Passive House buildings are found to be almost four times as efficient as other high energy performance buildings.
In an article published by an independent group (D. Johnstona, D. Farmera, M. Brooke-Peata & D. Miles-Shenton) the heat loss coefficients of 25 new UK building projects that all boasted “high energy performance” were measured. As part of the assessment, the predicted performance was measured against the actual performance of the buildings, which were then compared to each other. The graph below displays the results.
3 of the buildings assessed were Passive Houses (numbers 23-25), and as you can see from the graph, these were by far the best performing buildings in terms of Watts lost (through the fabric) per degree Kelvin. What’s more, the Passive Houses also had the smallest performance gap (in that their actual measured heat loss coefficients were not as good as their predicted ones).
High Performing Passive Houses
The average W/K for the 3 Passive Houses were almost four times lower than that of the other “high efficiency” buildings. Wolfgang Feist has published an article in response to the study, in which he states that it is no coincidence the Passive Houses have the best performance results. He highlights the parameters used by Passive House to maintain temperature:
- Insulation level
- Avoiding thermal bridges
- High performance windows
- Heat recovery ventilation
Closing The Performance Gap
Wolfgang also points out that in order to close the performance gap and achieve the best possible energy performance for your building, the design, the workmanship and the materials used in construction all need to be the best they can possibly be.
There are three key areas that Natural Building Technologies achieve energy efficiency.
- Creating balance between u-values, thermal bridging and air tightness
- Ensuring long-term high performance in energy reduction
- Providing effective moisture control in the building fabric by using the right materials AND the right specification
The Holistic Approach
Natural Building Technologies take a holistic approach to building thermal performance, ensuring that all materials in the building fabric work together, insuring not only winter thermal performance, but also summertime heating control alongside fabric moisture control. We achieve this by offering support, training and information as well as supplying products such as Isolair, Diffutherm and Pavatherm Combi, used extensively in Passivhaus constructions throughout the UK and mainland Europe. If you’d like more information on the work that NBT do, please get in touch.