Foto: Wohnhaus der SolarCity

CityCalc - Calculation Tool for Energy-Efficiency in Urban Planning

To assess the energy performance of urban planning projects in early design stages with low input and evaluation effort within the project CityCalc, an easily applicable planning and evaluation tool will be developed.

Short Description




Starting point / motivation

As current energy planning and assessment tools for early design stages (urban planning, architectural competitions) are focusing on individual buildings, the interactions of buildings such as mutual shading and shadowing due to the surrounding objects are not taken into account. Although a great variety of tools for solar design are available, most of them are not suitable for architects and early design stages.

In future it will be of increasing importance to quantify the passive and active solar gains in order to fulfill ambitious legal and funding requirements and to implement future-oriented building concepts (eg passive house , zero energy, zero carbon or plus energy standard).

Contents and goals

Within the research project CityCalc, an easily applicable energy planning and assessment tool for urban planning projects in early design stages and for analysis of the existing building stock will be developed. CityCalc focuses exclusively on energy efficiency - the reduction of energy demand - with the best possible use of site-specific energy sources (gains from solar thermal and photovoltaic plants, wind energy, combined heat and power). In order to ensure a simple, user- friendly application for architects, a three-dimensional geometry and data acquisition and an interface to energy calculation software will be developed.


The assessment is based on the established algorithm of the Austrian energy certificate, following OIB directive Nr. 6 (OIB, 2011). The practical implementation is done with the calculation algorithm of the widely-used calculation software ArchiPhysik (ArchiPHYSIK, 2013), whose developer A-NULL Bauphysik GmbH is partner of the project.

Expected results

The developed planning and assessment tool is a prototype that will be tested and validated in selected planning competitions and projects within the research project.

After completion of the project a commercial use by third parties is intended together with accompanying support. Guidance documents (FAQs, manual, etc.) will be provided to ensure an easy application.

To avoid huge storage space and time consuming installation, CityCalc will be offered as online solution. This approach ensures a smooth integration in architectural competitions having a lot of participants.

Project Partners

Contact Address

AEE - Institute for Sustainable Technologies (AEE INTEC)
Heimo Staller
Feldgasse 19
A-8200 Gleisdorf
Tel.: +43 (3112) 5886-3648 200
Fax: +43 (3112) 5886-3648 200 DW 18

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