Vent-Axia Highlights Overheating Challenge in New White Paper

As the research shows, architects are increasingly recognising the importance of effective mechanical ventilation strategies in their buildings

With the UK experiencing four heatwaves so far this year and with heat-health warnings currently in place across parts of England, Vent-Axia has sponsored a new white paper examining the growing challenge of overheating in UK buildings. Published by Architects Datafile (ADF), the ‘Solutions for Mitigating Overheating in Residential and Commercial Buildings’ report explores how architects are responding to the need to mitigate overheating in new-build properties, amid tightening regulations and rising temperatures, including highlighting the increasing role of ventilation as part of the overall mitigation strategy.

With more than 2,800 excess deaths estimated during the May and June 2026 heatwaves, and the impact of July’s heatwaves yet to be assessed, overheating in our homes has become a serious public health issue. It is therefore no surprise that three-quarters of those surveyed in the white paper were actively considering ‘climate-responsive strategies’ that go beyond regulatory minimums when designing buildings.

However, there are a range of challenges in mitigating overheating. As new homes become more thermally efficient to reduce carbon emissions and help meet the UK’s Net-Zero 2050 target, the risk of overheating is increasing. Some 77% of respondents believed that medium or high-rise residential buildings designed to Part L 2021 were at risk of overheating, with volume housebuilding not far behind at 68%. Education buildings were considered to be the third highest risk, with 66% of those surveyed identifying them as vulnerable to overheating.

When removing excess heat, Approved Document O of the Building Regulations 2021 prioritises passive measures to reduce overheating. However, findings suggest effective mechanical ventilation is becoming an increasingly important part of the overall strategy, particularly where passive design alone cannot adequately remove excess heat. Some 69% of respondents cited Mechanical Ventilation with Heat Recovery (MVHR) as the ventilation approach they use most frequently. In addition, almost six in 10 (59%) believe the Future Homes Standard will accelerate demand for intelligent ventilation systems capable of automatically responding to changing indoor and outdoor temperatures.

“In the recent heatwaves, we have all experienced how overheating is becoming a challenge in our homes. With homes becoming more airtight to reduce carbon emissions, while global temperatures continue to rise, this challenge is only set to increase. As a result, architects are finding it more difficult to achieve the requirements set out to combat the overheating risk in Part O and TM59 standards,” said Steve Pearce, Product Manager at Vent-Axia.

“In line with Part O, passive design should always be considered first. However, where these measures alone cannot adequately mitigate overheating, effective ventilation has an important role to play in helping remove excess heat, improve indoor air quality and create healthier, more comfortable buildings. As the research shows, architects are increasingly recognising the importance of effective mechanical ventilation strategies in their buildings, with MVHR frequently the mechanical ventilation of choice in new-build properties.”

When removing excess heat, Part O lists acceptable methods in order of preference, starting with opening windows, followed by ventilation louvres, mechanical ventilation, and finally mechanical cooling. When natural ventilation options are restricted, mechanical ventilation provides a valuable solution with a number of different types of technology available.

With today’s developments demanding flexibility to meet building regulations, provide good thermal comfort, and good indoor air quality, there is no longer a one-size-fits-all approach to ventilation. Instead, a range of adaptable solutions are needed to meet project-specific requirements. As a result, ventilation manufacturers have been developing a raft of future-ready and climate-responsive solutions.

Vent-Axia’s latest range of Mechanical Ventilation with Heat Recovery (MVHR) units, the award-winning Lo-Carbon Sentinel Econiq, delivers coolth or heat recovery efficiencies of up to 93%. The Lo-Carbon Sentinel Econiq comes with intelligent automatic 100% summer bypass capabilities, offering free cooling.

But when free cooling via an MVHR summer bypass alone is insufficient to mitigate overheating throughout the year, specifiers can consider MVHR systems with integrated DX cooling modules, such as Vent-Axia’s Lo-Carbon Sentinel Econiq Cool-Flow. This option features intelligent controls that switch automatically between heat recovery, summer bypass and active cooling via the DX cooling module.

One of the latest innovations available is a combined MVHR unit with a hot water air source heat pump. This type of system combines two technologies, offering 2-in-1 – renewable hot water and a free cooling solution. For example. The Lo-Carbon Sentinel Econiq-Cool (KERS), Vent-Axia’s latest flagship MVHR system, features all-new controls allowing communication with the KERS Coolboost Heat Pump.

To download Solutions for Mitigating Overheating in Residential and Commercial Buildings' sign up here.

To find out more about Part O Vent-Axia has also published a useful eBook ‘A Guide to Meeting Part O with Confidence’ it is available for download by signing up for the eBook guide here

Vent-Axia also runs a CIBSE-approved Continuing Professional Development (CPD) course: ‘Overheating in Residential Properties: Part O - How ventilation can be part of the solution to remove excess heat'. To book Vent-Axia’s CIBSE-approved CPDs with one of its experienced ventilation experts, email cpd@vent-axia.com

For further information on all products and services offered by Vent-Axia telephone +44 (0)344 856 0590 or visit www.vent-axia.com.

- Ends –

Notes for Editors
1. Boasting over 90 years’ experience, Vent-Axia is the ventilation sector’s clear leader, chief innovator and forerunner in energy-saving, lo-carbon products. Committed to helping improve indoor air quality and comfort in both homes and buildings, Vent-Axia provides the sector’s most comprehensive choice from any single manufacturer. Vent-Axia’s range covers not just air movement and ventilation technologies but heat recovery, electric heating, hand dryers, cooling and clean-air systems for residential, commercial, public sector and industrial applications.

Media Contact:
Sara MacLean
MacLean Communications
Tel: 07976 782817
Email: macleancomms@gmail.com