Ventilation challenges in social housing

Ventilation challenges in social housing

By Sophie Neaves on Fri 15 December 2023

Exploring Ventilation Challenges in Social Housing

Proper ventilation is important in all buildings, especially homes, because it keeps the indoor conditions comfortable and healthy for inhabitants. This is particularly important in an age when people spend so much of their time inside. Research indicates that people spend around 90% of their time indoors, where the air quality can be significantly worse than outdoors - on average 3.5 times worse


Inadequate ventilation can have a number of negative effects on the health and well-being of residents as it leads to a build-up of airborne pollutants and humidity in the air inside homes. This allows indoor spaces to become a breeding ground for pollutants, mould and dampness, which can trigger respiratory problems or allergies associated with dust mites.


When homes are poorly ventilated, it can also be difficult to maintain a comfortable temperature. This can lead to increased energy consumption, and therefore costs, as residents may need to use more heating or cooling.


All of these issues apply to social housing, where residents may not have the same power or means to improve their situation and may remain at risk. Every year, social housing residents make thousands of complaints about issues like damp, mould and leaks in their homes. If these issues take hold, it can take a toll on both tenants’ health and finances.


At Airflow, we specialise in ventilation solutions and provide social housing developments with mechanical ventilation systems, helping social housing landlords meet legal requirements and tenants' needs. Through the analysis of government data, our report aims to uncover the living conditions and state of ventilation in social housing, and whether residents' needs are being met.


Key findings

  •  Only 1 in 5 mechanically ventilated social homes are fitted with supply and extract ventilation
  •  Social homes are 14% less energy efficient than they could be
  •  Social housing residents are 11 times more likely to experience ventilation issues than plumbing issues
  •  The top reasons that residents were dissatisfied with their homes were: mould, damp, or condensation, insulation and ventilation
  •  The average social housing dwelling has an energy efficiency rating of 67.9 (band D) - most new build homes have an EPC rating of A or B (81+)
  •  With improved ventilation and heating, social housing could be 16% more energy-efficient


What issues are social housing customers facing?

According to the Social Housing Residents Survey, 21% of residents are not satisfied that their home is well maintained. The most common reason social housing residents are dissatisfied with the maintenance of their homes is the presence of mould, damp, and condensation (55%). This was followed by home insulation (33%), and ventilation (23%). These three issues are intrinsically linked - a third of residents who mentioned mould, damp or condensation also mentioned problems with ventilation (33%) - and have led many residents to believe that their homes are not safe to live in.


In fact, tenants were more than 11 times more likely to experience ventilation issues than plumbing issues, and almost five times as likely to experience ventilation issues as heating issues. 


When discussing ventilation, residents mentioned draughty windows and doors and air vents or extractor fans either did not work or were missing. Whilst drafts can allow air into spaces, the air is uncontrolled and can cause significant heat loss in the home. A lack of extractor fans, on the other hand, can lead to a build-up of condensation which can lead to damp and, in turn, mould. 


How are social housing residents in London faring?

When comparing Londoners living in social housing with their counterparts in the rest of the country, those in London were much more dissatisfied with the maintenance of their properties - 30% compared to 21% outside of the capital. Dissatisfaction was even higher among those aged 35-44 (47%), many of whom would have children. 


In London, mould, damp and condensation were an issue for 60% of dissatisfied residents. London residents were also more likely than average to cite ventilation as an issue in their homes.


Mechanical ventilation vs. passive ventilation

Broadly speaking, mechanical ventilation and passive ventilation, previously known as natural ventilation, are the two core ways to ventilate a building. Mechanical ventilation relies on fans to move air, whilst passive ventilation relies on natural forces to move air.  

How many social homes in the UK have ventilation systems installed

Looking at over 4.3 million social housing properties in the UK, only 82.3 thousand (1.9%) showed that they had mechanical ventilation installed and in use. The data was gathered from the Department for Levelling Up, Housing & Communities’ Energy Performance of Buildings Data, which relies on EPC information on houses. Because the data is informed by EPC Certificates, a building may have a mechanical ventilation system that is not turned on. In this case, the EPC would classify the ventilation system as “natural”, or passive, inflating the percentage of UK social homes with no mechanical ventilation.


A 2016 study found that 31% of the homes analysed had some form of mechanical ventilation system. In the years since, mechanical ventilation has increased in popularity and availability, but there still remain many homes that are reliant on natural ventilation alone, despite potential associated risks.


Of the mechanically ventilated social homes we analysed, the majority of these had ‘extract only’ ventilation (78.5%), with only 17.7 dwellings (21.5%) having ‘supply and extract’ ventilation installed, i.e. the system continuously both introduces fresh outdoor air and removes indoor air - these 17.7 dwellings make up only 0.4% of all social homes.

With almost half a million people receiving a new social letting in 2021/22 – an increase of 52,000 people from the previous year - that’s thousands of people moving into homes that could benefit from improved ventilation.


The benefits of improving ventilation

Ventilation removes stale, humid air from a building and replaces it with outdoor air, ensuring there is fresh, ‘clean’ air available for occupants to breathe.


Control of impurities and moisture in the air

Improving ventilation helps expel impurities like pollutants, particulate matter, chemicals, moisture and odours from the indoor environment. Gas stoves, chemicals from cleaning products, air fresheners and other household items can all contribute to indoor air pollution that needs to be filtered out. Effective ventilation also removes moist air, reducing the risk of damp and mould caused by condensation. Damp conditions caused by condensation can also cause certain surfaces to deteriorate and even rot. 


Temperature and comfort

As poorly ventilated rooms become more crowded or temperatures rise, the lack of ventilation can lead to stuffy indoor spaces which are unconformable for occupants. Mechanical ventilation can help replace stale air with fresh air and can also be integrated into air-conditioning, controlling both the temperature and humidity. This improves overall air quality and indoor comfort for individuals. 

Health benefits

Home ventilation (or lack thereof) has a significant impact on the health and well-being of residents. Poor indoor air quality has been linked to lung diseases like asthma, COPD and lung cancer. Ventilation helps to remove pollutants and allergens that exacerbate these issues. Improved air quality can also reduce fatigue and improve alertness and cognitive function. Stale air can contain low levels of oxygen and high levels of carbon dioxide, making people feel tired or contributing to headaches and dizziness. Installing and using ventilation systems effectively removes the pollutants and gases that contribute to these adverse reactions.

Energy efficiency savings

Effective ventilation also has the benefit of making a property more energy efficient by heating more efficiently. MVHR, one form of mechanical ventilation, uses a heat exchanger to capture the warmth of the air from inside the building to heat the incoming air. This is a highly efficient way of introducing preheated air to the building, saving the need for additional heating. They also reduce the need for cooling by removing moisture from the air. Some types of mechanical ventilation require homes to be airtight. The more airtight a home is, the more effective the mechanical ventilation will be, increasing the efficiency savings residents can make.


Whilst there is an upfront cost involved in installing mechanical ventilation, this can save residents ongoing energy bills in the long term. 


Energy efficiency in social housing

In England and Wales, rented social housing properties had an average energy efficiency rating of 67.9 - an EPC rating of D. This was over 9% more energy efficient than privately rented properties and 12% more energy efficient than owner-occupied homes. This gives social rented dwellings, on average, the highest energy efficiency rating of all property tenures. This may be in part due to the higher habitation standards social housing landlords are held to, as well as the fact that many of these dwellings are flats. Flats typically have better insulation and are thus more energy efficient.


With the right ventilation and insulation measures installed, social homes could be, on average, 16% more energy efficient than at present. The average ‘potential energy efficiency’ of social rented properties was 78.9 - an EPC rating of C - although some houses had energy ratings of B and even A. Improving energy efficiency, for example, by switching from passive to mechanical ventilation, can help the individuals paying the energy bills (a responsibility that typically falls with tenants and not landlords) cut costs.

Landlords' responsibilities for ventilation

In March 2019, the new Homes (Fitness for Human Habitation) Act came into effect in England and Wales. The act amends the Landlord and Tenant Act 1985 to require all landlords to ensure that their properties are ’fit for human habitation’, which means that it’s safe, healthy and free from things that could cause anyone in the household serious harm. Similar guidelines exist in Scotland and Northern Ireland. As such, landlords have important legal obligations to fulfil regarding indoor air quality. They must ensure that the building meets health and safety requirements.


Some responsibility to properly ventilate the property, however, lies with the residents, as landlords can provide their tenants with all the necessary tools to ventilate the property but they may neglect to use them properly. 


For example, landlords are responsible for damp caused by any structural defects, lack of damp proofing, poor ventilation, inadequate heating systems or a hole in the roof. However, damp caused by condensation due to ineffective use of heating and ventilation is the responsibility of the tenant.

What can landlords do to improve ventilation?

With the above responsibilities in mind, social housing landlords can take certain steps to test and improve the ventilation in their properties. 


One simple change landlords can make is to listen to tenants. Government data found almost a third (32%) of tenants in social housing are not satisfied with the extent to which their landlord listens to and acts on their complaints. One in five residents also say they disagree that the landlord consults them on decisions that impact their home.


Landlords can install ventilation systems in their properties. One popular option is a Mechanical ventilation with heat recovery (MVHR) system. Historically these have been central systems and therefore are more likely to feature in newly built dwellings due to the ease of installing ducting at the first fix stage. With technology development, it is possible to have a MVHR system that can be retrofitted, like the UNOhab. This system gives all the advantages of a central MVHR but as ducting is not needed as the units are placed in each room and work with each other it means that existing homes can also have MVHR retrofitted. In the past, other systems have been used in social homes, but as dwellings have become more airtight, the air in these homes have nowhere to go but stay in the home and contribute to the issue of mould.


Central MVHR systems use fans to pull fresh air from the outside through a filter, whilst simultaneously extracting stale air through another vent from ‘wet rooms’ like bathrooms and kitchens. Both the incoming and outgoing air streams pass through a heat exchanger (except in the summer), making incoming air preheated. Centralised systems ventilate a whole building, using a large heat recovery unit.


Single-room MVHR solutions operate similarly to central systems, where the same air comes in over the heat exchanger and goes back out, except the unit only ventilates one room. Single-room MVHR lends itself better to retrofitting. 


Landlords can also educate their tenants on how to properly use installed ventilation systems, as well as on the need to ventilate properly in order to reduce associated risks.


How can residents take action into their own hands?

Government data shows almost a third (31%) of social housing residents aren’t aware of how to make a complaint about their landlord’s service. However, there are a number of ways residents can reach out for help.


Tenants should contact their landlords as a first point of contact, as they may be able to help straight away. Alternatively, tenants can file a complaint.


The Housing Ombudsman is an independent body that investigates complaints from social housing tenants in England, Scotland, and Wales, and can be a good place for tenants to complain directly if they feel their landlord is not responsive.


The Housing Ombudsman had 1,993 enquiries and complaints about damp, mould and leaks in 2020-21. This figure increased by 77% in 2021-22 to reach 3,530. As of December 2022, they had already received 3,969 enquiries and complaints for 2022-23.


Residents should also ensure they are opening windows where possible and making use of any ventilation systems in the property. This can include using extractor fans in kitchens and bathrooms when in use.



Proper ventilation is essential for maintaining a healthy, safe and comfortable living environment for residents of social housing. However, our research has found that many such residents are dissatisfied with the ventilation in their homes and the actions taken by their landlords. 


This is due to a number of factors, including the fact that most social homes rely on passive ventilation or old technology not designed for airtight homes, which is heavily reliant on external factors and cannot be controlled. Additionally, many social housing landlords are not taking the desired steps to improve ventilation in their properties.


However, whilst social housing landlords have improvements to make in their properties, for the health and financial benefit of their customers, social housing properties performed better than privately rented properties - a sign that greater education on the risks of poor ventilation is required.



To calculate the data on energy performance, potential energy performance and ventilation systems in place in residential properties, we analysed data on over 23.5 million properties in the UK, from the Energy Performance of Buildings Data: England and Wales dataset from the Department for Levelling Up, Housing & Communities. From this, we calculated the average energy performance scores and compared them to standard EPC ratings. 


To calculate the percentage of dwellings with passive vs. mechanical ventilation, we counted the number of properties that listed each type of ventilation under the ‘Mechanical ventilation’ category of the Energy Performance of Buildings Data and compared this to the total number of properties. Around 240,000 buildings returned no data, or the tenure had not yet been determined. However, these properties only accounted for 1% of the total properties so have little impact on the overall findings.


This Energy Performance Certificates dataset was updated on 31 July 2023 and includes certificates issued up to and including 30 June 2023.


We also analysed data from the Social Housing Residents Survey to determine current social housing residents' satisfaction with their living situations and their landlords' involvement in improving this.