Ruth MacEachern at EnviroVent looks at ensuring compliance with ventilation regulations and achieving good indoor air quality in new homes.
Approved Document F of Building Regulations has set stringent requirements for ventilation in new homes, with a greater focus on energy efficiency and environmental sustainability.
The updated regulations outline the requirements for ventilation systems in new homes, ensuring that indoor air quality is maintained at acceptable levels due to a required increase in airflow levels. The regulations specify minimum airflow rates, which are measured in litres per second, which are tailored to different room types and the number of bedrooms in a property. This is crucial to prevent the buildup of pollutants and to ensure a healthy living environment.
Airflow measurements must be taken using appropriate equipment and results should be documented for submission to building control. As well as the whole dwelling ventilation rate increase in the last update to Building Regulations, the requirements now state that all habitable rooms must incorporate background ventilation, regardless of the air permeability of the building, when using continuous or intermittent extract ventilation with the exception of MVHR.
Approved Document F works in conjunction with other regulations, such as Part L, which focuses on energy efficiency, ensuring that improvements in one area do not compromise another.
The increasingly stringent targets for indoor air quality have resulted in traditional methods like intermittent fans and trickle vents being inadequate to meet the requirements for new and renovated homes.
The latest industry legislation therefore requires a ‘systems approach’ to ventilation, where a continuous flow of fresh air and removal of pollutants are essential to maintaining optimal indoor air quality. This requirement is perfectly compatible with our whole-house ventilation systems, such as MVHR (Mechanical Ventilation with Heat Recovery), c-MEV (Mechanical Extract Ventilation), and d-MEV (Decentralised Mechanical Extract Ventilation). Since ventilation became a controlled service, this means that systems must be installed by a competent person who is registered under a third-party competent persons’ scheme, which is helping to drive up standards.
Importance of IAQ
Poor indoor air quality can lead to significant health implications. Studies have linked inadequate ventilation to various health issues, including respiratory diseases, heart conditions and even premature death. The World Health Organisation has highlighted that household air pollution is responsible for millions of deaths annually, which highlights the need for effective ventilation systems.
Health risks associated with poor ventilation can include respiratory issues, as prolonged exposure to pollutants can exacerbate conditions like asthma and chronic obstructive pulmonary disease (COPD). Insufficient ventilation can create damp conditions, promoting mould growth that poses additional health risks. In addition, indoor air can contain volatile organic compounds (VOCs) from household products, which can lead to long term health problems.
One of the challenges in implementing mechanical ventilation systems is managing noise levels. Updated guidelines in Approved Document F address acoustic performance, providing a framework for reducing noise in ventilation systems. Selecting ventilation systems that are proven to operate at very low noise levels can help maintain a peaceful indoor environment while ensuring adequate ventilation.
Energy efficiency & ventilation
With the UK government’s commitment to achieving net zero emissions, energy efficiency has become a focal point in Building Regulations. Approved Document F emphasises that ventilation systems must not compromise the overall energy efficiency of a building.
Because of the regulation changes, housebuilders and developers are taking a much more proactive approach to ventilation. This includes working closely with ventilation manufacturers early on in the design of the buildings, ensuring they can achieve compliance with the new regulations, both now and in the future.
Selecting the right systems
Choosing the right ventilation system is vital for compliance and for good indoor air quality that benefits the health of occupants.
Mechanical Ventilation with Heat Recovery (MVHR) systems are increasingly being specified to meet Building Regulations in new and refurbished homes, which not only provides a high level of indoor air quality but also recovers heat from extracted air, therefore saving energy. In addition, continuous Mechanical Extract Ventilation (MEV), which are ideal for dwellings with low air permeability as it ensures consistent air exchange.
Positive Input Ventilation (PIV) systems are also extremely effective in managing humidity levels and helping to prevent condensation and mould which can be easily retrofitted into most properties.
Housebuilders can ensure compliance with Part O of the Building Regulations (Overheating) by selecting effective ventilation solutions designed to remove excess heat and promote thermal comfort within dwellings.
Correct commissioning
The commissioning process is crucial for ensuring that ventilation systems operate as intended. This involves testing and adjusting the system to meet the specified airflow rates and performance criteria. In addition, there is a need to maintain detailed records of the commissioning process, including any measurements and adjustments made.
Educating homeowners on the operation and maintenance of ventilation systems can also enhance their effectiveness and longevity.
There are many ways that ventilation manufacturers can work with housebuilders and developers to ensure they can achieve compliance with the latest legislation. This includes the delivery of CPDs, workshops and webinars on Approved Document F, L and O compliance. There is also an opportunity for onsite contractor toolbox talks, onsite installation support and best practice compliance training.
Some manufacturers also provide ventilation system design support for a project, which includes supplying detailed technical drawings to fully comply with your project needs, the latest building regulations and SAP requirements. This can remove some of the complexities of ventilation system design for housebuilders and contractors.
Ruth MacEachern is product manager at EnviroVent