How an ‘mpg for your home’ unlocks our zero-carbon future

By Knauf Insulation UK & Ireland
February 18, 2021

This week I took part in a panel discussion on decarbonising the UK’s homes for The Bottom Line on BBC Radio 4, with Dr Sara Walker from Newcastle University, and Phil Hurley, chairman of the Heat Pump Association.

We all know that significant improvements to housing energy efficiency are required. On the programme, we explored what individuals, the industry and government need to do to make them happen. If you’ve not heard it yet, you can listen here.

It’s perfect timing for this conversation. Yes, the need to reduce our emissions remains as urgent and profound as ever. But I also believe we’re standing on the cusp of a radical change to the construction industry; one that will enable it to deliver the millions of genuinely efficient homes we need. And all made possible by a new technology solution.

First, let me recap some important things we know.

1) We know that more efficient homes are a key piece of the puzzle to achieve zero carbon.

Our homes make up around 15% of the UK’s greenhouse gas emissions. There is no path to net-zero without significantly improving their energy efficiency. And that applies to all 29 million homes in the UK – new and existing – because if you do the maths, as many as 85% of 2050’s houses are already standing today.

2) We know that insulation works brilliantly when it’s well installed.

Domestic gas usage in the UK dropped by 30% between 2005 and 2013, when previous government insulation schemes were at their height. Poorly insulated homes lose up to 50% of their heating energy through the roof, walls and floors, and the Energy Saving Trust estimates that the correct insulation saves households up to £250 per year.

3) And we know that there’s a gap between the theoretical energy efficiency of homes on paper, and their real-world performance.

Currently, Energy Performance Certificates (EPCs) are a tickbox exercise – they’re not based on measurements, and so can misrepresent how well a home performs. Our data suggests this performance gap is often as much as 30% (and we’ve found cases where it’s even higher). This means homes aren’t as warm as they should be, use more carbon and cost more to run – so homeowners, landlords and the taxpayer often aren’t getting the outcome that they’ve paid for. That’s simply not fair.

New technology gives us an unprecedented opportunity to close this performance gap and achieve our zero-carbon emissions.

Until now, we had no way to measure this performance gap, let alone address it. But thanks to new sensor technology, developed by Knauf Energy Solutions, it’s now possible to measure how well a home’s walls, floors and roof actually perform in the real world. In effect, we can now measure that home’s mpg.

That’s important, because it means we can change the way we build or renovate our homes. We can shift to a model that measures their actual energy performance, and uses that insight to provide a quality assured outcome. In other words, we can stop measuring success in terms of inputs – millions of m2 of insulation installed – and start talking instead of outcomes – how many MWh of energy or tonnes of CO2 emissions have been saved.

We all have a part to play to make this a reality.

The construction industry must read the room on future buildings policy and proactively embrace new approaches that de-risk ‘in-use’ energy performance for their customers. This transition is inevitable, but technology like ours can help, and we’re ready to support the supply chain on this journey.

Mortgage providers need to take energy efficiency into account in their lending decisions (and again, this is already beginning to happen).

And homeowners should value energy efficiency like we do location and garden space. It means lower bills for the life of the building, more comfortable living and a lower carbon footprint for all of us.

But the lead actor is still the government. It must take concrete action to put real performance front and centre whenever we build or refurbish our homes.

That means building real performance into legislation and future policy. We’re already seeing a clear direction of travel with the EPC Action Plan, changes to the Building Regulations and the New Homes Ombudsman. We know it is currently reviewing measurement technologies and is due to report next month on how they might be included in the new EPC regime. It’s critical that these proposals quickly crystallise into firm policy and clear actions, underpinned with long-term support in other policy areas.

The transition to on site measurement clearly holds risks, but the potential rewards for homeowners and taxpayers are greater, especially as we begin a transition to electric heating. We recognised this shift some time ago, and have been preparing for it ever since. So, if you have questions about how real performance affects you, we can help.

Neil Cropped

By Neil Hargreaves, Managing Director - Knauf Insulation