DESIGN · BUILD · AUTOMATE
LITTLETON SERVICES
ADU / Backyard Cottage in Littleton
Licensed adu / backyard cottage services for Littleton and Arapahoe County. Build an income-producing unit in your backyard.
- Full Design Lifecycle
- Construction & Tenant Finish
- Smart Home · A/V · Edge Compute
Build an income-producing unit in your backyard
EVERY PROJECT STARTS WITH DESIGN
Proof in the Field
Real adu / backyard cottage work, delivered
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.Section 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
- Code reference
- Littleton, CO uses its Unified Land Use Code (ULUC, Title 10) with neighborhood-specific residential districts regulated primarily in Chapter 10-4 (including Table 10-4-2.2 for lot/building standards such as minimum lot size/area, maximum height, minimum setbacks, and maximum building/lot coverage
- Code reference
- Exact numeric standards (lot coverage %, building height, setbacks) vary by specific district and are detailed in Table 10-4-2.2 and related sections; they are not uniformly listed across secondary sources with district codes.
- ADU max size
- Capped at the gross floor area of the main house or 1,000 square feet, whichever is less (recent ordinance updates raised prior limits, e.g., from 750 sq ft in some references).ordinance updates
- Code reference
- Specific rear/side setbacks for detached ADUs vary by district and type (e.g., often reduced in rear yard per district rules or state compliance); confirm via the city’s Zoning Portal or Table 10-4-2.2.
- Code reference
- All figures should be verified directly in the current ULUC (online.encodeplus.com) or via Littleton’s Zoning Portal for a specific parcel/district, as standards are district-specific and subject to updates (e.g., 2024–2025 ADU ordinances).
Codes are amended regularly — verify current requirements with City of Littleton — Community Development Department (Building Division / Permit Center).
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).Ordinance 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).
text
What an ADU or backyard cottage involves
An accessory dwelling unit (ADU), sometimes called a backyard cottage, is a secondary living unit on a lot that already has a primary home. Common forms include detached backyard cottages, garage conversions, and attached additions with a separate entrance and living space. In the Denver metro, feasibility usually turns on zoning and lot standards, utility capacity, access and parking rules, setbacks, height limits, and how the unit will be used (long-term housing, multigenerational living, or flexible guest space). Early planning should confirm what your city or county allows on your specific parcel before design is locked in.
text
Design and site factors that drive the project
Strong ADU plans start with the lot, not just the floor plan. Key inputs include buildable area after setbacks, existing structures and easements, grading and drainage, tree and landscape impacts, alley or side-yard access, and where water, sewer, gas, and electric can connect. Interior planning typically covers a compact kitchen, full or three-quarter bath, sleeping space, storage, daylight, and code-required egress. Exterior design should fit the primary home and neighborhood context while meeting height, lot coverage, and exterior material standards set by the local jurisdiction. Detached units also need clear decisions on foundation type, insulation and energy detailing for Colorado’s climate, and durable exterior assemblies that handle freeze-thaw cycles and sun exposure.
text
Permits, inspections, and trade coordination
ADU projects generally require building permits and may also need zoning review, utility permits, and separate trade permits. Requirements vary by city and county across the Denver metro, so the submittal package should match the rules for the property address. A municipally licensed Denver general contractor coordinates the overall project and works with licensed specialty trades for work such as electrical, plumbing, and mechanical systems. That coordination covers sequencing, inspection readiness, and keeping architectural, structural, and MEP details aligned as the unit moves from plans to construction.
text
Typical build path
Most ADU projects follow a clear sequence: feasibility and code check, measured site review, schematic design, construction documents, permit submittal, procurement, construction, inspections, and closeout. Detached cottages often involve site work, foundation, framing, roofing, windows, insulation, drywall, finishes, and final utility tie-ins. Garage conversions and attached ADUs can reduce some site work but may add structural, fire-separation, moisture, and existing-condition challenges. Conversion projects need careful assessment of foundation, framing, insulation, head height, and whether the existing shell can support a comfortable, code-compliant dwelling.
text
What influences cost without a one-size price
ADU cost is project-specific. Major drivers include unit size, detached versus attached or conversion scope, foundation and site work, utility run lengths and capacity upgrades, kitchen and bath layout, finish level, structural complexity, energy detailing, access constraints, and local permit requirements. Soft costs also matter: design and engineering, survey or site documentation when needed, permit fees, and longer lead times for selected materials. A clear scope and early utility/site review usually reduce redesign and change orders later.
FAQ
Common questions
What is the difference between an ADU and a backyard cottage?
They often describe the same idea: a secondary dwelling on a lot with a primary home. “Backyard cottage” usually means a detached unit behind the main house. “ADU” is the broader planning term and can include detached units, attached units, or conversions, depending on local definitions.
Who handles the trade permits and licensing on an ADU project?
A municipally licensed Denver general contractor coordinates the project and the permit path. Licensed specialty trades perform regulated trade work such as electrical, plumbing, and mechanical, and those trades pull the permits required for their scopes where applicable.
Can every Denver-metro lot add an ADU?
No. Eligibility depends on local zoning and lot standards, including use rules, setbacks, height, lot coverage, parking, and utility constraints. The right first step is confirming what the jurisdiction allows for the specific address and lot configuration.
Is a garage conversion simpler than a new detached cottage?
Sometimes, but not always. Conversions may reuse an existing shell and reduce some site work, yet they can require structural upgrades, insulation and moisture improvements, fire separation, ceiling-height solutions, and new utility routing. A detached cottage adds foundation and full exterior scope but can offer a cleaner layout when yard space and setbacks allow.
How long does an ADU project usually take?
Timeline depends on design complexity, utility work, permit review duration, material lead times, weather, and inspection scheduling. Projects with clear feasibility, complete drawings, and fewer existing-condition surprises generally move more predictably than conversions discovered midstream to need major upgrades.
What decisions should homeowners make early?
Confirm intended use, target size, detached versus attached or conversion, access and privacy needs, parking implications, budget range as a planning input, and whether the unit must function independently year-round. Those choices shape site layout, utility design, and the permit strategy.
text
How to start planning
Begin with parcel realities: zoning path, buildable envelope, access, and utility capacity. Then define the unit type and must-have program so design and budgeting stay aligned. From there, construction documents and permit coordination can proceed with fewer revisions. If you are comparing options, bring basic lot information, any prior survey or improvement location certificate if available, rough size goals, and notes on how the unit will be used. That preparation helps a general contractor and design team give a clearer read on scope and sequence.
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
Common questions
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?
Three phases run in sequence: design (site measure, concept, construction documents), permitting (zoning and building review, which move on the municipality’s calendar), then construction. Conversions generally move faster than detached new builds because the shell and foundation already exist. We lay out the phase-by-phase schedule in your proposal, and you track progress on our operations platform once work starts.
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
01
Survey
02
Design
03
Build
04
Verify
DESIGN SERVICES
Discovery & Site Analysis
Needs + preference programming, site survey, as-built documentation, feasibility.
We walk, measure, and photograph your property — existing conditions, utilities, structure, and constraints. You get the as-built documentation and feasibility read that every later decision rests on.
Learn more →Concept Design & Space Planning
Schematic design, floor plan studies, layout options.
Your scope becomes schematic floor plans you can compare side by side — circulation, daylight, adjacencies, and what each option does to the budget. Layout decisions happen on paper, where changes are cheap.
Learn more →Architectural Design & 3D Renderings
Design development, materials + finishes, photorealistic visualization.
The chosen concept resolves into materials, finishes, fixtures, and lighting — with the automation layer drawn in. Photorealistic renderings let you walk the space and adjust before anything is priced.
Learn more →Construction Documents & Permitting
Full CD sets, structural + MEP engineering coordination, permit-ready drawings.
Approved designs become coordinated architectural, structural, and MEP sheets — the set your jurisdiction permits from and trades build from. We submit, track, and answer review comments.
Learn more →CONSTRUCTION
New Construction & Custom Homes
Ground-up homes and light commercial, dirt to keys.
Ground-up residential and light commercial builds — foundations through finishes, including modular and steel construction. One accountable builder from dirt to keys.
Learn more →Remodels & Additions
Kitchens, baths, basements, pop-tops, whole-home.
Kitchens, baths, basements, pop-tops, and whole-home renovations that respect the house you already have. We handle structure, permits, and the dust.
Learn more →Commercial Tenant Finish & Build-Outs
Shells to working spaces — retail, office, restaurant, school.
Raw shells become working spaces — showrooms, offices, restaurants, schools. Dealer-spec finishes, code compliance, and opening dates held.
Learn more →ADUs & Modular Construction
Backyard cottages, garage conversions, factory-built homes.
Backyard cottages, garage conversions, and factory-built homes — zoning, design, permits, and set. Denver’s ADU rules are a specialty, not a surprise.
Learn more →Outdoor Living & Patio Structures
Decks, pergolas, and dining patios built for Colorado weather.
Decks, pergolas, and dining patios engineered for Colorado sun, snow, and hail — structure, shade, and drainage done right the first time.
Learn more →TECHNOLOGY
Smart Home Automation
Lighting, shades, climate, audio, security — one interface.
Whole-home control of lighting, shades, climate, audio, and security from a single interface — Crestron, Lutron, Savant, and Control4 designed in, not bolted on.
Learn more →A/V Systems
Theaters, distributed audio, video walls, commercial sound.
Theaters, distributed audio, video walls, and commercial sound — designed, installed, and tuned by the same team for over 20 years.
Learn more →Control Systems
Custom programming — scenes and schedules that fit the space.
Every subsystem brought into one elegant interface — custom programming for homes and venues, with scenes and schedules that match how the space is actually used.
Learn more →Networking & Edge Compute
Enterprise Wi-Fi, structured cabling, racks, on-prem compute.
Enterprise-grade Wi-Fi, structured cabling, racks, and on-premise compute — the backbone that makes everything else reliable, including our own Barbot platform.
Learn more →Solar & Energy Storage
Solar arrays, Tesla Powerwall, EV charging — certified install.
Solar arrays, Tesla Powerwall, and EV charging designed and installed by a Tesla Energy Certified team — roof, electrical, and app in one scope.
Learn more →TRUSTED TO BUILD FOR
- Punch Bowl SocialFirst four locations
- Spectrum RetirementSenior living communities
- Denver HighlandsFirst modular custom home
Let's design your perfect ADU / Backyard Cottage together
Get a personalized estimate in about 2 minutes — no pressure, no obligation.
How This Works (2 minutes)
- 1Tell us about your project (30 seconds)
- 2Answer a few quick questions for an accurate estimate (60 seconds)
- 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.
Explore
Also serving
Explore