Although not typically recognised as a discrete engineering discipline; building physics is identified within Arup as an activity that is integral to the design process and adds another layer to our understanding of the built environment. We include a broad range of physical and physiological topics including fundamentals of heat transfer, fluid mechanics, light & colour and human thermal & visual comfort. By digging in and exploring some of the fundamental physics normally hidden within the conventional design processes, we emerge with a much richer understanding of the behaviour of the built environment and our interaction within it.

Building physics can be applied across a range of scales; from single buildings and the people within up to the larger city-system and human interaction at the urban scale. At the smallest scales it may be applied to understanding individuals and their physiological response to the built environment. At much larger scales, an example application of building physics might be the design of clusters of buildings, precincts and ultimately cities, via an assessment of building energy and water demand and consumption and links to energy and water supplies. The design of net-zero energy systems would fall into this category.

The potential of building physics is realised when partnered with other engineering disciplines to add insight to the design process and enabling better outcomes. As an example, we apply building physics to our facade engineering design process, which is enhanced through a multi-faceted consideration of daylight, glare, energy, heat and moisture transfer, to provide a more complete understanding of the building envelope as a filter and modifier of the outdoor environment. Through this broader consideration of facade exposures and desired outcomes we can realise an optimised facade solution that is tuned to the site and climate and which achieves the desired aesthetic and indoor environment qualities.

Simulation can be used as an effective means of uncovering patterns and trends within the complex behaviour of building systems, revealing constraints and opportunities for system design as well as providing a useful means of communication within the design team.  And of course it’s not always about simulation.  So long as we understand enough about the fundamental behaviour of the problem were facing, then building physics is often best applied through hand-calculations or thought experiments that complement the more traditional rules-of-thumb.