Blog Layout

Sweating it out: the overheating headache

Doug Johnson • 23 June 2021

Like it or not, our climate is warming and becoming more unpredictable. Weather is becoming more extreme, and winters are warmer than they have ever been. Combined with the rapid pace of materials development, new construction techniques, and our increasingly obsessive behaviour concerning building energy losses; there is a big issue. It is calculated that over 4.5 million buildings a year suffer from overheating, with the vast majority of those being newly constructed.


In fact, the problem has become so much of an issue that the regulation of building overheating in the 2021 Building Regulations under a new section - Part S - is also expected to come into force in Q1 2022 to ensure that sufficient due diligence is undertaken for new buildings.


Paradoxically, as we advance and focus on highly insulated buildings with managed ventilation and less natural air infiltration, we make the very buildings we hope to be fit for purpose and progressive, become uninhabitable and uncomfortable. In addition, in trying to reduce build costs and improve the speed of construction, the very materials and techniques that make this possible go against some fundamentals of building physics which have for centuries allowed buildings to remain comfortably cool throughout the year.


The real risk to developers of ignoring the threat or possibility of overheating is that once a project is completed, to resolve overheating issues costs considerable money and time to put even partially right. As an afterthought, this can not only be expensive but ugly and will invariably add to the long-term running and maintenance costs of the build.


The good news is that this risk can be mitigated by some increased understanding of what causes it and basic analysis at the conceptual design and pre-planning stages.

Top 3 Causes of Overheating

There are three main causes of overheating in buildings. We will quickly cover these as well as how to reduce their impact.

Underfloor heating: 7 myths busted! Mythbusting with Mesh Energy

1. Low thermal mass

The density of the materials used in a structure strongly affects daytime overheating and the long-term retention of heat or cool in the structure. Lightweight structures such as SIPS and timber-framed buildings respond far quicker to high exterior temperatures. Higher density structures such as masonry and concrete respond far more slowly and peak daily internal temperatures remain lower on even the hottest days of the year.

2. Large areas of glazing

High proportions of glazing above 35% of the total wall area on east, south or west building elevations can be a significant cause of detrimental solar gains in spring, summer, and autumn. Where increased levels of glazing are desired, solar shading should be investigated and engineered to ensure fully functional and appropriate use for the building type.

3. Poor natural ventilation

The poor ventilation of spaces, particularly at night-time, in domestic dwellings is a great cause of overheating in homes. More generally, a lack of air movement or cross-ventilation in buildings can quickly become a nuisance and lead to high levels of discomfort. Single aspect buildings such as flats are a particular example, and the use of purge ventilation should be considered at the earliest stages of design to save costs later!

The way forward

One of the most effective ways to better understand the potential overheating risks of your development as designed is to use dynamic thermal and ventilation modelling from as early as possible in the building’s design process. Costs vary based on the building size and complexity, but for as little as £1,000 +VAT you can have a detailed first pass of the design and quickly identify room-by-room where any issues may lay. Once digitally modelled, as the design develops, an intelligent and focused approach can be taken providing feedback to the design team as to appropriate changes with a high level of confidence in performance once built.

How Mesh can help

At Mesh, our analysis eradicates overheating from a property by using a step-by-step high end calculated approach. We take all the necessary steps and passive design strategies to not only reduce/remove overheating from a property, but also to reduce energy bills. We can perform calculations related to Part O compliance, TM59, TM52, general overheating and planning for new builds, as well as provide solutions for domestic and non-domestic projects. Mesh believes in using the most resourceful passive design strategies to remove/reduce overheating in both new build and retrofit projects. 


FIND OUT MORE

SHARE THIS POST WITH YOUR NETWORK

by Doug Johnson 24 March 2025
Mesh Team Blasts Half Marathon for Cancer Charities
by Doug Johnson 24 March 2025
Offsite housing specialists TALO and building performance consultants Mesh Energy have announced a collaboration agreement to accelerate the delivery of ultra-low energy homes. The collaboration will combine TALO’s advanced timber superstructure technology from Finland with Mesh’s experience of providing net zero building performance and engineering services for housebuilders, architects and residential property developers. Working closely together, TALO and Mesh will aim to significantly increase the energy efficiency of new homes for market sale, rent and affordable housing, exceeding both Passivhaus energy standards and Future Homes standards, in compliance with the latest regulations. Doug Johnson, Director of Mesh Energy: “TALO’s timber superstructure solutions for low rise housing are the very best we have seen in the UK in terms of energy efficiency, air tightness, cost and quality. Their latest projects are achieving at least a 30 per cent improvement on Passivhaus energy standards and at no cost premium. We don’t believe there is anything like this on the market today and yet it is very needed. Some of the biggest issues facing housebuilders and developers are managing risk and addressing skills shortages. TALO’s system addresses both of these challenges extremely well. New regulation is coming which will make it increasingly difficult for developers to balance the rising cost of building new homes to the required energy and air tightness standards and the risk of non-compliance. New homes simply need to perform better. And yet the risk for developers is in the fabric and performance of each home. Our new collaboration will give housebuilders the benefit of much greater certainty of delivery to the required quality, air tightness and energy standards from the inception of a project. Our work on the energy strategy, data and compliance will support TALO’s extremely efficient way of building new homes to reduce risk for residential property developers.” TALO and Mesh have already collaborated on a number of projects. Under the new agreement, both businesses can leverage their respective experience to enhance the efficiency and economics of new residential projects. Dr Anthony Greer, Corporate Strategy Director of TALO said: "Our vision is to transform UK housebuilding by taking proven technology which has been used to build thousands of units in the Nordics – in one of the most extreme climates in the world. Our goal is to address some of the difficult problems that have been challenging the UK construction industry for many years – skills shortages, speed of delivery, sub-standard quality, and poor energy efficiency. Our ultimate goal is the offsite construction of high quality, ultra-low energy homes that can eradicate fuel poverty and snagging. By radically reducing time on site, developers can achieve a faster return on investment. They need fewer trades on site because we are using highly efficient offsite technology. Our processes are entirely dry – from forest to site – which means better air tightness performance and more accurate programme scheduling for the fitout phase to further reduce risk. Homes built by TALO exceed Passivhaus energy and air tightness standards at no cost impediment. This means homeowners and tenants will have hugely reduced energy costs that are verified by A-rated EPC certifications. Our housebuilding solutions will be enhanced with our collaboration with Mesh, helping to solve the technical and economic challenges that are constraining the sector and compounding the housing and cost of living crises.” In the new arrangement, Mesh will provide the energy strategy, data analysis and compliance work to support TALO’s delivery of the offsite superstructures for low-rise housing projects – which range from terraced housing, semi-detached family homes and larger executive schemes for developers and housebuilders across the UK.
by Pablo Jiménez-Moreno 29 April 2024
Discover the critical role of a feasibility study in integrating renewable technologies into your home. Learn how to make informed decisions for sustainable living.
by Doug Johnson 11 January 2024
As we come out of our end of year hibernation period for 2023 and try to both digest and interpret what 2023 had in store for us, how we dealt with it, and what we would change if we could; we drag ourselves out into the blinding light of 2024 and hope for a less tumultuous year in the UK’s sustainable construction sector. I am an optimistic person and ‘glass half-full thinking’, as well as doing my best to gaze into the future, is my default position. When working with a team on the sharp end of sustainable building design, there are some trends which simply cannot be ignored and hold great promise for 2024. The following trends are in areas we’ve seen growing design time and client fees being spent to great effect, and that’s why these are my top four sustainable construction prediction of 2024.
by Doug Johnson 7 December 2023
In recent years, sustainability has seen a massive increase in priority within the construction industry. As climate change and its effects worsen around the world, architects, builders, and developers are now feeling more compelled to adopt more environmentally friendly practices. While pursuing sustainable building design is definitely a commendable course of action, the process itself has its own set of challenges; introducing potential risks to the construction industry that must be addressed.
by Rebecca Boehme 3 August 2023
In May 2023, we discovered we’d been included in The Sunday Times’ ‘Best Places to Work in 2023’ list . This phenomenal achievement was the icing on the cake of what’s been a great few years for Mesh as an employer. From achieving our B Corp in November 2021, to being recognised in B Corp’s ‘Best in the World’ category for workers in March 2022, to growing the business to the 22-strong team it is today, it’s been both incredible to see our recognition grow, and a mammoth effort to get here.
by Doug Johnson 27 July 2023
Incorporating low-energy solutions like solar PV, battery systems, and other energy-efficient technologies into commercial buildings offers several key benefits. We cover the top 5 in our latest blog.
by Doug Johnson 20 July 2023
In this second blog on the technology behind low-energy commercial projects, I'll be exploring why solar PV, energy storage, EV charging systems, and LED lighting are crucial assets to any low-energy commercial building.
by Doug Johnson 13 July 2023
It's estimated that commercial buildings contribute around 8% of the UK's total annual carbon emissions, and carbon associated with heating, ventilating, and cooling buildings makes up about 40% of a building's total annual energy usage.
by Lewis Caudy 5 July 2023
When it comes to sustainable and energy-efficient building design, architects are increasingly turning to geothermal technology as a viable option.
More posts

Subsribe to memo from mesh

Share by: