Research standards

Methodology

DWELVRA is built around a simple rule: the calculator should never look more precise than the evidence behind it.

How cost ranges are selected

We review identifiable cost guides, capture the project scope, unit, publication or update date, and the exact range being used. We prefer recent U.S. sources with clear units and scope. When two publishers use different methodologies, we show them separately instead of silently averaging them.

What “modeled typical” means

When a source publishes a low and high range but no directly comparable typical value, DWELVRA may display the arithmetic midpoint as a planning aid. It is always labeled modeled. It is not called a national average or observed market average.

What the calculator does not do

DWELVRA does not invent regional factors, contractor markups, story multipliers, waste percentages or add-on prices. A factor is only added mathematically when the source and project definition support that calculation.

Review cadence

Published calculators display a last-reviewed date. Material changes in source pricing, scope or availability trigger a review. Older source dates can still be used when the source remains the clearest available reference, but the source date stays visible.

Local quotes remain necessary

Published cost ranges are planning tools, not bids. Local labor, site conditions, permit requirements, product choices and contractor scope can move a real quote outside a published range.