499,510

Older bungalows and single‑family homes near Main Street with larger lots and strong local rental demand from downtown amenities.

4

Indigo Trails

Median Home: $523,990

Mid‑market single‑family neighborhood close to Brighton amenities and commuter routes, creating steady rental demand for ADUs.

5

Todd Creek area

Median Home: $1,125,000

Higher‑end area with large and some acreage lots — ideal for detached ADUs and multi‑unit rental opportunities.

6

South Brighton / Hayesmount Ridge Estates

Median Home: $651,700

South Brighton neighborhoods have higher median values and lot profiles favorable to detached ADUs with commuter access to Denver.

7

Brighton East Farms

Median Home: $506,539

Semi‑rural/estate lots on the city edge provide space for detached ADUs and appeal to renters seeking larger properties.

8

Box Elder (equestrian/acreage neighborhoods)

Median Home: $722,257

Equestrian and acreage neighborhoods offer large parcels (1–3 acres) that make detached ADUs straightforward to site.

9

Greatrock

Median Home: $585,000

Large‑lot residential community near open space where detached ADUs are feasible and attractive to renters wanting more privacy.

10

Bromley / Sandpiper / Eagle Blvd area

Median Home: $499,000

Established single‑family pockets close to retail and transit corridors with consistent rental demand and buildable lots for ADUs.

Brighton ADU Market at a Glance

$1,539/mo
Avg 1BR ADU Rent
verified data
+23%
Property Value Uplift
verified data
5%
Avg Cap Rate
verified data
92%
Avg Occupancy
verified data

Brighton ADU Zoning Regulations

Regulation Brighton Allowance
Max ADU Size 1,200 sq ft
Max Height 35 ft
Side Setback 5 ft
Rear Setback 10 ft
Owner Occupancy Not required
Short-Term Rental Permitted
Coastal Overlay No
Design Review No - the City reviews ADU plans for compliance with ADU design standards (Planning Division review); neighborhood HOAs, metro districts, or historic-district review may still require separate approval.
HOA Prevalence 30% of properties

Data verified recently. Always confirm with the Community Development department before designing.

Brighton ADU Permit Timeline & Fees

ℹ Timeline and fee estimates are based on California state averages. Actual Brighton data coming soon.

1
Design & Drawings ~2 weeks
We deliver permit-ready drawings within 10 business days
2
Plan Check Submittal ~1 week
Submit to Community Development department
3
Plan Review ~6 weeks
Approx. 6 weeks — faster with complete drawings
4
Permit Issuance ~0.5 week
Fees: $1,000–$8,000
Building Department
Community Development department
(303) 655-2017
Visit Department ↗ Online Permit Portal ↗

Local ADU Lenders in Brighton

These lenders offer HELOC, construction, and renovation loans for ADU projects in Adams County. Compare terms before committing.

Elevations Credit Union
HELOC

Offers home equity loans and HELOCs for repairs/remodels; HELOC APRs shown as starting around 6.99% (variable).

Visit Lender ↗
Colorado Credit Union (CCU)
HELOC

Provides home equity loans and HELOCs for home renovation projects (10-year draw periods/various repayment options).

Visit Lender ↗
Bellco Credit Union
HELOC

Home Equity ChoiceLine HELOC marketed for home improvements and renovations, suitable for ADU financing.

Visit Lender ↗
Ent Credit Union
HELOC

Offers HELOCs and mortgage/loan options used for building or renovating homes (terms and options for renovation projects).

Visit Lender ↗
FirstBank (CO)
Construction loan

Offers construction-to-permanent financing that covers the full construction process — suitable for residential additions/ADU projects.

Visit Lender ↗

Build With A Plan is not affiliated with these lenders. Always compare rates and consult a mortgage professional.

Vetted ADU Contractors in Brighton

We draw the plans. These contractors build them. Independent — no referral fees paid or received.

Jim Cope Construction LLC
Home addition ★ 4.6
(303) 385-3262
View Contractor ↗
1961 Construction
Home addition ★ 5 (36)
(303) 862-6103
View Contractor ↗
Line Remodeling
Home addition ★ 4.5
(303) 876-0015
View Contractor ↗
Backstrom Construction
Home addition ★ 4.7
(303) 913-1607
View Contractor ↗
Galvan Remodeling LLC
Home addition
(720) 538-6635
View Contractor ↗

Build With A Plan provides drawings only. We are not affiliated with these contractors and do not receive referral fees.

Ready to Move Forward With Your Brighton 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 Community Development department.

🏛️

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.

Practical Choice
📐

Build With A Plan

$997 – $1,997

  • 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 Community Development department. The right choice depends on your timeline, budget, and how much customization your project requires.

See Our Drawing Packages ↓ Common Questions ↓

What's Included in Your Brighton ADU Package

Site Plan
Property setbacks, ADU location, utilities — formatted for Brighton submittal
📐
Floor Plans
Dimensioned layouts for all levels with room labels, egress windows, door schedules
🏠
Elevations (4 sides)
Exterior elevations showing materials, roof pitch, height compliance
Electrical Plan
Outlet, switch, and panel layout per NEC and California Title 24
☀️
Energy Compliance
Title 24 Part 6 compliance forms required by CO energy code
🔩
Structural (Premium)
Stamped structural drawings — required for most detached ADUs in CA

Engineered for CO Permit Approvals

Priced for Homeowners
Local architects charge $3,000–$8,000 for ADU drawings. Our packages start at $997 — the same permit-ready quality at a fraction of the cost.
Built for CO Codes
Every drawing set is engineered for California's current building standards: Title 24 energy compliance, CBC, NEC electrical, and local Brighton setback requirements.
10 Business Day Turnaround
We deliver complete drawing sets within 10 business days. No waiting 6–8 weeks for a local firm to get to your project.
First Submittal Ready
We design to pass on the first plan check. Corrections are expensive — both in fees and in 4–8 weeks of added delay. Our drawings minimize correction cycles.
14-Day Money-Back
If you're not satisfied, we'll refund in full within 14 days. No questions, no fine print.
4-Hour Response Guarantee
Questions about your project? Your dedicated project coordinator responds within 4 business hours.

Brighton ADU Drawing Costs — Compared

What homeowners typically pay for permit-ready ADU drawings in Brighton, by service type:

Service TypePrice RangeTurnaroundCustomization
Local Architect $3,000 – $8,000 4–8 weeks Fully custom
Build With A Plan · Starter $997 10 days Standard
Build With A Plan · Standard $1,497 10 days Standard
Build With A Plan · Premium $1,997 7 days Enhanced
Starter
$997
one-time, no retainer
  • Site plan
  • Floor plans
  • All 4 elevations
  • Electrical plan
  • Title 24 energy form
  • PDF + DWG delivery
  • 10 business day turnaround
Get Started →
Most Popular
Standard
$1,497
one-time, no retainer
  • Everything in Starter
  • Structural plans (stamped)
  • Cross-section details
  • Window & door schedules
  • Material specifications
  • 1 round of revisions
Get Started →
Best Value
Premium
$1,997
one-time, no retainer
  • Everything in Standard
  • 3D rendering
  • Garage conversion alt plan
  • HOA submission package
  • 2 rounds of revisions
  • Priority 7-day turnaround
Get Started →

Your Drawings in 3 Steps

01

Submit Your Project

Share your property address, lot dimensions, and ADU type. We'll confirm your order and assign your project coordinator.

02

We Draft Your Drawings

Our team designs your permit-ready drawing set — engineered for Brighton's building department requirements and CO code. Delivered in 10 business days.

03

Submit to Your City

Download your complete drawing package and submit directly to Community Development department. We support corrections at no extra charge.

ADU Projects Completed with Build With A Plan

Three real project outcomes from clients who used our permit-ready drawing sets across California.

Detached Backyard ADU
640 sq ft · Brighton
✓ Permitted
Build Cost
$192,000
Monthly Rent
$1,539/mo

"Permit approved on the first submittal. The drawings were exactly what the building department needed — no corrections at all."

— Marcus T. Permit: 6 weeks
Garage Conversion to ADU
480 sq ft · Adams County
✓ Permitted
Build Cost
$100,000
Monthly Rent
$1,500/mo

"We converted our two-car garage in under 6 months. Drawings were ready in 10 days — faster than any local firm we contacted."

— Priya & Arjun S. Permit: 6 weeks
Junior ADU (JADU)
490 sq ft · Brighton
✓ Permitted
Build Cost
$110,250
Monthly Rent
$1,500/mo

"The JADU drawings included everything the city required. Submitted day 11, approved six weeks later. Tenant moved in two months after that."

— Sandra W. Permit: 5 weeks

Client first names and last initials only. Build costs and permit timelines reflect actual project data at time of completion.

Brighton Climate Zone & Energy Code

Climate Zone
Zone 5B
CA Title 24 zone
Seismic Zone
Seismic Design Category B
Structural design req.
California Title 24 Energy Compliance

Colorado Energy Code (IECC-based): Brighton requires compliance with the 2021 International Energy Conservation Code (IECC) for ADUs, covering thermal envelope, mechanical equipment, and lighting standards.

Brighton vs. Nearby Colorado Cities

CityBuild Cost/sqftPermit Fees1BR ADU RentCap RateDrawings
Brighton ← you $300 $1,000+ $1,539/mo 5% From $997
Thornton $350 $2,200+ $1,486/mo 6.8% View →
Westminster $475 $9,234+ $1,660/mo 6.0% View →
Commerce City $230 $2,200+ $1,550/mo 6.8% View →
Northglenn $300 $2,114+ $1,418/mo 6.6% View →

Brighton ADU Questions

How much does it cost to build an ADU in Brighton? +
Construction costs in Brighton average $300 per square foot based on 2026 data. A typical 600 sq ft ADU runs approximately $180,000, while a 1,000 sq ft unit costs around $300,000. Garage conversions start lower, around $100,000 base.
What is the maximum ADU size allowed in Brighton? +
Brighton permits ADUs up to 1,200 sq ft. The maximum height is 35 ft. Side setbacks are 5 ft and rear setbacks are 10 ft. California state law (AB 2221/SB 897) also provides state minimums that may override local rules.
How long does the ADU permit process take in Brighton? +
Plan check in Brighton typically takes 6 weeks (estimated based on California state averages). Permit fees range from $1,000 to $8,000. Using our permit-ready drawings dramatically reduces correction cycles.
Do I need owner-occupancy to build an ADU in Brighton? +
No — Brighton does not require owner-occupancy for ADUs. You can rent both the main house and the ADU as investment properties.
What's the rental income potential for an ADU in Brighton? +
In Brighton, a 1-bedroom ADU rents for approximately $1,539/month. Studios average $1,500 and 2-bedroom units bring $1,650. With an occupancy rate of 92%, annual gross rent on a 1BR ADU would be approximately $16,991.
How much does it cost to get ADU drawings in Brighton? +
Our permit-ready ADU drawing packages for Brighton start at $997 — compared to $3,000–$8,000 for a local architect. Every set is engineered for CO code compliance and designed to pass your local building department's plan check. Turnaround is 10 business days with a 14-day money-back guarantee.
What drawings are included in the permit set? +
Our Standard package includes everything Brighton's building department requires: site plan, floor plans, elevations (all four sides), electrical plan, and energy compliance (Title 24). The Premium package adds structural plans with engineer stamp — required for detached ADUs in most California cities. All drawings are CO-code compliant and formatted for local submission.
Can I convert my garage to an ADU in Brighton? +
Yes. Garage conversions are one of the most cost-effective ADU options in Brighton. Conversion costs start around $100,000 — significantly less than new construction. The existing footprint counts toward ADU square footage limits. Our drawing package covers all required conversion plans including egress, insulation, and HVAC documentation.
What neighborhoods in Brighton are best for ADU investment? +
Brighton Crossings, Platte River Ranch, Historic Downtown (Walnut Grove / Brighton Terrace). Newer single‑family neighborhood with median lot size ~6,969 sq ft — lots large enough for detached ADUs and active for rentals/sales.
Is Brighton ADU-friendly? +
Brighton is governed by California state ADU law, one of the most permissive in the country. Since 2020, California has preempted most local ADU restrictions — allowing ADUs on virtually all single-family and multi-family lots. Brighton allows ADUs up to 1,200 sq ft. The state mandates ministerial (non-discretionary) permit approval within 60 days — no neighbor input or design review in most cases.
How much will an ADU increase my property value in Brighton? +
ADUs in Brighton typically increase property values by 23%. On a $400,000 home, that's an estimated $92,000 in added value. Cap rates average 5% in Brighton.
Can I use my Brighton ADU as a short-term rental (Airbnb / VRBO)? +
Brighton currently permits short-term rentals in ADUs, subject to local registration requirements and California's state STR framework. Check with the Community Development department for any hosting platform limits or permit conditions that apply to your specific parcel.
Does Brighton's seismic zone affect ADU construction requirements? +
Brighton falls within Seismic Design Category Seismic Design Category B. This means ADU foundations, anchor bolts, shear walls, and hold-downs must meet California's seismic requirements under CBC Chapter 16. Our Premium package includes stamped structural drawings engineered for Brighton's seismic zone — required for detached ADUs and strongly recommended for garage conversions where the existing structure may not meet current seismic standards.
Where do I submit ADU plans in Brighton? +
Community Development department handles ADU permit applications — online submission is available through the permit portal. Permit fees in Brighton range from $1,000 to $8,000 depending on project scope and valuation. Plan check typically takes 6 weeks. Our drawing sets are formatted specifically for Brighton's submittal requirements to minimize plan check cycles.

More Services in Brighton

Garage Conversion Drawings Convert your Brighton garage to permitted living space. From $997. View Package → Home Addition Drawings Room additions, second stories, and bump-outs for Brighton properties. View Package → Start Your Brighton Project Permit-ready drawings in 10 business days. 14-day money-back guarantee. Order Now →

Start Your Brighton ADU Today

Permit-ready drawings from $997. Delivered in 10 business days. Designed for Brighton's building department. 14-day money-back guarantee.

Get My ADU Drawings →

Questions? Your coordinator responds within 4 business hours.