Amended Approved Document Part F (Means of Ventilation) of the Building Regulations is being seen as a vital step to improve indoor air quality as we head toward the Future Homes Standard on the road to Net Zero. For existing homes, continuous ventilation offers a simple way to comply, as Natasha King explains.
Amended Part F of the Building Regs marks a step change for ventilation. Previously ventilation has taken a back seat to the need for improved energy efficiency in our homes to meet carbon emission targets. As a result, we have all seen what happens when sealing up homes to make them more energy efficient without considering ventilation – indoor air pollution.
The most visible signs of this have been condensation and mould, but this is only the tip of the iceberg, since homes with indoor air pollution can contain over 900 chemical and biological contaminants in the air we breathe. Part F has therefore started to redress the balance of ventilation with energy efficiency with a focus on the importance of good IAQ to health and wellbeing.
Part F changes
A key addition to Part F is a new sub section ‘Installing Energy Efficiency Measures’ in existing properties. Here it sets out that: “When carrying out energy efficiency measures to an existing dwelling, an assessment should determine what, if any, additional ventilation provision is needed, based on the estimated impact of the work.”
Part F provides two options for calculating these new ventilation requirements, the first is the simplified method which covers most properties, the second is seeking expert advice. The simplified method involves counting the energy efficiency measures that have been added and then using Table 3.1 in Part F to classify whether they are minor or major. Homes are then allocated to Category A, B, or C depending on the number of minor and major measures, with A the lowest and C the highest. The category then determines what ventilation is required. It is important to note that with category C, natural ventilation does not comply with Part F, without a full design by a competent person.
Another important point to note is that the energy efficiency measures that have been made since the home was built need to be considered, as well as ones that are planned. Since the UK has an ageing housing stock where many homes may have been fitted in the past with double glazing, insulation or had chimneys sealed up, it can be difficult to determine exactly how many energy efficiency measures may have been added to a dwelling. This could lead to an installer inadvertently fitting intermittent ventilation in what they think is a category B home but instead is a category C and as a result it will not provide sufficient ventilation to protect the occupants’ health, risking poor IAQ, condensation and mould.
Compliant solutions
The simple solution to comply with Part F is to choose continuous ventilation for existing homes since it is compliant with both category B and C and is the easiest and safest way of complying every time. There is a wide range of different types of continuous ventilation to choose from to ensure exactly the right solution. For example, there are extractor fans, such as our Lo-Carbon Svara, which offers condensation control; easy installation; quiet operation; helps improve IAQ; and is controllable via a smartphone. Vent-Axia also offers the PureAir Sense, which is the UK’s only bathroom fan with Odour Sense technology that increases airflow when the air is poor. Alternatively, there are de-centralised mechanical extract ventilation (dMEV) units, such as the Lo-Carbon NBR dMEV C, which is a highly efficient and offers almost silent operation at 7.4dB(A).
For landlords tackling condensation and mould and improve IAQ there are also continuous ventilation options aimed specifically at social housing, such as the Vent-Axia’s intelligent Lo-Carbon Revive and the powerful Lo-Carbon Response 7, which are both filter-less unitary fans that are energy efficient, near silent and easy to install.
Another solution for deeper refurbishment of properties including habitable rooms, such as bedrooms and living areas, combines continuous ventilation with heat recovery. The Heat Recovery Retrofit Solution range consists of three different de-centralised Mechanical Ventilation with Heat Recovery (dMVHR) units, the Lo-Carbon Heat Save, Lo-Carbon Tempra and Lo-Carbon Calido, which can be used on a room-by-room basis or used together to help maximise energy savings for the whole dwelling.
These latest ventilation solutions provide an effective way to ensure homes comply with Part F while delivering good IAQ, preventing condensation and providing multiple avenues for up-sell.
For further information on complying with Part F, visit Vent-Axia’s stand in the BEAMA Village at InstallerSHOW. Vent-Axia’s Product Management team will also be speaking at BEAMA’s Net Zero Design Theatre – discussing retrofitting ventilation and how indoor air quality is affected once energy efficiency measures are added to a home.
Registration for InstallerSHOW is open, go here to register for your free visitor pass: installer-2023-visitor.reg.buzz/el-website
