ADU Builder in Leesburg, VA

Leesburg writes its own ADU rules, and they run more detailed than most people expect. Inside the town limits, the Town of Leesburg Zoning Ordinance allows an accessory dwelling by right on a single-family detached lot, but it sets specific limits on lot size, height, floor area, parking and even how the water is metered. DLA Design & Build works in Leesburg, from brick homes near King Street to the 1990s and 2000s colonials in Exeter and Potomac Station. We design the unit to the Town's standards, get the Town zoning permit, then pull the building permits from Loudoun County and build it.
Town zoning, county permits, one builder for both.

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What Makes Leesburg a Good Place for an ADU

Leesburg is the county seat and has a real downtown, with courts, restaurants and the W&OD Trail a short walk from the older blocks. People want to live near that. For many families the reason is simpler: a parent who wants to stay in Leesburg, close to their doctors and their church, but not alone in a big house.
The Town changed its rules in late 2022. It rewrote the accessory dwelling section and dropped the old extended family residence provisions. If every standard is met, the unit is allowed by right with a one-time Town zoning permit, not a special exception. We read those standards against your plat before anyone draws a floor plan, because the minimum lot size alone rules out some parcels.
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ADU Types We Build in Leesburg, VA

Leesburg's ordinance treats almost every one of these differently, with its own size limit or approval rule. Here is what each looks like inside the town limits.

01Detached ADU

Detached ADUs in Leesburg

A one-story backyard cottage is allowed by right on a single-family detached lot of at least 10,000 square feet. The Town caps it at 60 percent of the main house's footprint or 900 square feet, whichever is less, and at 24 feet in height. It can't sit forward of the house, has to stay ten feet from side and rear lines, and can't encroach on a recorded public easement, which on some Leesburg plats means a utility strip along the back. The cottage must match the main house in style and materials. On a brick house near downtown, that means brick. In the Old and Historic District, the BAR reviews it first and can adjust its size, height and placement.

02Attached ADU

Attached ADUs in Leesburg

An accessory dwelling that is part of the main house needs its own entrance, and the Town requires it on a side or rear facade so the house still reads as a single-family home from the street. A unit carved out of existing space follows the district's normal dimensional standards, the same ones the house already meets. Keep in mind that Leesburg allows accessory dwellings only with single-family detached homes, so townhouse owners don't have this option. Inside, we plan the fire and sound separation between the two households, give each its own kitchen and bath as the ordinance requires, and keep the unit on the house's Town water meter, since a separate meter isn't allowed.

03Basement ADU

Basement ADUs in Leesburg

Leesburg sets no floor area limit on a basement used as an accessory dwelling, which makes the lower level the roomiest ADU the Town allows. That matters in subdivisions like Exeter and Kincaid Forest, where many homes from the late 1980s through the early 2000s have full basements. The other standards still apply: a lot of at least 10,000 square feet, two bedrooms at most, the owner living on the property and a dedicated parking space. The unit needs its own entrance on the side or rear, and bedrooms need code-compliant egress windows. On a lot that falls away to the back, a walkout makes both easy. On a flat lot, we dig an areaway with a stair.

04Garage Conversion

Garage Conversion ADUs in Leesburg

Here the Town's parking rule decides the project. Parking for an accessory dwelling can't displace the parking the main house is required to have, the unit needs its own dedicated off-street space, and a second driveway is prohibited. Convert a two-car garage, and the main house's required spaces have to fit somewhere else on the lot, usually the existing driveway, along with one more space for the unit. On many Leesburg lots the driveway can hold them. On some it can't. The converted garage also needs an entrance on the side or rear and the same matching exterior as any other accessory dwelling. We measure the driveway and settle the parking count before we design a single room.

05In-Law Suite

In-Law Suites in Leesburg

In 2022 Leesburg removed its old extended family residence rules, so a family suite is now one of two things. It can be a legal accessory dwelling with its own kitchen, meeting every standard on this page. Or it can stay part of the main house with an accessory kitchen, which the Town regulates separately. An accessory kitchen must be smaller than the main kitchen, can't be closed off from the rest of the house by doors or walls, can't be in a detached building, and needs a Town zoning permit plus an affidavit that no separate unit is being created. For a parent who wants company close by rather than an apartment, the second route is often the better fit.

06Guest House

Guest Houses in Leesburg

Leesburg has a specific guest house rule, which Loudoun County's ordinance does not. A guest house is an accessory building for temporary, non-paying guests. It can't have cooking facilities, can't be rented, and can't be anyone's permanent home. One is allowed per lot, on single-family detached lots of 10,000 square feet or more, up to 60 percent of the main house's footprint or 900 square feet, whichever is less. The height, setback, parking and matching-materials rules mirror those for a detached accessory dwelling, and the BAR reviews it in the historic district. If family will live there year-round, build it as an accessory dwelling instead.

07Above-Garage ADU

Above-Garage ADUs in Leesburg

The Town rewards this layout. A two-story detached accessory dwelling that includes at least one enclosed parking space can reach 60 percent of the main house's footprint or 1,200 square feet, whichever is less, compared with 900 for a one-story cottage. In practice that means a garage bay below and an apartment above, which also helps with the rule that the unit can't take away the main house's parking. The 24-foot height limit shapes the roof: a steep carriage-house roof over a full second floor has to fit under it, so we work out the building section early. In the Old and Historic District the form fits the neighborhood's history, but the BAR still sets the terms.

08ADU Addition

ADU Additions in Leesburg

Adding onto the house for the unit is allowed, but the limit is tighter than for a two-story detached unit. An addition used as an accessory dwelling has to be less than 40 percent of the total footprint and no more than 900 square feet. It must also meet the district's regular setbacks, because the ten-foot side and rear allowance in the ordinance applies only to detached accessory structures. Matching materials and an entrance on the side or rear are required. A one-bedroom unit fits under 900 square feet comfortably. Two bedrooms is tight, and that's usually when we suggest pairing a smaller addition with part of the existing first floor.

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Leesburg's ADU Rules and Who Approves What

As an incorporated town, Leesburg sets its own zoning, separate from the county rules that apply in Ashburn. The Town's ordinance allows one accessory dwelling per lot, only with a single-family detached house, and only on lots of at least 10,000 square feet. The owner has to live on the property, in either the main house or the unit, for at least 185 days a year. The unit can have no more than two bedrooms, needs its own kitchen and bath, and cannot be split off and sold as a condominium. It also can't have its own Town water meter.
Size depends on the form. A one-story detached unit is limited to 60 percent of the house's footprint or 900 square feet, whichever is less. A two-story detached unit that includes at least one enclosed parking space can reach 60 percent or 1,200 square feet, whichever is less, which is why an above-garage ADU makes sense on many Leesburg lots. An addition built for the unit must be under 40 percent of the house's footprint and no more than 900 square feet. A basement has no area limit. Detached units top out at 24 feet in height and must match the main house's style and materials.

The unit needs one dedicated off-street space that doesn't take away the main house's required parking, and a second driveway is prohibited. Approval is a one-time Town zoning permit, followed by building and trade permits from Loudoun County. The Town is also partway through rewriting its zoning ordinance, so we check the text in force on the day we file.
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Frequently Asked Questions About ADUs in Leesburg, VA

Not as a separate accessory dwelling under the Town's current standards, which set 10,000 square feet as the minimum lot size. Plenty of single-family lots in town are smaller than that. You may still be able to build an in-law suite that stays part of the main house, possibly with a smaller accessory kitchen under the Town's separate rules for those. We'll check your plat and explain which side of that line your plans fall on.

Possibly. Any exterior change in the Old and Historic District needs a Certificate of Appropriateness, and new construction goes to the Board of Architectural Review. For accessory dwellings specifically, the Town's ordinance lets the BAR make minor changes to the unit's location, size and height to keep it compatible with historic resources on the property. Expect design review to shape the building. Parking also works a little differently in the district, where a Town residential parking permit program may satisfy the unit's space requirement.

Both, in sequence. The Town of Leesburg issues a one-time zoning permit showing the unit meets every standard in its ordinance, from lot size and setbacks to parking and appearance. Loudoun County's Department of Building and Development then issues the building permit and the trade permits for electrical, plumbing, mechanical and gas work, and county inspectors check the construction. If you're in the historic district, the Certificate of Appropriateness comes before both.

Leesburg's ordinance addresses this directly. A tiny home built on a vehicle chassis can serve as an accessory dwelling only if it is under 600 square feet and the chassis is set on a foundation wall built under a Loudoun County building permit and inspected by the county. It also has to meet every other standard, including the rule that it match the main house's style and materials. By the time a tiny home is on a foundation and dressed to match a brick colonial, a site-built cottage often makes more sense.

The Town's rule is about the owner living on the property. Whoever lives in the unit doesn't have to be related to you, though the household has to fit the Town's zoning definition of a family. The owner must keep permanent residency in either the main house or the accessory dwelling for at least 185 days a year. So your mother can live in the unit while you live in the house, or you could move into the unit yourself and let family have the main house. The zoning permit can be revoked for uncorrected violations, so the residency rule is worth taking seriously.

Start with the basement if you have a good one. The Town sets no floor area limit on a basement unit, and the exterior change can be as small as a new door on the side or rear. Out back makes sense when the basement is shallow or the person moving in can't manage stairs. Then the choice is between a one-story cottage and a two-story unit with enclosed parking, which gets the larger size allowance. We also do home additions in Leesburg, so we can compare an ADU addition against the other options on your lot.

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Our Process for Leesburg ADUs

We start with the plat, because Leesburg's standards are mostly measured from it: lot area, distance to property lines, recorded easements, the driveway. Then we walk the house and yard and talk about who the unit is for. If the lot qualifies, we draw to the Town's limits.
Historic district projects go to the BAR first. Everything else goes to the Town zoning permit, then to Loudoun County for building permits, and county inspectors sign off at each stage of construction.

The Result

A legal second dwelling on your Leesburg lot that looks like it was always part of the property. It has its own entrance and parking space, and a Town zoning permit on file for the day a buyer's agent asks.
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ADU Builder in Nearby Communities

We plan and build ADUs across Northern Virginia. See local details for nearby areas.

Start Your Leesburg ADU

Call (703) 743-7777 or send the form with your address.
We'll pull the parcel, check it against the Town's standards and tell you honestly whether an accessory dwelling works there before you spend anything on design.

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