This 2-storey semi-detached home with shared brick wall is 14 years old. The home features recent upgrades to both a split system and a solar installation (6.08kW) with battery (9kW).
The Owners' Aims
This home is well on the way to reducing its power draw from the grid and making a good contribution to reducing CO2 emissions. The owners are interested in reducing the remaining energy costs and carbon emissions and, in the longer term, anticipate participating in a local community approach to energy independence.
The Assessor's Findings
The assessor highlighted that the main energy efficiency issue is the large front picture window in the living area that is single-glazed, metal-framed and has no window furnishings. This plus the existing old electric storage hot water system were main contributors to the home power bills. Other inefficiencies are being created by draughts caused by worn, ineffective door and shug window seals and old style downlights. It was not possible for him to assess the extent of ceiling insulation, but the thermal camera revealed there was no wall insulation. The building’s thermal efficiency is further compromised by the lack of wall insulation.
The Assessor's Recommendations
The assessor and the owners discussed the challenge of the thermal leakage from the large picture window which provides much-loved ocean and town views. Double glazing as a retrofit is a very expensive and an unacceptable solution. Other solutions suggested were secondary glazing or the installation of either cellular blinds or top-up/bottom-down blinds to create a thermal blanket, especially for night-time.
An insulation upgrade in the ceiling was also not a realistic option but it was suggested the owners could either paint the roof with cool roof paint to take the edge off heat absorption or, at a minimum, replace all downlights with IC rated sealed LED units. These actions would make some improvement to insulation performance and reduced power costs.
The lack of wall insulation could be addressed–but at quite some expense–with pumped loose glass-fibre silicon treated material. The assessor suggested that the owners contact an insulation specialist company, Enviroflex, if they wish to investigate this option.
The owners are currently poised to replace the old electric storage hot water system with a Reclaim315L heat pump, although the assessor suggested there would be efficiency and cost advantages in a smaller 250L or even 160L tank, especially if they changed the showerheads to water-efficient 'Methven Kirri Satinjet slow flow'. And finally, to complete the upgrade to more energy efficient appliances, the assessor recommended the owners could also consider replacing the existing ceramic cooktop with an induction cooktop.
