The oldest Woodbridge houses sit along Route 1, in the Census place that carries the name: about three homes in ten there went up in the 1950s and 1960s. They were built around a furnace, and in many the cooling came later, through ducts laid out for heat. A back bedroom at the end of the longest run, or a room built on since, is where one head on the wall earns its keep.
Dale City, about half of it built in the 1970s and 1980s, often has a different weak spot: the lower level that started out unfinished and became a family room, an office or a bedroom later. It may have one register or none, on a system sized for the floors above. A head down there gives that level its own setting without rebalancing the house.
Inside the Lake Ridge Parks and Recreation Association, about 7,200 homes, a mini split is an exterior change first. Its guidelines send every exterior alteration to the Architectural Committee, with only satellite dishes, antennas and a few signs excepted. The outdoor unit and the line set cover up the wall are what the committee sees, so file before anything is ordered.
About three homes in ten in the Census place called Woodbridge, and a quarter in Leesylvania, are in condo and apartment buildings. In a condo, where the outdoor unit can sit is the association’s call, and the wall the line set crosses is often common property, so the management office is the first stop. Leesylvania’s newer houses are the opposite case: ducts reach every room as built, so a head there usually serves space finished after closing. A second room on the same outdoor unit makes it two zones, $11,000 to $15,000 installed; three rooms run $12,500 to $18,000.