Chapter 3 Case Study: Volumetric Construction: Urbansplash ‘House’
Images with kind permission of Urbansplash
The volumetric house is exemplified well by the ‘House’ concept that is used by UK innovators ‘Urbansplash’. The building is formed using closed panel timber frame construction and results in an open plan form that can be assembles as two or three storey dwellings. The open plan form allows great flexibility in use with the potential for multiple configurations to be adopted by occupiers. The nature of volumetric construction is such that cellular building forms are the most suitable form.
The floor cassettes are formed using timber I section beams with OSB sheeting to create the floor surface. These units are manufactured with great accuracy in factory conditions before being assembled with the wall and roof sections to create the volumetric form.
Assembled volumetric units are shrink-wrapped in the factory for protection during storage and transit. Timber frame, closed panel units are heavily insulated.
Manufactured units are stored at the factory for minimum time before transporting to site for completion and connection to utilities before final sale and occupation.
Volumetric units are delivered to site in fully assembled is storey high units. These are located on pre-prepared bases with single entry points for utilities and services. The width of the volumetric units is limited by the ability to transport on the road network.
Volumetric units are stacked and connected to create 2 or 3 storey dwellings. Final external trimming and sealing of junctions ensures full weather tightness. The development site is designed and managed so that crane access for lifting and placing modular units is optimised. This is a major difference from traditional construction forms.
Multiple volumetric units are located to create the development. Two or Three house units can be placed per day. The enabling works such as foundations and utilities must be managed to allow the units to be placed without undue complexity. The project planning and design freeze stage are significantly different from traditional construction approaches. Rapid assembly on site is possible provided that the earlier planning stages are dealt with appropriately.
Connection of external rainwater goods and final trimming take place once the volumetric units are assembled. Whilst the volumetric units are assembled effectively in a controlled factory environment the final finishing still requires site based activity which needs to be well coordinated.