The Complete Guide to
Building an ADU in Erie, CO

Everything Erie 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 Erie's ADU Rules ↓

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

Quick Answers About Erie, CO ADUs

ADUs Allowed
Up to 750 sq ft
25 ft max height
🏠
Owner Occupancy
Not required
CA state law applies
📊
Average Build Cost
$250/sqft
verified 2026
💰
Avg Rental Income
$1,740/mo
1BR ADU · verified data
California home with a newly built backyard ADU — Erie property
Completed Project · Erie
Garage converted to ADU — exterior view after permitted conversion
Build With A Plan · Permit-Ready Drawings from $997

Market Context

Erie has a median home value of $590,000. Adding an ADU typically increases that by 23% — approximately $135,700 in added equity. A 1-bedroom ADU in Erie rents for approximately $1,740/month in the Weld County rental market , yielding a 5.2% cap rate on the investment. Occupancy averages 98% in this market.

Top Erie neighborhoods for ADU investment include Old Town Erie, Colliers Hill, Flatiron Meadows, Parkdale, Morgan Hill. Older single-family lots and existing ADU examples near downtown make it easy to add rental ADUs. Large lots and single-family homes in this master-planned community offer good space for detached ADUs.

Permit Process

Permit applications are reviewed by the Planning & Development Department , with a plan check timeline of approximately 6 weeks. Permit fees in Erie range from $2,200 to $8,500 depending on project scope. Design review: No — ADUs require standard building permits and compliance with Development Design Standards; design review is not required townwide, though historic/landmarked properties or larger discretionary developments may be subject to review by the Historic Preservation Advisory Board or development review processes.

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

Is My Erie, CO Property Eligible for an ADU?

Erie 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 Erie under California state law. No owner-occupancy requirement in Erie — 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 75% of Erie 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 — ADUs require standard building permits and compliance with Development Design Standards; design review is not required townwide, though historic/landmarked properties or larger discretionary developments may be subject to review by the Historic Preservation Advisory Board or development review processes.

Always verify eligibility with Planning & Development Department before designing.

Erie ADU Return Calculator — Built With 2026 Local Data

Pre-loaded with verified Erie 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
$18,374/yr
Annual Net Income
$12,862/yr
Value Added (~23%)
+$135,700
Total Return (10 yrs)
$264,320
Break-Even
12 years

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

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

Top Erie Neighborhoods for ADU Investment

1

Old Town Erie

Median Home: $459,500

Older single-family lots and existing ADU examples near downtown make it easy to add rental ADUs.

2

Colliers Hill

Median Home: $752,000

Large lots and single-family homes in this master-planned community offer good space for detached ADUs.

3

Flatiron Meadows

Median Home: $1,200,000

Quarter-acre lots and large homes provide strong opportunity for detached ADUs.

4

Parkdale

Median Home: $750,000

Master-planned neighborhood with generous lots and nearby amenities that attract renters.

5

Morgan Hill

Median Home: $900,000

Close to I-25 and regional job centers, with larger lot homes suited to ADUs.

6

Westerly

Median Home: $919,000

New master-planned community near I-25 with strong demand and family-sized lots.

7

Erie Highlands

Median Home: $536,500

Established single-family neighborhood with generous lots and community amenities.

8

Arapahoe Ridge

Median Home: $733,568

Mature neighborhood near central Erie with single-family lots and proximity to town services.

9

Northridge

Median Home: $733,568

Single-family subdivision with lot types and location that support rental demand from commuters.

10

Rex Ranch

Median Home: $733,568

Planned/PD neighborhoods with larger lots — a practical option for detached ADUs.

Erie ADU Market at a Glance

$1,740/mo
Avg 1BR ADU Rent
verified data
+23%
Property Value Uplift
verified data
5.2%
Avg Cap Rate
verified data
98%
Avg Occupancy
verified data

Erie ADU Zoning Regulations

Regulation Erie Allowance
Max ADU Size 750 sq ft
Max Height 25 ft
Side Setback 5 ft
Rear Setback 5 ft
Owner Occupancy Not required
Short-Term Rental Permitted
Coastal Overlay No
Design Review No — ADUs require standard building permits and compliance with Development Design Standards; design review is not required townwide, though historic/landmarked properties or larger discretionary developments may be subject to review by the Historic Preservation Advisory Board or development review processes.
HOA Prevalence 75% of properties

Data verified recently. Always confirm with the Planning & Development Department before designing.

Erie ADU Permit Timeline & Fees

ℹ Timeline and fee estimates are based on California state averages. Actual Erie 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 Planning & Development Department
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
Planning & Development Department
(303) 926-2780
Visit Department ↗ Online Permit Portal ↗

Local ADU Lenders in Erie

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

Erie Federal Credit Union
Construction loan

Offers residential construction and mortgage loans with programs that may waive private mortgage insurance.

Visit Lender ↗
Elevations Credit Union
HELOC

Provides flexible home equity lines of credit specifically marketed for funding home renovations in the Colorado area.

Visit Lender ↗
Alpine Bank
HELOC

Offers home equity lines of credit with flexible repayment terms secured by the equity in your home.

Visit Lender ↗
FirstBank
Construction loan

Provides residential construction loans with disbursements made at various stages of the development process.

Visit Lender ↗
RenoFi
Renovation loan

Specializes in renovation loans that use the after-renovation value of the home to increase borrowing power for ADUs.

Visit Lender ↗

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

Vetted ADU Contractors in Erie

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

Built By Krueger
Home addition
N/A
View Contractor ↗
Cornerstone Homes (Cornerstone Contracting)
Home addition
(303) 444-0433
View Contractor ↗
Mark Hammer Construction LTD.
Home addition
(720) 605-3885
View Contractor ↗
Summit Edge Builders
All
N/A
View Contractor ↗
Flatirons Painting & Remodeling
Garage conversion
N/A
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 Erie 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 Planning & 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 Planning & 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 Erie ADU Package

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

Erie ADU Drawing Costs — Compared

What homeowners typically pay for permit-ready ADU drawings in Erie, 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 Erie'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 Planning & 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 · Erie
✓ Permitted
Build Cost
$160,000
Monthly Rent
$1,740/mo

"We'd been quoted $6,200 by a local firm. Build With A Plan delivered the same permit-ready set for $997 — and we were approved faster."

— David & Lisa K. Permit: 6 weeks
Garage Conversion to ADU
480 sq ft · Weld County
✓ Permitted
Build Cost
$100,000
Monthly Rent
$1,650/mo

"Conversion permit came back approved on the first review. The drawings handled every detail — egress, HVAC, electrical. Nothing was missing."

— Sandra C. Permit: 6 weeks
Junior ADU (JADU)
490 sq ft · Erie
✓ Permitted
Build Cost
$91,875
Monthly Rent
$1,650/mo

"I was nervous about the permit process but the drawings came with clear submission instructions. Approved without a single correction cycle."

— Patricia M. Permit: 5 weeks

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

Erie Climate Zone & Energy Code

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

Colorado Energy Code; local jurisdictions are required by state law to adopt and enforce the 2021 IECC and the Model Electric Ready & Solar Ready Code when updating building codes.

Erie vs. Nearby Colorado Cities

CityBuild Cost/sqftPermit Fees1BR ADU RentCap RateDrawings
Erie ← you $250 $2,200+ $1,740/mo 5.2% From $997
Greeley $200 $13,924+ $999/mo 6.6% View →
Windsor $400 $17,516+ $1,562/mo 5.5% View →
Evans $300 $59,089+ $1,299/mo 6.7% View →
Denver $250 $2,200+ $1,588/mo 5.8% View →

Erie ADU Questions

How much does it cost to build an ADU in Erie? +
Construction costs in Erie average $250 per square foot based on 2026 data. A typical 600 sq ft ADU runs approximately $150,000, while a 1,000 sq ft unit costs around $250,000. Garage conversions start lower, around $100,000 base.
What is the maximum ADU size allowed in Erie? +
Erie permits ADUs up to 750 sq ft. The maximum height is 25 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 Erie? +
Plan check in Erie 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 Erie? +
No — Erie 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 Erie? +
In Erie, a 1-bedroom ADU rents for approximately $1,740/month. Studios average $1,650 and 2-bedroom units bring $2,030. With an occupancy rate of 98%, annual gross rent on a 1BR ADU would be approximately $20,462.
How much does it cost to get ADU drawings in Erie? +
Our permit-ready ADU drawing packages for Erie 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 Erie'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 Erie? +
Yes. Garage conversions are one of the most cost-effective ADU options in Erie. 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 Erie are best for ADU investment? +
Old Town Erie, Colliers Hill, Flatiron Meadows. Older single-family lots and existing ADU examples near downtown make it easy to add rental ADUs.
Is Erie ADU-friendly? +
Erie 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. Erie allows ADUs up to 750 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 Erie? +
ADUs in Erie typically increase property values by 23%. On a $590,000 home, that's an estimated $135,700 in added value. Cap rates average 5.2% in Erie.
Can I use my Erie ADU as a short-term rental (Airbnb / VRBO)? +
Erie currently permits short-term rentals in ADUs, subject to local registration requirements and California's state STR framework. Check with the Planning & Development Department for any hosting platform limits or permit conditions that apply to your specific parcel.
Erie has a high HOA rate (75%) — do I need HOA approval for an ADU? +
Approximately 75% of Erie 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 Erie's seismic zone affect ADU construction requirements? +
Erie falls within 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 Erie'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 Erie? +
Planning & Development Department handles ADU permit applications — online submission is available through the permit portal. Permit fees in Erie 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 Erie's submittal requirements to minimize plan check cycles.

More Services in Erie

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

Start Your Erie ADU Today

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

Get My ADU Drawings →

Questions? Your coordinator responds within 4 business hours.