March 20, 2014 is the first official day of spring. It also coincides with one of the dates often used for shadow diagrams for development proposals in the City of Vancouver.
Most people may not realize this, but this is also a chance to test the accuracy of professional architects and hold them publicly accountable (shadow diagrams are required in development applications to show the impacts of shadows on the neighbourhood, so the proponent benefits if the shadow impacts appear to be minimal). The results of your field test could be surprising, and interesting. Today is perfect for this, thanks to the blue skies and bright sunshine.
Is there any way to verify shadow diagrams? The simplest method is to go into the field. Put your shoes on, take your camera, and go take photographs of the length of shadows around a proposed (or existing) development site. For development proposals in the City of Vancouver, shadow study diagrams are produced for 10am, noon and 2pm of the spring and autumn equinox. Occasionally the City of Vancouver also uses the 4pm time for the Spring / Autumn Equinox.
The summer solstice is another date where shadow diagrams can be verified in the field. Rarely the winter solstice is also used for a study.
If you want to test the accuracy of an architect’s shadow drawings for a proposed project, you can look at the real lengths of the shadows for existing buildings and compare with the architect’s drawings. The length of shadows cast by buildings in the field should correspond to the length of shadows in a shadow study. If they do not match, this indicates that there are serious issues with the shadow study and that it is not accurate. In the illustration below, the arrows point to the corners of where the shadows cast by buildings really should be at 10am, as shown in the photographs:
Winter Solstice 12 noon (Broadway)
CityHallWatch: Tools to engage in Vancouver city decisions 