Although published at the end of January this year, the government鈥檚 new Environment Bill, with its far-reaching proposals to tackle plastic waste, poor air quality and the depletion of habitats and biodiversity, has barely registered on the construction industry鈥檚 agenda.
Pushed into the background by the Covid-19 pandemic, the Bill 鈥� which is due to pass into law in January 2021 鈥� will nevertheless introduce significant new obligations on developers of building and infrastructure projects.
Developers will need to deliver a 10% 鈥榖iodiversity net gain鈥� on their sites, a far more onerous requirement than the current situation, where developers only have to 鈥榤itigate鈥� the impact of their projects.听
In fact, according to ecologist Stephanie Wray, from environmental consultant RSK Wilding, a 10% biodiversity net gain is almost impossible to deliver on site. Typically, she says, a new-build development can take up 80% of the surface of the land. 鈥淚f you鈥檙e building on 80%, you simply can鈥檛 make the site 10% richer in habitats and species. Developers will therefore need to pay to offset their impact on biodiversity,鈥� she says.
Wray admits that the whole concept of 鈥榦ffsetting鈥� 鈥� most commonly encountered in the context of carbon emissions 鈥� is fraught with potential for misinterpretation. She points out that when an organisation claims to have offset its carbon emissions 鈥� for example by planting trees, whether locally or on the other side of the planet 鈥� it isn鈥檛 necessarily delivering a net benefit to the environment.
Paying someone to plant new trees in compensation for those you cut down to make way for a new development might reduce your carbon footprint but it鈥檚 unlikely to deliver an environmental net gain.听
鈥淚f you just focus on offsetting your carbon emissions and planting trees well, yes, you might actually get the equation to balance and your carbon to be settled but are you really sustainable?鈥� she asks.听
鈥淭he trees you cut down might not just have been sequestering carbon; they might have a role in managing the water catchment; they might be home to a range of species including pollinators that are important for local crops. There鈥檚 a whole range of benefits because the environment isn鈥檛 doing just that one thing for us 鈥� sequestering carbon 鈥� it鈥檚 got a whole range of goods and services that it offers us.听
鈥淭he key question is: 鈥榙oes it cancel out the environmental harm?鈥� and that鈥檚 a very different question to 鈥榙oes it balance my carbon budget?鈥� which is what a lot of organisations are trying to do.鈥�
Answering that question requires more than simply balancing an equation. 鈥淔or too long I think we鈥檝e focused our attention solely on carbon and believed that the unit of sustainability was the carbon molecule 鈥� and it鈥檚 really not. It鈥檚 much broader than that.鈥�
Wray borrows a quote from听Hitchhiker鈥檚 Guide to the Galaxy听author Douglas Adams: 鈥淓cology,鈥� she says 鈥渋s about 鈥榯riangulating the vectors of interconnectedness of all things鈥�. The reality of ecosystems is so complicated and you have to be able to deal with that complexity.鈥�
Biodiversity is 鈥渢he tricky bit鈥�, admits Wray. 鈥淚t鈥檚 the bit with all the complexities of interrelationships between animals and their environment,鈥� and it will be something the construction industry will have to get to grips with when the Environment Act comes into force next year.听
鈥淭his is looking at biodiversity specifically and making sure that where you鈥檝e lost biodiversity your development puts at least the same amount back,鈥� she says. The good news is that if you get that bit right, 鈥渢he rest of our dimensions of stability are quite likely to fall into place alongside them.鈥� The same cannot be said if you simply balance your carbon emissions, adds Wray.
The solution being put forward by Wray and her firm RSK is 鈥榬ewilding鈥� 鈥� not a new idea, but one that is not well understood and has yet to become mainstream. Wray heads up a newly-formed specialist division of the company 鈥� RSK Wilding 鈥� which has been launched with the express intention of helping businesses, large and small, 鈥渙ffset their carbon emissions and ecological impacts while helping to reverse decades of environmental degradation, biodiversity loss and climate impacts鈥�.
If the average UK resident ever thinks about 鈥榬ewilding鈥� it鈥檚 likely to be in terms of long-lost species reintroduced to the British countryside and recolonising remote forests and moorlands. Advocates of rewilding have indeed proposed the reintroduction of wild boar, wolves, lynx and even moose 鈥� much to the alarm of farmers and other rural dwellers. But while beavers and wild boar have indeed re-established themselves recently in parts of the UK, this really isn鈥檛 what RSK Wilding is advocating.听
鈥淩ewilding isn鈥檛 just about bringing back wolves and beavers,鈥� says Wray. 鈥淲hat we鈥檙e really talking about is not imposing a particular direction on the development but letting natural ecological processes take over and for the community of plant, insect and bird life to develop naturally,鈥� she says.
Wray is driven by the idea of a 鈥榬ewilding industry鈥� where the value of a piece of land is measured more broadly than just in terms of its development potential or even agricultural value. No such industry currently exists, but Wray is confident that it will emerge.
鈥淔ood production isn鈥檛 the only public benefit that we need from the land that we have here in Britain,鈥� she says. 鈥淪ome of the other benefits are clean air, clean water, not having our houses flooded every time it rains in the winter. Land can be managed for those benefits as well.鈥�
Perhaps the best-known example of rewilding in recent years is the Knepp Estate, a 3,500-acre farm in West Sussex which was, until about 20 years ago, a conventional arable and dairy farm. Then its owners, Charlie Burrell and Isabella Tree, took the commercial decision to let the estate literally run wild.
Now, as Tree describes in her book听Wilding, published two years ago, the estate is a haven for wildlife, spontaneously re-colonised by rare and endangered species of insect, bird and mammal, as well as numerous plants.听
The estate still farms Highland cattle and Tamworth pigs and is home to herds of Exmoor ponies and both red and fallow deer. And it is still commercially viable 鈥� albeit thanks more to its lucrative 鈥榞lamping鈥� and eco-tourism business than to its farming activities.
Wray considers the Knepp Estate to be a good example of how rewilding can make good business sense. And she thinks that given the Environment Bill鈥檚 forthcoming requirement to deliver a 10% net biodiversity gain on construction projects, it has plenty to teach other businesses.
RSK Wilding says its aim is to help 鈥渃lients,听landowners听and other stakeholders 鈥μ齬estore听some of听the UK鈥檚 landscape to the natural, biodiverse and wild place it used to be, connecting existing protected areas. By doing this, we will be playing our part in leaving a better legacy for future generations鈥�.
According to Wray there鈥檚 a lot of land that has little value for development but which could be harnessed to help businesses deliver their biodiversity obligations.听
听鈥淏rownfield sites can do really well,鈥� she says. 鈥淲e鈥檝e worked on a few projects where we鈥檝e gone back some years after a brownfield site鈥檚 been restored and done biodiversity calculations retrospectively and seen real improvements and genuine net gains in biodiversity.鈥�
Most local authorities have a number of vacant or derelict sites within their area and Wray believes it would be well worth these authorities carrying out an audit of these various plots of land.听
鈥淭hen you could say 鈥榯hese sites are the ones that are good for development and these are the ones where we could maybe develop some renewable energy technologies. But this one would be best kept for its natural capital value: let鈥檚 leave that for natural flood space 鈥� you know, so we flood somewhere that鈥檚 not valuable for people鈥�,鈥� says Wray.
But as Wray has already pointed out, not all landowners and certainly not all sites can provide enough space on which to deliver the 10% biodiversity gain that will be expected of them.听
When the Environment Act comes in next year and developers are required to deliver biodiversity net gain on their new developments, having existing pieces of land that they can manage for biodiversity to help them deliver their own offsets will prove very helpful, says Wray.
鈥淎nd of course you can stack those benefits so you can use that land for sequestering carbon, delivering your biodiversity net gain and for your social or community outreach,鈥� declares Wray. 鈥淚n fact, if I were a house-builder I might be looking now at adding into my landbank not just land that I think is viable to build houses on, but also land that I think is marginal and I might want to do some of these other things on and offset my impacts.鈥�
What you can鈥檛 do under the forthcoming legislation is simply pay someone to plant a few trees in a far-off country and pretend that you鈥檙e offsetting your biodiversity impacts, cautions Wray: your mitigation measures have to be 鈥渁s local as possible 鈥� in the same country; ideally the same county,鈥� she says.听
鈥淭he idea is that first of all you try to reduce the amount of net [biodiversity] loss. When you鈥檝e done that as far as you can, then you try to improve the development itself and get more biodiversity into that for the benefit of the environment and the people who are going to live or work there. Only then do you start to do things a bit further afield,鈥� Wray explains.
However, she says that on a small construction project that requires only a little net gain, there鈥檚 no point 鈥渄oing a tiny little bit in a field with no context to anything else鈥�. That鈥檚 where a consultant like RSK Wilding can help out by linking clients up to larger strategic initiatives.听
As Wray says, balancing your carbon emissions is a fairly straightforward process and is easily calculated; measuring biodiversity is 鈥渢he tricky bit鈥� 鈥� but it can be done.听
Some local authorities, such as Warwickshire, and large landowners, including Network Rail, have already developed their own biodiversity metrics but, says Wray, 鈥渢here is one metric, a measure that we鈥檝e all coalesced on: Defra has actually developed a way of measuring biodiversity.
鈥淚t鈥檚 not perfect 鈥� biodiversity is quite complicated 鈥� but what it does is use the areas of different habitat type as a proxy for biodiversity,鈥� she explains. 鈥淪o we look at how much woodland is there, how much grassland, ponds, rivers and so on, and for each of those habitats we measure how big it is and then [an ecologist] looks at the 鈥榙istinctiveness鈥� 鈥� how rare or special 鈥� each one is.鈥澨�
Scores are then attributed to each habitat 鈥� an ancient woodland would get you more points that a piece of well-mown grassland, for example. 鈥淪o we look at the condition each habitat is in, calculate the area, then add up all the habitat types on your site and come up with a number of what we call 鈥榖iodiversity units鈥�,鈥� says Wray.
鈥淭hen we look at your plans for that site and see what鈥檚 going to be lost under tarmac or whatever and what habitat you鈥檙e proposing to create in your open public space and we look at what the value of those habitats will be. We do exactly the same sort of calculation. Then we take one away from the other and see if you鈥檝e got a net loss, a gain or if it鈥檚 neutral.
鈥淚f you鈥檝e got a net loss, that鈥檚 when we start looking at an off-site offsetting area to make up the shortfall and, with the new legislation, make that 10% net gain,鈥� explains Wray.听
It鈥檚 probably as well that there are consultants like RSK Wilding stepping forward to offer their services, because the construction industry鈥檚 obligation to protect the natural environment is only going to become more onerous. As recently as September this year, prime minister Boris Johnson stood up at a virtual United Nations event to join other world leaders in promising to reverse the loss of natural habitats.
Signing the so-called Leaders鈥� Pledge for Nature, Johnson promised to increase the amount of protected countryside in the UK by 30% by 2030. 鈥淲e must turn words into action鈥nd agree ambitious goals and binding targets,鈥� he declared.听
Johnson鈥檚 goal is to protect an extra 400,000 hectares of English countryside for the natural environment. 鈥淭hat鈥檚 an astonishing thing if we can actually deliver it,鈥� says Wray. But, as she points out, Johnson is talking mostly in terms of national parks, which currently cover around 26% of the land in England.
鈥淣ational parks and AONBs [areas of outstanding natural beauty] aren鈥檛 really protected for biodiversity 鈥� they鈥檙e protected for landscape. But if we were adding even more 鈥� all those little sites; these rewilding areas, nature improvement areas and strategic habitat schemes 鈥� well, they鈥檙e all going to add up and maybe we can actually turn the tide on biodiversity extinction,鈥� she says.
It might seem that there鈥檚 little that contractors could do, beyond simply toeing the line, to actively get involved with improving biodiversity and delivering the 10% net gain on their projects. But Wray says that she is in regular contact with a 鈥渇air number鈥� of contractors who are taking a proactive stance.
鈥淚鈥檇 say the major contractors are quite switched on. Balfour Beatty is very strong on biodiversity and they鈥檝e been quite involved in the development of the biodiversity net gain and environmental net gain metrics,鈥� she says. 鈥淪o, yes, it is catching on and people are aware of it throughout the industry.鈥�
For smaller contractors and developers that lack the resources of our biggest contractor, the whole business is likely to be more daunting. Wray suggests that small house-builders seek advice from an ecologist before they option a piece of land for development. 鈥淕o and talk to an ecological consultant or perhaps the county ecologist at the local planning office, if they鈥檙e lucky enough to have one. If you鈥檙e a small house-builder putting six units in place and discover that you have significant biodiversity issues on that site, that could make the site uneconomic,鈥� she says.
But even if you discover your site is home to a protected species 鈥� the much-feared great crested newt is the archetypal culprit 鈥� all is not necessarily lost, says Wray. 鈥淎 lot of local authorities now have what鈥檚 called district licensing schemes. For example, if you鈥檝e got a regular site with six newts in a puddle, the law exists in a lot of authorities now where you can just pay into a scheme that does the offsetting for you 鈥� building ponds and moving newts into them 鈥� so you can get on and build houses, which is what you鈥檙e good at.鈥�
So the increasing need for biodiversity doesn鈥檛 have to become a problem for the construction sector. 鈥淚 think, once we get used to it and contractors are familiar with it, they鈥檙e going to get the idea of how to get the most biodiversity bang for their buck,鈥� says Wray.
鈥⑻�The full interview with Stephanie Wray can be heard on the 30th听September 2020 edition of Re:Construction, 海角社区app podcast. 听www.theconstructionindex.co.uk/podcast听
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