WHAT IS THE PASSIVE HOUSE PLANNING PACKAGE?
Architect Tara Gbolade explains how this modelling software leads to innovative, energy-efficient designs
The Passive House Planning Package, or PHPP, is modelling software developed by the Passivhaus Institute and used when designing energy-efficient buildings to calculate their operational energy use and carbon emissions. The software, which is easy(ish) to use and is based on Microsoft Excel, can be used to inform the design of both new buildings and energy-efficient renovations.
More than this, the PHPP is the starting point for designing and building a certified Passivhaus or Enerphit home.whatever your specific goals though, it can provide a key tool for creating an energy-efficient dwelling. For instance, a growing number of self-builders are choosing to go down the route of building to Passivhaus standards without applying for certification.
1 What energy efficiency credentials does it measure?
PHPP contains tools to calculate comfortable internal ventilation, heat load and summer comfort, as well as measure heat gains and losses. This allows you to ensure there is an adequate ‘energy balance’. Buildings lose heat through their fabric (walls, floors, roofs and windows) and attain it through solar gain, heating and other internal sources — all appliances generate a certain amount of heat. Designers and architects can use this information to control a building’s energy economy through good design, looking at things like building orientation, Heat Loss
Form Factor, fabric U values and external shading to achieve this.
Based on the performance targets the homeowner or self-builder hopes to achieve, PHPP also calculates their design’s annual Primary Energy demand (PE, the total energy used for heating, lighting, power and hot water in kwh/m2a) and Renewable Primary Energy (PER, the amount of energy generated from renewable resources) as well as breaking down its heating and cooling demands into separate figures and assessing annual renewable energy gains.
2 Why use the PHPP on a project?
PHPP is a worthwhile exercise to undertake because it can identify gaps in otherwise energy-efficient designs, bringing confidence that performance targets will be achieved at the end of the build process by closing the gap between predicted energy use and real-world performance.
Performance gaps are one of the biggest challenges in the construction industry. Buildings often do not perform as they are designed to, so using a tool such as PHPP to provide rigorous modelling before starting on site can be invaluable.