Rethinking Building Design for Environmental Autonomy
Advances in building science to lower the carbon impact of the built environment continue to be made in architecture and construction; the use of smart and sustainable materials, renewable energy and efficient mechanical systems are consistently improving building performance. Won Hee Ko, who will be joining the faculty at Hillier College this year brings with her a vision that looks towards the design of the autonomous building, addressing the capacity of a building to provide shelter and comfortable environment to its occupants, that will be high performing and resilient without relying on its mechanical systems.
“The concept of autonomy is popular in the lighting field; daylight autonomy is the percentage of occupied hours/year that a building can support the required lighting range for a space without mechanical systems. Thermal autonomy has also been around for 3-4 years. Ventilation to support human needs is not yet defined. The goal of the work we have been doing is to develop the parallel metrics for ventilation, and be able to look at all 3 aspects with the same metrics - unit wise - to compare light, thermal comfort and ventilation simultaneously in one building during the design process.”
This approach starts in the earliest phases of design and planning for a building such that the architect can simulate how their design decisions will impact thermal comfort, available natural light and ventilation. Designers can take into account resiliency and ‘passive survivability’, scenarios where the mechanical systems are offline due to flooding, power outages, or other extreme climate events, and simulate how well and for what time period a building can provide either heat or cooling, natural light and adequate ventilation.
“Right now, the experts of each area work separately, and with different units, and the focus is more on the mechanical systems. A high performing building is not just high efficiency, performance can be integrated with the building envelope and space design in a way that supports building autonomy,” said Ko.
Ko and her collaborators are developing and integrating the metrics in order to optimize these aspects of human comfort such that they can be considered together as the architect is designing their building. Being able to model how the shape of a building, its orientation to the sun, the materials of the building envelope, placement of windows and skylights in relation to time of day and prevailing climate enable designers to think in terms of passive survivability.
“We are proposing a fundamental shift in thinking. We have developed the metrics and also the method for visualization, that makes it easy to have a simultaneous understanding of light, ventilation and thermal conditions. Simulations can be done in the grasshopper environment.”
“I am interested in what happens on the human level. Nobody really knows if the lighting level is high and thermal conditions are cooler, what is the felt experience? When there is a window view people feel they are cooler - even when the temperature is identical to a space where there is no window view. Let's go back to the human level and how people really feel in their environment - so we can mitigate climate change - and also make people happier and more comfortable,” said Ko.
Ko is looking forward to sharing this approach to design with the students at Hillier College, “I am excited about bringing my knowledge and experience with building envelope design and indoor environmental quality to Hillier College, especially in the studio environment. Considering environmental autonomy will help the students to synthesize their knowledge in sustainability and resiliency with their design ideas. This will help them to develop building designs that are high performing in terms of both energy and human impact on the built environment.”