Architects use digital modelling and geolocation in the building design process to analyze solar heat gain and inform the use of solar shading to reduce energy use and optimize building efficiency. These tools permit simulation and visualization of the path of the sun throughout the year.
In the northern hemisphere, the sun’s highest point above the horizon is at the summer solstice on June 21st, and its lowest point is on the winter solstice on December 21st. Halfway between these two dates are the spring and fall equinoxes, March 21st and September 23rd, marking the point where the sun is directly above the earth’s horizon.
During the design of the Interdisciplinary Life Sciences Building, UMBC asked the architect to include a sundial in the design to demonstrate the changing path of the sun and mark the passage of time. The architects created a floor pattern for the building lobby and added a strategically located section of red glass in the middle skylight above. The red glass casts a red mark on the floor during the mid-day hours between the dates of the spring and fall equinoxes, March 21st through September 23rd. Each clear day, the red dot moves across the floor as the sun moves through the sky, identifying the time of the day.
The red glass visible in the skylight above the building lobby.
The floor pattern was created using architectural rendering software by mapping out and overlaying multiple light patterns at different times through the year. The lines of the floor were drawn from these patterns, and construction drawings were created using these lines to permit the design to be cast into the finished floor.
An example image depicting the overlay of the sun on the floor for June 21st, the summer solstice.
This simulation shows the sun’s pattern on the floor throughout the day on June 21st, the summer solstice, when the sun is at its highest point in the sky and the angle of sunlight is steepest.
A similar exercise was done to trace the movement of the sun at the same hour throughout the year. The pattern from the central skylight scribes the curved vertical line in the floor at noon between the dates of the spring and fall equinoxes.
The image below shows the sun cast onto the floor at the noon hour between March 21st and September 23rd.
The skylights were designed in such a way as to limit glare and control light levels in the space. The design limits the amount of time the sun directly enters the building to mid-morning through mid-afternoon, and only when the sun is at its highest, between the dates of the spring and fall equinoxes. The central portion of the floor pattern was established through these simulations. These geometries were then mathematically extrapolated across the rest of the floor to complete the pattern throughout the lobby floor. These visualizations were then translated into line drawings to guide the builder in constructing the floor pattern and skylights.
Diagram showing how dates and times are identified by the sundial.
Sundial pattern visible on the ILSB lobby floor.
Within the overall design of the ILSB, the sundial is intended to be a subtle ‘easter egg’ to reference the relationship between the built and natural worlds. The sweeping lines of the floor patterns are beautiful and graceful, but their generation was guided by inquiry and facts, rather than purely aesthetics.