Table of Contents
Variant calculations and economic assessment with PHPP 9
The Passive House Planning Package (PHPP) has a long track record as an accurate and easy-to-use tool for planning Passive House buildings and EnerPHit retrofits. It is also accepted as proof of compliance for certification purposes and subsidy programs. The Passive House Institute regularly refines, improves, and adds more functions to this tool.
PHPP 8, the latest version when this presentation was drawn up, allows users to input a single building with its geometry and the heat insulation properties of its building components etc. and calculates an energy balance for them. But a frequent PHPP user may be asked repeatedly to calculate various design options for the same building. This may arise with modernization projects if users need to calculate an unrenovated and renovated version, and possibly any intermediate steps, too. Comparing different designs may also help to come up with the most cost-effective combination of measures to achieve Passive House Standard for new builds as well. Up until now, users had to overwrite each cell entry with different values, for instance for insulation thickness. Looking at different designs in parallel was only possible by copying the PHPP project file once it had been filled out, unless users had advanced Excel programming skills. This process quickly became impractical, confusing, and prone to errors where several variants existed.
PHPP version 9, which is slated for release towards the middle or end of 2014, will feature two additional worksheets entitled Variants and Comparison along with other innovations. The Variants sheet gives users the option of inputting different designs and displaying the results in parallel. The Compare sheet allows two of these variants to be selected to compare their energy demand and affordability in depth.
Another tool, the PHeco external calculation tool (integrated into the new PHPP 9) has been developed by the working group for cost-efficient Passive Houses [AKKP42 2012]. This worksheet uses the PHPP’s findings to calculate affordability. It does so by comparing different building designs’ heating energy demand and the costs of their respective energy-saving measures.
The following in-depth articles are available exclusively to iPHA members!
Outlook and acknowledgements
A beta version of PHPP 9 with variant and economic feasibility calculations was available at the time when this presentation was drawn up (January 2014). Project partners are gradually testing this version for use in a gradual modernization project as part of the EU Euro-PHit initiative.
Both new functions were first integrated into PHPP 2007 as part of the European 3ENCULT project (Efficient Energy for EU Cultural Heritage; www.3encult.eu), but were not included in the PHPP version for distribution at that time. The EU EuroPHit project (“Improving the energy performance of step-by-step refurbishment and integration of renewable energies”; www.europhit.eu) is developing both functions and integrating them into the version of PHPP 9 for distribution.
Beyond the functions described in this presentation, the following innovations are also in the pipeline for PHPP 9:
- More accurate calculations of demand for energy for hot water
- Convenient generation of the entry for the Passive House project database (www.passivehaus-projekte.de) straight from the PHPP.
- A new Control worksheet: An overview of error and warning messages and suggestions about the reasons why calculation results are missing.
- A worksheet for the new Passive House sustainability rating and new classes of Passive House buildings.
- An amended Verification sheet to reflect new or altered certification criteria
[AKKP42 2012] Ökonomische Bewertung von Energieeffizienzmaßnahmen; Protokollband (only in German language) des Arbeitskreises kostengünstige Passivhäuser Phase V, Passivhaus Institut, Darmstadt 2013.