Contracts

What is the contract sum in construction?

The contract sum is the total amount the owner agrees to pay the contractor for performing the work, as stated in the agreement and adjusted over time only by approved change orders.

A contractor and plan reviewer discuss drawings and permit paperwork across an office desk.
Keep plans, permit requirements and approvals together when preparing construction work. AI-generated illustration.

The contract sum is the number at the top of the deal. On a lump-sum contract, it is the fixed price. On a cost-plus job with a guaranteed maximum price, the GMP plays a similar role as the ceiling. Either way, the contract sum is not supposed to change unless a change order or similar modification changes it.

AIA documents use the term "contract sum" throughout. Other forms say contract price or contract amount. The idea is the same.

How the contract sum shows up on a pay application

Every AIA G702 pay application starts from the contract sum. The first lines read: original contract sum, net change by change orders, and contract sum to date. Everything billed, retained, and owed is measured against that number.

Example: contract sum on pay app 7 for a $1,850,000 tenant improvement
LineAmount
Original contract sum$1,850,000
Net change by change orders (CO 1 to 6)$74,300
Contract sum to date$1,924,300
Total completed and stored to date$1,212,000
Retainage (10 percent)$121,200
Balance to finish, including retainage$833,500

Notice what is missing: pending change order requests. Until change order 7 is signed, its value is not part of the contract sum, and it cannot be billed as contract work. A PM who bills unapproved changes inside the contract sum is overbilling, and the owner's architect will strike it. The fix is simple: bill only signed changes, list them on their own lines, and keep pending requests on a separate log that the owner sees every month. When the change order is signed, it moves from the log onto the pay app as a new line, and the contract sum to date goes up by exactly that amount.

Why the contract sum matters

  • It sets the base for retainage, bond premiums, and often insurance.
  • It is the revenue number on the WIP report for percent complete accounting.
  • It caps what the contractor can recover without a change order or a successful claim.
  • Liquidated damages and some fee calculations are tied to it.

Common mistakes

  1. Including allowance overruns in billing without a change order to adjust the allowance.
  2. Letting the schedule of values total drift from the contract sum to date after changes.
  3. Recording revenue on the WIP from pending changes as if they were approved.
  4. Forgetting deductive changes, so the contract sum to date is overstated.
  5. Not adjusting the bond: some sureties need to know when the contract sum grows significantly.

Related terms

See schedule of values, balance to finish, executed contract, and AIA G703. The guide on how to fill out AIA G702 and G703 shows each line.

Frequently asked questions

Is the contract sum the same as the contract price?

Yes, in practice. AIA forms use contract sum; other contracts use contract price or contract amount.

Can the contract sum change without a change order?

Generally no. Changes to the contract sum come through signed change orders or, on some forms, the final pricing of a change directive.

Does the contract sum include sales tax?

It depends on the contract and the state. Many contracts include all taxes in the contract sum, so check before bidding.

What is the contract sum to date?

The original contract sum plus or minus all approved change orders up to the current pay application.

Written and edited by

Maurice Francois writes and edits construction operations guides for Smart Business Automator. More from Maurice on the Scaling Legends podcast.

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