Why are contractor estimates so different?

When three estimates for the same kitchen come back at meaningfully different numbers, the instinct is to assume someone is overcharging. Usually the real explanation is that all three priced a different project.

Scope assumptions are the most common cause. One builder assumed the existing floor stays; another priced replacing it. One included painting the adjacent rooms where new work meets old; another stopped at the doorway. Neither is wrong — they just made different assumptions in the gaps your drawings didn't cover.

Allowances are the second cause, and the most misleading. If one proposal carries a modest tile allowance and another carries a generous one, the lower bid looks better today and costs more later, because you'll choose the tile you actually want either way.

Then come exclusions. Permit fees, dumpsters, temporary protection, appliance installation, electrical upgrades and structural work are sometimes carried and sometimes excluded. The exclusions page is often the most informative page in a proposal.

Finally, real differences exist: quality of materials and subcontractors, level of supervision, insurance, warranty practice, and how much contingency and overhead a builder carries. A well-run job with a full-time supervisor genuinely costs more than one where the builder visits twice a week — and it's often the better value.

The practical fix is to normalize the bids: line them up against a single written scope so you're comparing the same project. That's exactly the kind of review Northline does for homeowners as a consulting service.