What is bid leveling? How to level subcontractor bids, step by step
By The GeneralBid team · Last reviewed
Short answer
Bid leveling (also spelled bid levelling) is how a general contractor makes subcontractor bids comparable before award. Each bid is checked line by line against one scope list, every excluded or unmentioned line is priced with a plug, and the bids are ranked on those levelled totals rather than the numbers written on the proposals.
Why do general contractors level bids?
Because the numbers on subcontractor proposals are not comparable as they arrive. Each sub reads the drawings and spec its own way, prices what it thinks is in scope, and says so in its own format.
- Bids price different scope. One carries the insulation, another excludes it, a third never mentions it. The numbers on the proposals are not comparable until that is fixed.
- The lowest number is often low because it leaves something out. Levelling shows whether the low bid is still low once its gaps are priced.
- A line that no bid mentions becomes a change order during construction. Levelling finds it while it can still be clarified, before the subcontract is signed.
- An award needs a record. A levelled sheet shows the owner, the project manager and the file why the recommended bid was recommended.
What is the difference between an exclusion and an omission?
An exclusion is a line the bid says it leaves out. An omission is a line the bid never mentions. Both are scope gaps and both get priced, but the omission is the one that turns into a change order, because nobody notices it. Every line of every bid is one of four things:
| Answer | What it means | How it reads | What to do |
|---|---|---|---|
| Priced | The bid gives its own price for the line. | “Shaft wall: $28,000” | Nothing. Compare it against the other prices for the same line. |
| Included | The bid says the line is in its number, without a separate price. | “Access panels included” | Nothing, as long as the wording is unambiguous. |
| Excluded | The bid says the line is not in its number. | “Insulation by others”, “NIC”, “excl.” | Price it with a plug, and ask for an add price. |
| Not mentioned | The bid is silent about the line. | No mention of patching after MEP rough-in | Price it with a plug, and ask the sub to confirm in writing. This is the gap people miss. |
How do you level subcontractor bids?
In six steps, the same way for every trade:
- 1.
Build one scope list for the trade
Start from the spec section, a trade checklist, or your own list. One line per item a sub would price separately, including the ones that usually fall between trades, such as testing, protection, hoisting and clean-up.
- 2.
Read every proposal against that list
For each bid and each line, record one of four things: a price, included, excluded, or not mentioned. Keep the proposal's own words beside each answer so anyone can check it.
- 3.
Price every gap with a plug
For each excluded or unmentioned line, add a plug: your own estimate if you have one, otherwise the median of the bidders who priced it, or the highest price if you want to be conservative.
- 4.
Rank the bids on the levelled totals
Each bid's levelled total is its stated number plus its plugs. Rank on that. Check the spread, the coverage, any line priced far from the others, and whether the line prices add up to the base bid.
- 5.
Send each sub a clarification
List the exact lines to confirm or price, with a reply-by date. Put each answer back into the sheet so the ranking reflects it.
- 6.
Award, and keep the record
Award at the levelled number, write down why, and keep a watchlist of the lines the winning bid excluded or never mentioned. Those are where change orders come from.
For step 1, start from one of the scope checklists for 16 trades. Before step 6, run the fifteen-question pre-award check.
A worked example: three drywall bids
Three drywall subs bid a tenant fit-out against the same 11 scope lines. Gaps are plugged at the median of the bidders who priced the line. Summit Interiors is lowest on paper at $412,000, but once its gaps are priced Keystone Wall Systems is the lowest levelled bid at $448,500.
| Scope line | Summit Interiors | Keystone Wall Systems | Ridgeline Drywall |
|---|---|---|---|
| Metal stud framing | $138,000 | $131,500 | $134,200 |
| Hang and tape | $152,000 | $149,000 | $151,700 |
| Level 5 finish where scheduled | Excl. | $18,500 | $16,000 |
| Acoustical ceilings | $64,000 | $61,000 | $66,500 |
| Batt insulation in walls | Excl. | $22,000 | $24,800 |
| Backing and blocking | Not mentioned | $9,500 | Incl. |
| Shaft wall | $28,000 | $26,500 | $27,900 |
| Fire-rated assemblies | $21,000 | Incl. | $12,300 |
| Access panels, install | Incl. | $3,200 | Incl. |
| Patch after MEP trades | Excl. | $14,300 | Not mentioned |
| Clean-up and debris removal | $9,000 | $12,000 | $6,500 |
The levelled result
| Rank | Bidder | Bid as stated | Plugs | Levelled total | Coverage |
|---|---|---|---|---|---|
| 1 | Keystone Wall Systems | $448,500 | +$0 (0) | $448,500 | 100% |
| 2 | Ridgeline Drywall | $439,900 | +$14,300 (1) | $454,200 | 91% |
| 3 | Summit Interiors | $412,000 | +$64,450 (4) | $476,450 | 64% |
The levelled spread is 6.2%. Alternates, such as the abuse-resistant board, are compared separately and never counted in these totals. Open this example in the free Bid Leveler to change any cell or the plug method and watch the ranking move.
How should an excluded line be priced?
With a plug, the same way on every bid. The median is the usual default because one very high or very low price does not move it. Use your own estimate when you trust it more than the bids.
| Method | How it is worked out | When to use it |
|---|---|---|
| Median of the other bids | The middle price among the bidders who priced that line. | The default. Fair to every bidder, and not pulled around by one very high or very low price. |
| Highest price | The highest price any bidder gave for that line. | When the budget is tight and you would rather overstate a gap than understate it. |
| Your own estimate | The figure you or your cost history put against the line. | When you have a reliable number, or when only one bidder priced the line and the median means little. |
Bid leveling in Excel or in a leveling tool?
Most general contractors level in a spreadsheet, and it works. A leveling tool does the same arithmetic; the difference is how much of the reading, checking and follow-up it does for you.
| Spreadsheet | Levelling tool | |
|---|---|---|
| Getting bids in | Typed or pasted from each proposal by hand. | Proposals read onto your scope lines, each with the quote it came from, for you to check. |
| Excluded and unmentioned lines | Marked by hand; easy to leave a silent line blank and move on. | Every gap listed and priced the same way on every bid. |
| Plugs | A formula per cell, rebuilt on every job. | Median, highest or your estimate, switched for the whole sheet at once. |
| Checks | Whatever the estimator thinks to check. | Low bid flipped, outliers, arithmetic errors, and lines nobody carries, flagged automatically. |
| Clarifications | Written from the sheet, one email at a time. | One email per sub, listing its exact lines. |
| Flexibility | Anything you can build. Familiar to everyone. | Built for one job. You can still paste from, and export to, a spreadsheet. |
Frequently asked questions
Is it bid leveling or bid levelling?
Both. Bid leveling is the usual US spelling and bid levelling the British one. Both mean the same thing, as do bid tabulation and bid comparison when they include pricing the gaps.
Who does bid leveling?
The estimator or preconstruction team at the general contractor or construction manager, for each trade package, after the bids arrive and before the subcontract is awarded. On smaller jobs it is often the project manager.
How long does leveling a trade package take?
By hand, from an hour for a simple trade with three bids to a day or more for a trade with many bidders and long proposals. Most of the time goes into reading proposals and typing them into one sheet.
Should the lowest levelled bid always win?
No. Levelling makes the prices comparable; it does not judge the sub. Schedule, capacity, safety record, bonding, past performance and how complete the clarification answers are all belong in the decision. Write down why when you award to someone else.
What is a plug number?
A plug is the amount added to a bid for a line it excluded or did not mention, so every bid covers the same scope. It is usually your own estimate, the median of the other bidders' prices for that line, or the highest of them.
What happens to alternates?
They are compared side by side and kept out of the base totals, because the owner may or may not accept them. Level the base bid first, then show each alternate's price per bidder.
Is there a free bid leveling tool?
Yes. The GeneralBid Bid Leveler is free, needs no account, and runs in your browser. It reads proposals onto your scope lines, prices every gap, ranks the bids, and writes a clarification email for each sub.
Level your own bids, free
Drop in the proposals or paste them from Excel. Every gap is priced, the bids are ranked like for like, and each sub gets a clarification email. No account.
Sources and further reading
- Construction bidding — How construction work is tendered and bid.
- General contractor — The role that invites and levels sub bids.
- Subcontractor — Who submits the bids being levelled.
- MasterFormat — The CSI divisions trade packages and cost codes follow.
- Change order — What an unpriced scope gap usually becomes.
- Median — Why the default plug is not thrown off by one outlier price.