How is a precast house installed? Day by day

The structure of a single-storey single-family house is usually completed in a single installation day. That is no figure of speech — it is the consequence of everything that dries slowly or needs formwork having already happened, in the factory. Here is what that day looks like and what has to be ready before it.

Before the first delivery arrives

• Foundations signed off by a surveyor. The slab or strip foundations must be built within the tolerances given in the shop drawings — the foundation stage is where it is decided whether the installation will go ahead without corrections.

• Access and a crane position. The low-loader needs a way onto the plot, or unloading from the road; the crane needs a hardstanding with reach across the whole floor plan.

• A delivery schedule. Walls travel in installation order. Each element comes off the trailer straight onto the crane hook — on a small plot there is no room for storage, and none is needed.

Installation day

The external walls go first, starting from a corner, levelled and supported with diagonal braces. Then come the internal load-bearing walls, and finally the non-standard elements: gables following the roof pitch, lintels over large glazed openings, the stair flight. The crew makes the connections to the design — the braces stay in place until those connections have cured.

On a two-storey building the cycle repeats: filigree floor slabs on the ground-floor walls, pouring the in-situ topping, then the upper-storey walls. A storey is completed in a few working days.

What happens after installation

Once the braces are removed, the structure is ready for the roof trusses. Walls straight from the mould have a smooth surface — finishing begins without any plastering. Chases and electrical boxes are in the elements from production, exactly as set out in the BIM shop drawings.

The whole chain — design, production, transport, installation — is our responsibility, and we describe it in our services. Examples from construction sites can be found in our projects.