Type 31 is the standard flat layout in east-west-facing terraces. (As far as I can tell it is absolutely identical to Type 32, and it differs from Type 26 and Type 27 only in the position of the entrance door. In Types 31 and 32 the entrance door opens off the building central corridor into a hall area near the bathroom, whereas in Types 26 and 27 the flat door opens into the centre of the living area.
Type 31 provides a flat with 1 bedroom, a living room, and a dining area (3 rooms). There are 27 in Gilbert House, 15 in Mountjoy House and 21 in Seddon House. Floors either have Type 26s and 27s or 31s and 32s.
