Winner of the Sunday Times /
British Homes Awards 'Resilient Home' Competition
More than 5 million people in the UK live and work in 2.4 million properties that are at risk of flooding from rivers or the sea,1 million of which are also at risk of surface water flooding. The UK's Annual flood damage costs are around £1.1 billion. These could rise to as much as £27 billion by 2080.
Estimates put the need for additional housing in England at between 232,000 and 300,000 new units per year, a level not reached since the late 1970s and 2-3 times the current supply.
The term resilience is not widely understood, so there is work to be done in translating this into something that consumers can understand and make informed decisions about.
(Jo Smit, 2016)
Why has there not been more consideration of the role of building regulations in encouraging flood resilience,& resilient repair in the UK? Recent flood events show the vulnerability of the built environment to damage. We need to look at solutions for new development as well as existing buildings.
(Dr Stephen Garvin, 2016)
The Home for All Seasons
The 'Home for All Seasons' is designed to take extreme weather in its stride - a place to live in comfort throughout the year. Whether torrential rain causes flooding, blazing sun causes a heatwave or it’s so cold that there’s a big freeze, the 'Home for All Seasons' will keep you safe and sound.
This future-proof design provides protection, comfort and independence to residents through an approach of resilience, rather than resistance, to the very real issue of extreme weather conditions. It works inline with the principles of good place-making and rather than seeing 'resilience' as a compromise uses it as a feature to enhance the way in which residents live in and enjoy their homes. As a result those living in the 'Home for All Seasons' have peace of mind in the knowledge that their home can be quickly and easily adjusted to cope with the wide range of challenges the future holds.
The 10 Principles of the 'Home for All Seasons'
Habitable zones are positioned on the first floor level and above to ensure a future proof, high flood datum design. This strategy avoids reliance on temporary add on measures for flood protection.
The ground floor ‘garden room’ zone is a flood resilient, multi-use space that can be quickly adapted and cleaned post flood.
The elevated ‘causeway’ at first floor level provides safe access and egress during a flood event and reduces the demand on emergency services.
Water and power utilities are elevated to first floor level to enable continuity of services during a flood event.
The buildings' minimal hardstanding 'footprint’ provides space for the integration of SuDs / swales and avoids displacing water to surrounding developments.
House design is suited to compact plot with reduced back-to-back distances. This means a density of 60 dwellings per hectare can be achieved.
The building form is designed to encourage passive stack ventilation effect with air drawn in through the high thermal mass ground floor zone
Thick and continuous super insulated envelope – ensures comfort in extreme cold.
Roof orientation designed to support on-site energy generation
The core house plan can be adapted to suit the changing needs of the homeowner and works for a range of different house types and layouts.
The flood risk management strategy in this scheme can be applied and adapted to suit the diverse range of flood risk contexts in upper, middle and lower catchment zones. For upper catchment areas (where the mantra of ‘Let rain Slow’ is recommended), both SuDs and swales can be incorporated into the layout of the development to help slow down & buffer the movement of water through the site. Flood water storage capacity is provided by permeable paving, storage crates, green roofs & minimal building footprints to ensure a large porous surface area for absorption of water into the ground plane. In mid and lower catchment zones (where the mantras of ‘Let rivers flow’ & ‘Let tides go’ is recommended), the porous ground floor configuration provides unobstructed channels for the flow of water, avoiding backlogging & displacement of water to surrounding areas.
To avoid the threat of overheating, this proposal incorporates a number of strategies. Firstly, the building is configured to be mixed mode, with its form design to provide shade during the summer months and use the stack effect to pull cool air from shaded ground floor zone. Secondly, the high thermal mass of the ground floor ‘garden room’ acts as a labyrinth, pre-cooling the air before it enters the living area on the first floor and moves up through the natural ventilation chimney stack (that incorporates a heat exchanger) on the roof ridge. Finally, adjustable horizontal louvers and solar thermal tubes provide shade to the glazed side façade, thereby minimising solar gain.
The design proposal embeds passive design principles and would seek to achieve Passivhaus standard with a space heating demand of up to 15kWh/m2 and a primary heat demand of up to 120kWh/m2a.Key to retaining a comfortable and consistent temperature inside the home during periods of extreme cold, the scheme includes:
· Air tightness of <0.6 at 50Pa through thorough design and detailing
· Super insulated closed panel timber frame construction system with U-values of 0.15W/m2K
· Triple glazed windows with insulated frames with U value of 0.8W/m2K.
· Heat recovery from exhaust air from bathrooms and kitchens.
The core house plan is easy to expand and adapt so that as families grow and populations continue to increase the residents can amend the building layout to suit their needs. This loose fit approach also provides flexibility in the house type, such that homes can be split into flats or extended over time and even space for growing food on site.
The building design incorporates long life, durable materials that require little maintenance and on the event of failure are easily repairable. The dwellings are designed to require minimal maintenance; they will age naturally and retain their distinctive appearance over many years. Detailing and in particular the movement of water over the dwelling has been considered and integrated from the outset. The costs associated with recovery after a flood event have also been considered, with the resilient ground floor zone reducing the need for expensive insurance claims or reconstruction.
Achieving resilience does not have to come at the detriment of good design. It can instead be used as a mechanism to actively enhance the quality of placemaking in communities. The house design in the 'Home for All Seasons’ scheme not only provides resilient strategy but also creates attractive and safe public realm. Compact plot layouts are complemented by generous street dimensions, with green space used as an active ingredient in the flood risk management strategy (SuDs, swales) whilst providing both shade and cooling. This scheme looks to encourage a change in how risk is perceived, making living with uncertainty a more enriching and positive experience.
PLACE-MAKING IN MIND
THE JUDGES VERDICT
The design for the Home for All Seasons combines resilience with placemaking. It creates an attractive streetscape, while providing a comprehensive response to future environmental challenges.
The Home for All Seasons considers flooding, heat, cold, societal change, economics and lifecycle cost. The team behind its design have given careful consideration to what resilience really means, and the resulting home concept clearly reflects that.