UCL Institute for Environmental Design and Engineering


What are the trade-offs between ventilation, health, building fabric and energy in dwellings?

Despite significant numbers of open domestic chimney flues remaining in properties, there is a low level of understanding of their energy implications. In many properties, the chimney flues are not used as primary heating, but may be retained in addition to central heating as a back-up - particularly in rural, off-gas grid areas where the occupant perceives issues of local energy security.

In the UK, SAP governs our perception of dwellings and it attributes a low value of energy loss to chimney flues. This discourages consideration of their impact on energy efficiency. The SAP figures are based on limited information and need to be questioned.

The principle areas of investigation are anticipated to be as follows:

  • Using building simulation, the investigation of the air flow relating to flues in dwellings and their energy implications
  • Measurement and modelling of a group of actual dwellings
  • Examination of the implications for IAQ of the reduction in air change rate, taking into account ventilation effectiveness
  • Examination of the air flow needed in order to prevent detrimental moisture levels within flues
  • Wider consideration of SAP’s treatment of dwelling ventilation
  • Identification of the potential carbon savings for the UK housing stock.