Harmondsworth Immigration Removal Centre (IRC) is adjacent to Heathrow Airport. It is a closed facility which provides accommodation, health care, education and recreational activities for up to 259 men detained by the UK Border Agency who are awaiting removal from the UK.

The Harmondsworth IRC accommodation wing ABG is approximately 72m long and 15m wide, and houses two rows of three storey pre-cast concrete secure bedrooms either side of an association area.

The superstructure from ground floor SSL to plant room SSL comprises precast walls, floor slabs and stairs tied to each other and tied to the ground floor slab using insitu dowels cast into the slab.

All walls are 150mm thick, and floor slabs are 175mm or 200mm thick depending on the slab. The walls and floor panels are supplied ‘flat-pack' to suit the location they will be erected, and are temporarily held in position until insitu concrete stitches are made to tie the units together. The stability of the precast frame is provided by precast reinforced concrete shear walls. The walls and slabs are tied together to make the building more robust and to transfer lateral loads to the shear walls.