DESIGN · BUILD · AUTOMATE
THORNTON SERVICES
Thornton ADU / backyard cottage — local feasibility & estimate
ADU Feasibility Consultation, $350
Compare both studiesExploring a backyard ADU in Thornton? 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.
- Full Design Lifecycle
- Construction & Tenant Finish
- Smart Home · A/V · Edge Compute
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.
FREE PLANNING TOOLS
Both tools are free and take a couple of minutes — start in either one.
EVERY PROJECT STARTS WITH DESIGN
Local Service
ADU / Backyard Cottage Services in Thornton, Colorado
Autotelic provides professional ADU / backyard cottage services throughout Thornton and the surrounding Adams 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 Thornton (one of Colorado's fastest-growing cities) or nearby communities, our team delivers quality workmanship, licensed and insured.
Permit Thresholds
Thornton permit thresholds
- Code reference
- This applies to residential remodels and is governed by the city’s adopted codes (2024 International Residential Code, 2024 International Existing Building Code, and related codes with local amendments, effective for applications on or after July 1, 2025).
- Code reference
- Attached decks of any height; any deck serving the main exit door; decks with attached roofs; decks/porches 200 sq ft or larger; any deck or porch in the front yard.
- Code reference
- Fences over 7 ft tall; retaining walls over 48 inches (measured from bottom of footing; engineering required).
- Code reference
- Room additions; attached/detached garages; accessory buildings larger than 200 sq ft.
- Code reference
- Detached decks less than 200 sq ft and less than 30 inches above grade that do not serve the main exit door.
- Code reference
- One-story detached accessory structures less than 200 sq ft.
- Code reference
- Fences 7 ft tall or less.
- Code reference
- Painting; minor roofing repair (one square or less); replacement of less than 100 sq ft of asphalt shingles.
Codes are amended regularly — verify current requirements with **The Building Inspection Division of the City of Thornton (Colorado) issues residential building permits.
Zoning & ADU
Thornton zoning & ADU quick facts
- SFD-L — Minimum Lot Area
- 6000 sfSFD-L
- SFD-L — Minimum Lot Frontage
- 60 ftSFD-L
- SFD-L — Front Setback (min)
- 20'SFD-L
- SFD-L — Side Interior Setback (min)
- 5'SFD-L
- SFD-L — Side Setback Abutting Street (min)
- 20'SFD-L
- SFD-L — Rear Setback (min)
- 15'SFD-L
- SFD-L — Lot Coverage (max)
- 85%SFD-L
- SFD-L — Building Height (max)
- 35'SFD-L
Codes are amended regularly — verify current requirements with **The Building Inspection Division of the City of Thornton (Colorado) issues residential building permits.
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.
The build sequence for a ADU / Backyard Cottage project
This service is a component of How a ADU project works in Thornton.
- First contact for a ADU / Backyard Cottage project
- ADU / Backyard Cottage feasibility in Thornton
- How a ADU / Backyard Cottage project is estimated
- Designing a ADU / Backyard Cottage project
- Booking a ADU / Backyard Cottage service
- Managing a ADU / Backyard Cottage job in the client portal
- On site: the crew app
Energy Code
Thornton energy code quick facts
- Code reference
- 2024 International Energy Conservation Code (IECC), including the Colorado Model Electric Ready and Solar Ready Code (with local amendments), effective July 1, 2025.
- Code reference
- This is adopted by reference in Thornton City Code Sec. 10-174 (with amendments in Sec. 10-175), along with the 2024 International Existing Building Code.§10-174
- Code reference
- Permit applications submitted on or after July 1, 2025, must comply.
- Code reference
- No specific local numeric amendments to prescriptive requirements (e.g., R-values, U-factors, or air-sealing thresholds for Climate Zone 5B) or details on remodels/additions beyond the base 2024 IECC + state model code are identified in available sources.
Codes are amended regularly — verify current requirements with **The Building Inspection Division of the City of Thornton (Colorado) issues residential building permits.
Service Area
Serving Thornton and Adams County
We serve Thornton, 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 Thornton project.
FAQ
ADU feasibility FAQ
How much does ADU Feasibility Consultation cost in Thornton?
$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 Thornton’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 Denver-metro 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.
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.
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.
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.
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 →Explore
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