How Do You Price a Bid Alternate?

Owners use alternates to keep options open until bids show what the money buys: a better roof, an extra classroom, a canopy that may have to go. Each is priced separately from the base bid, and the owner chooses which to take at award, or sometimes later, within a time the bid documents set.

On public work the alternates can decide who wins. A Department of Veterans Affairs provision makes the low bidder the one offering "the lowest aggregate amount for the first or base line item, plus or minus (in the order stated in the list of priorities in the bid schedule) those additive or deductive line items that provide the most features within the funds determined available" (VAAR 852.236-92). The Department of the Interior's version says award "may be made to the bidder having the lowest total of the base bid and a combination of additive and deductive items" (DIAR 1452.236-71).

The worked example in VAAR 852.236-92, the same numbers as the bid alternate definition, has $100,000 available: Offeror A bids $85,000 with a $10,000 first additive, Offeror B $80,000 with $16,000. The provision finds A low at $99,000: the base bid plus the first and fourth additives. "The second and third additives were skipped because each of them would cause the aggregate bid to exceed $100,000." Offeror B had the lower base bid by $5,000 and still lost, because its first additive was $6,000 higher. Alternates are priced to win, not filled in last.

1. Read each alternate's description and the drawings and specs it points to; write down what is in and out.
2. List every trade it touches. A deleted canopy changes steel, concrete, electrical and roofing flashing, not one trade.
3. Put the alternates in your invitation to bid so each sub prices them on the same basis, and level them like base bids.
4. Add your own work: self-performed scope, protection, and any extra weeks of supervision the alternate adds.
5. Apply the base bid's markups in the same order: contingency, fee, insurance and bond as your bid carries them.
6. For a deduct, take off the cost and the markups on it, and check that the base bid really includes the work you are deducting.
7. Enter each one on the bid form as an add or a deduct, with any qualification, such as a date the price holds until.

The job is fictional: a library renovation. The GC's base bid carries 3% contingency on cost and then a 5% fee on cost plus contingency, so each alternate gets the same two markups in the same order (a factor of 1.03 × 1.05 = 1.0815).

Each price checks against the factor: $92,000 × 1.0815 = $99,498.00, $30,000 × 1.0815 = $32,445.00 and $41,800 × 1.0815 = $45,206.70. Had the canopy deduct been entered at its $30,000 cost, the owner would still pay $2,445 of contingency and fee on work that is gone. Alternate 1 also adds a week of supervision, so its $5,600 includes general conditions; alternate 3 adds none, and the bid form says so.

• Pricing an alternate from one trade's number and missing the other trades it touches.
• Leaving markups off a deduct, so you refund less than the work carried.
• Leaving markups off an add, so you do the work at cost.
• Missing the schedule effect: an added scope that extends the job also extends general conditions.
• Deducting work your base bid never included.
• Letting an alternate price stand forever: say how long it holds.

The base bid the alternates sit on is assembled in how to build an estimate from sub bids, and the markups in how much overhead and profit a GC should carry. More for GCs is in the general contractor's guide.

In Conflo's Estimate, alternates have their own tab. Each one is numbered, marked Add or Deduct, and priced with its own lines, like the base estimate, with a With markups setting. With markups on, an alternate is priced as the price of the job with it minus the price without it, so the base bid plus the alternate is exactly the price of the job with the alternate taken. Unit prices sit beside them.

The Client Proposal can offer the alternates and unit prices of a version frozen for bid, and the client's answer can accept only the alternates that proposal offered.

Price an alternate as carefully as the base bid: every trade it touches, your own work and time, and the same markups in the same order, given back in full on a deduct.

On public work the owner may add your alternates to your base bid to find the low bidder. The alternate you priced in the last ten minutes can be the one that decides it.

See how the estimate works in Conflo

1. VAAR 852.236-92, Notice to Bidders—Additive or Deductive Bid Line Items (APR 2019) — Acquisition.gov, U.S. General Services Administration. Read October 22, 2026.
2. DIAR 1452.236-71, Additive or Deductive Items (JUL 1996) — Acquisition.gov, U.S. General Services Administration. Read October 22, 2026.