A description of the design and practical application of a new precast concrete building is presented. The system combines two basic structural components: a modular ribbed panel of size 10 × 20 ft (approximately 3 × 6 m) in plan, and a three-dimensional H-shaped module of up to 10 × 40–45 ft (approximately 3 × 12–15 m) in plan and 8–12 ft (approximately 2.4–4 m) in height.It is designed for speedy erection of multistorey buildings. The main feature of the system is the simplicity of connections. Large-size, H-shaped modules are erected by stockpiling them one on top of another with simple bearing connections located at mid-height of the supporting columns or walls. The spaces between module stockpiles are filled with modular ribbed panels. In some areas panels are omitted, thus open spaces are created to accommodate staircases or elevator shafts where required. The panels are simply supported on continuous edge brackets that are formed along the entire perimeter of the modules.This system was used in the design of a large building complex recently erected in Edmonton, Alberta. It combined a four-storey hotel, eight-storey office tower, and covered courtyard, all situated above a two-storey underground parkade.A description of the building, production of modules and panels, erection, and some details of the connections are discussed in the paper.