The 'Jigsaw' House is an adaptable, sustainable building solution that aims to address the standard of contemporary living within a community-based society. The evolution of the concept of a building that whilst being robust, maintains a 'life cycle light touch' meaning that as the community evolves and restructures, the buildings will not leave a detrimental lasting footprint upon the sites in which they are placed.

Conceptual Content

Related Links:

Read ECD Architects Biography

The 'Jigsaw' House has been conceived as an 'Adaptable Sustainable House' that addresses the holistic aspects of sustainability, namely those of social, economic and environmental, in an integrated way. The original concept of this building was as a reaction to the mass urban and suburban residential housing being built on a dense scale. Flats and apartments are spaces for transient living. Houses are places for families to live and grow. Communities are built around families; settled people with children and friends nearby. The transient nature of modern living doesn't allow for communities to evolve. Modern communities should have the ability to develop around the families that inhabit them.

Energy and Performance

The 'Jigsaw' House offers considerable internal flexibility and lends itself to a modular form of construction, or a 'kit of parts' approach, so residents can easily customise their homes. For example, living spaces can be double height or located on either the ground or first floor. Bedrooms or study areas are generally located on the ground floor in this scheme; however these spaces could easily be relocated. Attached garages are provided as requested by the 3^rd International Architecture Brief brief but an alternative approach might be a free standing car port or an off-street parking space. Nearer the centre of the community there might be only street parking adjacent to terraced housing. Extra space can be created to allow addition of further bedrooms in the future by providing rear extensions or by adding a further floor to the building.

The core design obviously relates to the housing sizes requested in the brief, however the adaptability of this building allows for a flexible solution with many outcomes. It is this flexibility that is one of the reasons that this design is called the 'Jigsaw' House. The other is the flexibility in site layout terms, resulting in the ability to have a mix of dense urban type housing through to a more open rural feel away from the hub of the community.

In generic terms, we have devised a building that is a simple rendered element over two storeys with a steel crust. This basic type of house is the starting level which can be adapted to achieve the various permutations and combination that are the 'Jigsaw' House. All the additions to this initial phase are timber forms and wrap around the building. The wrap-around elements are designed to complement the initial structural form of the building and are therefore realised at only a ground-floor level.

The steel within the building being emphasised through its verticality and protective roof, with the complementary softer elements relating more to the landscape within which the building is sited.

We have chosen a Corten type of steel - a pre-weathered steel - for the building crust, as it is a heavy duty element that requires no maintenance. Also it sits in juxtaposition to the natural landscape and gives the design a sculptural standing that emphasises the use of steel within this community project.

Corten has that warm velvet colour and texture that reflects the natural tones of nature whilst being unashamedly manmade.. This is a material that looks contextual whether it is in the woods, in the desert, or in the middle of a neighbourhood. There is no maintenance required, and it just keeps looking better over time.

The house is entered through a lobby space or ‘buffer', preventing draughts and maintaining the airtight envelope. The lobby functionally provides a threshold into the home, allowing storage of outdoor clothing, whilst also increasing security.

All the bedrooms are situated on the ground floor with the living space above. This allows the bedrooms to benefit from the cooler grown floor conditions, and the living spaces from the warmer, well-lit spaces on the first floor.

Positioning the living space above ground floor allows these spaces to benefit from views across the community, whilst also providing direct access into the external terrace. The roof section creates an interesting open plan living space, with high floor to ceiling dimensions. The wood burning stove creates the focus to this family space.

We have designed the house around family life; creating a large open plan space where the family spend the majority of their time. It is, however, important that we also provide smaller, quieter spaces for study and relaxation. The library/study area on the ground floor achieves this. The ‘wall of books' and the finishes ensure this internal environment is very different from that upstairs. We believe it is important for the design to aid and encourage environmental living. The design includes a compostor, located on the terrace next to the kitchen, secure bike storage and recycling facilities. The large plot sizes also allow space for the family to create their own allotments and orchards.

Energy and Performance

Climate responsive design: The concept for the climate responsive house in this location is one that 'closes down' in winter and 'opens up' in summer. At 59^o08'N latitude the site receives a good amount of solar radiation, around 930 kWh/m². In such a cold climate a significant proportion of this is potentially useful for space heating, so a passive solar design strategy is feasible. High levels of thermal insulation are cost effective in reducing heat losses in winter but also insulating against excessive solar gain in summer. The sun path diagram indicates sun angles of 80⁰ in summer and 30⁰ in winter.

Energy efficiency: Our approach to energy adopts a three tiered strategy. First we will reduce demand by adopting high standards of thermal insulation (German Passivhaus standards). Second we will supply energy efficiently and third we will use renewable energy supplies where appropriate, e.g. solar, wind, biomass. Consideration of renewable energy supplies will influence both the design of the individual house and the master plan. In particular it is important that roof areas are oriented to the south at an optimum inclination to allow solar energy collection in the future when costs are more economic. At the scale of 500 dwellings there is the possibility to provide heat and power by means of community heating and CHP (Combined Heat and Power). This could be powered by natural gas or preferably biomass ( woodchip) as there appears to be a plentiful local supply. Additional electricity could be provided by a large scale wind turbine and ( in the future ) roof mounted solar photovoltaic cells. Space heating would be provided by underfloor heating, topped up by a wood burning stove in living rooms. Waste heat from the CHP system in summer could be diverted to a community swimming pool.

Passive solar design: The Jigsaw concept is for an adaptable sustainable house type with living accommodation at first floor and bedrooms at ground level. Thermal mass integrated in the construction ensures bedrooms keep warm in winter and cool in summer. By optimising solar orientation it is possible to utilise passive solar heat gain during 6 months of the year and a south facing sunspace can facilitate this whilst at the same time provide an additional 'thermal buffer'. In summer an overhanging roof provides solar shading together with horizontal timber lowers. The concept is similar to a house designed by ECD for a south facing site in Rock, Cornwall. The ideas now need to be refined to match local climatic data and tested using dynamic thermal modelling. South facing homes have lower winter fuel consumption than east/west-however site layout and urban design considerations will require a variety of access and orientation options. External walls are more expensive than party walls and add heat loss so short lengths of terrace houses or semi detached arrangements would be preferred.

The PassivHaus approach: The PassivHaus approach has been developed and tested widely in Germany. To meet the standard a building must have an annual heat load of less than 15 kWh/m² pa and a combined primary energy consumption of no more than 120 kwh1 m².pa for heating, hot water and electricity. This is usually achieved by the following:

• Very high levels of thermal insulation and no thermal bridging
• Utilisation of solar and internal heat gains
• Excellent air tightness < I m3lm2 @ 50 pascals
• Whole house mechanical ventilation and heat recovery
• Solar water heating
• Low energy lights and appliances

PassivHaus dwellings typically achieve an energy saving of 9096 compared to current norms, with annual C02 emissions of 4 kgC021 m2.pa. We have used the PassivHaus Planning Package ( PHPP) as a design tool to evaluate the performance of the Jigsaw House, using climate data from the Vologda region. Fabric U Values are 0.1 W/m2.K with triple glazing at 0.7 and mechanical ventilation with heat recovery is assumed. The heating fuel is biomass. The summary sheet indicates a primary energy demand of 54 kWh/m2.pa, well below the target of 100. Annual C02 emissions are 6.4 kglm2 and overheating frequency at 7% is within acceptable limits.

Environmental Performance: In the UK we are now using the Code for Sustainable Homes as an environmental benchmark. Credits are allocated against nine categories; energylC02, water, materials, surface water run off, waste, pollution, health and well being, management and ecology. The assessment is carried out for an individual dwelling and expressed as a Level - between 1 and 6. Minimum standards must be met for energy and water consumption in order to meet the higher code levels. Level 6 is zero carbon for all energy consumption including lights and appliances. The Jigsaw house would meet Level 415 of the Code. Water and Waste: Water is an increasingly scarce resource and the Code sets a target of 90 litres per person per day. This is achieved by using low flush wc's, flow restrictors and 'tailored' baths. Recycled rainwater will also be used for flushing wc's. At site level a water management plan is envisaged to minimise surface water run off and to maximise use of re cycled rainwater alongside a range of other technical measures to reduce water consumption. Likewise, facilities for segregation, storage and collection of domestic waste need to be embedded in the master plan, together with composting facilities.

Materials: Steel provides the material for the main structure as well as the cladding at first floor and roof level. Precast concrete floors can be made locally using waste fuel ash from the steel works. It is envisaged that a local factory could be set up to provide the bulk of components in prefabricated form. At the end of the construction period the factory could be re used as a community1 leisure centre, ideally a swimming pool to take waste heat from the CHP system in summer. External cladding at ground level is locally grown timber and windows will be high performance triple glazed.

For more details about this design, see the Summary Document.