Foundation installation in Arlington VA - the right start for the house you're building

Laying a foundation in the Washington, D.C. area usually costs about $7 to $50 per square foot, and that's the going range in the market, not a quote from us. Where yours lands depends mostly on whether it's a basement, crawl space or slab, then on the size of the dig, the wall type and how much water control you add.

You need a land disturbance permit from Arlington County once the work disturbs 2,500 square feet of land or more, and the county counts separate projects within a two year period toward that total. If the dig comes in between 2,000 and 2,499 square feet, the county wants it certified and surveyed, with survey markings on site, so the disturbed area stays under the line. The county also requires single family home projects to add stormwater detention, a way of holding rainwater back so it drains off slowly instead of running onto downhill neighbors, into the storm drains and toward local streams. If your job needs a permit, we handle the application with the office your address falls under and tell you what's needed before work starts.

A basement usually makes sense when you'll use the extra living or storage space enough to justify the cost. A slab or crawl space is often the better call on a lot with ongoing groundwater trouble, on a very tight budget, or when it solves the problem with less risk. We talk it through with you before anything's dug, since it's the hardest choice to change later.

Usually not, if you want a dry finished room, because dampproofing keeps a basement a little drier but doesn't stop leaks or flooding. One building guide advises anyone planning living space below ground, now or down the road, to consider a full waterproofing system instead. If you might finish the basement someday, we talk about keeping it dry now, while the outside of the walls is still open and easy to reach.

One concrete guide puts it at about 7 days at 70°F and 14 days or more below 50°F, which is how long a poured wall takes to reach 70% of the strength it's designed for. Backfilling, pushing the soil back against the wall, before then is a common way walls get damaged on site. We let new walls gain their strength before the soil goes back, so a cool spring or fall can stretch the schedule.

Ask for the contractor's license and compare its class with your quoted price, because Virginia's Board for Contractors gives each license a class that sets the size of job it covers and a specialty that sets the type of work. A Class C license covers a single contract over $1,000 but under $30,000, and Class B covers $30,000 or more but under $150,000. If the quote is bigger than the class allows, the license doesn't fit the job.