Sustainable By Design is the consulting firm of Christopher Gronbeck, Seattle, Washington, USA.

Christopher provides solar engineering, green building consulting, graphic design, and web site design and programming services, primarily within the sustainable energy and architecture fields.

What would you like more information about?

• Solar Design Tools


• Consulting Services


• Christopher & Sustainable By Design

Christopher's premiere solar design tool is SunAngle, a shareware, web-based program used around the world since 1995 to calculate solar angles based on location, date, and time.

The new (Jan. 2020) version of Overhang Analysis features a new graphic interface for optimizing a window overhang for seasonal shading. You can visualize the shadow at any date and time, and review annual performance at a glance.

The new (Feb. 2020) version of Panel Shading features a new graphic interface for optimizing the geometry and spacing of rows of horizontal solar collectors on a rooftop or the ground.

A more sophisticated version of SunAngle is also available for purchase. The SunAngle Professional Suite includes additional features for $40 and is distributed via e-mail.