Concrete House, East Sussex, UK

Constructed almost entirely of concrete, this single-storey building on a rural site in East Sussex, has been designed and constructed on a very-tight budget to provide a unique low-energy home for a young family.

The pioneering bunker-style design, which featured in Channel 4’s ‘Grand Designs’ programme, provided an experimental showcase for next-generation high efficiency concrete construction. It combines a structural frame of advanced fibre-reinforced self-compacting concrete, chosen to minimise reinforcement, with an external envelope of modular concrete blocks, cast in-situ around a central 150mm layer of XPS insulation, using a new type of thermally-efficient concrete.

To achieve optimum thermal performance, every detail and junction of the external thermal envelope was carefully computer modelled in conjunction with experts at the University of Zurich, to maintain air-tightness and prevent thermal bridging.

The Challenge

To provide a visual break in the brutal concrete elevations, RAW Architecture used a series of external features, including a large balcony, two canopies and two one-metre deep hollow concrete beams, which had to be attached through the external envelope to the concrete frame.

The challenge was to find a high-strength support solution for the heavy concrete structures that would provide an effective thermal break to maintain the integrity of the external thermal envelope whilst meeting fire and other performance requirements.

The Solution

The solution was Ancon’s Isotec insulated balcony connectors. The engineered units, comprising corrosion-resistant, high integrity, low thermal conductivity, stainless steel tension bars and short compression studs and a thick layer of non-combustible mineral wool insulation, were individually manufactured for each location in a non-deformable cage for maximum rigidity and dimensional stability.

As a critical structural component, the Isotec units were designed to transfer moment, shear, tension and compression forces at the concrete-to-concrete interfaces, have integral fire resistance, and also minimise cold bridging across the internal-external joint.

Three different types of Isotec element were supplied direct to site to suit the build schedule – ISO 80MV straight units for the balcony, ISO 80 MV-WB angled units for the two canopies and ISO 80 DV to provide connection at the top and bottom flanges of the deep hollow beams.

Concrete House featured in the popular ‘Grand Designs’ television series, first aired on 24^th October 2018.

Related Products

Isotec Concrete-to-Concrete Connectors

Ancon Isotec is a high performance thermal break system comprising 100% stainless steel reinforcement and fire-resistant mineral wool insulation.

Insulated Balcony Connectors

Ancon connectors minimise heat loss at balcony locations while maintaining structural integrity.