Spotlight on a Student: Sareh Naji

Multi-objective optimisation of a prefabricated house in Australian climate zones

S Naji

Sareh Naji has just submitted her thesis for her PhD, undertaking research under the joint supervision of academic staff in Department of Infrastructure Engineering and the Faculty of Architecture, Building and Planning. We interviewed Sareh on her research, and her plans for the future.

What is your research about?

Energy efficiency and indoor environmental quality (IEQ) are two main principles of environmentally sustainable buildings. In my PhD research, I conducted building performance optimisations with multi objectives in early design stages to minimise life cycle costs while maintaining satisfactory indoor environment.

The optimisation uses various passive envelope components and parameters as input variables. The life cycle costs considered, include initial costs of envelope components and operation costs for space heating and cooling over building’s useful life. The IEQ parameters considered, include thermal comfort, visual comfort, auditory comfort and indoor air quality. The focus of my research is on a prefabricated house in various Australian climates. The outcomes represent optimal combinations of envelope components in the form of Pareto optimal solutions for all selected climate zones.

The framework developed for conducting multi-objective optimisation includes a number of sequential rational steps. Those steps are model development, model validation, sensitivity analysis, development of input library and multi-objective optimisation. This framework can be used by designers and building performance simulation practitioners across any types of buildings. The obtained optimal solutions and the trade-offs among the objectives, provide useful insights and decision support towards the design solutions with minimal life cycle costs and satisfactory indoor environment.

Who are your supervisors?

I was fortunate to benefit from valuable input and guidance of my PhD supervisors Professor Lu Aye from the Renewable Energy and Energy Efficiency Group in the Department of Infrastructure Engineering and A/Professor Masa Noguchi from the Faculty of Architecture, Building and Planning.

What do you want to do next?

I would like to pursue a career where I can continue to practice environmentally sustainable building design. I would also like to expand my PhD research by applying the developed framework on more climatic conditions and potentially further develop it into an online tool to allow industry practitioners access the framework and generate results for specific projects and locations.

Any awards?

In 2016 I was awarded the Melbourne Research Scholarship which provided financial support throughout my PhD. Also, I was a recipient of the ‘Best Research Poster Award’ from the Melbourne Energy Institute in 2018.

Sareh and her supervisors welcome any enquiries about her research. You can email her at

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