References
BRE (2008) Passivhaus Primer: Introduction, An aid to understanding the key principles of the Passivhaus Standard, Watford: Building Research Establishment, [online] available from: http://www.passivhaus.org.uk (accessed 20 September 2011)
EST (2011a) Here Comes the Sun: a Field Trial of Solar Water Heating Systems, Energy Saving Trust, [online] available from: http://www.energysavingtrust.org.uk (accessed 13 September 2011).
ESTIF (2011) Solar Thermal Markets in Europe, European Solar Thermal Industry Federation, [online] available from: http://www.estif.org (accessed 19 September 2011).
CEC (2009) Directive 2009/28/EC on the Promotion of Energy from Renewable Sources, Commission of the European Communities, [online] available from: http://eur-lex.europa.eu (accessed 20 September 2011).