Prefabricated modular construction has become more widespread in commercial and industrial contexts of late, but that is where the concept has stayed, for now at any rate. The concept of individual modular residential dwellings is a market that has yet to get fully up to speed in the UK. Reticence exists at a fairly deep level among private home-owners in this country, who are perhaps not as comfortable as mainland Europeans are with the idea of buying a home that has evolved from a manufactured kit of parts, even if they are happy to work in an office or stay in a hotel room that has a similar factory-based origin.
In part, this could be due to a feeling that with everything in the pre-manufactured modules arriving on site in as near a finished state as possible, the opportunity for the people who are to inhabit the spaces to have any influence over their own living environment is limited. Modern modular houses are based on prefabricated, factory-produced, easy-to-transport units. Seeking to change perception, and allow individual participation amongst homeowners, is the next logical step in encouraging the UK residential market to adopt this form of construction.
A Dutch firm, Flexline, has now collaborated with a firm of architects to take forward an existing form of steel-framed residential modular construction in a consultative process that allows the owner to have an active input into the configuration of their home. The project is a development for the HBS Ons Belang Housing Association at Het Broek, Hengelo, in the Netherlands.
Flexline, like other systems, aims to minimise the cost of production, resulting in cheaper, energy- and waste-reducing buildings, by constructing them in factories using assembly-line production. Dutch developer Helgelose Bouwstichting (HBS) Ons Belang commissioned Architektenburo Willem Smid & Jim Peters. It evolved a process that allowed homeowners to influence the layout and design of houses to be built on a site in Hengelo, before the modular units went into production at the Flexline factory.
One of the problems with the modular approach to construction is attracting the occupier to the concept of modular living in the first instance. People like to see the end result before they sign a contract. To generate interest in the flexible concept, the first two 5rows of houses on the site were designed and built for tenants who chose their favourite layout from a number of options. When these two rows were built, prospective buyers could see the end result, and the potential for flexibility.
Interest was immediately there for collaboration in the layouts and sizes of individual units in the next row of houses. At this point, all the remaining houses were quickly sold.
As each house on the next phase of the development was sold, architect Willem Smid and his colleague Coraline Vester spent time with the buyers, agreeing the configuration of the interior layouts to suit individual aspirations. Location of doors, windows and openings is decided, along with room configuration and specification. 'Owners can have two or more bedrooms, depending on if they want to buy another box to add on to the system, ' said Smid, 'or perhaps they might want another unit at ground-floor level to extend the kitchen or living space.' The strong steel frame carries all building loads, leaving the location of the lightweight infill walls to be decided in collaboration by owner and architect. The only internal fixture which could not be influenced was the location of the stairs. The customised units arrived on site with everything from external facade to wallpaper and electrics in place, all configured under a simple, flat asphalt roof.
Flexline is a simple, adaptable building concept based on a lightweight, steel-framed box. When building a modular home, great care has to be given to the layout and strength of the floor which will, after all, carry the weight of the rest of the home.
Extra strength and stability to the Flexline steel frame is provided through the solid floor where reinforcement bars are added for stability, enclosed within a factory-poured concrete slab 80mm thick.
After the floor system is in place, wall panels are put up and electrical, plumbing and HVAC systems are added. After the wiring and piping is done, wall panels, roofing and external cladding are installed. At the same time, factory crews install windows, doors, bath and kitchen fixtures and floor coverings specified by the homeowner. Simple really.