An existing two storey 1970’s house with a flat roof was completely transformed by the addition of an additional storey on top to create a five bedroom family home. The whole house was refurbished to EnerPHit standard (the Passive House Institute standard for existing buildings), which is the highest standard of energy efficient construction.

EnerPHit is the ultimate standard in energy efficiency for renovation projects and offers approximately the same benefits as offers the retrofit equivalent to the new build Passive House certification. The owners have experienced a significant uplift in comfort and energy economy, as well as the reduction in emissions.

There were a number of technical challenges involved, such as the dig out of the old lobby and the reinforcement of the back and middle walls to ensure structural integrity. Total demolition was considered, but eventually decided against, as part of the strategy to limit impacts on embodied carbon.

The overall goals were increased thermal performance, enhanced functionality and an improved building aesthetic while honouring EnerPHit and Passive principles.

Thin-R XT/PR_UF insulation was used in the floor of this project. The floor in any building is an area of considerable downward heat loss when not properly insulated. Using XT/PR_UF (Floors) had the aim and outcome of significantly improving the U-Value of the floors in Dartry.

The insulation is lightweight and easy to install as it combines a high compressive strength with a low thermal conductivity. This provides a high performance solution for floor insulation within new build and renovation projects.