What Is a Shadow Study and When Architects Need One
Quick answer: A shadow study shows how a building's shadow falls on surrounding properties and public space at specific times of day and times of year, usually the equinoxes and solstices. Architects need one whenever a project's height or massing could affect a neighbor's light access, a public hearing requires it, or a zoning code sets shadow limits on adjacent parcels.
A shadow study, sometimes called a sun study, is a set of renderings or diagrams that show exactly where a proposed building's shadow will fall at specific times, typically the spring and fall equinoxes and the summer and winter solstices, since those dates represent the range of shadow lengths a building will cast across a year.
Why timing matters more than the image itself
A shadow study is only useful if it uses accurate dates, times, and the building's real geographic coordinates, since shadow length and direction change significantly by latitude and season. A study built on approximate location data can understate or overstate shadow impact enough to matter in a public hearing.
When a project actually needs one
The most common trigger is a zoning or planning department requirement, particularly for taller buildings near residential neighbors or public open space. Beyond a strict requirement, a shadow study is worth commissioning proactively whenever a project's massing could plausibly affect a neighbor's access to daylight, since it gives the design team a chance to adjust before the concern surfaces in a hearing.
What a shadow study needs to be credible
Accurate site coordinates and true north orientation, the real massing of the proposed building rather than a simplified block, and the specific dates a jurisdiction requires. A study missing any of these can be challenged as inaccurate during a public review process.
Common questions before commissioning one
- Does the local zoning code specify which dates and times a shadow study must cover?
- Is the study based on the actual proposed massing or a simplified placeholder?
- Will the study be used for internal design review, a public hearing, or both?
See our architectural visualization and 3D rendering services for how shadow studies fit into a broader presentation package.