Shadow Hours
The average hours of shadows per day on the ground, over the course of one year. The impact of a development project on existing shadows is frequently a topic of concern from a sustainability and quality-of-life perspective.
Developments in warm climates should aim to maximize shadow hours, and in colder climates should review sun hours for maximizing solar comfort.
How are shadow hours measured?
Delve uses historical weather data and the project’s geographical location to simulate sunlight rays for every hour of the day throughout a full year. Delve then samples the ground to see if these sunlight rays are obstructed by generated buildings or existing structures in the surrounding context. The obstructed vectors are then summed up to provide the average shadow hours received per day.
How to interpret shadow hour scores?
Six hours of shadow or less on vegetated open space is acceptable according to the City Environmental Quality Review for New York. This threshold ensures the health of vegetation and increases comfort level in public spaces for temperate climates. Spots receiving more than six hours may struggle to support plant growth and will likely impact pedestrian comfort.
Data Sources
Historic weather data (Energy Plus)
Existing buildings (OpenStreetMap)