Convergence and interoperability of BIM with passive design principles

Michael Crilly, Linda Toledo

Research output: Contribution to conferencePaperpeer-review

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The Passive House Planning Package (PHPP) is a parametric modelling spreadsheet for building energy performance designed initially for the certification of buildings that meet passivhaus and EnerPHit refurbishment standards. However there is also a growing use of PHPP as a design stage tool to test strategic options for new build, hybrid and refurbishment development projects.

As passive design principles follow a fabric-first approach to achieve a whole-house energy performance, the concept design stages are critical to success as decisions are made regarding orientation and heat-loss parameters arising out of the building geometry. In this context, PHPP is a trusted calculation tool that is comprehensive in the scope of factors and variables included to make it one of the most scientifically superior tools available. Its practical value is reinforced from a series of comparative studies which have undertaken triangulation in design stage energy assessments and PHPP has proved to be more accurate and more cost effective in practice than other standard modelling tools and methodologies such as IES and SAP.

Where building information modelling (BIM) is a combination of geometric or spatial data generally found within a 3D architectural model and a connected document management system (DMS), PHPP data has largely been limited to the latter as one of the main instances in architecture and design modeling with a bias towards non-geometric data. This has changed with the introduction of designPH as an add-on tool for SketchUp and the BIM enabling in the recent versions of SketchUp.

The paper is a case study in the practical application of the designPH tool for two separate UK based domestic design projects; one new build and one refurbishment; and the practical issues of interoperability with PHPP and BIM enabled software. The case studies review (1) the potential benefits of improved accuracy and quality control that address the technical performance gap between ‘design’ and ‘as-built’ standards; (2) the requirements regarding data collection, specifically the level of definition / detail (LoD) of data needed to describe the geometry and attributes of the existing structure and input climate data; (3) the technical limitations around ICT and software skills.

Recommendations are made on the value of a simplified and integrated BIM workflow to benefit passive design projects. Critically the projects explore BIM interoperability using the addition of an energy domain to the IFC schema based on the input requirements for PHPP to make it more compatible with 3D modelling packages and achieve better integration between mathematical / parametric modelling of the energy performance and the building geometry.
Original languageEnglish
Number of pages7
Publication statusPublished - 9 Mar 2018
Event22nd International Passive House Conference 2018 - MOC Veranstaltungscenter, Munich, Germany
Duration: 9 Mar 201810 Mar 2018


Conference22nd International Passive House Conference 2018
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