Area & Pitched Area tools Coming
ComingThis feature is designed but not in DimSum yet. This page describes how it will work.
The Area Tool is the standard flat-area takeoff with coverage-unit quantities; the Pitched Area Tool slopes the area by a pitch from a picked eave edge and tags every edge (eave, rake, ridge, hip, valley, wall) with its own LF total.
Overview
Area Tool (Basic Area): the everyday area takeoff with good defaults: net area, perimeter, cutouts, thickness for 3D, waste, and a Coverage Unit that converts area into sheets, boxes, bundles or squares. For slabs, floor sheathing, flooring, ceilings, insulation and paving.
Pitched Area Tool: an Area Tool whose plane is sloped by a pitch, with roof-edge intelligence. You draw the roof section in plan, click the eave edge, enter the pitch, and DimSum builds the true sloped plane, computes Plan / Sloped / Surface area and squares, and classifies every edge so drip edge, ridge cap and ice & water are one formula each. For roof planes, sloped ceilings, ramps and sloped slabs/driveways.
Where to find it
- Tools panel → DimSum Defaults → Basic → Area Tool / Pitched Area Tool.
- Takeoff ribbon → Area (
2) with variants Rectangle, Circle, Pick Region, Cutout (C). - Pitch factors: Behind the scenes → Pitch Factor table 🔒.
How to use it
Area Tool
- Arm the Area Tool (or a duplicate like "Floor Sheathing 3/4"").
- Draw the polygon (or Rectangle / Circle / Pick Region). Close it with
Enter, a double-click, or by clicking the first point. - Add cutouts with
Cfor stairs, chases or openings, drawn by points or by box (a cutout may extend past the edge; only the overlap is deducted). - In Properties, set Coverage Unit (e.g. sheet 4'×8' = 32 sf) and Waste % (list-linked; see below).
{Coverage Qty}updates.
Pitched Area Tool (roof plane)
- Arm the Pitched Area Tool.
- Draw the roof section outline in plan (or click inside it with Pick Region).
- DimSum asks for the base (eave) edge: click the edge that is level at the bottom of the slope. The slope runs perpendicular to it, uphill across the shape.
- Enter the pitch (
6/12, degrees, or from two heights: eave Z + ridge Z) and the eave elevation (default{Level > Elevation} + {Plate Height}). - DimSum computes the vertex elevations. The shape shows a downhill slope arrow and a pitch label in 2D.
- Check the edge tags (colored by type). Click any edge to change its tag (e.g. a rake that's really a wall/headwall).
- Repeat for each roof plane (
Nstarts the next plane in the same instance). Adjacent planes that share hip, valley or ridge edges snap to meet cleanly in 3D.
Make roofs always use 25% waste (list-linked Waste %)
- In your roof tool (a duplicate of the Pitched Area Tool), click Waste % → Link to list → Waste % → 25%.
- Every roof placed with that tool now uses 25%, while walls and floors stay on the list's default row (10%).
- Change the company default later by reordering the Waste % list; the roof stays on its 25% row.
Options & settings
Area Tool defaults
| Property | Meaning | Default |
|---|---|---|
| Area / Plan Area | Net area (Gross − Cutouts) | |
| Perimeter | Outer perimeter | |
| Cutout Area | Total deducted | |
| Thickness | 3D extrusion (0 = flat plane) | 0 |
| Extrude Direction | Up / Down / Centered | Up |
| Waste % | Used by coverage formulas; list-linked (Waste % list, default row 10%) | List default |
| Coverage Unit / Coverage Size | Sheet 4'×8' = 32 sf, bundle, square = 100 sf, box, roll… | Set on the tool |
{Coverage Qty} | A convenience property with a visible, editable default formula: RoundUp({Area} * (1 + {Waste %}) / {Coverage Size}, 0) |
{Coverage Qty} is the one place the Area tool ships with a rounding formula, and it's just a default formula you can see and change (e.g. remove the RoundUp, or apply waste after rounding). DimSum itself never rounds {Area} or any base quantity.
Pitched Area Tool defaults
| Property | Meaning | Default |
|---|---|---|
| Pitch | x/12, degrees, or from two heights | Prompted |
| Pitch Factor | From the editable table; per-instance override available | e.g. 6/12 → 1.118 |
| Plan Area | Flat projected area | |
| Surface Area | True sloped area from vertex elevations | |
| Sloped Area | Plan Area × Pitch Factor (= {Area} by default) | |
| Squares | {Surface Area} / 100 | |
| Eave Elevation | Z of the eave edge | {Level > Elevation} + {Plate Height} |
| Ridge Elevation | Highest Z | Computed |
| Overhang | Optional extension beyond the eave edge | 0 |
| Thickness | Sheathing thickness, extruded perpendicular to the plane (up/outward) | 7/16" |
| Waste % | Set on the tool | |
| Edge LF totals — flat | {Eave LF}, {Rake LF}, {Ridge LF}, {Hip LF}, {Valley LF}, {Wall LF} — the plan (horizontal) length | Computed |
| Edge LF totals — sloped | {Eave LF Sloped}, {Rake LF Sloped}, {Ridge LF Sloped}, {Hip LF Sloped}, {Valley LF Sloped}, {Wall LF Sloped} — the true length along the slope | Computed |
Flat and sloped edge totals
Every edge type reports both numbers. DimSum doesn't choose for you:
{Rake LF}— the flat (plan) length, as measured on the drawing.{Rake LF Sloped}— the true sloped length along the roof surface.
The same pair exists for eaves, ridges, hips, valleys and wall edges. Use whichever your pricing needs: rakes and hips are usually bought sloped, eaves and ridges flat, but that is your call, made in your part's formula. Level edges (eave, ridge) have the same value in both properties; sloped edges differ by the pitch factor.
Edge types
| Tag | Typical edge | Used for |
|---|---|---|
| Eave | Level edge at the bottom of the slope | Drip edge, ice & water, gutters, starter |
| Rake | Sloped edge at a gable end | Drip edge, rake trim |
| Ridge | Level edge at the top | Ridge cap, ridge vent |
| Hip | Sloped edge where two planes meet on an outside corner | Hip/ridge cap |
| Valley | Sloped edge where two planes meet on an inside corner | Valley liner, ice & water |
| Wall | Edge against a wall (sidewall or headwall) | Step/counter flashing |
Example parts (in the roofing example tool; edit or delete freely)
| Part | Qty basis |
|---|---|
| Sheathing sheets | Surface Area + waste ÷ 32 |
| Underlayment rolls | Surface Area + waste ÷ roll coverage |
| Shingles | Bundles/squares |
| Drip edge | {Eave LF} + {Rake LF Sloped} (the eave flat, the rake up the slope) |
| Ridge cap | {Ridge LF} + {Hip LF Sloped} |
| Ice & water | {Eave LF}, {Valley LF Sloped} |
| Labor (optional) | Per square or per sf, however you price it |
Examples
Framing: floor sheathing (Area Tool)
Area 1,245 sf, Waste 10%, sheet = 32 sf: {Coverage Qty} = RoundUp(1,245 × 1.10 ÷ 32) = RoundUp(42.80) = 43 sheets.
Finishes: flooring boxes (Area Tool)
850 sf of LVP, 10% waste, 22 sf per box (sample): 850 × 1.10 = 935 ÷ 22 = 42.5 → 43 boxes.
Roofing: one plane of a gable roof (Pitched Area Tool)
Plan outline 30' (eave) × 14' (run), pitch 6/12, level 10' + plate height 9' → eave Z 19'.
| Property | Calculation | Result |
|---|---|---|
| Plan Area | 30 × 14 | 420 sf |
| Pitch Factor | √(1 + 0.5²) | 1.118 |
Sloped Area ({Area}) | 420 × 1.118 | 469.56 sf |
| Surface Area | 420 × 1.11803 | 469.57 sf |
| Squares | 469.57 ÷ 100 | 4.70 sq |
| Rise / Ridge Elevation | 14 × 6/12 = 7' → 19 + 7 | 26' |
| Eave LF (flat) | level edge, so flat = sloped | 30.00 |
| Eave LF Sloped | 30.00 | |
| Ridge LF (flat) | level edge, so flat = sloped | 30.00 |
| Rake LF (flat) | 2 × 14 | 28.00 |
| Rake LF Sloped | 2 × (14 × 1.118) = 2 × 15.65 | 31.30 |
| Drip edge | {Eave LF} + {Rake LF Sloped} = 30 + 31.30 | 61.30 LF |
| Ridge cap | {Ridge LF} + {Hip LF Sloped} = 30 + 0 | 30 LF |
| Sheathing | RoundUp(469.57 × 1.10 ÷ 32) = RoundUp(16.14) | 17 sheets |
| Shingles (3 bundles/sq) | RoundUp(469.57 × 1.10 ÷ 100 × 3) = RoundUp(15.50) | 16 bundles |
| Underlayment (1,000 sf roll) | RoundUp(516.5 ÷ 1,000) | 1 roll |
The second plane of the gable gives the same numbers; the ridge between them is shared (see rules below). The formulas in the table (sheathing, shingles, underlayment) use 10% waste and RoundUp; both are the tool author's choices.
Same plane with the roof tool linked to the 25% Waste % row: sheathing RoundUp(469.57 × 1.25 ÷ 32) = RoundUp(18.34) = 19 sheets; shingles RoundUp(469.57 × 1.25 ÷ 100 × 3) = RoundUp(17.61) = 18 bundles.
Editing the factor
If your company uses 1.116 for 6/12, {Sloped Area} becomes 420 × 1.116 = 468.72 sf, and every part that uses {Area} follows. {Surface Area} (exact) stays 469.57 sf.
Concrete: sloped driveway
A driveway outline with its low edge picked as the "eave" at Z 0' and "from two heights" = 0' to 2'-6" over 40' → rise 2.5' / 40' → pitch 0.75/12, factor √(1 + 0.0625²) = 1.002. Thickness 4", Extrude Down. Surface Area is barely more than plan area, as expected.
Tips & shortcuts
- Draw each roof plane as its own shape in one "Roof" instance; totals roll up, and each shape keeps its own pitch.
- Pick the eave first when roofs have many small planes. The slope arrow confirms direction at a glance.
- Use "from two heights" when the elevations show eave and ridge heights but not the pitch.
- Pair with a Pitched Joist (Rafter) on the same plane for framing plus roofing.
Rules, limits & edge cases
- A ridge or hip edge shared by two shapes of the same instance is counted once in
{Ridge LF}/{Hip LF}. - Different pitches on shapes in one instance: each shape uses its own factor (see Takeoff tools).
- Hips/valleys are tagged, but hip and valley rafters (with jacks) are a v1.x item for the Rafter tool.
- Hips/valleys use the same Waste % as the rest of the instance; use a separate instance (or a formula on edge LF) if valleys need extra.
