Roof overhang: the eave and rake, how it adds to the roof, and the code near the lot line
The overhang is the part of the roof that runs past the walls: at the eaves along the bottom edge, and at the rakes up the sloped ends. It counts in the roof's area, so a 12 inch overhang all around a 40 by 30 foot house adds 12% to the footprint the roof covers. Near a property line, the code bars any overhang within 2 feet of the line and calls for fire-resistant construction from 2 to 5 feet (IRC Table R302.1(1)).
Anthony Hicks30+ years in construction. Updated November 5, 2026.
Reading as
Eaves and rakes
| Edge | Where it is | What closes it in |
|---|---|---|
| Eave overhang | Along the bottom edge of the roof, past the wall | Soffit underneath, fascia across the rafter or truss tails, gutters on the fascia |
| Rake overhang | Up the sloped edge at a gable end | A rake board or fascia, and soffit underneath where it’s boxed in |
The soffit and fascia guide covers the boards that close in the eaves, and the rake guide the sloped edges.
How the overhang adds to the roof
The roof covers the house plus its overhangs, so the overhang is in every roof measurement. A 40 by 30 foot house is 1,200 square feet on the ground. With 12 inches of overhang all around, the roof covers 42 by 32 feet, 1,344 square feet, before the pitch is counted: 12% more.
| Overhang all around | Plan area of a 40 by 30 ft house | Added |
|---|---|---|
| None | 1,200 sq ft | |
| 12 in | 1,344 sq ft | 12% |
| 18 in | 1,419 sq ft | 18% |
| 24 in | 1,496 sq ft | 25% |
The pitch then adds its own factor on top. The roofing calculator takes the overhang as one of its inputs, and the roof measuring guide works a roof from the ground.
The code near the lot line
The residential code limits how close an overhang, a projection in its words, can come to the property line, by the fire separation distance from the line (IRC Table R302.1(1), for houses without fire sprinklers):
| Distance from the lot line | What the code allows |
|---|---|
| Less than 2 feet | No projection |
| 2 feet to less than 5 feet | A projection with 1-hour fire resistance on the underside, heavy timber or fire-retardant-treated wood |
| 5 feet or more | No fire rating needed |
Under the eave, the rating can drop to 0 hours where fireblocking runs from the wall’s top plate to the underside of the roof sheathing; under a rake, where there are no gable vents. Houses with fire sprinklers have their own table, R302.1(2).
Common questions
How far can a roof overhang?
On a house without sprinklers, not within 2 feet of the property line, and with fire-resistant construction from 2 to 5 feet (IRC Table R302.1(1)). The framing that carries the overhang, rafter or truss tails and lookouts at the rakes, sets how far it can reach structurally.
Does the overhang count in the roof’s squares?
Yes. Shingles cover the overhang like the rest of the roof, so a roof is measured to its edges, not to the walls.
What’s under a roof overhang?
The soffit, which can be vented to let air into the attic, with the fascia board across the front edge.
Is the overhang the same as the eave?
The eave is the bottom edge of the roof; the eave overhang is how far that edge runs past the wall. The sloped ends have rake overhangs.