The bids you get back are only as good as the scope you send out. A vague scope gets you five numbers that can't be compared, because each trade filled in the gaps differently. A clear one gets you five numbers you can actually choose between.
Start with what a trade needs to price it
Before a roofer, framer or tile setter can give you a real number, they need to know five things:
- What's being done. Tear-off or overlay. New or replacement. Which rooms, which elevations, which floors.
- How much of it. Squares, square feet, linear feet, number of openings or fixtures. Attach a measurement report if you have one.
- With what. Brand, product line and color, or "contractor's choice, equal to" a named product.
- Who supplies what. Labor only, or labor and materials. Say who provides the dumpster, permits and disposal.
- When. The start window and anything that affects it, like inspections or another trade finishing first.
Spell out the things that change the number
Most bid surprises come from a short list of items nobody mentioned:
- Unknowns. Rotted decking, hidden water damage, old wiring. Ask for a unit price ("per sheet of decking after the first three") so unknowns don't turn into change-order fights.
- Access. Steep pitch, three stories, tight lot, no driveway access for a dumpster, occupied home.
- Protection and cleanup. Landscaping, floors, daily magnet sweeps, haul-away.
- Permits and inspections. Who pulls them and who meets the inspector.
- Warranty. The workmanship warranty you expect, and any manufacturer system warranty.
Tip: If you'd ask the question on the walkthrough, answer it in the scope. Every question a trade has to ask is a chance for two bids to assume different answers.
Attach the files
Plans, measurement reports, photos of each elevation or room, and the spec sheet for any product you're naming. On Contracting Bridge you can attach PDFs, photos, spreadsheets and ZIP files up to 50 MB each, and only approved companies who can see the project can open them.
A scope that works
Here's a roofing scope written the way trades like to see it:
Tear off one layer of asphalt shingles to the deck on a two-story colonial, about 34 squares at 8/12. Replace damaged decking as needed, priced per sheet after the first three. Synthetic underlayment; ice and water shield at eaves (6 ft) and in valleys. GAF Timberline HDZ, Charcoal, with matching ridge cap and ridge vent. Replace 140 ft of 5 in. seamless gutters and four downspouts. Dumpster on the driveway, magnetic sweep daily, protect landscaping. Contractor pulls the permit. Start window: week of December 1. Labor and materials.
Every bidder reading that will price the same job. That's the point.
Before you post
- Did you name the products, or say "equal to"?
- Did you say who supplies materials, dumpster and permits?
- Did you ask for unit prices on the likely unknowns?
- Did you attach measurements and photos?
- Did you give a start window and a bid due date with enough time to price it? A week is fair for most residential packages.