Zehnder Ventilation

Following COP26’s shining a light on the zero carbon challenge, NaCSBA member Zehnder shares its take on the role MMC can play on delivering on these ambitions.

As our homes are still responsible for around 27% of the UK’s greenhouse gas emissions, the construction industry is facing constant pressure to continually enhance not only what goes into our homes and offices but how they are built, writes Jason Bennett, National Business Development Manager, Zehnder Group UK.

That’s not surprising, of course, when you consider that cement alone contributes about 8% of the world’s CO2 emissions.

Environmental concerns are exacerbated still further when considering the impact that embodied carbon can cause. This refers to all the CO2 that’s emitted in both producing materials and constructing properties, as well as deconstruction and disposal where relevant.

As a general rule, refurbishment is more preferential than demolition in terms of carbon reduction. This issue is more pressing than ever, given the fact that there are no legal requirements to meet reduction targets for embodied carbon at present.

The government’s post-Covid recovery plan is pressing for a huge national building project, while in its recommendations for the Sixth Carbon Budget, the Climate Change Committee laid out its most audacious plan yet to achieve net-zero by 2033. This casts the spotlight firmly on the sector’s responsibility sitting in the middle of those demands.

At the same time as switching to environmentally sound processes, it will need to react with a drive for much greater use of Modern Methods of Construction (MMC) to attack the shortfall in house-building targets, and to publicly lead the sustainability agenda.

The debate over off-site construction

Developers will play a vital role in helping the UK reach net zero, and they need to shout about it, in particular, through the off-site construction model that has been enjoying fantastic success and is set to only continue growing.

It’s estimated it will be worth around £174bn globally by 2030, and with a capability to reduce 90% of the waste generated from traditional construction, while using 67% less energy, you can see why.

Build time is significantly reduced, often by as much as 50%, and wastage can be more easily monitored and minimised. Multi-site works can also be developed simultaneously, potentially halving the build time. This is further decreased as lighting, heating and ventilation systems can all be installed in modules off-site, ready to be quickly and easily fitted together.

While MMC is widely recognised as more environmentally friendly, some industry experts note that it’s not perfect.

Hauling large, finished sections of the build onto the site requires cranes, and there’s the problem of urban sites with restricted access and work space. A lean Just-in-Time ordering system can also increase a carbon footprint via more frequent delivery schedules.

In January 2021, the Future Buildings Standards consultation was published and with it came a fresh targeting on the problems of overheating and ventilation in homes. With UK house design heavily focused on heat retention, there is now a renewed call on making sure that buildings are able to cope with a warmer climate. So much so that overheating in buildings has been highlighted as a key public health risk.

Meeting the challenge

There are a number of ways in which Zehnder Group is positioning themselves at the forefront of a drive towards a greener future that will also prove to be a safer future.

It has developed high-performance cold recovery ventilation solutions, and is understandably delighted that the highly influential Passive House Institute has recognised those efforts. A correctly-balanced ventilation system can help to make overheated, poorly-ventilated properties a thing of the past.

In a similar vein, the introduction of pre-insulated ductwork is rightly regarded as an important step, one that incorporates the many qualities of expanded polypropylene (EPP) in order to reduce thermal loss in both new and retrofitted properties.

Is MMC becoming mainstream, is it on the radar with the public?

It’s clear that modular construction offers significant benefits over traditional methods. It’s a bold step forward and continues to drive design and innovation, propelling the sector to become far more environmentally friendly.

It’s important to push the kind of positive messaging that the sector should be involved in, changing perceptions and showcasing the good work already underway.

The accurate measurement of embodied carbon is clearly crucial to the sector’s future success, and it won’t be long before businesses will be judged on their overall footprints.

If investors are looking to sustainability metrics to measure the performance of housebuilders, MMC could prove to be a very meaningful measurement tool. In January 2021, the publication of a practical toolkit to measure embodied carbon was rightly seen as an important step towards accountability in this area.

It’s time to raise the profile of MMC’s green credentials and to underline how organisations like Zehnder Group can operate at the very forefront of the MMC revolution. The conversation has already started, and they intend to keep it going.

About Zehnder Group

Zehnder Group UK offers a world of Indoor Climate Solutions for residential, commercial and industrial applications including heating, cooling, ventilation and clean air products. Comfort, Health and Energy Efficiency are core to the business operations through product design and development to technical advice and service.


Caption: A correctly balanced ventilation system can help make overheated, poorly ventilated properties a thing of the past.

This is a NaCSBA member update

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