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Design-build, one in-house team, Fairfax and Loudoun County

Second stories, rooms over the garage, family room and kitchen extensions, main level suites, bump-outs and in-law suites, designed, engineered, permitted and built by one in-house team. EA Home Design has completed close to 2,000 remodels across Fairfax and Loudoun County since 2009, from a design studio in Sterling.

Updated October 2026

Most addition projects in Northern Virginia start with a house the family likes on a street they do not want to leave. The kitchen is too small for the way they cook. A parent is moving in and there is no bedroom on the main level. Two children share a room that was fine five years ago. Moving means bidding against buyers with fewer contingencies, paying commissions and moving costs, and trading schools and commutes, so the honest comparison is rarely between an addition and a similar house nearby. It is between an addition and a more expensive house farther out. The scope below is what we design and build, in whatever form the house, the lot and the family need.

Every addition is three structural questions before it is a room. Can the lot take it: setbacks, lot coverage and height rules decide how far out and how far up you may build before design taste enters the picture. Can the foundation carry it: a second story needs the existing footings and first floor walls to take the new load, and a room over the garage needs walls that were framed for a roof to carry a floor full of furniture, which usually means new footings or reinforced framing inside the garage. And how does the new roof meet the old one: the tie-in and the beams that carry the opening between the house and the addition are where the engineering lives, and where a cheap addition shows its age first.

Those answers come from a structural engineer before anything else happens, and they are the reason we do not quote an addition from a sketch. Many mid century ramblers in Fairfax County were built with foundations that will take a second story with modest reinforcement; some cannot without major work, and it is far better to learn that from an assessment than from a framing crew. A bump-out of a few feet can sometimes be cantilevered off the existing structure with no new foundation at all, which is why we often price one next to a full addition so you can see whether four more feet of kitchen solves the actual problem. Our guide to second stories, rooms over the garage, bump-outs and garage conversions goes through each type in detail.

Every addition needs a residential building permit plus electrical, plumbing and mechanical permits for that work. In Loudoun County the application runs through the county’s LandMARC portal and must include a plat showing the addition with its distances to every property line; the county’s locational clearance mapper covers simple lots, and a surveyor’s plat is needed when the addition sits close to a setback line. Loudoun rewrote its zoning ordinance in 2023, so older setback information is wrong, and we confirm your district’s setbacks with the county before design rather than after. Fairfax County runs its own permit office with the same logic: setbacks, lot coverage and height first, structure and energy code second.

Towns add a second government. Inside the Town of Leesburg a town zoning permit through the town’s eTRAKiT system comes first, and the county will not release the building permit until it is approved; additions in Leesburg’s Old and Historic District also need Board of Architectural Review approval, which adds 30 to 60 days and shapes rooflines, materials and massing before anyone draws a floor plan. Purcellville, Middleburg, Hamilton, Round Hill, Lovettsville and Hillsboro follow the same two step pattern. Inside Fairfax County the Town of Herndon runs its own inspections office, while a Vienna address gets its building permit from Fairfax County and Town review for the exterior, which an addition always changes. Most eastern Loudoun neighborhoods, Ashburn, Brambleton, South Riding and Lansdowne among them, also need HOA architectural approval, typically 30 to 60 days. In western Loudoun a home on well and septic needs Health Department sign off before a bedroom can be added, because the septic system is rated for a set number of bedrooms.

Plan review typically takes two to four weeks for a complete submission and longer when comments come back, and a failed inspection is usually a one week delay. We build all of it into the schedule you sign. Our home additions in Loudoun County guide covers the county’s rules town by town, our Northern Virginia home remodeling guide lists every building department in the region, and our permits and inspections checklist walks through what each inspection looks at.

Almost everyone does. An addition is built outside your existing walls for most of the project, and we seal the connection point until the last practical moment, so daily life continues behind fences, protected pathways and a clean site. We tell you honestly which days the wall comes down and plan them with you. A second story is the exception: the roof comes off in planned sections under a temporary weather protection plan, and there are several weeks when the house is genuinely disrupted. Some families stay through it and some rent nearby for the loudest phase. We plan that with you rather than promising comfort that construction cannot deliver.

That is the test of a good addition, and where we put the design effort. Rooflines that continue naturally, siding and brick matched or deliberately complemented, windows aligned with the originals, and floors that run through at the same level. Heating and cooling are part of the same question: your existing system was sized for the house it serves, and a large addition can overwhelm it, so we calculate the load and recommend either an extension of your system or a dedicated mini split or zoned unit for the new space, decided in design, not discovered on the first hot day. Inside and out, the goal is simple: nobody should be able to tell where the old house ends.

Loudoun splits into two markets. Eastern Loudoun, meaning Ashburn, Sterling, Brambleton, South Riding, Lansdowne and the suburbs around Leesburg, is mostly 1990s to 2010s colonials and townhouses on quarter acre or smaller lots governed by HOAs, where the common projects are a rear family room or kitchen extension, a main level suite, a sunroom off the kitchen, a bump-out for a kitchen or primary bath, and a room over the garage. Western Loudoun, from Purcellville, Round Hill and Hamilton to Lovettsville, Waterford and Middleburg, is older homes and newer custom homes on one to ten acre lots on well and septic, where additions run larger: wings with in-law suites, detached garages with living space above, screened porches and outdoor rooms, and second stories on ranches and capes. In Fairfax County the older neighborhoods in Falls Church, Annandale and Vienna sit on small lots where going up is often the only way to double the house, and the mid century ramblers there are the second story candidates we assess most.

We design and build across Fairfax County and Loudoun County from our studio and showroom in Sterling. Home remodeling pages with local detail: Sterling, Leesburg, Chantilly, Middleburg, Bristow, Clifton, Lorton, Springfield, Dunn Loring, Round Hill, Woodbridge and Hamilton. For a whole house planned as one project, see whole home remodeling; completed projects with photos and timelines are in our case studies.

A whole home remodel, not an addition, shown for the finish standard: the same in-house crew frames, ties in and finishes every addition we build.

Why homeowners choose EA

Virginia Class A licensed (#2705157182), five-star rated everywhere we are reviewed, with close to 2,000 remodels complete.

I had an exceptional experience working with EA Home Design to redesign my kitchen. From the initial consultation to the final installation, their team demonstrated professionalism and creativity.

Iman, a verified EA Home Design kitchen client

A free in-home design consultation comes first: a designer walks the lot and the house with you, and you see the addition drawn on your property in 3D with a realistic price for your scope before any commitment.

Fairfax County and Loudoun County, from our Sterling studio.