PHPP modelling in support of planning applications

Increasing numbers of local authorities are setting ambitious targets for new buildings in their local plans, including total energy and heating demand. Many of these are also offering Passivhaus as a route to compliance. In addition, organisations such as LETI, through their Climate Emergency Design Guide and the RIBA, via the RIBA 2030 Climate Challenge are recommending the use of stringent targets for total energy used in buildings. LETI and the RIBA refer to the total energy use target as Energy Use Intensity (EUI), which is the total regulated and unregulated energy use in the building per unit gross internal floor area. The EUI figure is the same figure as the total energy requirement of local authorities such as Bath & Northeast Somerset.

Whitsbury Road Refuge, Havant

Danes Lane, Keynsham for Aequus Developments

LETI recommend the use of PHPP (Passive House Planning Package) for modelling operational building performance and calculating EUI. Other local authorities accept PHPP as a tool to demonstrate compliance. This is because PHPP is a versatile operational building energy model which enables the quick assessment of key strategic decisions, such as U-values, windows performance data, airtightness, thermal bridging and ventilation and heat pump design, which can be incorporated into designs at an early stage. SAP is less powerful in this respect and does not have the capability of accurately modelling the full range of design decisions which affect building energy performance.

Delta Q are experts in the use of PHPP; we have four experienced Passivhaus Consultants including: Piers Sadler who has been using PHPP for more than 10 years and who has been training PHPP on the Coaction Training (formerly Carbonlite) Designer course since 2017; and David Bryan who is a qualified PHPP expert. Dave is also expert in 3D modelling such as interactions between BIM software and DesignPH.

The DeltaQ UK Metrics Plugin for PHPP

Delta Q have developed a plugin tool for PHPP which enables performance against LETI and RIBA standards to be reported from PHPP. Endorsed by the Passivhaus Trust, LETI and RIBA.

This PHPP plugin, developed by PHT members Delta Q, in just a few clicks will help project teams swiftly and easily check alignment with RIBA and LETI targets. By drawing calculations from an active PHPP, the plugin displays essential metrics, including Energy Use Intensity (EUI), both regulated and unregulated energy, and even operational energy costs. The plugin’s integration with PHPP ensures accuracy and reliability, making it an indispensable tool for professionals striving to meet and exceed the industry’s rigorous standards.

The Plugin can also be used for assessing compliance for different local authority planning criteria.

Example output from DeltaQ UK Metrics Plugin

The targets chosen by local authorities do not allow a reliance on PV to achieve the desired outcomes and typically require the same approaches as Passivhaus buildings, such as air tightness, low thermal bridging, triple glazed windows, high performance heat recovery ventilation and efficient domestic hot water distribution.

We use PHPP modelling and our in-depth knowledge of building energy performance to support clients’ planning applications; developing building fabric and servicing strategies to comply with planning and other voluntary standards. We can also support these projects through detailed design and construction to the Passivhaus or other chosen standard.