Apron, the flat trim board or paving slab installed directly beneath a window sill or slab‑on‑grade entry.

Apron is a commonly used term in the construction industry. In finish carpentry, an apron is the horizontal interior trim board fitted beneath a window stool to conceal framing and add visual support. In concrete and site work, an apron denotes the concrete slab or paving placed at garage doors, loading docks, or culvert outlets to protect against erosion or spalling. Material selection, flashing, and slope ensure drainage away from structures.

Fun Fact: Historic Victorian homes often featured ornate apron profiles under deep window sills to showcase their millwork craftsmanship.

• Awning Window
• Bay Window
• Egress Window