Pennyland project

The Pennyland project was one of a series of low-energy building experiments sparked by the 1973 oil crisis . It involved the construction of an estate in the Pennyland area of Milton Keynes , Buckinghamshire , United Kingdom . It possible future Compared UK building efficiency standards with newly Introduced Danish ones.

Although identical, half the Pennyland houses (Area 1) were built to the 1982 UK Building Regulations energy efficiency standards. The other half (Area 2) were built to the much more demanding 1977 Danish BR77 standard. (In Europe, BR77 and the Swedish Standard SBN-80 set the benchmark for low-energy housing at the time.)

Sponsored by the UK Department of Energy, Department of Environment and Milton Keynes Development Corporation , and using the technical expertise of the Open University Energy Research Group, The Houses were constructed during 1979 and 1980.

For comparison, two additional groups of control houses, already built in 1978, were studied on an adjoining site at Neath Hill. In a further group, the Linford Low Energy Houses were built to the Pennyland Area 2 standard and used for more detailed tests.


The Pennyland estate was laid out to take advantage of solar gain . The majority of houses are located on the south side. They Were designed with an insulated cavity wall with a Poured concrete inner leaf to Provide thermal mass . This has the added benefit of increasing airtightness. Nearly all were fitted with a central radiator heating systems.

Several levels of insulation, heating system efficiency and passive solar design were compared:

At Neath Hill most houses featured

  • conventional heavyweight gas boilers
  • 50 mm roof insulation
  • no cavity wall insulation
  • Single glazing
  • No floor edge insulation
  • No special passive solar measures

About 20 of the Neath Hill Houses have been retrofitted with foam cavity wall insulation.

The Pennyland Area 1 houses featured:

  • low thermal capacity gas boilers
  • 80 mm loft insulation
  • 50 mm cavity wall insulation
  • Single glazing
  • No floor edge insulation
  • Passive solar layout and features

The Pennyland Area 2 houses (almost Danish BR77 standard) featured:

  • low thermal capacity gas boilers
  • 150 mm loft insulation
  • 100 mm cavity wall insulation
  • Double glazing
  • 25 mm insulation under the edge of the floor slab
  • Passive solar layout and features

Lessons learned

The houses were monitored over the years 1981 and 1982, and measured in a large sample of houses on a weekly average basis. More detailed monitoring on an hourly basis was carried out on the Linford Houses.

Among the lessons learned were:

  • Overall the Pennyland Area 2 houses shown to halt in gas consumption for space and water compared to the ‘normal’ Neath Hill houses.
  • The low thermal capacity gas boilers showed large energy savings compared to the conventional heavyweight type.
  • The poured concrete construction used at Pennyland made the houses extremely airtight.
  • The overall package of energy conservation measures had a payback time of only four years.
  • The passive solar features were popular, but the energy savings were modest and their use constrained estate layout. The savings were limited by the use of net curtains and privacy considerations.
  • The Pennyland House of Mining Growth in Kitchens and Bathrooms; a downside of the good airtightness.


The short payback times encouraged by Milton Keynes Development Corporation to introduce its own Building Regulations for the World 1986 Energy World demonstration project and exhibition.

The issue of mold growth in air-tight houses.

The levels of insulation tested at Pennyland and Great Linford in the early 1980s were only surpassed in the UK Building Regulation requirements in 2002.

See also

  • Energy World
  • Energy efficiency in British housing
  • Energy use and conservation in the United Kingdom
  • Sustainable development
  • Energy conservation
  • Passivhaus low-energy building standard
  • Category: Low-energy building


  • The Pennyland project report , Chapman J, R Lowe & R Everett (1985); Open University Energy Research Group, Summary and Main report
  • Social survey – Pennyland residents; S Meikle; Milton Keynes Development Corporation
  • Linford Low Energy Houses , Everett R, A Horton and J Doggart (1985); Open University Energy Research Group, Summary and Main report

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