Self Sufficient Housing Developments: A Case Study

When looking for good examples of sustainable build, there can be few more fitting candidates than Nottinghamshire’s Hockerton Housing Project (HHP).

Over the past few years, Hockerton – the UK’s first earth-sheltered, self sufficient ecological housing development – has helped to educate people from across the globe about “green” developments, saving energy and protecting the environment.

Its members have also advised many people on how to do something similar through the project’s consulting business.

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Lengthy Planning

The original plan for a self-sufficient community took a number of years to come to fruition – but it was worth the obstacles along the way and today, it is a fine example of what can be achieved by ordinary people who share a dream to live a more sustainable lifestyle.

The homes are earth-sheltered which means they are almost invisible from the road. They are super-insulated and use sun spaces to harvest passive solar energy to negate the need for a space heating system.

Energy Use

One of the main aims of Hockerton was very low energy consumption and it has achieved this through a variety of methods.

The houses use only a tenth of the energy used in the average UK home. They have no central heating systems, instead relying on the high thermal mass construction to store the heat generated by the passive solar gain and release it over a long period of time.

Misconceptions

Many people expect that being earth-sheltered, the houses will be “dark and dingy” but they are south west facing and enjoy good natural daylight.

The design also makes the most of solar gain and low emissivity (low E) glass reflects energy from warm surfaces inside which reduces heat loss.

The homes use an average of 3,400 kWh of energy per year (around 75 per cent less than current building regulation requirements) but the families haven’t sacrificed modern comforts and youngsters can still have their computers, music systems and mobile phones!

The low energy design of the houses is complemented by a variety of environmental and energy saving policies and because there was no spending on heating systems, build costs were similar to a traditional house.

In addition to the houses, the development includes:

  • an office for Hockerton’s own trading company
  • rainwater harvesting for all its water needs
  • a reed bed system for waste treatment
  • organic fruit & vegetable gardens
  • a lake and wildlife pond
  • two on-site wind turbines and a photovoltaic array for renewable energy generation

Rob Cartwright, the newest resident of the Hockerton community, says not everything worked out as originally intended.

The wind turbines, for example, produce less than half of the output originally projected and water-to-air heat pumps stopped working in four homes.

But despite the lower energy production, the turbines provide extremely low cost electricity and when excess power is produced, it is exported to the National Grid. This helps to offset the cost of importing power when supplies are low.

Combined with the output of the PV array, 80-85% of the annual energy requirement of the homes is generated on-site.

New Wind Turbine

Currently, the project is working with the local community to install a 225kW village wind turbine, which will generate sufficient energy to cover the total consumption of the village. Since HHP opened, more than 10,000 people have toured the site and countless people have been inspired to seek a more sustainable lifestyle themselves.

Help and Advice

The project also runs a consultancy business to help people build low carbon homes or retrofit their existing homes to make them more energy efficient.

“Retrofit is vitally important because the real challenge in the domestic sector is the houses that are standing today,” said Rob.

The families living at Hockerton have achieved their dream of an extremely sustainable lifestyle – but deciding to follow their example is not a decision that should be taken lightly.

There are many considerations – not least of which is the need for a committed team prepared to put in a lot of effort to see their dream realised.