Anonymous wrote:OP, you need to understand that areas like Capitol Hill and Kalorama will feel like a suburb to you. Downtown DC is very small and only a few blocks wide. And most of the actual suburbs in DC (like Alexandria away from Old Town) are ghastly.
Isn't OP living in North London now? This describes a large area, but much of it is pretty suburban. The more close-in neighborhoods, like St. John's Wood, compare to maybe Cleveland Park/Woodley Park in density, but some neighborhoods in North London are where people from Central London go for Ikea and giganto-supermarkets with parking.
I moved here from Central London almost a decade ago, though I'm American. Initially, I had my eye on Capitol Hill, but I found I liked it less than the Dupont/Logan/Adams Morgan areas. Don't get me wrong-- I do like the Hill, but the architecture just left a flavor of Washington-as-a-small-Southern-city in my mouth (because it really was during the 19th century decades when the Hill was developed), and I thought the air was oppressively still and heavy with extra humidity. I get a lot happier as I move into City Beautiful-era neighborhoods and climb a little higher uphill to enjoy the breeze.
But these are personal preferences, and I'd say Capitol Hill sounds like a great place for OP's family. There will be many families with children the same age as OP's DC, and the commute to Virginia is much easier from the Hill than from NW. Clarendon is also very reasonable for commute and company purposes (if OP won't mind that it's ugly-- I do, but then again, that's me and for me, the built environment is really important), and I expect Old Town and Del Ray would do, too.