Insights

Volumetric construction and the floorspace predicament

Every day, we read that in order to solve the skills shortages and boost productivity we need to adopt Modern Methods of Construction; one of the main elements being the use of volumetric offsite construction.

In volumetric construction, the transportability and size of the module are commonly a limiting factor. When modules are to become hotel or student bedrooms for example, the viability of a project can be dependent on every cm of space gained or lost in the unit.

Volumetric modules which need to form an integral part of the building structure are a further limiting factor to room size. The construction materials lining the loadbearing elements of the structure need to provide the necessary levels of fire protection, demanding thicker walls.

In order to comply with building regulations, the traditional solution in these cases would be to line the walls with three layers of 15mm fire resistant plasterboard. In a typical volumetric module, this means a loss of >4% of the floor space to the wall linings.

For one of our clients, this standard wall thickness was proving a barrier to the viability of its student accommodation project. The loss of almost 1m2 of the floorspace in each module to wall linings made the project untenable.

The challenge: How to meet Building Regulations whilst at the same time minimising wall thickness and maximising floor space.

Protecting loadbearing elements of a building from fire is not simple. For this project, the walls of each module formed part of the building’s superstructure and required fire protection of 120 mins on a loaded test. We needed to find a solution, and fast.

Within our product portfolio, we were able to offer a wide range of high performance calcium silicate boards which would have met these requirements; however, they would not meet the client’s other needs which included having a high quality surface finish and bringing the project in on-budget.

Working in partnership with our client, our experts were able to devise, test and deliver a solution which combined our traditional plasterboards with a thinner yet high performance calcium silicate board; enabling us to reduce the wall thickness by some 15mm.

Whilst 15mm may not seem like a lot, it represents 30mm across the width of a room – or the width of a Mars Bar. When space is at a premium, this can mean the difference between whether a bed and desk will fit across a room or not.

In the rapidly emerging Build to Rent market, additional floorspace can mean additional revenues. By making this simple change, it could add as much as 2m2 of floorspace to a typical apartment when built with volumetric modules. This delivers two key benefits – a more spacious, less tunnel like space for the occupier, and more rentable space for the investor generating higher returns on their investment.