Scope of Work Calculator

Errors of magnitude, not errors of detail. A line-item budget can be wrong by a few thousand dollars in a dozen places and still look plausible, because every individual number looks plausible. Divided by the square footage, though, the same budget produces a single figure you can compare against every rehab you have ever done and every one your contractor has. A number that lands well below the light band usually means whole systems are missing from the scope; one well above the gut band usually means an addition, a foundation problem, or a bid that has been padded.

Ten percent is the floor and it is only defensible on a house you have walked with your contractor, where the mechanicals are visible and nothing structural is in question. Fifteen is normal. Twenty to twenty-five belongs on anything vacant, anything that has been winterized, anything where the crawlspace or attic was locked, and anything built before wiring and plumbing standards you would recognize. The contingency is not padding to be negotiated away — it is the line the sewer lateral, the failed panel and the rotted roof deck come out of, and if it is not there they come out of the profit instead.

If you are hiring a general contractor, yes, and it belongs on top of the trade costs rather than buried inside them. A GC typically charges ten to twenty percent over the subcontractor pricing to carry scheduling, supervision, insurance and warranty. Splitting it out means you can compare a GC-managed job against self-managing the trades, which is the actual decision — and it makes the change-order math honest, because a change order carries the same markup as the original work. If you are managing the trades yourself, set it to zero and price your own time somewhere else.

Because they cover the entire country and every vintage of house. Labor in a coastal metro can be twice what it is two states inland for identical work; a 1920s house with plaster and knob-and-tube costs more per square foot to bring current than a 1990s house with drywall and a panel that only needs breakers. The bands are a sanity check, not a quote. Once you have completed two or three projects in one market, your own historical cost per square foot is a far better band than these, and that is the number you should be comparing against.

Demolition, dumpsters and the haul-away of what was already in the house — which on a hoarder or estate property is a project of its own before a single trade shows up. After that: permits and the plan work some jurisdictions require to issue them, temporary power and portable toilets, the trip charges and mobilization fees each trade bills for coming back a second time, and the punch list, which is small line after small line and reliably runs into four figures. Every one of them has a field below. Leaving a line at zero should be a decision, not an oversight.

Use it as the skeleton and not the document. A contractor bids from a specification — the tile, the fixture model, the grade of cabinet, the number of coats — and a dollar figure next to the word Kitchen tells them nothing they can price against. What this is genuinely good for is the reverse direction: taking three bids that are organized differently, mapping each one onto the same sixteen lines, and finding the line where they disagree. That is almost always where the scope was ambiguous rather than where one bidder is cheaper.