I did this in los angeles, and put in a beautiful pilates studio.

OP, we did this with our beach house. I don't remember the cost but it was not much compared to the value we received.

I wish we had added a bathroom too. Think about that if you don't have a full bath on the main floor.

If this had been our house here, we would have changed the driveway, but since this is a rental, keeping the big driveway is a plus. That's also something to think about if you convert.

Here's a pic: http://vrbo.com/182801

In many parts of dc the garages are too narrow for modern cars. We had this situation, converted, and house became 4 bedrooms at resale instead of 3 plus some thing that used to work as a garage 70 years ago. Main cost was having three layers of plaster put on the wall blocks to match the rest of the house. Total cost w electric, door and window about 15 k.

ackward

It is not a selling point in NWDC. Most homes in the best neighborhoods, at least the beautiful older homes (pre-1940) don't have them and no one cares. I am talking about properties above $1.25 million and upwards of $4 million in Wesley Heights, Spring Valley, Kent, etc... Same for best parts of CC, MD.

I'm surprised that so many say losing the garage would hurt the value of the house. I thought for sure everyone would say they'd prefer to have additional square footage.

I know someone who got estimates for this (in SF area not here) and it was going to be around $150,000.