Our investigations were largely based on information and reports from accredited organizations and companies, which are listed below:
- British Geological Survey (BGS)
- Building Research Establishment (BRE)
- Chartered Institution of Building Services Engineers (CIBSE)
- Digest of UK Energy Statistics (DUKES)
- Energy Matters
- Energy Saving Trust
- ENERGY STAR - U.S. Environmental Protection Agency (EPA)
- Energy Systems Research Unit (ESRU) - University of Strathclyde
- National Renewable Energy Laboratory (NREL) - U.S. Department of Energy
- Office of Gas and Electricity Markets (Ofgem)
- Passive House Institute (PHI)
- Suntech Power
- Stiebel Eltron