01 — Above the opening
Roofline and header depth
The first constraint is what sits above the opening. A housing needs somewhere to mount, and the depth and construction of the header decides whether that is a surface-mounted or a recessed option — or, occasionally, whether it is possible at all without modification. This is measured, not estimated from a photograph.
- Header depth decides housing type and position.
- Soffit construction affects concealment options.
- Some headers need blocking added before mounting.