Contech Takeoff

What it does

Pull up satellite imagery for any site. Drop a PDF or image plan set on top, georeferenced to the satellite. Trace lines, polygons, and points to measure the work. Attach a thickness and a material to any polygon and get instant length, area, cubic yards, and tons of asphalt, concrete, dirt, base, etc.

Effectively a Google Earth front end with the takeoff math (Agtek / Trimble Business Center / PlanSwift territory) baked in. 3D earthwork (cut/fill from elevation) is on the roadmap, not in v0.1.

v0.1 features

• Satellite map with pan, zoom, address search, scale bar.
• Draw tools: point (count), line (length), polygon (area), rectangle (area).
• Auto totals: length (LF), area (SF / AC), count (EA).
• Per-polygon thickness in inches → volume in CY.
• Material catalog: HMA, concrete, CABC, crushed stone, topsoil, common fill, sand, riprap. Density and swell/shrink applied automatically.
• CY → tons via density, with a loose vs compacted toggle for earthwork.
• Plan overlay: load a PDF or image, click two known points on the plan and the matching two on the satellite to align.
• Save / load: projects persist to browser storage, exportable as JSON.

The math

CY    = area_sf * (thickness_in / 12) / 27
Tons  = CY * density_lbs_per_cf * 27 / 2000
loose_CY     = compacted_CY * (1 + swell)
compacted_CY = bank_CY * (1 - shrink)

All material defaults are editable per item. Density and swell/shrink defaults live in data/materials.json.

Roadmap

• v0.2: CSV export, dollar-cost layer (rate × qty), print summary, multi-project dashboard.
• v0.3: 3-point georeferencing, regional material spec packs, per-item density override.
• v0.4: 3D terrain via Cesium + USGS 3DEP elevation data → real cut/fill volumes and mass haul.
• v1.0: User accounts, cloud sync, integrations with the Contech Estimator and Edgevanta bid intelligence.

Notes

• Imagery is Esri World Imagery (free for non-commercial, attribution shown). For production, swap in Mapbox satellite or a paid Esri tier.
• 2-point alignment handles translate + rotate + uniform scale. Plans with skew or non-uniform horizontal/vertical scale will need the v0.3 3-point upgrade.
• Browser storage is capped around 5 MB. Large overlay PDFs are kept in memory only and need to be re-attached when reopening a saved project.