Northern Virginia has been my home for almost 25 years. Clients have used my services all over northern Virginia. The majority of my experience has been inside the Beltway, particularly in Arlington, Alexandria (both the city of and in Fairfax Co.), McLean, and Falls Church (both the city of and in Fairfax Co.). However, I also have strong experience in communities outside the Beltway such as Burke, Fairfax, Kingstowne, Reston, Springfield, and Vienna. From time-to-time I have even helped clients buy or sell homes in the exurbs, places like Bealton, Leesburg, Manassas, Stafford, and Warrenton.
Northern Virginia covers a very wide area from places that are barely outside the city of D.C. to places where your neighbors could be cows. The region has gone through tremendous change since I moved to the area in 1986 mostly due to strong job growth and in-migration from other parts of the country and the world. Back then the Toll Road was flanked on both sides by miles and miles of trees starting at the Beltway, the metro didn't go nearly the places it goes to today, DCA only was the original terminal, and places like Manassas, Leesburg, and Fredericksburg seemed so very far away. Today it’s an entirely different story. Nothing feels as far as it used to and every place is connected to every other place by larger, busier roads, trains and subways, buses, and even water taxis and ferries.
Where people choose to live in northern Virginia usually depends first and foremost on budget, followed by commuting distance to work, followed by some combination of other priorities like schools, proximity to retail, house size, house age, lot size, and amount of open space. The Beltway (highway I-495 that encircles D.C., running through northern Virginia and suburban Maryland) is an often-used reference point. As a general rule of thumb, one's money goes further the farther away from D.C. a home is located, so homes outside the Beltway generally sell for less when compared to similar homes inside the Beltway.
Inside the Beltway...
Inside the Beltway covers the following areas. Very broadly, people often choose to live here because commuting distance to D.C. is shorter and they don't mind smaller, older homes at higher prices.
Arlington County - The smallest self-governing county in the USA at 26 sq. miles, it's popular because it's right across the Potomac River from D.C., feels like a cross between urban and suburban living, and its overall quality of life.
City of Alexandria - Probably best known for its Old Town and Del Ray neighborhoods, Alexandria offers a wide variety of housing options from hi-rise condos to pre-1800 townhouses. (Note parts of Fairfax Co. also have Alexandria mailing addresses, but they are not part of the city of Alexandria.)
The City of Falls Church - Calling itself "The Little City," Falls Church was originally established in part to give residents more control over public education. Today its schools have a strong reputation, but with a small geographic footprint and few homes on the market at any one time, housing often is priced at a premium compared to other areas in the region. (Note parts of Fairfax Co. also have Falls Church mailing addresses, but they are not part of the City of Falls Church.)
Parts of Fairfax County - Fairfax Co. is the largest jurisdiction in northern Virginia. The majority of the county is outside the Beltway, but communities like Annandale, Bailey's Crossroads, McLean, Lake Barcroft, Lincolnia, north Springfield and others, plus some of the homes with mailing addresses of Falls Church (not the city of) and Alexandria (not the city of) are all located inside the Beltway.
Outside the Beltway...
Outside the Beltway covers the following areas. Very broadly, people often choose to live here because they want to get a larger home with more yard than the same budget would afford them inside the Beltway.
Parts of Fairfax County - Fairfax Co. is the largest jurisdiction in northern Virginia. The majority of the county is outside the Beltway. It spans quite a distance and has a variety of communities from Alexandria, Ft. Belvoir, Lorton, Newington, and Springfield in the south/southeast to Burke and Clifton in the southwest to Fairfax, Falls Church, Oakton, Tysons Corner, and Vienna in the center to Great Falls and parts of McLean in the northwest to Centreville, Chantilly, Herndon, and Reston in the west. (Embedded within Fairfax Co. is Fairfax City, a separate jurisdiction.) Each of these areas offers their own combination of commute times, schools, housing stock, amenities, and quality of life.
Loudoun County is the next county west of Fairfax Co. and used to be considered "far," but that's no longer the case as better and faster roads connect its communities to Fairfax Co. transportation corridors into D.C., and the area around Dulles airport continues to create new jobs. The eastern part of Loudoun is the more developed with new/newer communities popping up near Aldie, Ashburn, Chantilly, Gainesville, Haymarket, Leesburg, Nokesville, and South Riding. As one goes west the county is more rural and has smaller towns like Lovettsville, Lucketts, Middleburg, Purcellville, and Waterford.
Prince William County has a northwest-southeast layout and is the next county south of Fairfax Co. Embedded within it are the separate jurisdictions of Manassas Park and the City of Manassas -- although there are homes in the county with Manassas addresses outside these separate jurisdictions. On the opposite side of the county are the communities of Woodbridge and Lake Ridge, adjacent to I-95. South of Woodbridge are places like Dale City, Dumfries, Occoquan, and Triangle. Homes in this county are less expensive than those closer in, although the commute to D.C. is longer and somewhat legendary. Many county residents use the commuter rail into D.C. known as the Virginia Railway Express (VRE).
Farther out the housing is generally cheaper still and more variable in age, size, and quality. Many choose to live in these far suburbs/exurbs because of the price/affordability attractiveness and the desire for a life that feels less hurried and less crowded than in those communities closer in. Residents commute to jobs closer to D.C. and even in D.C. proper. These areas include the counties of Culpeper, Fauquier, and Stafford, as well as the city of Fredericksburg.