Green Design Decision-making ToolBox (GDDT)

 Masters Thesis (Fall, 2015) | Prof Volker Hartkopf                                                                                    Carnegie Mellon University, Pittsburgh, PA

Over the past decade, the use of photovoltaics (PV) as a source of renewable energy has grown exponentially. During this period, photovoltaics have developed immensely from small-scale applications to becoming a major source of electricity generation in various sectors. Due to technological advancements and implementation of solar investment tax credit, the production and installation cost of PV has declined significantly, resulting in continued growth of solar deployment. Therefore, significant application of PV will become prevalent involving built-up areas (Hofierka and Kanˇuk, 2009).

Admittedly, erected buildings in urban areas change the flow of energy and natural ecosystems, creating environmental problems such as Urban Heat Island (UHI) effect and global warming. One simple method to mitigate urban symptoms is by providing more green spaces. Moreover, an integrated system of PV and green roofs was shown to have reciprocal synergies in terms of performance and influence. For long-term strategies for sustainability, the installation of both PV and green roofs are inevitable both as a sustainable concept of surface design and a new source of energy. However, integrating PV and green roofs into a building design is no simple task and typically requires consideration during the early design phase. To support this, relevant tools and data such as product specifications are essential for the architect to carry out any environmental analysis (EA). However, the gap between designers’ objectives to use EA tools and actual platform of tools are massive due to the technical attributes implemented in the platform. These include lack of graphical user interface for data transfer which makes it difficult for users to use and understand without advanced knowledge or familiarity with green technologies. Furthermore, current tools used to evaluate green technologies do not consider long-term benefits, which is one of important factors that affect decision-making process.

In order to encourage designers to consider the use of PV and green roofs during early design, a new platform is proposed. Exploiting parametric modeling tools (Rhinoceros and Grasshopper), the proposed platform is able to assess the environmental performance of PV and green roofs by providing different quantifiable benefits based on users’ objectives.

The platform is interactive, providing instant feedback through changes in geometries based on different design objectives. An added functionality is that the workflow is designed to be flexible so that it could be easily connected to optimization tools such as ‘Galapagos’ (Rutten, 2014) and ‘Octopus’ (Vierlinger, 2013), both of which are widely used optimization tools on Grasshopper. Demonstrated through a case study, this research shows that the proposed platform is user-affable, computationally practical when running multiple design options, and furnishes simplified interpretation of assorted benefits of PV and green roofs.


Keywords: Green technology, Photovoltaics, Green roofs, Design decision-making, Multi-objective optimization, Parametric modeling

Optimization Process using GDDT in Grasshopper