Twinwall construction is a walling system that combines the speed of erection and quality of precast concrete with the structural integrity of in-situ concrete to provide a hybrid solution. The prefabricated panels comprise two slabs separated and connected by cast-in lattice girders. The units are placed, temporarily propped, then joined by reinforcing and concreting the cavity on site. Twinwall is usually employed in association with precast flooring systems.

The panels are manufactured to exacting tolerances, have a high quality finish, and can incorporate cast-in cable ducts, electrical boxes and service ports. Installation rates are of up to 100m2 per hour. Twinwall has excellent inherent fire resistance and acoustic performance.

Further information on twinwall can be found in the publication Design of hybrid concrete buildings.