12 | ECD ARCHITECTS: A NEW MODEL FOR TACKLING ESTATE REFURBISHMENT AND FUEL POVERTY EnerPHit was launched by the Passivhaus Institute (PHI) in 2010 as the target standard for the refurbishment of buildings. It uses the same five principles as Passivhaus to ensure that design proposals address all the key aspects of building performance. These include: 1. Building Envelope: This should be a continuous layer, without gaps around a building which minimises heat transfer relative to the function of each element, whether it is a window, wall, floor or roof. Threshold levels of performance are required for each element to ensure overall integrity. The efficiency of the envelope relative to floor area also plays an important part in reducing energy demand. 2. Airtightness: The airtight layer plays a crucial role in reducing heat losses from draughts as well as protecting the building fabric from condensation. The measurement of airtightness should be done during construction and on completion to ensure performance. 3. Solar Gain: Windows are typically required in all building types and seasonal variations need to be carefully modelled to provide sufficient heat in the winter whilst avoiding overheating in the summer. 4. Thermal Bridges: A thermal bridge is a localised weak spot in the envelope of a building where heat losses are substantially greater than surrounding areas. This weakness is common in many existing buildings and careful detailing is required to resolve this. 5. Ventilation: This means providing optimal indoor air quality for the health and comfort of residents whilst avoiding uncomfortable draughts and associated heat losses caused by excessive uncontrolled ventilation. In practice this means using mechanical ventilation with heat recovery (MVHR) extracting from bathrooms and kitchens whilst supplying fresh preheated air to living rooms and bedrooms. Applying these five measures and their respective targets, Passivhaus and EnerPHit buildings are designed to achieve specific performance outputs for a range of measures such as Space Heating/ Cooling Demand; Space Heating/ Cooling Load; Frequency of Overheating; Frequency of excessive high humidity; Airtightness; Non- Renewable Primary Energy Demand (PE); Primary Energy Renewable (PER). WHAT IS ENERPHIT? The Importance of Quality Control.