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Mind the Gap: Measuring the Performance Gap

Most major development projects will have a gap between emissions measured during tests and in real life. To close it, we first have to measure it.

Almost every project has one: a gap between the performance as measured by design calculations and the actual performance once the building has been occupied for some time. However, by measuring these gaps you can learn lessons which will help you close it next time. 

At Carbon Green Consulting, we were recently called in to work on a major regeneration project in the town of Bordon, which will include up to 4500 new homes, a town centre, schools and leisure facilities. The project came with specific requirements including measuring how buildings performed after they had been built.

The performance gap is nothing new. Unfortunately, the methods used to measure CO2 in buildings for compliance are not ideal and rarely reflect real life. A performance gap of some kind is almost inevitable.

As part of this project, they wanted the performance gap to be measured so they could learn lessons going forward. 

Mind the Gap: Measuring the Performance Gap

Most major development projects will have a gap between emissions measured during tests and in real life. To close it, we first have to measure it.

Almost every project has one: a gap between the performance as measured by design calculations and the actual performance once the building has been occupied for some time. However, by measuring these gaps you can learn lessons which will help you close it next time. 

At Carbon Green Consulting, we were recently called in to work on a major regeneration project in the town of Bordon, which will include up to 4500 new homes, a town centre, schools and leisure facilities. The project came with specific requirements including measuring how buildings performed after they had been built.

The performance gap is nothing new. Unfortunately, the methods used to measure CO2 in buildings for compliance are not ideal and rarely reflect real life. A performance gap of some kind is almost inevitable.

As part of this project, they wanted the performance gap to be measured so they could learn lessons going forward.

Reducing the gap

Whenever we’re working on a project, our first task is to reduce the performance imperfections as much as possible. We can do this in a number of ways such as by analysing places where energy could potentially be lost such as at junctions at doors or windows. We can then take a close look at the design of the building and the construction methods used to ensure it is as energy efficient as possible. For example, we may look at whether they are orientated properly or if they have thermal mass which can store energy from the sun.

Education also plays a role. Any construction project depends on the skills of the people tasked with delivering it. Brickies putting up a cavity wall need to understand that bridging the cavity with mortar is a bad move because it forms a bridge for energy to be lost from that building. Education and skills levels are critical.

At various stages in the build process, we will work with site managers and hold toolbox talks with people on site to ensure they are aware of what’s required and what impact it could have if they get it wrong.

Monitoring performance

This is what we did at Bordon. We worked with all stakeholders to assess where energy could be lost and did everything we could to ensure the people managing the construction were on the same page. Once the buildings were completed, we set up monitoring devices in the houses and collected data for analysis. 

Sometimes if a serious issue is detected, the developer may go into the house to see what can be put right. For the most part, though, this is an assessment exercise where we can measure the actual performance against what was predicted. 

This process can take around two years. The data, once collected, belongs to the developer, and they will hold it under GDPR secure conditions and analyses any trend which may be highlighted to then improve their design and building of high energy efficient buildings. As consultants, meanwhile, we can use our own experience from the project to inform strategies for the future.

The performance gap, therefore, can be frustrating, but it has real value. The data we collect creates insights which provide ongoing learnings and help to ensure each project will be better than the last. It’s a crucial part of the drive to deliver more efficient and sustainable major construction projects.

Reducing the gap

Whenever we’re working on a project, our first task is to reduce the performance imperfections as much as possible. We can do this in a number of ways such as by analysing places where energy could potentially be lost such as at junctions at doors or windows. We can then take a close look at the design of the building and the construction methods used to ensure it is as energy efficient as possible. For example, we may look at whether they are orientated properly or if they have thermal mass which can store energy from the sun.

Education also plays a role. Any construction project depends on the skills of the people tasked with delivering it. Brickies putting up a cavity wall need to understand that bridging the cavity with mortar is a bad move because it forms a bridge for energy to be lost from that building. Education and skills levels are critical.

At various stages in the build process, we will work with site managers and hold toolbox talks with people on site to ensure they are aware of what’s required and what impact it could have if they get it wrong.

Monitoring performance

This is what we did at Bordon. We worked with all stakeholders to assess where energy could be lost and did everything we could to ensure the people managing the construction were on the same page. Once the buildings were completed, we set up monitoring devices in the houses and collected data for analysis. 

Sometimes if a serious issue is detected, the developer may go into the house to see what can be put right. For the most part, though, this is an assessment exercise where we can measure the actual performance against what was predicted. 

This process can take around two years. The data, once collected, belongs to the developer, and they will hold it under GDPR secure conditions and analyses any trend which may be highlighted to then improve their design and building of high energy efficient buildings. As consultants, meanwhile, we can use our own experience from the project to inform strategies for the future.

The performance gap, therefore, can be frustrating, but it has real value. The data we collect creates insights which provide ongoing learnings and help to ensure each project will be better than the last. It’s a crucial part of the drive to deliver more efficient and sustainable major construction projects.

Ready to talk?

If you'd like to talk to us about your project, do get in touch.