Current best practice highlights that we can reduce CO2 emissions for different building types to very low levels without any loss of amenity by just fine tuning the building envelope:
Office: Fielden Clegg Bradley BRE office: 8kgCO2/m2/per year
Home: Jestico and Whiles Home of the Future:
However, the above examples are new buildings, which only replace existing buildings at 1.5% per year. Therefore it will take until 2050 to meet these targets by just improving new buildings at these targets. What we need is to aim for even lower targets for new buildings and set stringent targets when we are refurbishing existing buildings.
Density is a key indicator in achieving sustainable development. This not only limits the impact on green spaces, but together with mixed use schemes reduces the need for commuting and therefore transport CO2 emissions.(refer to Rogers Urban Task Force Sustainable Futures Report)
Current typical density: 20 dwellings per hectare (unsustainable)
Suburban benchmark: 40 dwellings per hectare (real energy savings)
Urban benchmark: 80 dwellings per hectare (optimum balance for energy efficiency)
High Density examples: Islington: 100 dwell/hectare
Bloomsbury: 200 dwell/hectare
Barcelona: 400 dwell/hectare
There are a small but growing number of projects that not only try to maximise the passive benefits from the building envelope but integrate renewable energy sources such as wind, photovoltaics (PV's ), solar water heating, and wood chip combined heat and power systems. The integration of renewables mean that no fossil fuels are used at all.
These schemes are called carbon neutral or zero energy or carbon developments.
The Vales House, Nottingham
Hockerton Housing, Nottingham
Bill Dunster Bed Zed, Beddington, London
Bedzed is seen as a key example of what be achieved now.
- It uses 90% less energy than current housing and workspaces.
- It uses PV's to power a fleet of 30 electric cars for use by the residents
- It has a density of 100 dwellings per hectare
By working and living in this model residents have achieved the goal of using resources equivalent to a single earth.
Bedzed is a living example of the wider benefits of contemporary ecological design where we keep all the advantages of our current way of life and minimise the negative aspects. This interconnectness can be illustrated by our Ecological Matrix, which highlights the links between resource consumption and life benefits.
However, Bedzed is just one example. To create a diverse and stimulating city we need many examples of various building types with their own distinct characters.
The ecomatrix illustarted