According to this recent article in The Telegraph they are. The feature tells us to forget images of dank and dreary basements and to consider instead the desirable prospect that a basement has become. The article points to Knights House in Knightsbridge as an example of the London basement penthouse. A four-floor townhouse flaunting three apartments, its three-bedroom basement apartment is the most expensive and luxurious there, offering 4,451sq ft. over the ground and lower-ground floors with a screening room,…