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LITTLETON SERVICES

Littleton ADU / backyard cottage — local feasibility & estimate

ADU Feasibility Consultation, $350

Compare both studies

Exploring a backyard ADU in Littleton? Autotelic helps assess feasibility against lot, setbacks, HOA, and local rules—then provides a clear estimate and build path with one team. No fake zoning envelopes. No invented prices or license claims.

What Littleton requires

Code reference: Standard IRC Section R105.2 exemptions typically apply (e.g., certain minor non-structural repairs, painting, or very small accessory structures), but Littleton provides no separate local valuation threshold below which permits are automatically waived for remodel/alteration work. §R105.2

See full local requirements ↓
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ADU / Backyard Cottage

Build an income-producing unit in your backyard

Book an ADU feasibility study

Two fixed-price studies, booked online before you pay for design: a site visit with a go/no-go read on your lot, or a written report you can take to a lender.

Pay when you book. We confirm within 24 hours or refund you in full.

  • ADU Feasibility Consultation

    An on-site review of your lot against local ADU zoning, setbacks, and utility access.

    Pay when you book · morning (8–12) or afternoon (12–4)

    What's included

    An on-site review of your lot against local ADU zoning, setbacks, and utility access. You get a verbal go/no-go read plus a one-page summary of constraints and next steps.

  • ADU Feasibility Package

    Site visit plus a written feasibility report: local ADU zoning check, buildable envelope sketch, utility routing notes, and a preliminary budget.

    $475 deposit to book, the rest when the work is done · morning (8–12) or afternoon (12–4)

    What's included

    Site visit plus a written feasibility report: local ADU zoning check, buildable envelope sketch, utility routing notes, and a preliminary budget. A documented go/no-go you can take to a lender.

Studies for additions, custom homes and commercial space

FREE PLANNING TOOLS

Both tools are free and take a couple of minutes — start in either one.

Local Service

ADU / Backyard Cottage Services in Littleton, Colorado

Autotelic provides professional ADU / backyard cottage services throughout Littleton and the surrounding Arapahoe County area. Accessory dwelling unit construction across the Denver metro — detached new builds, garage conversions, and basement conversions compliant with Colorado HB 24-1152. One veteran-owned design-build team runs the full Denver sequence under a single contract: zoning verification and concept design, municipal zoning and building permit reviews, then construction and inspections through certificate of occupancy. Whether you're in Littleton (historic downtown Littleton) or nearby communities, our team delivers quality workmanship backed by Colorado licensing and full insurance coverage.

Permits & Licensing

Permits in Littleton

Littleton building permits are issued by the Community Development Department's Building Division and Permit Center, and a license or registration certificate is required to obtain permits for work within city limits. Applications, plan submittals, and inspection scheduling run through the eTRAKiT online system. Authority: City of Littleton — Community Development Department (Building Division / Permit Center).

Permit Thresholds

Littleton permit thresholds

Code reference
Littleton has adopted the 2024 International Residential Code (IRC) and other International Codes (with local amendments) under Littleton City Code Title 4, Building Regulations, Chapter 1.
Code reference
Standard IRC Section R105.2 exemptions typically apply (e.g., certain minor non-structural repairs, painting, or very small accessory structures), but Littleton provides no separate local valuation threshold below which permits are automatically waived for remodel/alteration work.§R105.2
Code reference
Exempt work lists and structural triggers are governed by the adopted 2024 IRC (with amendments) and Littleton’s submittal policies.
Code reference
Minor cosmetic or non-structural work (e.g., painting, flooring replacement without affecting structure) is typically exempt under IRC R105.2.
Building permit fees follow a tiered schedule based on total valuation (e.g., $1
$25.85; higher tiers add incremental amounts per $100 or $1,000).
Code reference
Plan review fee is 65% of the permit fee(s) when blueprints/construction documents are reviewed.
Code reference
Use tax deposit = 0.01969 × total job valuation, calculated as ((total job valuation × 52.5%) × 3.75%).
Code reference
Arapahoe County Open Space Tax = 0.00125 × total valuation, calculated as ((total job valuation × 50%) × 0.25%).

Codes are amended regularly — verify current requirements with City of Littleton — Community Development Department (Building Division / Permit Center).

Zoning & ADU

Littleton zoning & ADU quick facts

ACR — Minimum Lot Area
2.75 acACR
ACR — Minimum Lot Width
175'ACR
ACR — Front Setback (min)
25'ACR
ACR — Side Interior Setback (min)
20'ACR
ACR — Side Setback Abutting Street (min)
50'ACR
ACR — Rear Setback (min)
50'ACR
ACR — Lot Coverage (max)
17%ACR
ACR — Building Height (max)
30'ACR
Littleton Unified Land Use Code Title 10 (Ord. 18 Series of 2022; Ord. 20 Series of 2023) ACR setback standards (Table 10-4-2.2 NB Lot and Building Standards) — effective 2023-10-13Source: online.encodeplus.com

Codes are amended regularly — verify current requirements with City of Littleton — Community Development Department (Building Division / Permit Center).

A recent build

Backyard ADU in Denver

Denver · 2026

Status
Under construction — 2026
Managed on
Buildbot — Autotelic’s own PM platform
  • Architecture, site plans, and full MEP design completed in-house
  • Permits pulled — electric and plumbing rough-ins permitted and underway
  • Spray-foam insulation and exterior work in progress
  • First project managed end-to-end on Buildbot, Autotelic’s construction-PM platform

A ground-up backyard ADU in Denver — designed, permitted, and now under construction by Autotelic, and the first project managed end-to-end on Buildbot, Autotelic’s own construction-management platform.

Energy Code

Littleton energy code quick facts

Code reference
2024 IECC (residential and commercial provisions), as adopted by reference with amendments in Littleton City Code Title 4, Chapter 1 (Ordinance 11, Series 2025). The city also adopts the Colorado Model Electric Ready and Solar Ready Code (June 1, 2023 version).Ord. 11
Code reference
Prescriptive R-values/U-factors are unchanged from the 2024 I-codes (no local reductions or increases).
Code reference
Littleton is in Climate Zone 5B.
Code reference
Alterations/additions to the building thermal envelope (new assemblies, modifications, or change-in-use) must generally meet the new-construction prescriptive requirements below; existing assemblies that are exposed but not modified may be insulated to the greatest extent possible without exceeding
Code reference
Some exceptions apply (e.g., storm windows, roof recovers) provided energy use is not increased (amended C503.2 / R503.1.1).
Ceiling/attic insulation
R-49 (or R-38 over 100% of the area if uncompressed R-38 extends over the wall top plate at eaves; limited reduction to R-30 allowed for certain roof/ceiling designs up to 500 sf or 20% of ceiling area).
Adopting reference/ordinance
2024 IECC Table R402.1.2 / IRC Table N1102.1.2 (as consolidated in city table, note b/c).
Wood-framed above-grade walls
R-20ci only, or R-13cav + R-10ci, or R-20cav + R-5ci, or R-30cav only.

Codes are amended regularly — verify current requirements with City of Littleton — Community Development Department (Building Division / Permit Center).

Service Area

Serving Littleton and Arapahoe County

We serve Littleton, CO and all surrounding Denver metro communities. Our team is based in Denver and operates throughout the Front Range, from Castle Rock to Longmont and everywhere in between. Contact us for a free estimate on your Littleton project.

FAQ

ADU feasibility FAQ

How much does ADU Feasibility Consultation cost in Littleton?

$350.

How do I book?

Press Book next to the job, pick a date and a morning (8–12) or afternoon (12–4) window, and pay in full. We confirm within 24 hours or refund you in full.

Can I build an ADU on my lot?

It depends on lot size, setbacks, HOA rules, and Littleton’s code. Autotelic helps assess feasibility—we do not invent zoning envelopes or guarantee permit outcomes.

Is the online sizing tool a permit determination?

No. Lot-aware sizing on /adu/ is illustrative only and is not a permit determination. A clear estimate and local review come next.

What happens after I start an estimate?

You move from feasibility into a clear estimate with the same design-build team, then permit coordination and build with a licensed Littleton crew when you proceed.

What will an ADU cost?

The lot lookup is free. Our ADU cost page shows planning ranges for a detached backyard cottage; your lot, utility connections and finishes affect the price. Start an estimate for your project, or call (720) 287-7958 to talk it through. A fixed-price build proposal comes after feasibility.

Who builds the ADU?

Autotelic’s local design-build team takes your project from the first concept through an estimate, permits and construction. You have one team to talk to along the way.

Is an ADU allowed on my lot?

It depends on your city’s zoning — lot size, setbacks, and parking rules vary across the metro. We run the zoning check as the first step and tell you what your lot supports before you spend money on design.

Do you handle ADU permits and inspections?

Yes — ADU permitting is municipal, and we manage zoning review, permit application, and every inspection through certificate of occupancy.

Detached, attached, or garage conversion — which is right?

Each has different zoning, cost, and site implications. We design all three and recommend based on your lot, budget, and how you plan to use the unit.

What does an ADU cost?

Getting a real answer costs less than most people expect: an ADU feasibility consultation is $350, and the full ADU feasibility package — zoning check, site analysis, and concept direction — is $950, both listed at fixed prices on our booking page. Construction cost depends on the path: garage and basement conversions reuse existing structure, while a detached backyard cottage is new construction from the foundation up. After feasibility we quote the build itself as a fixed-price proposal, so you know the number before work starts.

How long does an ADU project take?

First we check your lot and agree on the scope. Then come design and drawings, city permit review, and construction with inspections. Your lot, utility connections, design changes and the city’s review schedule affect the timing. Your proposal includes a project-specific schedule before you commit to the build. A consultation booking is the first planning conversation, not a construction start date.

How small a lot can support an ADU?

Smaller than most people assume — many Front Range single-unit lots that owners write off can carry a detached unit, and each city sets its own minimum lot size, setbacks, and building coverage. Whether your district’s standards leave room for a backyard cottage — or point you toward a garage or basement conversion instead — is exactly what the feasibility check answers for your address.

What is the ADU permit process?

Two municipal reviews run in order: a zoning review confirming the unit fits your district’s standards, then a building permit review of the construction documents, with inspections during the build and a certificate of occupancy at the end. Colorado HB 24-1152 now requires most Front Range municipalities to allow ADUs on single-unit lots, and we confirm how your city implements it as the first step of feasibility.

How It Runs

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Survey

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Design

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Build

04

Verify

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Let's design your perfect ADU / Backyard Cottage together

Get a personalized estimate in about 2 minutes — no pressure, no obligation.

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How This Works (2 minutes)

  1. 1Tell us about your project (30 seconds)
  2. 2Answer a few quick questions for an accurate estimate (60 seconds)
  3. 3Get your personalized estimate instantly (30 seconds)

No pressure. No obligation. No spam calls. If we're not the right fit, we'll tell you — and even recommend someone who is.