»Pre-fabricated modules: flexibility
There is a hierarchy to the prefabricated unit design. The primary units contain the essentials: kitchen, bathroom, utility/plant stairs and lift. These facilities are contained in two modules and form the minimum support. The second units can be added depending on the occupants' requirements. These modules contain carports and storage, studies, kitchen extensions, dining rooms, additional bedrooms, terraces, etc. These modules have been planned to a 300 grid with an overall internal dimension of 4200 x 4200 to maximise efficiency of space use and optimise site potential.

These modules can be combined in many ways, and can be added retrospectively to respond to changing requirements. For the purposes of this submission, a number of variations are presented to explore and demonstrate the concept's potential. The designers have responded to the existing property and proposed a refurbishment strategy that is appropriate and sensible for the size of dwelling and its location.

It is intended that this refurbishment strategy could be rolled out nationwide where there are large numbers of empty properties that have potential.

The name of this design is derived from the way in which the prefabricated modules connect into the existing house. Although the number of modules is variable - based on the occupants' requirements - four modules seems to be the optimum.

The designers' key objectives in the development of these proposals are accessibility, flexibility and sustainability. The brief to retain numbers 81-87 Shakespeare Street has generated the following design strategy.

The designers' proposal is to take out all the services, bathroom, kitchen, boilers, etc, and accommodate these facilities in a prefabricated unit that is constructed off site to very high standards and tolerances. This means that a lot can be planned in a very small space. The designers also believe that this approach is very cost effective, given the standardisation and mass production factor.

»Accessibility
While exploring this approach, the designers also started to consider the inclusion within these prefabricated units of stairs and a lift. The inclusion of a lift as standard in any dwelling over one storey is a recurring theme in the designers' work. Unlike a retrofitted platform, which is often located between living room and bedroom, a proper lift planned into the scheme from the very beginning has many benefits. It provides full accessibility over two or three floors for the elderly and disabled. It also allows for flexible planning with regards on the location of the bedrooms and living rooms. The proposals demonstrate this flexibility by presenting a variety of plan configurations.

With regard to the house plots, the designers have worked to the site plan and boundaries in the brief. In terms of the site context, the designers have adopted for this exercise the layout that forms the basis of the access statement. This has provided a discipline with which to test the design concept. It also proposed to flip the access arrangements so that the main approach is towards the rear and the front looks over a linear park, public pedestrian and cycling route.

»The existing building
For the existing houses, the design approach allows for a simple strip out, capping off services, making good, and partitioning to suit the preferred layout. This is an efficient cost effective refurbishment solution. It also follows a traditional refurbishment solution of extending the original dwelling by accommodating the kitchen and bathroom in the extension.

Externally, there are many options based on architectural and practical factors. The designers chose to make new openings, and fill in those that are no longer required. The building is insulated externally to a very high standard and clad with appropriate materials, a range of options being indicated including timber, render, and metal cladding such as zinc. This approach contributes considerably to the energy performance of the building, and produces a fresh contemporary scheme. An alternative is to insulate internally and refurbish the exterior if the appearance of the existing building is worth retaining.

For the purposes of the competition, the building is clad in a standing seamed metal, this material being chosen for its durability, variety and flexibility. It can be used on the roof and walls to reinforce the strong architectural form of the original building.

»Sustainability
The home is designed to a high environmental standard and includes:

• Triple glazed windows, reducing heat loss
• Insulation to at least a 25% improvement on 2006 Building Regulations
• Air permeability - 2.5air changes per hour at 50 Pa
• Passive stack system to naturally ventilate the building
• Heat recovery to shower and bath waste water
• A+ rated white goods
• Integrated energy solution, including: photovoltaic cells on the roof; solar hot water collectors; air source heat pumps; future proofing for district heating system

The use of water will be reduced through highly efficient water fixtures and fittings and the use of rainwater:

• Aerated taps on sinks
• 6 litre per minute showers
• Vacuum sewage system reducing toilet flushing demand below 6/4 litre flush
• Dishwasher volume of less than 16 litres
• 50 litre maximum washing machine
• Rainwater recycling will account for 30% of the water used for washing machines and toilet flushing.

Permeable paving and holding tanks will ensure that water run-off will not exceed run-off prior to development.

The modular design will reduce the waste produced in the construction of the buildings. Each home will be provided with internal and external recycling space to encourage homeowners to reduce waste sent to landfill.

The ecology on the site will be maximised through the consideration of existing habitat and provision of a green roof.

© British Homes Awards |  Site design: LW design