In October 2019, the UK government announced the Future Homes Standard, an ambitious plan to improve the energy efficiency of new build homes that will be introduced by 2025. As part of this plan, significant changes to Part F of the Building Regulations (ventilation) are set to take place.

As leading suppliers of window actuators, vents and controls for natural and smoke ventilation systems, we have been helping domestic and commercial properties to comply with Part F of Building Regulations since we were founded over 20 years ago. We have compiled the proposed changes and taken a closer look at the effect this might have on the industry.

Removal of the guidance for Passive Stack Ventilation in Dwellings

Natural Ventilation DiagramThe current guidance for Passive Stack Ventilation systems in Approved Document F, Volume 1: Dwellings is set to be removed. However, despite being removed from the approved documents, Positive Input Ventilation, Passive Stack Ventilation and other less common ventilation systems can still be used to achieve regulatory compliance. The use of system numbers to denote the type of ventilation system is also set to be removed.

As windows, actuators and vents are one of the most common ways to provide Passive Stack Ventilation, installers should be aware of this change.

Approach for determining the minimum whole building ventilation rates

The revised method for determining the minimum whole ventilation rate in dwellings based on the number of bedrooms set out in the 2019 draft of Approved Document F, Volume 1: Dwellings (table 1.3) is set to be introduced.

As a result, windows, actuators and vents could be set to play an important role in meeting this value once it is introduced.

Guidance for airtight naturally ventilated homes

Guidance on natural ventilation systems will now only be provided for less airtight dwellings. The distinction between more and less airtight homes has also been clarified in the 2021 draft of Approved Document F, Volume 1: Dwellings.

As the government concluded that natural ventilation requires specialist design in order to be implemented in more airtight dwellings, installing windows, actuators and vents in more airtight homes may become more difficult without specialist design.

Changes to performance-based ventilation standards

manual actuator with chain limiter for windowThere are various proposed changes to the performance-based ventilation standards:

  • Referencing Public Health England guidance for ventilation standards
  • Adding a long-term testing level for formaldehyde. This includes a 30-minute limit value of 100µg/m3 and a long-term annual limit value of 10 µg/m3
  • Adding a long-term CO exposure limit of 10mg/m3 over 8 hours
  • Adding that the mould check should also be used for windows, rooflights and doors
  • Changing the name of table B.3 from Surface Water Activity to Indoor Air Relative Humidity Water Activity.
  • Therefore, natural ventilation strategies are likely to undergo changes so that these new standards can be met.

How designers assess ventilation strategies

Whilst designers previously had to assess ventilation strategies using a total volatile organic compound limit, they will now be able to assess them against individual volatile organic compounds informed by Public Health England’s Indoor Air Quality Guidelines for selected Volatile Organic Compounds (VOCs) in the UK.

It’s common for actuators, windows and vents to be used as part of a natural ventilation strategy in a building. So, it will be interesting to see whether this change influences their usage in dwellings.

If you would like to discuss any of the proposed changes to Building Regulations further, please get in touch with us at Teal Products today. We are available to call on 01242 620318 or you can contact us online.

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