ROM (rough order of magnitude)
An early, rough estimate of cost, given before the design is developed enough to price properly.
by Jack Butler-Kettle · About 1 min readShare
Further detail
Read this alongside NRM 2: Detailed measurement for building works.
A rough order of magnitude is an early estimate based on limited information. It should state assumptions, exclusions, uncertainty and the purpose for which it can be used. It is different from an agreed quotation or a supported claim calculation, even when all three are expressed in pounds.
Label the estimate's scope, assumptions, exclusions and uncertainty as information develops. Our Construction estimating and cost planning service prepares an early budget on that stated basis and reconciles later revisions.