Approved Document ADL2B covers Non Domestic extensions, renovation, change of use, change of energy status and work on controlled fittings and services.
It should be noted that large extensions which are over 100m2 AND greater than 25% of the existing building area are assessed under the same rules as a new building and subject to the ADL2A SBEM requirements.
ADL2B gives three routes to compliance:
- Reference Method i.e. use of tables
- Area Weighted average U value method
- Whole dwelling calculation method (using SBEM)
There are a number of other complications which makes the ADL2B a complex document.
Hibec Ltd are specialists in establishing the most cost effective route to compliance, providing ADL2B advice, calculations and reports for Building Control Approval.