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Part L2

Airtightness is a key consideration in the latest building regulations. Read more about PART L2.

April 2006 Part AD-L2A England & Wales
Part F2:2006 N. Ireland and Section 6:2007 Scotland (in preparation)

The 2006 enhancement of the Regulations requires a designer to use the National Calculation Methodology (NCM) to determine the energy use of the whole building, including the fabric, lighting, heating, ventilation and cooling systems. The software calculation tool - the interface for Simplified Building Energy Model (iSBEM) is used within the NCM for buildings other than dwellings.

The 2006 TER (Target Emission Rate) is approximately 24% lower than the 2002 notional building level for buildings other than dwellings.

Airtightness - Increasing airtightness from the 2002 level of 10m3/sqm/hr will generally show a significant benefit, thus increasing air tightness may be chosen by the designer as a significant contributory factor to aid compliance with the Building Regulations.

PART L2 building regulations (PDF - 322Kb)