To compare contractor bids properly, don't compare the bottom-line numbers. Normalize the bids first — rebuild each one against your own scope, add back what each contractor excluded, and only then look at price.
To compare contractor bids properly, don't compare the bottom-line numbers. Normalize the bids first — rebuild each one against your own scope, add back what each contractor excluded, and only then look at price. A $38,000 bid and a $52,000 bid usually aren't the same project. Once you make them the same project, the gap often shrinks to almost nothing, or it tells you something important.
The low bid wins more remodels than it should. Not because homeowners are careless, but because bids arrive in three different formats with three different assumptions, and the only number that's easy to compare is the wrong one.
Quick answer
Send every contractor the identical written scope. Without that, comparison is impossible.
Normalize each bid onto one worksheet using your scope lines, not theirs.
Add back exclusions, thin allowances, and missing line items before comparing totals.
If a bid is more than about 15% below the others after normalizing, find out why before you celebrate.
Step one happens before the bids arrive
You cannot fairly compare bids for projects that were never defined the same way. If you asked three contractors to "quote a kitchen remodel," you will get three different kitchens. Write the scope first, send the same document to everyone, and ask each contractor to price your line items in your order.
Some will push back and want to use their own format. That's fine — ask them to include a mapping to your lines. A contractor who won't itemize against a written scope is telling you how the rest of the project will go.
The bid normalization worksheet
Build a simple spreadsheet. Your scope lines run down the left. Each contractor gets a column. Then work through four passes.
Pass 1: Place every dollar on a line
Move each contractor's numbers onto your lines. Anything that doesn't map — "general conditions," "supervision," "overhead and profit" — goes into its own row at the bottom. Don't judge those yet; just isolate them.
Pass 2: Find the holes
Any line where a contractor entered nothing is either an exclusion or an oversight. Mark each blank. This is usually the single most revealing pass — the cheap bid is frequently cheap because four of your lines are blank.
Pass 3: Add back
For each blank, estimate what filling it will cost and enter it as an adjustment. Same treatment for allowances: if Contractor A allowed $8/SF for tile and Contractor B allowed $14/SF, and you priced real tile at $13, adjust A upward. You're not accusing anyone of anything. You're making the columns describe the same house.
Pass 4: Compare adjusted totals
Now the numbers mean something. Look at the adjusted totals, the spread between them, and where each contractor is high or low line by line. A contractor who's 30% high on electrical and 20% low on tile is telling you where their crew is strong and where they're subbing out.
The low bid gap test
After normalizing, measure the lowest bid against the median of the others.
Gap below median | What it usually means | What to do |
|---|---|---|
0–10% | Normal variation in overhead, crew efficiency, and how badly they want the work | Proceed; compare on references and communication |
10–20% | Possible thin allowances, an aggressive schedule, or a genuine efficiency | Ask them to walk you through three specific line items |
Over 20% | Frequently a missing scope element, an unrealistic allowance, or a plan to recover through change orders | Assume something is missing until you find it. If you can't find it, that's your answer. |
A bid can be legitimately low. Contractors with their own crews, no showroom, and a slow month price differently than a design-build firm with a project manager and an office. The test isn't meant to disqualify anyone — it's meant to make you ask the question.
What to check besides price
Price comparison is half the decision. The other half:
License status. Verify it directly with your state's licensing agency rather than taking a number off a business card. In Arizona, for example, the Registrar of Contractors states that a license is generally required if labor and materials exceed $1,000, or if any permit is required regardless of price. Thresholds and rules differ by state, so check yours.
Insurance. Ask for a certificate of insurance sent directly from the agent, naming you. General liability and, where applicable, workers' compensation.
Who is actually on site. Which parts are self-performed, which are subcontracted, and who supervises day to day.
Schedule realism. Ask for a start date, a duration, and how many other jobs run concurrently.
Payment structure. A large up-front deposit relative to the contract is worth a hard conversation.
References with the same scope. Not "any three clients" — three clients whose projects looked like yours.
The mistake that costs the most
Telling contractors what the other bids came in at, and asking them to beat it. It sounds like negotiating. What it actually does is invite the contractor to reduce the number without reducing the work on paper — which means the reduction has to come from somewhere else later. Ask instead: "Here's my scope. Where would you spend less if this were your house?" That question gets you value engineering instead of a thinner promise.
Your action plan
Finish your written scope before you invite anyone to bid.
Invite three contractors. Two is not a comparison; five is a scheduling problem.
Build the normalization worksheet and run all four passes.
Apply the gap test and ask the questions it raises.
Verify license and insurance independently for your finalist.
Choose on adjusted price plus clarity of communication, not on the raw bottom line.
Frequently asked questions
How many contractor bids should I get?
Three is the working standard. It gives you a median to measure against without consuming weeks of scheduling. Fewer than three leaves you without a reference point; many more tends to produce diminishing returns and strains relationships with builders who invested real time in pricing.
Why are contractor bids so different from each other?
Usually because they're pricing different work. Differences come from what each one included, how they set allowances, whether they self-perform or subcontract, their overhead structure, and how much risk they're carrying in the number. Normalizing the bids against one scope removes most of the mystery.
Should I always avoid the lowest bid?
No. You should always understand it. A low bid that survives normalization and comes from a licensed, insured contractor with matching references is a good outcome. A low bid you can't explain is a risk you're accepting without pricing it.
Is it rude to ask a contractor to itemize their bid?
It's standard practice. You're asking for the information you need to make a decision. Most professional contractors expect the request. If itemizing is a problem, that reluctance is itself useful information.
What should I do if all three bids are over my budget?
Reduce scope rather than squeezing price. Cut or phase specific line items, extend the timeline, or substitute materials deliberately. Cutting the number without cutting the work just relocates the problem into the middle of your project.
Do I have to pay for a detailed estimate?
Sometimes, particularly for complex projects where the contractor invests significant time in takeoffs. A paid estimate is often more accurate and more detailed than a free one, and many contractors credit the fee toward the contract if you hire them.
Keep going
Before you bid anything, get the scope right — see what a remodel scope of work should include. And before you sign, know whether your project needs a permit and who's responsible for pulling it.
Plan your project with better information.
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This content is provided by Smart Tools Construction Academy for general educational purposes. It is not project-specific construction, engineering, architectural, legal, tax, environmental, or safety advice. Codes, permits, licensing rules, costs, conditions, and accepted practices vary by project and jurisdiction. Consult the applicable building department and qualified licensed professionals before making project decisions or performing hazardous or regulated work.
