Using lightweight materials to mitigate England's housing crisis and save building costs and energy

The SIG I-House, based on Kingston University research, could be the solution to the UK housing market's need for new, affordable homes.

The UK is currently in a housing crisis, caused mainly by the insufficient number of new houses being built. First-time house buyers face an additional difficulty: many houses, both new and old, are simply not affordable.

There is an urgent need for innovative solutions to this crisis. Presently, builders are rushing to develop systems to quickly produce quality housing. Quick building, however, cannot compromise structural integrity. This reasoning spurred Dr Ted Donchev and Professor Mukesh Limbachiya, of Kingston's School of Engineering and the Environment, to research lightweight materials and the behaviour of wall systems. Their findings have led to a potential solution to the housing crisis: an offsite method of construction that joins lightweight elements without compromising structural integrity.

One of the main approaches to this method involves exploiting the properties of lightweight materials as alternatives to steel for reinforcing concrete structures.

Dr Donchev and Professor Limbachiya have focused their work on reinforcing fibre-reinforced polymers (FRP). FRP materials have long been used in civil engineering for the purpose of strengthening structures. These materials reduce compression forces within structures and demonstrate excellent resistance to tensile forces. The researchers have also developed important modelling guidelines and simulations to reduce harmful effects of FPR structures such as buckling and horizontal shifts, which would compromise buildings' structural integrity.

Dr Donchev and Professor Limbachiya's research led to H+H Celcon (a manufacturer of lightweight, concrete structural elements called ‘aircrete') commissioning a report on the behaviour of one of their wall systems and a thin-layer mortar. The report forms the basis of the SIG I-House, an innovative wall system that provides affordable housing in England.

The socioeconomic and environmental impact that the SIG I-House has had on construction efficiency is remarkable.

Since July 2016, over 500 SIG I-Houses have been built. The system reduces the average cost of a house's structural frame by 56%, helping save over £7 million for the sector. This system supports the reduction of the overall house construction time by 35% by shortening the time required for a structure to become watertight.

The lower price of dwellings, the significant reduction in CO2 emissions and the energy savings are valuable for buyers. The building system has been applied as part of Affordable Housing Schemes and in 2019 Barratt Developments used it at seven sites across England.

The Technical Director at H+H described how Dr Donchev and Professor Limbachiya's results "were the main factors allowing the development of the SIG-I House". He concluded that "the developed innovative housing system is helping to meet housing demand, allowing for fast and economic construction".

The SIG I-House system received several accolades in 2017.

These included the Product Innovation Award at the Barratt Developments' Supplier Excellence Awards, and the Best Building Fabric Product and the Best Product at the Housebuilder Awards. In May 2020, the National House-Building Council accepted this new Modern Method of Construction (MMC), with NHBC's Innovation Manager noting how these solutions meet the need of the housing supply in the UK and will "help bring benefits and certainty to manufacturers, developers, and builders".

The research of Professor Donchev and Professor Limbachiya has brought benefits to local communities and the environment in ways that help alleviate the UK housing crisis.