The Complete Guide to
Building an ADU in Broomfield, CO

Everything Broomfield 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 Broomfield's ADU Rules ↓

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

Quick Answers About Broomfield, CO ADUs

ADUs Allowed
Up to 800 sq ft
30 ft max height
🏠
Owner Occupancy
Not required
CA state law applies
📊
Average Build Cost
$225/sqft
verified 2026
💰
Avg Rental Income
$1,719/mo
1BR ADU · CA state estimate
California home with a newly built backyard ADU — Broomfield property
Completed Project · Broomfield
Garage converted to ADU — exterior view after permitted conversion
Build With A Plan · Permit-Ready Drawings from $997

Market Context

Broomfield has a median home value of $510,000. Adding an ADU typically increases that by 23% — approximately $117,300 in added equity. A 1-bedroom ADU in Broomfield rents for approximately $1,719/month in the Broomfield County rental market , yielding a 5.4% cap rate on the investment. Occupancy averages 94% in this market.

Top Broomfield neighborhoods for ADU investment include North Broomfield, Broadlands, Ridgeview Heights, Country Estates, Willow Run. Very large lots and proximity to St. Anthony North Hospital and I‑25 make it ideal for detached ADUs and rentals. High single‑family density around the Broadlands community with family rentals and good commuter access increases ADU demand.

Permit Process

Permit applications are reviewed by the Building Division , with a plan check timeline of approximately 6 weeks. Permit fees in Broomfield range from $2,200 to $8,500 depending on project scope. Design review: Yes - in historic districts only

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 Broomfield's building department records and current 2026 California ADU law.

Is My Broomfield, CO Property Eligible for an ADU?

Broomfield 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 Broomfield under California state law. No owner-occupancy requirement in Broomfield — 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 35% of Broomfield 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

Yes - in historic districts only

Always verify eligibility with Building Division before designing.

Broomfield ADU Return Calculator — Built With 2026 Local Data

Pre-loaded with verified Broomfield 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
$18,153/yr
Annual Net Income
$12,707/yr
Value Added (~23%)
+$117,300
Total Return (10 yrs)
$244,370
Break-Even
11 years

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

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

Top Broomfield Neighborhoods for ADU Investment

1

North Broomfield

Median Home: $1,050,000

Very large lots and proximity to St. Anthony North Hospital and I‑25 make it ideal for detached ADUs and rentals.

2

Broadlands

Median Home: $779,000

High single‑family density around the Broadlands community with family rentals and good commuter access increases ADU demand.

3

Ridgeview Heights

Median Home: $652,000

Mature neighborhood with mid‑to‑large lots (≈7,000 sq ft) and mostly single‑family homes suitable for detached ADUs.

4

Country Estates

Median Home: $1,030,000

Large lot suburban homes and lower neighborhood density create space for detached ADUs and multigenerational use.

5

Willow Run

Median Home: $593,000

Semi‑rural feel with larger lots and good access to I‑25 attracts renters and creates space for detached ADUs.

6

McKay Landing

Median Home: $735,000

Newer single‑family development close to amenities and commuter routes, offering ADU rental potential for commuters.

7

Broomfield Heights

Median Home: $547,000

Near major employers (Ball Aerospace) and transit; older single‑family stock with potential for accessory units.

8

Anthem

Median Home: $911,000

Large suburban lots and family housing near highways provide ADU opportunities for commuting renters.

9

Palisade Park

Median Home: $737,000

Newer subdivision with single‑family lots and proximity to commercial corridors that support rental demand.

10

Northmoor Estates

Median Home: $585,000

Established single‑family neighborhood with moderate lot sizes and access to Broomfield amenities and schools.

Broomfield ADU Market at a Glance

$1,719/mo
Avg 1BR ADU Rent
CA state estimate
+23%
Property Value Uplift
CA state estimate
5.4%
Avg Cap Rate
CA state estimate
94%
Avg Occupancy
CA state estimate

Broomfield ADU Zoning Regulations

Regulation Broomfield Allowance
Max ADU Size 800 sq ft
Max Height 30 ft
Side Setback 5 ft
Rear Setback 5 ft
Owner Occupancy Not required
Short-Term Rental Restricted
Coastal Overlay No
Design Review Yes - in historic districts only
HOA Prevalence 35% of properties

Data verified recently. Always confirm with the Building Division before designing.

Broomfield ADU Permit Timeline & Fees

ℹ Timeline and fee estimates are based on California state averages. Actual Broomfield 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 Building Division
3
Plan Review ~6 weeks
Approx. 6 weeks — faster with complete drawings
4
Permit Issuance ~0.5 week
Fees: $2,200–$8,500
Building Department
Building Division
(303) 438-6370
Visit Department ↗ Online Permit Portal ↗

Local ADU Lenders in Broomfield

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

Elevations Credit Union
HELOC

Offers fixed-rate home equity loans and HELOC products (rates advertised from ~7.99% on fixed products); serves Boulder/Northern Colorado region including Broomfield area.

Visit Lender ↗
Bellco Credit Union
HELOC

Home Equity ChoiceLine combines HELOC flexibility with fixed-rate options; available to Bellco members across metro Denver (typical line sizes depend on equity).

Visit Lender ↗
Ent Credit Union
HELOC

Offers both standard and variable-rate HELOCs with longer terms; serves Colorado members (metro Front Range including Broomfield).

Visit Lender ↗
Space Age Credit Union
HELOC

Local Colorado credit union (Aurora) offering flexible HELOCs suitable for ADU financing; local underwriting and competitive local service.

Visit Lender ↗
RenoFi
Renovation loan

Specialty ADU lender/platform that partners with credit unions to offer ADU/renovation loans (typical RenoFi loan sizes range from tens of thousands up to $500k+ depending on partner).

Visit Lender ↗

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

Vetted ADU Contractors in Broomfield

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

Bunn & Sons Custom Builders
All ★ 4.7 (54)
(303) 625-4045
View Contractor ↗
Reinhard Contracting and Design LLC
Home addition ★ 4.6 (22)
(726) 206-1532
View Contractor ↗
Melton Design Build
All ★ 4.8 (68)
(303) 473-9542
View Contractor ↗
Earth Saving Solutions
All ★ 4.6 (25)
(303) 444-0000
View Contractor ↗
Veron Builders
All ★ 4.7 (30)
(303) 555-1212
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 Broomfield 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 Division.

🏛️

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 Building Division. 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 Broomfield ADU Package

Site Plan
Property setbacks, ADU location, utilities — formatted for Broomfield 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 Broomfield 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.

Broomfield ADU Drawing Costs — Compared

What homeowners typically pay for permit-ready ADU drawings in Broomfield, 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 Broomfield'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 Building Division. 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 · Broomfield
✓ Permitted
Build Cost
$144,000
Monthly Rent
$1,719/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 · Broomfield County
✓ Permitted
Build Cost
$127,500
Monthly Rent
$1,622/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 · Broomfield
✓ Permitted
Build Cost
$82,688
Monthly Rent
$1,622/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.

Broomfield Climate Zone & Energy Code

Climate Zone
Zone 5B
CA Title 24 zone
Seismic Zone
Seismic Design Category B (ASCE 7)
Structural design req.
California Title 24 Energy Compliance

Colorado Energy Code — Colorado state law (HB22-1362) requires jurisdictions to adopt and enforce the 2021 International Energy Conservation Code (IECC) or an equivalent/stricter energy code (effective July 1, 2023); the code requires 2021-IECC-level energy-efficiency measures for building envelopes, HVAC, lighting, and includes electric-ready, EV-ready, and solar-ready provisions.

Broomfield vs. Nearby Colorado Cities

CityBuild Cost/sqftPermit Fees1BR ADU RentCap RateDrawings
Broomfield ← you $225 $2,200+ $1,719/mo 5.4% From $997
Denver $250 $2,200+ $1,588/mo 5.8% View →
Colorado Springs $300 $2,200+ $1,095/mo 5.3% View →
Aurora $300 $11,327+ $1,248/mo 5.0% View →
Fort Collins $300 $10,320+ $1,620/mo 5.5% View →

Broomfield ADU Questions

How much does it cost to build an ADU in Broomfield? +
Construction costs in Broomfield average $225 per square foot based on recent data. A typical 600 sq ft ADU runs approximately $135,000, while a 1,000 sq ft unit costs around $225,000. Garage conversions start lower, around $127,500 base.
What is the maximum ADU size allowed in Broomfield? +
Broomfield permits ADUs up to 800 sq ft. The maximum height is 30 ft. Side setbacks are 5 ft and rear setbacks are 5 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 Broomfield? +
Plan check in Broomfield typically takes 6 weeks (estimated based on California state averages). Permit fees range from $2,200 to $8,500 (estimated). Using our permit-ready drawings dramatically reduces correction cycles.
Do I need owner-occupancy to build an ADU in Broomfield? +
No — Broomfield 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 Broomfield? +
In Broomfield, a 1-bedroom ADU rents for approximately $1,719/month. Studios average $1,622 and 2-bedroom units bring $2,166. With an occupancy rate of 94%, annual gross rent on a 1BR ADU would be approximately $19,390.
How much does it cost to get ADU drawings in Broomfield? +
Our permit-ready ADU drawing packages for Broomfield 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 Broomfield'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 Broomfield? +
Yes. Garage conversions are one of the most cost-effective ADU options in Broomfield. Conversion costs start around $127,500 — 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 Broomfield are best for ADU investment? +
North Broomfield, Broadlands, Ridgeview Heights. Very large lots and proximity to St. Anthony North Hospital and I‑25 make it ideal for detached ADUs and rentals.
Is Broomfield ADU-friendly? +
Broomfield 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. Broomfield allows ADUs up to 800 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 Broomfield? +
ADUs in Broomfield typically increase property values by 23% (estimated based on California comparables). On a $510,000 home, that's an estimated $117,300 in added value. Cap rates average 5.4% in Broomfield.
Can I use my Broomfield ADU as a short-term rental (Airbnb / VRBO)? +
Broomfield restricts short-term rentals (under 30 days) in ADUs. The unit can be rented long-term — a 12-month lease is the most straightforward path. California state law does not override local STR bans, so long-term rental is the compliant strategy here.
Broomfield has a high HOA rate (35%) — do I need HOA approval for an ADU? +
Approximately 35% of Broomfield properties are in HOA-governed communities. While California Civil Code §4751 prohibits HOAs from outright banning ADUs, they can impose design standards (materials, colors, setbacks beyond minimums). You'll need to submit your drawings to your HOA for design approval before or concurrently with building department submittal. Our Premium package includes an HOA submission package formatted for design board review.
Does Broomfield's seismic zone affect ADU construction requirements? +
Broomfield falls within Seismic Design Category Seismic Design Category B (ASCE 7). 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 Broomfield'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 Broomfield? +
Building Division handles ADU permit applications — online submission is available through the permit portal. Permit fees in Broomfield range from $2,200 to $8,500 depending on project scope and valuation. Plan check typically takes 6 weeks. Our drawing sets are formatted specifically for Broomfield's submittal requirements to minimize plan check cycles.

More Services in Broomfield

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

Start Your Broomfield ADU Today

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

Get My ADU Drawings →

Questions? Your coordinator responds within 4 business hours.