Section 8: Mechanical ventilation

8.1 Scope of guidance

This section provides guidance on the specification of mechanical ventilation systems in dwellings to meet relevant energy efficiency requirements in the Building Regulations.

The guidance covers the following types of mechanical ventilation:

• intermittent extract

• continuous extract

• continuous supply

• continuous supply and extract with heat recovery.

8.2 Energy efficiency of mechanical ventilation systems

Mechanical ventilation systems should:

a. follow the guidance in the DCLG Domestic Ventilation Compliance Guide

(available at

b. meet the minimum standards for specific fan power, heat recovery efficiency and controls in Table 34

c. comply with European Commission Regulation No 327/2011 implementing Directive 2009/125/EC with regard to ecodesign requirements for fans driven by motors with an electric input power between 125 W and 500 kW.

****Table 34 Recommended minimum standards for mechanical ventilation systems****

****Supplementary information****

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