You imagine it. We bring it to life.(301) 832-0409
Modern detached accessory dwelling unit built by Excell Homes in Northern Virginia

Turnkey ADU Builder · DC, Maryland & Northern Virginia

Your backyard could earn $2,000+/mo

A legal, income-producing backyard home, or an in-law suite steps from your door. We handle architectural design, all the permitting, and the complete build. One contract. One team.

20+Years building
2,500+Projects done
$2,211Avg 2BR rent · Annandale

100% turnkey

We design it, permit it, and build it.

An accessory dwelling unit is one of the highest-return improvements you can make to a Northern Virginia property, added rental income and six figures of equity from a single build. We handle architectural design, every Fairfax County, Arlington, and Alexandria permit, and the complete construction. You just turn the key.

Design · Permits · Build

The NoVA ADU reality

Three things that derail most ADU projects.

We built our process to remove each one.

The problem

The zoning maze

Setbacks, lot coverage, owner-occupancy rules, NoVA's ADU regulations differ by county and change often.

We've navigated Fairfax, Arlington, and Alexandria permitting offices for years.
The problem

Hidden costs

Surprise utility connections, impact fees, and change orders can blow up a budget mid-build.

Transparent, upfront pricing, the number we quote is the number you pay.
The problem

Juggling vendors

Architect, engineer, expediter, GC, inspectors, coordinating them all is a part-time job.

One team handles design, permits, and construction end to end.

How it works

From first call to move-in, in three phases.

Average total: 5–7 months. One team, start to finish.

Phase 1

Custom ADU Design

2–3 weeks

We design an ADU tailored to your lot, goals, and budget, and prepare the drawings for permitting.

Phase 2

All NoVA Permits

30–60 days

We file and manage every permit and approval through your county or city, you don't chase a single office.

Phase 3

Build & Key Delivery

12–16 weeks

We build it turnkey and hand you the keys, ready to rent or move family in.

The numbers

What a backyard ADU can return.

Illustrative 600 sq ft detached ADU in the Annandale / Fairfax area.

600 sq ft detached ADU · Annandale / Fairfax

A snapshot of typical economics, your numbers depend on lot, design, and finishes.

Build cost (600 sq ft)
$150K–$200K
2BR rent
$2,211/mo
Annual gross rent
$23,256–$26,532
Home equity bump
+$100K–$175K
Break-even
5–7 years
20-year net
$280K–$380K+
Apartment List, Feb 2026; assumes ~3% annual rent growth. In Fairfax County, ADUs are for long-term rental (leases of 30 days or more); short-term lodging is not permitted. Illustrative only, not a guarantee.

Estimate your ADU

Ballpark your build cost and rental income.

Slide your ADU size and pick your area for a quick estimate. When you’re ready, the feasibility quiz turns it into a real plan with upfront pricing.

Estimated build$157K$191K
Est. monthly rent$2,211/mo
Annual gross rent$26,532

Illustrative estimate only, not a quote or financing offer. Actual cost depends on design, site conditions, and finishes. Rent figures: Apartment List, Annandale 2026.

Get your exact ADU plan

Transparent pricing

No surprises, just the home you signed up for.

  • Transparent, upfront pricing, no surprise change orders.
  • Design, permits, materials, and build in a single contract.
  • A dedicated project manager from first drawing to final inspection.
  • Industry-leading warranty on labor and materials.

Prefer to pay over time? Financing is available →

Free feasibility check

See if your property qualifies.

A few quick questions. We’ll follow up with your ADU options.

Step 1 of 5

What's your main goal for an ADU?

ADU FAQ

Questions homeowners ask us.

Can I build an ADU in Fairfax County, Arlington, or Alexandria?

In most cases, yes, each jurisdiction has its own rules on lot size, setbacks, and owner-occupancy. We assess your property up front and handle the zoning and permitting for you.

How much does an ADU cost to build in Northern Virginia?

A turnkey 600 sq ft detached ADU typically runs about $150K–$200K, depending on size, finishes, and site conditions. We give you a clear, upfront price before you commit.

How long does an ADU take from start to move-in?

About 5–7 months on average: 2–3 weeks of design, 30–60 days of permitting, and 12–16 weeks of construction.

How much rent can an ADU earn?

In the Annandale/Fairfax area, a 1BR rents for roughly $1,938/mo and a 2BR for about $2,211/mo (Apartment List, 2026).

Are there rules on short-term rentals or owner-occupancy?

Short-term lodging, stays under 30 days like Airbnb, is not permitted in an ADU in Fairfax County, so an ADU is a long-term rental (leases of 30 days or more). Owner-occupancy rules also vary by jurisdiction. We walk you through what applies to your property during design.

Can I finance an ADU?

Yes. Through our RenoFi partnership you can finance your ADU based on your home's after-renovation value. See our financing page for details.

Free · No obligation

Ready to unlock your backyard?

Tell us about your property and goals. We'll come back with a detailed ADU plan and upfront pricing.

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