黑洞社区

The government has set a UK target of achieving net zero carbon emissions by 2050. Throw in a growing number of local authorities setting their own ambitious emissions goals, and it鈥檚 easy to see why pressure is mounting for the construction industry to deliver a greener built environment.

The sector needs to ensure that any building it puts up results in a minimal carbon impact 鈥� from the materials and processes used to build it, the amount of energy used in its operation and maintenance, any refurbishment work and ultimately its end-of-life disposal.

And all of this is set against a background of keeping costs down and build quality high. It鈥檚 quite the challenge.

To discuss this thorniest of subjects, 黑洞社区 magazine gathered a group of industry experts in a virtual setting. Meeting chair and 黑洞社区 group technical editor Thomas Lane kicked off the proceedings by asking how data might play a part in delivering net zero carbon buildings.

ISG鈥檚 head of sustainable business, Debbie Hobbs, said it was important to start with the basics, namely understanding what was meant by 鈥渘et zero鈥�. Hobbs said that while there were London Energy Transformation Initiative (LETI) targets, there ought to be a wider definition around what net zero actually meant.

鈥淒o you mean getting to an energy efficiency level where your building can use its percentage of renewable grid? And if so, what is that, and how do you calculate it? And if your building doesn鈥檛 meet that with on-site renewables, can you still claim to be net zero if you buy offsets? We need some kind of certification scheme in the industry that keeps these standards working for us.鈥�

Where to start?

Roger Macklin, associate director at engineers Hoare Lea, said that from the outset it was essential to know how much carbon was being emitted from a building. 鈥淚f you don鈥檛 start there, how do you know what net zero looks like? I appreciate the concepts associated with embodied carbon for construction are different, but from an operational viewpoint the question is around: How much and what sort of energy are you using? When are you using it?

鈥淏eing able to make a calculation of the amount of carbon emitted by your activities is vital, because unless you know what that is it鈥檚 very difficult to carry out a net zero calculation 鈥� because quite simply you don鈥檛 know what it is that you鈥檙e calculating.鈥�

We need some kind of certification scheme in the industry that keeps these standards working for us

Debbie Hobbs, ISG

 James Chambers, regional director UKI at software provider Bluebeam, suggested that after having expended so much energy and activity on delivering a building it was a bit of a contradiction to then call it net zero.

鈥淪ome serious consideration should be given to the construction approach and methodologies in putting up the building to start off with, along with asking the question, 鈥榃hat鈥檚 your goal here?鈥�.鈥�

Accurate modelling

While reducing carbon emissions to as low a point as possible was the prime goal, 黑洞社区鈥檚 Lane wondered how a developer might gather the relevant carbon-related information to inform how it could deliver, say, a six-storey office scheme, and what information would be required?

Craig Robertson, head of sustainability at architect Allford Hall Monaghan Morris, said it was vital to model such a scenario accurately 鈥� and at an early stage in the design process 鈥� around what would be going into a building, so as to be able to interrogate where the carbon is contained.

鈥淚t鈥檚 also important to get data from one鈥檚 supply chain. And we need to be able to interrogate our contractors and their supply chains to ensure that we get the things that we think we鈥檙e going to get, or that we鈥檝e accounted for,鈥� he said.

鈥淏ecause if that鈥檚 going to change through the procurement process we need to be able to have a model which is nimble enough to account for that and give us a running carbon total, so we can adapt the design as we go.鈥�

Environmental product declarations (EPDs) can help, Robertson said, provided they鈥檝e been created with the right sort of methodology. Large organisations are more up to speed, but smaller local suppliers, where the value to the local economy might suggest a more sustainable option, don鈥檛 have the money to invest in EPDs.

鈥淪o having a consistent methodology used across the industry would really help. Then information could be tagged into software material characteristics that we could then tag into a model, suck out volumetric data and get a carbon picture pretty quickly.鈥�

Alex Edmonds, associate director at engineering consultant Robert Bird Group, agreed. 鈥淲e鈥檙e quite good at identifying our raw materiality per project. But then the construction methodologies often vary between contractor to contractor and subcontractor to subcontractor. And there鈥檚 a very broad-brush application of kilogrammes of CO2 per 拢100,000 capex on the project, which doesn鈥檛 necessarily consider the complexity of build and doesn鈥檛 help in understanding the true embodied carbon in a project.鈥�

One way to arrive at the true carbon content of a material 鈥� for example, as steel imported from overseas 鈥� was to 鈥渄ive into the shipping information鈥�, said Andrew Pratt, associate director for structures at WSP. 鈥淎lso, how did they heat the warehouse where it was stored, how has it been fabricated?鈥�

It was challenging, he said, and not least because the potential data you would be looking at could almost be limitless. But it was 鈥渟uch rich information and there鈥檚 so much of it, [but] you鈥檝e also got to have the client with an appetite to actually take that data on to that level鈥�.

Operational carbon

黑洞社区鈥檚 Lane moved the debate onto another point, that of a building鈥檚 operational carbon. 鈥淎 designer won鈥檛 necessarily know who is going to use the building over the course of its life. Someone鈥檚 got to keep a record of what energy is being used, of what servicing is being done, and the carbon impacts of that activity,鈥� he said.

Digital twins were one solution, suggested Kathryn Donald, digital design leader at engineering consultant Max Fordham, but it was important to get the right data out of a building and into the twin set-up in the first place.

鈥淭here鈥檚 a need to ensure you鈥檝e got the right specification of meters and sensors, because you need that data before that鈥檚 then fed into the digital twin. How do we better suit that building for the activities that are taking place in it? I think there鈥檚 a lot of data crunching going on there.鈥�

The idea that we can try to make some sort of estimate about usage over a lifetime that could be 30 years or more is a fool鈥檚 errand

Roger Macklin, Hoare Lea

While a building can benefit from data in order to become more flexible and adapt to different needs, it still needed to be able to gather all that information, Donald added.

鈥淗aving systems in place that can talk to each other, using open protocol, and trying to integrate all of this together, is really important. That is one of the big challenges that software developers face; you鈥檙e not going to get a one-product-fits-all.鈥�

One of the biggest headaches around assessing the carbon output of existing buildings, according to Hoare Lea鈥檚 Macklin, was the difficulty in getting verifiable data out of them.

鈥淚 would pretty much guarantee you that 90% of electricity meters in buildings in the UK don鈥檛 work. Part of the reason they don鈥檛 work is because historically there鈥檚 been no interest in using them. The only thing most people use them for is to pay the bill.鈥�

Macklin went on to suggest that assessing the energy usage of a building over its life would also be extremely difficult. 鈥淭he idea that we can try to make some sort of estimate about usage over a lifetime that could be 30 years or more is a fool鈥檚 errand.鈥�

One could look at individual components, and the different efficiencies of delivering a particular service.

鈥淩ather than focusing on how much of that service is consumed, which is very difficult to do, you鈥檝e got to make sure that the way that service is provided is as efficient as it can be,鈥� he added.

ISG鈥檚 Hobbs warned that for any of this to be of use, the technology installed to gather the information had to be maintained to the highest standard. 鈥淗aving done thousands of energy audits, I can鈥檛 tell you the number of buildings I鈥檝e been to where the outside air temperatures aren鈥檛 calibrated. Controls won鈥檛 work if you don鈥檛 maintain them properly.鈥�

Net zero contracts

Hobbs went further, suggesting that from a building鈥檚 conception the relationship with the client had to be different. 鈥淲e鈥檝e got to change contracts so that as builders and designers, we鈥檙e contracting to deliver a building that performs not only in theory, but in practice. So we take a bit more risk, but we get a bit more reward once the buildings perform for the first couple years.鈥�

Bluebeam鈥檚 Chambers agreed, and said the lessons learned through prior experience of digitisation, along with efficiency growth, would hopefully play their part. 鈥淚f you look at a contract nowadays, there鈥檚 probably nothing in there about the net zero, who 鈥榦wns鈥� it, who鈥檚 responsible for it. What鈥檚 the litigation background on that? Because it鈥檚 not built into the contracts currently.鈥�

Meanwhile, assessments around what to do with a building once it has outlived its useful purpose 鈥� knock it down and rebuild, or retain and renovate 鈥� should be part of any carbon calculation process, suggested 黑洞社区鈥檚 Lane. Responding to this point Richard Powell, partner at consultant Alinea, said clients of his firm were looking at this as a key criteria.

鈥淭hey鈥檝e got an existing asset, which may not be performing as efficiently as a new-build asset, but the carbon factor of a rebuild versus refurbishment 鈥� is actually a much more significant consideration now than it would have been many years ago.鈥�

How do we start making it economical to get a city-scale digital twin in order to start targeting which buildings to start renovating?

Matt Wheelis, Nemetschek

Powell also said his firm was looking into carbon benchmarking and he would like to think this data would be shared, 鈥渨ith the supply chain being intrinsic to that as well. It鈥檚 vital that it is shared, in terms of consistency of data and advice.鈥�

That data should be transparent and shared was certainly an important consideration, said AHMM鈥檚 Robertson. The LETI numbers were often a 鈥渟tretch and difficult to meet鈥�, he said. 鈥淲e need to share data openly, transparently and without judgment across the industry, to share methodologies for [hitting them], because we鈥檙e not going to solve this on our own.鈥�

Another aspect around information sharing was that clients had to be willing to accept failure, Robertson said. 鈥淲hatever the reason [for our failure to hit certain carbon targets] is 鈥� our clients can take an informed decision about why we鈥檙e not hitting those targets.

鈥淏ut then they need to be mature enough to share that widely and say, 鈥業n order to get down to these numbers, we have to do all this other stuff that we didn鈥檛 do because we didn鈥檛 think market would take it.鈥�

鈥淭hey need to say to the rest of the industry, 鈥楲ook, here鈥檚 this information, take it and develop it, and pass the baton on to other people鈥�.鈥�

Nemetschek vice president of industry strategy Matt Wheelis said: 鈥淲e can talk about digital twin systems and new buildings, which is an area where you can have a model at handover and soft landing or you can have some kind of a verifiable model at that point.

鈥淏ut how do we start making it economical to get a city-scale digital twin in order to start targeting which buildings to start renovating? Because the moment you start renovating a building, trying to save energy, you鈥檙e releasing carbon in the demolition and you鈥檙e consuming carbon in the new parts.鈥�

There was also a whole culture issue which needed to be addressed, according to Melanie Robinson, project manager at the BIM Academy, one that fed into both digital ways of working and sustainability. 鈥淚 believe the two go hand in hand. But I think we鈥檝e just got a lot of work to do to feed that down the supply chain regarding why this is important. Not only from a sustainability point of view, but from a pure information availability one.鈥�

The accuracy 鈥� or inaccuracy 鈥� of the data could be an issue, especially if a client made a decision based on suspect numbers, according to Alinea鈥檚 Powell. 鈥淲hen we鈥檙e using models for cost advice, we can harvest quantities from architects鈥� or MEP structured models, but we will always own that quantification advice, because we would test it internally first, before advising the client.

鈥淲ith carbon, because it鈥檚 potentially supply chain driven, it鈥檚 quite difficult for us to take on that kind of responsibility. It doesn鈥檛 really feel right.鈥�

Meanwhile, Bluebeam鈥檚 Chambers was optimistic about the sector鈥檚 ability to make progress towards the mandated target of net zero by 2050, since it had taken BIM on board, albeit after some initial reluctance.

鈥淔olks are going to realise very quickly that they have to get onto this, that they have to jump on it sooner rather than later. There鈥檚 no way they can wait until 2045 to say, 鈥楢ll right, I鈥檓 gonna start to think about net zero鈥�.鈥�.

Rating systems

The deadline of 2050 is just one aspect. Whole-life carbon calculations, as laid out in the New London Plan, could be the first step in a move towards legislation around whole-life carbon modelling, suggested 黑洞社区鈥檚 Lane.

Hoare Lea鈥檚 Macklin, while he thought regulation was inevitable, pointed to the Australian National Australian Built Environment Rating System (Nabors), recently introduced into the UK, which rates buildings on their environmental credentials via a star system. In many cases potential clients 鈥� such as government departments 鈥� stipulated that if the building wasn鈥檛 going to achieve five stars, it simply wouldn鈥檛 get developed, he said.

Macklin also said some form of digital passport could be applied to an environmentally sound building, one that was 鈥渞etained and maintained with the building and was reported on each year, as part of some sort of government regulation鈥�.

I鈥檓 hoping that every technology we add is an extra weapon that can be used to combat the carbon issues that we have today.鈥�

Andrew Pratt, WSP

Despite some landlords paying scant regard to reducing energy use in their buildings, the demand for assets that fulfilled an ambitious environmental brief would only increase, said Robert Bird Group鈥檚 Edmonds, as companies responded to the desire of staff to work in open, airy, well-ventilated, energy-efficient workspaces that were digitally enabled and flexible.

鈥淥ur task groups look at that, and they tend to be the younger generation that are coming through the business and want to see more of those kind of environmentally friendly features and sustainable features in buildings.鈥�

As the meeting concluded, WSP鈥檚 Pratt said he wanted to end on a positive note. 鈥淲hen I first joined this industry 20 years ago, the tech was minimal. We had drawing boards, fax machines, paper copies and envelopes and franking machines.

鈥淣ow we can work in a 3D environment, online. I can go onto a website, pick up my BIM 360 model, and it all works fine. I鈥檓 hoping that every technology we add is an extra weapon that can be used to combat the carbon issues that we have today.鈥�