Sometimes it's the house. Sometimes it's the neighborhood. And sometimes, if you're very lucky, it's BOTH. Rarely does Spring Valley come in such a charming, manageable package. Poised above the street on a corner lot beneath mature trees, 4700 Sedgwick has a commanding presence without a hint of pretense. And a fabulous front deck gives you a front-row seat. The foyer may be a little extravagant, but consider it perfect preparation for the living room-which isn't exactly what you would call modest. A soaring, beamed ceiling delivers the drama, the fireplace anchors the room, and a glass door opens directly to the deck. The dining room is generously proportioned without making a production of it-equally comfortable with Tuesday-night dinner or a little Thanksgiving situation. The kitchen is crisp, efficient and entirely up to the task. Best of all, a door opens directly to the rear patio-because outdoor dining is considerably more appealing when dinner doesn't have to tour the house first. Out back, the bluestone patio has room for dining and lounging-and absolutely no opinion about which goes where. Very civilized. The house is only half the story. The other half surrounds it. Tree-lined streets invite walking and biking, and the neighborhood manages the rare trick of feeling quiet and serene while keeping Massachusetts Avenue just steps away and downtown within easy reach. A new routine might include Millie's, Pizzeria Paradiso, Compass Coffee, Crate & Barrel and Starbucks-all close enough to walk. Unless, of course, you're planning to lug home a new espresso machine. And tell me you know Wagshal's. I would understand if you bought this house just for that. Turtle Park and its playing fields are an easy walk away, and when Washington finally gets enough snow to do something with, the neighborhood's favorite sledding hill at Wesley Seminary is just a block from home. Sometimes it really is BOTH.