Ventilation specialist, Vent-Axia, welcomes the publication of the new approved documents for Part F and Part L of the Building Regulations calling it 'an essential step change and a key stage towards reaching zero carbon homes in 2016'.
The Approved Documents, (released April 30), for Part F (Means of Ventilation) and Part L (Conservation of Fuel and Power) set out significant changes to drive the adoption of low carbon ventilation as an industry standard.

Part of the government's aim to cut the UK's carbon emissions, is Part L's new Target Emission Rate (TER) which represents a 25% improvement over the previous regulations and is in line with achieving Code for Sustainable Homes Level 3. The TER for new buildings will fall by 25%. In the case of dwellings, the 2010 TER for any given building will be 25% below the 2006 TER for that building.

For non-dwellings, the 2010 TER will be the emissions from a newly-defined notional building. The specifications for the notional building will be set so that buildings on aggregate will achieve 25% lower emissions than under the 2006 Part L. This means that the 2010 TER for certain buildings may be more than 25% lower than the 2006 TER.

Another change sees CO2 emissions calculations having to be submitted at design stage in addition to the completion stage calculation that is currently required

Both approved Part L and F include major revisions which underpin compliance with stated minimum energy efficiency levels for all ventilation systems.

With the launch of Part L's new Domestic Building Services Compliance Guide, ventilation performance levels are highlighted. For the first time a specific fan power requirement of less than 0.5 watt/sec is included for intermittent fans used in both refurbishment and new build developments.

To further lower dwelling emission levels homes need to be increasingly air tight. As a result, changes to Part F publish guidelines for airtight properties with infiltration rates tighter than 5m3h/m2 at 50pa. For Intermittent System 1 and Passive Stack System 2 approaches, in airtight dwellings the guidance increases background ventilation rates by 50%.

This looks set to cause some developers to re-evaluate their designs and move any new planning applications away from intermittent fans since the previous provisions in approved document F 2006 have already been difficult to achieve when using trickle ventilators in windows.

The changes to Part F and Part L, favour continuous ventilation since it performs better in SAP, is easier to specify and easier to standardise, as trickle vents are not required.

For Continuous Mechanical Extract, system 3 approaches, the guidance removes the requirement for background ventilation in dwellings designed with infiltration rates above 5m3h/m2. It is likely that these factors, along with the Dwelling Emission Rate (DER) benefits of SAP Appendix Q will combine to boost the adoption of whole house Mechanical Extract Ventilation systems (MEV and dMEV) and Mechanical Extract Ventilation systems with Heat Recovery (MVHR).

In addition, for the first time Part F will require post-completion testing of ventilation equipment. Part F's new Domestic Ventilation Installation and Commissioning Compliance Guide has been introduced to ensure that ventilation not only delivers the required airflow, but does it efficiently and quietly. The guide includes sign off procedures and paperwork completion to ensure performance and efficiency are met.

The changes incorporated in approved document Part F now require the ventilation rate of a given property to be calculated dependant on the designed infiltration rates. This eliminates the need for background ventilators in habitable rooms when specifying MEV or dMEV systems for applications at 5m3h/m2 or above.

'Approved Documents Part F and L represent an important step change in Building Regulations. If we are to meet the UK's carbon targets and reach zero carbon homes by 2016 it is essential to meet staged efficiency targets. These sweeping changes to the Building Regulations set out a clear agenda for low carbon ventilation,' said Ronnie George, managing director at Vent-Axia.

George added: 'They recognise the contribution that ventilation equipment with energy efficient, Lo-Carbon DC motors can make in reducing fuel consumption, both in new, airtight properties and in retrofit projects. As such, they are hugely significant. They will reward those forward-thinking companies who are already ahead of the game in developing technologies that meet or exceed these new demands and help reduce a building's carbon footprint.

'Vent-Axia is the only ventilation company offering a full range of Lo-Carbon fans which will meet the approved document's specific fan power requirement of less than 0.5 watt/sec for all applications'.