What does it mean?
NRM is the RICS suite of measurement guidance for building cost management. The suite distinguishes order-of-cost estimating and cost planning, detailed measurement for building works, and maintenance cost planning. A reference to NRM should identify the relevant volume and edition. These calculators perform arithmetic; they do not apply all NRM description, classification or deduction rules.
In practice
An estimator may use slab dimensions to establish concrete volume, then classify and describe that quantity under the project’s selected measurement rules before including it in a cost document.
Keep in mind
For a project record, note the document reference, revision and agreed measurement or contractual basis beside the quantity. Keep assumed information visibly separate from confirmed information. If two parties use different definitions or inclusions, resolve that difference before comparing amounts. These explanations are general estimating context; the wording of the applicable contract and its administration process must be checked for the particular job.
Reference: RICS New Rules of Measurement.