Where a refurbishment assessment contains existing systems which are impractical to retro-fit in accordance with the sub-metering criteria, a practical alternative metering strategy may be acceptable (see also KBCN00071). Where existing systems cannot be retro-fitted, however, the credit is not awarded by default; this does not meet the intent of the guidance for additional metering beyond a whole building approach.
In all cases, suitable evidence should be provided to QA that demonstrates the inability to fully comply with the criteria, and that all practical means have been taken towards fulfilling the intent of the credit.
In refurbishment projects it is not always practical to undertake significant retro-fits to existing building systems. Where such changes require disproportionate effort in relation to the scale and complexity of the project, BREEAM will accept more practical solutions that still meet the intent of the credit.