Passivhaus Affiliate

Technical Guidance - Modelling existing dwellings in PHPP Periodic Heating

Category: Guidance

PHPP has been shown to be an accurate and effective tool for modelling energy use in low-energy buildings. However, for existing houses which have a relatively poor fabric performance, and thus utilise intermittent heating patterns, the average internal temperature needs to be adjusted to account for the unheated periods. The problem is determining this adjusted internal temperature as it will depend on the building’s fabric performance and the time the heating system is switch on.

The Passivhaus Trust has developed guidance accompanied by a PHPP plugin to calculate more representative monthly average internal temperatures for existing buildings and an overall average for the heating season. These temperatures can then be used in the PHPP heating demand calculation to achieve a more accurate indication of energy demand.


Modelling existing dwellings in PHPP Periodic Heating [PDF]                 

Download (high quality print version)





PHPP Plugin: Periodic Heating Tool

The Periodic Heating Tool is an additional tab that can be applied to the PHPP software. This tool is provided free of charge and can be used with any legitimate copy of PHPP 9.6a. It is intended as an aid to understand the space heating demand of existing buildings.

Follow the link below to download the tool together with instructions for integrating it into PHPP.


Download PHPP Plugin: Periodic Heating Tool



Published: September 2021

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