

PERI and Concrete House
An in-depth look at how our DUO formwork, along with our sevices and expertise, contributed to this unique and fascinating project.

A bold concrete structure built entirely with DUO formwork

Concrete House, Sussex, UK (as featured on Grand Designs)


“The project’s goal from the outset has been to simplify the construction process. By using DUO, we have been able to reduce our transport costs dramatically.

Due to the size and weight of the panels and associated pieces of the system, standard delivery can be used. This has allowed transport vehicles to access the site easily and offload without causing traffic issues.”

- Adrian Corrigall, Developer


The inspiration behind Concrete House stems from Adrian’s experience with concrete throughout life, from riding bikes and skateboards in skate parks at a young age, to developing a keen interest in Brutalist architecture more recently.


Digital Technology

The DUO formwork system has been designed to give operatives the independence to erect panels without requiring detailed technical drawings. However, due to Concrete House’s complex design, it was crucial for formwork designers to specify panel sizes and configurations in addition to concrete pressure tolerances, especially for irregular corners.

Additionally, planning had to capture design specifications, such as the alignment of visible panel joints and tie points. This involved using PERI’s DK ties to create the required architectural detail in the concrete.

PERI worked with augmented reality software and produced drawings in 3D to facilitate the design stage. By doing this, the developer and sub-contractor were able to understand the relationship between formwork, concrete pressure and the site before construction started. A major benefit of visualising DUO in-situ ahead of the build was that issues could be identified and construction output optimised.

Why DUO?

Adrian first discovered DUO during its launch at the UK Concrete show in 2017. At this point, CEMEX (concrete supplier) had been appointed to trial its unique Resilia concrete mix, another experimental means of improving construction output.


From the onset, the idea was to use DUO panels for horizontal and vertical applications to form slabs, columns and walls. The lightweight panels, the largest weighing no more than 25kg, were ideal for the project due to its location and confined site space.



The Trial Wall

An L-shaped wall was poured on site to establish the finish produced by the concrete mix and formwork panels. The architect-defined feature, comprising a regular tie-hole pattern and panel joints can be seen across adjacent walls in the image above.

Design work & Resilia concrete




PERI’s technical team had to control the balance between achieving the architect’s design requirements and ensuring that the arrangement of DUO shutters was compatible with the system’s limitations. In addition to formwork design, seamless construction and a steady supply of concrete  is crucial when achieving a consistent finish. Resilia is a fibrereinforced self-compacting concrete mix. Due to its fluidity, the concrete exerts a higher pressure than conventional concrete. Panels were limited to a maximum pressure of 50 kN per sq m.



The pours in detail


All walls were completed in 29 pours, with pour heights varying from 2.3m to 3.8 m. ALPHA props provided direct support for 345 sq m of concrete slabs, which were concreted in five pours. The customer also used DUO to pour 0.3 m and 1.4 m-high slab steps and upstand walls independent of technical drawings, demonstrating its ease of erection for simple structures.