Energy Modeling as Sketching

by Chris Baker

January 20, 2017

Energy Modeling, like sketching, should be used throughout the design process to inform and shape the design. As design professionals, we are trained to explore and flesh out our ideas and ultimately test them via sketching, whether with a sketchbook and pen or with computer software. But many firms only use energy modeling as a grading exercise after all the decisions have been made. This results in energy models that do not inform the design and that may not help the team understand the energy impacts of decisions. We use energy modeling throughout the design process which leads to different results for our projects.  Our clients often achieve 30% or greater savings relative to the energy code while staying within their budgets.


Just like a sketch can allow you to explore some detail without knowing all the other details, an energy model can let you see the impacts of different design choices. With just a handful of design details, we can build an energy model with relatively low uncertainty. This allows us to use energy models created during Pre-Design to compare different building forms, glazing locations, construction types, lighting concepts, HVAC systems and other strategies.

This allows promising ideas with strong potential energy savings to be incorporated early, but just as importantly, it allows ideas that have less savings potential to be considered and abandoned early, letting the team focus on the ideas that will have the greatest cumulative savings, an attractive return on investment, or whatever other goal they are pursuing for the project.

The true value of this approach is—when used early during design—we are able to find the optimal combination of strategies in real-time during design meetings. Seeing instant results from design decisions during these meetings is important since schedules and budgets are tight and the design process can move very quickly. This is how we work to design in high-performance from the beginning rather than being a list of features tacked on at the end of design.

The models are then refined with the design throughout the process. In this way, the modeling can be used to continuously inform the design, allowing us to achieve a truly integrated high-performance building. We update the model to reflect the final design, allowing us to use it with the owner and operator over time to ensure the performance is achieved. We are then able, as a team, to use energy modeling to inform not only the early design concepts, but also achieve certifications and assist with on-going performance.

By using modeling tools that allow us to quickly create combinations of energy efficiency measures and calculate their cumulative impact on annual energy costs, paybacks and utility incentives, we are able to maximize savings. This allows us, together with the owner, to find the unique solution that balances the energy performance, other design goals and first costs with the organization’s other goals to truly achieve a high-performance building.