Why roof shape matters on a measurement report
A measurement report is a set of facets, each with its own pitch, area, and edges classified as eave, rake, ridge, hip, or valley. The shape of the roof determines how many facets there are and how those edges connect. Two houses with the same footprint can differ by 20 squares or more once you account for hips, dormers, and valley returns, because every hip and valley adds cut length and waste that a simple gable does not have.
For estimating, this matters at the line-item level: ridge cap length, hip cap length, valley metal length, and starter strip all come from the facet edges, not from the footprint alone. Getting the roof type right before you order tells you whether a standard report will capture it cleanly or whether you need the complex-roof option.
Roof types and measurement notes
| Roof type | Typical facets | Hips / valleys | Measurement notes |
|---|---|---|---|
| Gable | 2 | None | Two rectangular planes meeting at a ridge. Simplest shape to measure; lowest waste factor; usually a standard report. |
| Hip | 4 | 4 hips, no valleys (simple form) | All sides slope to the ridge or a point. More cut length at hips than a gable of the same footprint; ridge is shorter than the building length. |
| Gambrel | 4 (two per side, different pitch) | Ridge only, no hips on the classic barn form | Two pitches per side (a steep lower slope and a shallow upper slope) means two multipliers per elevation; each slope must be measured and reported separately. |
| Mansard | 8 or more | Hips at each corner, sometimes valleys at dormers | Nearly vertical lower slope plus a shallow or flat upper deck. High facet count and a mix of pitches; frequently needs the complex-roof report. |
| Flat | 1 (or a few low-slope sections) | None, or internal crickets | Pitch multiplier is near 1.0. Area is close to footprint, but drainage detail (crickets, tapered insulation) still needs to be captured for the estimate. |
| Shed | 1 | None | A single sloped plane. Straightforward to measure; watch for a single long rake and eave that can run longer than expected on additions. |
| Cross-hipped | 8 or more | Multiple hips and valleys where wings intersect | Two or more hip roof volumes intersecting at right angles. Valley length and count rise quickly with each added wing; almost always a complex-roof report. |
Facet and hip/valley counts are typical ranges for the classic form of each shape; dormers, bay windows, and additions add facets to any of them.
Pitch and the multiplier: how shape becomes squares
Every facet's flat (plan) area is multiplied by a pitch multiplier to get actual roof area. The formula is pitch multiplier = square root of (rise squared plus run squared), divided by run, with rise and run both taken over a 12-inch run. One roofing square is 100 square feet, so area in squares equals footprint area times the multiplier, divided by 100.
This is why a mansard or gambrel roof, with two different pitches on the same elevation, cannot be measured with one multiplier for the whole side. Each pitch band is measured and converted separately, then summed.
| Pitch (rise/12) | Multiplier | 1,000 sq ft footprint area |
|---|---|---|
| 4/12 | 1.054 | 10.54 squares |
| 6/12 | 1.118 | 11.18 squares |
| 8/12 | 1.202 | 12.02 squares |
| 12/12 | 1.414 | 14.14 squares |
Matching the shape to a report order
Gable, shed, and simple flat roofs are typically covered by a standard report. Gambrel, mansard, and cross-hipped roofs, along with any hip roof carrying multiple dormers or wings, are the shapes most likely to need the complex-roof option because of the facet count and mixed pitches.
If you are not sure which to order, describe the shape and facet count on the order form; the published menu from the site sponsor, Sketch My Roof, separates Standard ESX ($19) from Complex-roof ESX ($25) precisely because facet count changes the work involved. You can order a roof report by address and pick the format once you know the shape.
Checklist: identifying a roof type before you order
- Count the ridges, hips, and valleys visible from the ground or in photos
Hip and valley count is the fastest signal for whether a roof needs a complex-roof report.
- Look for a change in slope partway down a plane
A break in pitch on the same elevation usually means gambrel or mansard, which need each pitch band measured separately.
- Note any wings or additions that meet the main roof at an angle
Cross-hipped and L-shaped roofs add valleys at every intersection, which adds length and waste beyond a simple hip or gable.
- Check whether the roof is low-slope or level
Flat roofs use a multiplier near 1.0 but need crickets and drainage detail captured separately from the pitch calculation.
- Confirm detached structures on the parcel
A garage or shed with a different roof type than the main house should be named on the order so it is measured or excluded on purpose.
Frequently Asked Questions
What is the most common roof type on a residential claim?
Does roof type change the price of a measurement report?
How do I calculate area for a roof with two pitches, like a gambrel?
Is a flat roof measured the same way as a sloped roof?
What counts as a cross-hipped roof?
Sources
- Pitch multiplier formula: sqrt(rise squared + run squared) / run; example multipliers for 4/12, 6/12, 8/12, 12/12; area = footprint x multiplier; 1 square = 100 sq ft: Xactimate® official documentation (as of August 2026)
- Published residential menu: Standard ESX $19, Complex-roof ESX $25, PDF-only $25, ESX + PDF $29: Sketch My Roof residential order page (as of August 2026)
- Order terms: order by property address, no subscription, no minimum, corrections available from the delivery email: Sketch My Roof service facts page (as of August 2026)
