The smarter way to build a custom ADU in Colorado. Colorado’s modern ADU builder.

High-performance modular construction — faster, more reliable, and engineered for Colorado — without the headaches of traditional contractors, prefab kits, or manufactured ADUs.

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An ADU is a smart investment — choosing who builds it is the hardest part.

In Colorado, you generally have three paths: traditional stick-built, prefab kits, or high-performance modular. Understanding the difference is key to avoiding budget overruns and year-long delays.

How Olerra compares to custom ADU builders in Colorado.

Three ways to add a backyard home — and why homeowners across the Front Range are choosing high-performance modular.

Option 1

Traditional “stick-built”

Built 100% in your backyard. Projects often drag on for 12–18 months due to weather and labor shortages, and costs are rarely fixed — they typically increase by 20% during construction.

  • 12–18 month timelines
  • Budgets typically balloon ~20% mid-build
  • Months of noise, dumpsters, and crews on site

Option 2

Prefab “kit” homes

Parts are shipped to you, but you must hire the labor to assemble them. Often advertised with “low prices” that exclude the foundation, utilities, and assembly labor — leading to shock costs later.

  • You still hire and manage a builder
  • Foundation & utilities sold separately
  • Advertised price ≠ delivered price

The Olerra way

High-performance modular

95% factory-built. We build your home indoors while your foundation is poured on-site — resulting in a fixed price, a 3–6 month timeline, and steel-frame durability designed for Colorado winds and snow.

  • One fixed-price contract, no change orders
  • 3–6 months from contract to completion
  • Steel frame rated for 165 mph winds

The Olerra Modular Flex-Flat redefines the traditional accessory dwelling unit, offering unmatched versatility for any need — whether as a home office, rental, guest house, or personal retreat. We coined “Flex-Flat” to capture the adaptability and modern essence of these spaces. Explore the Flex-Flat models

Interior of a completed Olerra ADU in Colorado Living space of a steel-frame Olerra Flex-Flat ADU Finished interior detail of a modular ADU built for Colorado

Engineered for Colorado.

  • 0mph

    Wind rated

    Cold-formed steel engineered for Front Range gusts and heavy mountain snow loads.

  • 0%

    Factory built

    Built indoors while your foundation is poured on-site — materials never exposed to rain or snow.

  • 3–6mo

    Total timeline

    From contract to completion, versus 12–18 months for a typical Colorado stick-build.

  • 0yr

    Structural warranty

    Plus 5 years on the building envelope and 2 years on systems — most builders offer just 1.

  • $2,500/mo

    Rental potential

    What a private, rentable Flex-Flat can fetch monthly in Colorado’s major cities.

  • 0day

    Crane installation

    Your home sets on its foundation in a single day — you get your backyard back almost immediately.

See every Flex-Flat feature

Top 5 reasons people choose Flex-Flats over custom or prefab ADUs.

What Colorado homeowners tell us — open any reason for the full detail.

Unlike traditional builders who provide estimates that balloon later, our factory process allows us to give you a fixed price upfront. No surprises, no change orders.

Traditional builds take over a year. We build in the factory simultaneously while site work happens on your land.

This cuts the project timeline by 50%, getting you rental income or extra space months sooner.

Precision factory manufacturing ensures tighter building envelopes than site-built homes, resulting in lower heating and cooling bills year-round.

Colorado winters are harsh. Our steel-frame modules are rated for 165 mph winds and heavy snow loads.

Because they are built indoors, the materials are never exposed to rain or snow during construction.

Stop juggling architects, engineers, and general contractors. Olerra handles everything from permitting to installation under a single contract.

Flex-Flat ADU models.

Two footprints, over 10,000 finish combinations — modern, factory-built ADUs delivered across Colorado.

Olerra 490 sq ft studio ADU, the most versatile model

490 sq ft · Studio or 1 BR

The 490

The epitome of versatility and modern living — perfectly designed for efficiency, this space serves multiple purposes.

Best for: short-term rentals (Airbnb), a home office or gym, and tight Denver lots.

Olerra 735 sq ft one or two bedroom ADU

735 sq ft · 1–2 BR

The 735

The perfect blend of functionality and luxury — spacious one- and two-bedroom layouts with premium materials throughout.

Best for: full-time living, aging parents, or a guest house.

*Starting price before installation — for a site-specific, all-in estimate, start with a free property check

Who Flex-Flat ADUs are for.

See why homeowners in Colorado are choosing Flex-Flats as the smart way to enhance their lifestyle, keep loved ones nearby, and earn extra income — all without the hassle of moving or extensive renovations.

Olerra backyard ADU used as a home office and extra living space

Expand Without Moving

Flex-Flat ADUs add extra space — like an office, gym, or playroom — without the need to relocate, making them ideal for homeowners who love their current neighborhood.

Family visiting a private backyard ADU built for aging parents

Keeping Family Close

Designed for aging parents or adult children, Flex-Flat ADUs provide a private, nearby space that supports family connection while maintaining independence.

Rentable Olerra ADU generating monthly income in Colorado

Generating Rental Income

Flex-Flats create income opportunities by offering a private, rentable unit that can fetch over $2,500 monthly in major cities.

Is your property Flex-Flat ready?

No matter the use case, adding a Flex-Flat increases your property value while enhancing your lifestyle — extra space, family kept close, or rental income. Find out what's possible on your Colorado lot — no pressure, no obligation.

The Olerra ADU build process.

A seamless journey from concept to completion — typically 6–7 months from launch to final turnover of your new modular home.

01Free Property Check & QuoteStart here
  • On-site visit and feasibility study to confirm your Colorado lot.
  • Zoning, setbacks, floodplain, and solar-shadow analysis for your local jurisdiction.
  • Site plan, interior and exterior renders, and floorplans.
  • Estimated budget with financing options.
02Contract, Pre-Permit Planning & Approval8–12 weeks
  • Two contracts: a preliminary planning agreement, then a fixed-price build agreement.
  • ISP survey, soils report, and foundation design.
  • Architectural and structural engineering drawings.
  • Permit submission handled for you — Boulder, Denver, and jurisdictions across Colorado.
03Manufacturing4 weeks
  • Steel frame with mechanical, electrical, and plumbing.
  • Drywall, flooring, cabinetry, and fixtures — finished indoors to 90%.
  • 200+ quality-control checks.
  • State-inspected for quality and code compliance.
04Pre-Delivery Site Work & Shipping3 weeks
  • Excavation, underground utilities, and a helical-pile or concrete foundation — run in parallel with the build.
  • Fully insured, monitored transport to your site.
05Installation & Final Completion3 weeks
  • One-day crane placement onto the foundation.
  • Matelines closed, roof set, utilities connected, and landscaping.
  • Final inspection and adjustments to Olerra's standards.

Modular vs. custom ADU builders: your questions, answered.

Traditional contractors build 100% of the home in your backyard, exposing your project to weather delays, material theft, and prolonged noise. Olerra builds 95% of your ADU in a climate-controlled factory while your foundation is being poured. This ‘parallel processing’ cuts the timeline in half and guarantees a fixed price.

While the raw material costs are similar, modular saves you money on soft costs and time. Traditional builds often run 20% over budget due to labor shortages and change orders — Olerra provides a fixed-price contract.

Additionally, finishing in 3–6 months (vs. 12+ months) saves you thousands in loan interest and gets you rental income sooner.

We don’t wait for the foundation to cure before we start framing. We build your home in our factory at the same time your site is being prepped. This concurrent schedule typically reduces a 12-month project to just 3–6 months.

Kit homes (or ‘flat-packs’) are just pallets of parts — you still have to hire a builder to assemble them, wire them, and plumb them. Olerra modules arrive 95% complete with walls, floors, electric, and plumbing already installed and inspected. We are the builder, not just a parts supplier.

No. Mobile homes are built to the federal HUD code. Olerra Flex-Flats are built to the International Residential Code (IRC) — the exact same building code used for luxury custom homes in Denver and Boulder. They are permanent real estate.

Colorado’s fluctuating humidity and heavy snow loads can warp wood framing over time. Our cold-formed steel frames are impervious to moisture, fire-resistant, and engineered to withstand 165 mph winds and heavy snow loads, ensuring your ADU lasts longer with less maintenance.

To maintain our speed and low cost, we do not offer custom structural changes (like moving walls). However, we offer over 10,000 combinations of exterior finishes, flooring, cabinets, and fixtures, allowing you to personalize the look without the high cost of custom architecture fees.

Yes. Because we build in a factory with precision jigs, our walls are perfectly square and air-sealed, eliminating the drafty gaps common in site-built homes. Combined with spray foam insulation, this results in lower heating and cooling bills year-round.

Flex-Flats are built to last with high durability. They have steel frame construction, are resistant to fire and wind, and come with warranties: 10 years for the structure, 5 years for the building envelope, and 2 years for systems.

No. Unlike ‘kit’ sellers who leave you to figure out the foundation, Olerra acts as your turnkey partner. We manage the site prep, excavation, foundation, and utility trenching as part of our comprehensive service.

A traditional build involves 9–12 months of daily noise, dumpsters, and porta-potties in your backyard. Olerra completes the on-site foundation in a few weeks, and the actual crane installation takes just one day. You get your backyard back almost immediately.

We prefer helical piles because they are faster to install, require less excavation (less mess), and are excellent for Colorado’s shifting soils. However, we can also build on traditional concrete foundations if your specific site requires it.

We conduct a feasibility study for every project. We have successfully craned units over existing houses and navigated difficult terrain. If a crane isn’t possible, we will tell you upfront before you spend a dime.

Yes. Because Olerra Flex-Flats are attached to a permanent foundation and built to the International Residential Code (IRC), appraisers value them exactly the same as any other square footage added to your home. They add immediate equity.

We do. Permitting in Colorado can be complex (especially in Boulder and Denver). Our team handles the entire submission process, engineering stamps, and inspections, so you don’t have to navigate the bureaucracy alone.

Yes. Our units are designed to be compliant with the latest state and local ADU ordinances, including energy codes and setbacks. We verify your specific zoning allowance during our initial property check.

Yes. One of the biggest risks in construction is ‘cost-plus’ billing, where the builder charges you for every overrun. Olerra operates on a fixed-price contract for the modular unit, so you know exactly what the manufacturing cost will be before we start.

Most builders offer a standard 1-year warranty. Olerra provides a 10-year structural warranty, a 5-year warranty on the building envelope, and 2 years on systems, giving you peace of mind long after the project is finished.

No. Payments are made in milestones: a deposit to reserve your slot, a progress payment when materials are ordered, and final payments upon delivery and completion. This aligns with most construction loan draw schedules.

Build your Colorado ADU the smarter way.

Start with a free property check of your lot, or book a consultation with our team — whichever fits where you are.