Environmental Design
We considered the topology of the land together with its coastal position and investigated how best to harness the natural resources available to produce a highly efficient and sustainable development.
The group of buildings are shaped and orientated to harvest the prevailing south westerly and north easterly winds at the same time as maximizing the potential of both passive and active solar energy. Each ‘elliptical residential pavilion’ is articulated to provide balconies and sundecks with indents brightly coloured against a predominantly white skin.
The spaces between each ellipse have been aerodynamically designed to focus wind onto pairs of vertical helical turbines providing approximately half the developments annual electric demand, at the same time as celebrating the sculptural kinetic architectural forms inherent in the ‘functionalist’ tradition of costal objects. Each residential block overlooks above a glass folded plate canopy which prevents down draughts and protects most of the public areas. The canopy is stitched into an active frontage that animates the promenade deck, and provides a mixture of both shelter and distant vista with open horizons.
Each flat layout has been planned so that bathrooms and circulation are adjacent to turbines, with the thick super insulated walls, heat recovery ventilation and high performance triple glazing providing excellent acoustic attenuation. Living rooms, master bedrooms and kitchens have been positioned to maximise views and sunlight, with open summer verandas turning into glazed winter conservatories to provide seasonal extensions to the living space.
Materials & Technology
The building integrated renewable energy micro generation systems have been carefully composed to both maximise their performance and create a sculptural fresh aesthetic. The team have been careful to compose the different types of solar panels and turbines so that they become both decorative and functional elements within an overall sculptural concept. The use of translucent glass / glass photovoltaic panels for balcony balustrading and public canopy areas, with evacuated tube solar thermal collectors arranged as a linear block, and opaque photovoltaic’s used as rainscreen and roof cladding, is designed to act as a foil to calmer areas of white rendered hempcrete curving wall. Natural hot dip galvanised steelwork, aluminium clad timber windows and laminated timber canopy beams will enclose the upper floors. The lower shop fronts will be detailed using laminated timber windposts with frameless glass windows and doors.
Different insulating materials such as sheepswool, cellulose fibre and hemp within 300mm cavities will be mixed with clear shop windows to provide a natural palette of colours with panel variations allowing a multitude of different uses, ranging from display shop fronts, to cafes, craft studios and live work units. Photovoltaic’s are integrated into the façade and within the balustrade of an unheated enclosed balcony.
As well as the mixed use aspect of the pedestrian ground plane, providing around the clock security and employment opportunity to the area, each tower has its own wood pellet boiler providing all the winter hot water needs. Each home consumes no more than its fair share of the limited national stocks of biomass (250 dry kg / person / year – with no national loss of agricultural land)
It is important that each resident understands the amount of energy they consume and produce, and is able to watch their own meters go backwards at times of net export. The site actively promotes a low energy lifestyle from the LED display of individual energy consumption to the wood pellet display indicating how much the heating is used in each of the blocks. The mixed use nature of the site means that residents do not need to jump into a car to get a coffee or something to eat.
A site wide composting system compliments the recycling separating bins in the kitchens and the separated waste collected by the local council.
The renewables on site in the form of silently turning helical turbines and Photovoltaics will establish a new benchmark for sustainable architecture by providing all the electrical needs for each of the residential units.
In the unlikely event that the turbines cause too much noise or flicker effect from the blades an electric control system will brake the turbines affected. Sophisticated shadow projections have been used to determine when these electronic brakes are actuated.
As part of the lower basin road level there is a car pool consisting of four electric cars powered from the PV panels on site and four pure vegetable oil powered cars run by a local company called ‘blooming futures’ as part of the development a garage and offices would be provided for this purpose. The oil would be delivered by local farmers thus providing a low ecological footprint transport solution to the site complimenting the existing public transport routes on the A259.
Building fabric Energy load reduction
Before considering any innovative new renewable technologies or efficient services solutions, the energy demand of a building must be reduced. The base ZEDstandard to all homes can be subdivided into the following headings:
Super-insulation
By providing a super-insulated, highly airtight envelope the buildings minimise their heat loss. Any warmth generated within the home is therefore kept and stored within the thermal mass, to be released slowly during times when the heat source falls away: i.e. cool cloudy days and night time or when there is little activity within the building.
High performance glazing ensures that large areas of glazing on southerly aspect facades can be used to give excellent daylight and good solar gain (with shading to prevent summer overheating).
A ZEDstandard typical wall, floor and roof construction has a U value of 0.1W/m2/k. This means that if it is freezing outside and a normal room temperature of 20 deg.C inside, a square metre of wall, floor or roof will only loose 2 Watts of heat to the outside. (A typical adult gives off 106W of heat)
Masonry wall construction is typically (from inside to outside) 13mm of traditional dense wet applied plaster, 140mm dense concrete block (minimum density 1400kg/m3), 300mm of mineral fibre insulation and an external skin of block. The block is faced with a self coloured lime render. There is no vapour barrier as the wall is a ‘breathing’ construction.
High performance glazing
Even the highest performance window you can buy has a U value ten times worse that ZEDstandard wall construction. Windows must therefore be made to work hard for the building. By having a South facing sunspace/conservatories with both screens double glazed, the building effectively has quadruple glazing with a very large internal air space. This configuration means that the overall flow of heat energy in the winter is from the outside to the inside. ZEDstandard specification for sunspace windows are double glazed, soft low E coated, argon filled sealed units with a minimum overall U-value of 1.6 W/m2 deg. C.
Early super insulated houses had the tendency to reduce window sizes to reduce energy losses. However the interiors became dark and depressing, requiring artificial light throughout the day. This both decreased desirability in marketability terms and increased CO2 production as although heat energy was being saved, much more carbon intensive electrical energy was being used to light spaces.
ZEDstandard windows to the North East and West must be designed carefully to provide maximum daylight to spaces that otherwise would have little, provided visual connection between inside and outside and finally and very importantly, positioned to produce a pleasing elevation to the building. The compromise between energy loss and the three concerns above must be carefully balanced so on one hand, the building is not ugly, and on the other, it does not loose excessive amount of energy.
ZEDstandard specification for windows are triple glazed, soft low E coated, argon filled sealed units with a minimum overall U-value of 1.2 W/m2 deg. C. This helps both with heat loss performance but also with the acoustic value compared with an opaque piece of building fabric.
