Siding Bids That Hold: Pricing the Details Behind the Square Footage

The Field Is the Cheap Part

A long uninterrupted wall is the fastest square footage on the job. Every bidder prices it about the same, because there is not much room to be clever about it.

The money is in everything that interrupts the field: windows, doors, corners, roof intersections, decks, vents, hose bibs, electrical penetrations, and the trim that resolves each one. A wall with fourteen openings and a wall with two have the same area and nothing else in common.

Where Bids Diverge on the Same Drawings

When you level three siding bids and find a wide spread, the difference is almost always in one of these, and it is worth asking directly rather than assuming the low number found an efficiency.

• Whether exterior trim, soffit and fascia are included or carried separately
• Flashing scope: who supplies, who installs, and whether kick-outs are included
• Substrate repair, and what happens when the sheathing behind the old siding is soft
• Staging and access, which changes with height, grade and site constraints
• Whether the weather barrier is in this scope or someone else's
• Caulking and paint at the exterior, which is frequently assumed by both sides

Substrate Is the Biggest Unknown on Renovation

On new construction the substrate is known. On a re-side it is a guess until the old material comes off, and the honest answer is that nobody can price it exactly at bid time.

The bid that holds says so. It carries a defined allowance for repair, states the unit rate beyond it, and names how the additional work gets documented and approved. The bid that does not is either carrying a hidden contingency or planning to be back with a change order in week two.

Water Management Is a Scope, Not a Detail

Flashing is where exterior work either performs or fails, and it is also the easiest item to leave ambiguous. Head flashing, window pans, kick-outs at roof to wall transitions, deck ledger flashing and terminations at grade each need an owner.

When the bid is silent on these, the assumption on both sides is that someone else has them. That assumption is discovered on the day the elevation is being closed in, which is the worst possible moment to price it.

What Makes a Siding Bid Easy to Level

The same thing that makes any bid easy to level: it reads as a scope, with the assumptions visible. Field area separated from trim and flashing, substrate repair defined with a rate, access stated, and exclusions written by name.

That bid takes longer to read and less time to argue about. It also survives the buyout meeting, which is the only real measure of an estimate.