There's only one Type 106. They had built eight Type 105 penthouses along the top of Willoughby House and there wasn't quite room enough for a ninth, so they slipped in a slimmed down version and called it a Type 106. From the entrance to the flat there are steps up to the living area, kitchen and WC; more steps up to the next floor which contains a bedroom and a bathroom; and a final flight up to a studio or third bedroom at the top.
