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Raising the roof

Updated Thursday, 16th September 2010

Horticultural consultant for greenroof Alex Mortleman shows his passion for encouraging biodiversity and takes the OU's Joe Smith on a tour through sustainable roof design This interview was recorded at the ecobuild 2010 event in London, UK

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Alex:  And my name’s Alex and I work for a company called Blackdown Horticultural Consultants, based in Somerset, otherwise known as green roof.  We basically design, supply and maintain green roofs.  We grow all our own plant material and we do ecological consultancy; basically the whole process from start to the end as a cohesive product to reduce contractual fragmentation.

Interviewer:  Yeah.  What’s your involvement in it?

Alex:  Basically, I do quite a few roles.  I’m a horticultural consultant, but I also do the research and development side of the company, trialling out new plants and new systems, designing new systems and working out how they’re going to work and say even like writing a good impression for the website and various bits and bobs like that.  Plant procurement, also trying to ascertain, you know, the right plants for the right situation, trying to grow the plants also and, yeah.  So a very varied role, which can go from the office to installing roofs, to out in the fields taking photos of my trials, measuring them up, helping out, you know, cultivate mat and nursery quotes.

Interviewer:  Can you show us a bit of something that amounts to the sort of the bread and butter work for the business?

Alex:  Yes.

Interviewer:  And then maybe show us something you’re playing with at the moment that might become important

Alex:  Okay.  And this is our core product, it’s called Nature Mat® and it’s, so basically mixed season matting with roughly about six to eight species in.  In the summer, it’s like a flower carpet.  Then it reddens off a little bit after flowering, and then it goes green.  And we put it on 70 mils of substrate and various drainage layers as you can see there.

Interviewer:  Can we just have a look at this? Yeah.

Alex:  Yes, I mean.

Interviewer:  So when you say substrate.

Alex:  Yeah, well basically you start off with your waterproofing.  We do everything above the waterproofing.  Although we’re associated with companies like Sarnafil and Calzit who do that, and then above that we have a drainage layer.  This one’s made from recycled materials, like car seats and old flip-flops and stuff.  Then we have a water retention fleece, which also protects the drainage from the substrate actually getting into it and retains water so the seam remains greener.  Then we have 70 mils of substrate, which is the amount that we recommend to allow healthy plant growth.

If you think about it, basically the plants need like room for their roots to go and that is the key to long term success.  There are a lot of systems on the market with very low substrates and, yeah, very low substrates and even systems where you have just like a water fleece with irrigation and little or no substrate with your mount on top.  And the thing about them is that they’ll look nice for a bit, then they’ll go red, stay red and won’t flower – I mean we offer that as well but we recommend that you would use 70 mils of substrate.  

Interviewer:  So this is the bread and butter stuff.

Alex:  This is the bread and butter, yeah.

Interviewer:  What are you working on at the moment that feels like a bit of an experiment?

Alex:  Right, this is the stuff I’ve been playing around with recently.  

Interviewer:  What’s this?

Alex:  It’s basically trying to tune plant species, mate plant species and various other probation perennials and wild flowers and bulbs to basically a) attract bees, hover flies, butterflies and day flying moths, and that’s in well basically what’s termed the nectar stream system, aiming to provide a good resource for nectar from March until October/November.  Then we have the lepidopteron system.

Interviewer:  So when you say nectar stream.

Alex:  Yes.

Interviewer:  That means you’re offering.

Alex:  A flow of nectar.

Interviewer:  Yeah, yeah.

Alex:  Yeah.

Interviewer:  It’s a menu across the seasons.

Alex:  Yeah, for all the little calf invertebrates.  Then we have the lepidopteron system.  Lepidopteron means butterflies and moths, and it’s more of a meadow-based system, including food plants for local biodiversity action plan, or national biodiversity plan species, like butterfly, moth species.

Interviewer:  And this is still a roofing system.

Alex:  Oh yes, yes.  This is the extensive system as well, so it’s a reasonably low substrate one.  You’re looking from 70 to 140 millimetres.  The complexity of the plant increases the more substrate you put on it.  Then other than green roofs you get things called brown roofs or biodiverse roofs, and they were originally constructed to recreate brown field site conditions.  So when you build a building on a brown field site, what you’re trying to do is to recreate what was on the ground back on the roof.  Now the one thing about brown roofs, which were initially designed to support ground nesting birds, they serve a biodiversity function very well, but they don’t necessarily look very good, and in Britain people like their roofs to, you know, have a nice ornament aspect and still help retain the biodiversity benefit.

So basically what I’ve done, I’ve taken the ornamental extensive systems and a brown roof system and I’ve come up with something called the camouflage roof, which basically combines native habitat creation, things like dry grass lands and rocky outcrops, with the benefits of a brown roof.  So you’d have your wildlife areas with your specific food plants, bits of rubble and shellstone for invertebrates to get under and shelter.  Different substrate types and depths, you know, to create different like moisture retention pockets.  So say if you’re a spider and you want like a drink, you know, a bit of the earth, like he can burrow down and get a bit of a drink, you know.  But obviously I mean you have like your nectar plants to support the hover flies, butterflies, bees and day flying moths.  Then I’ve got, I mean what you can also do is add a tailor-made ornamental effect to it.

So you’ve got all this benefit, and then you can say you have like patterns or stripes for certain species.  That way you’re ticking all the boxes in terms of biodiversity benefit, water retention and so you can add basically just water retention properties and ornamental elements.  Also, this is tied into something called BREEAM.  BREEAM assessment, which is, it’s conduct for sustainable homes.  And if you’re building a building sometimes you need to get like reassessed and you need to tick boxes.  So what this does, it fulfils a lot of the criteria in the land use and ecology sections.  You have eight points, two which are only achieved by, well, or depending on site placement.  The other six points we help fulfil with this system.

So you’re enhancing site ecology, you know, replacing what’s been lost through the construction process, looking at habitat management, and with this system, if you’re attempting to get BREEAM points, you would also have an ecological survey which we have an associate ecologist who does that for us.  Because a lot of problems we get with the green roof specification is ecologists who will specify certain plants to go on a roof but they won’t know necessarily what will work.  So contractually we’re obliged to supply plants that might not necessarily work, you know, which.  So now we have our own ecologist who goes out and does that, and he works with us and he knows what plants you can use, and then we can supply a system to be proud of and that’s going to work the best way possible to give green roofs a good name.

Interviewer:  So, Alex, you’re clearly completely passionate about what you do.  Obviously there’s a strong environmental dimension to what you’re doing.  Is that motivating you, is that just an incidental?

Alex:  Yeah.  Yeah, no I mean if it fulfils my creative potential as well as it’s nice to feel that you’re doing good for, well something good.  I mean the thing about green roofing is that a lot of focus is put on water retention because that’s the economic benefit that can be valued.  Now biodiversity benefit isn’t valued in the same way because it’s very hard to put like an economic value on it.  So it’s very, so I mean that’s my thing really to try and help get the biodiversity thing out there and push that as much as possible because if you want to create like wildfire corridors and stuff like that you can basically reduce fragmentation of like natural environments.  Which I mean if you think about the amount of building that we have today, it’s not going to get any better either, we need to really carve, try and put as many wild flowers where we can as enough plant material.

Interviewer:  Do you know what motivates you to want to do that?  Where did it come from?

Alex:  I don’t know really.  I just like nature.  I like plants, I like insects, and I like birds, bats, butterflies, you know.  I think it might be really like from my upbringing; I was brought up in Sussex in a very wooded place.  It’s very nice and I always went abroad across France and the Mediterranean on my holidays and there’s something about that arid environment that really struck me and obviously produce like very directives from plants with green roofs satisfies that xerophytic urge to landscape and, you know, creating something beautiful.

Interviewer:  Yeah and if you’re looking one year, five years and ten years out at the work you’re doing, either the business or your own work, can you see where you’re going to be?

Alex:  That’s very hard one actually.  I mean I quite like the ecological survey side of things.  I studied ecology in my degree as well.  So I’ve got a good understanding of that.  Apart from that I mean it’s either, it’s just trying to get green roofs to develop to the best possible point really, and when that point will be I’m not sure.  It’s trying to, as I say with the camouflage roof it’s trying to get the ornamental, the biodiversity, the water retention, you know, every benefit there.  I mean probably, I’ll probably concentrate on semi-intensive roofs next which are a bit deeper.  I mean we have systems in place for them now but it’d be really nice to take that to its optimum point, and then after that intensive roofs with trees and that kind of thing.  I’d say there’s a lot of work and research that needs to be done in green roofing, and it’s an extensive growing trade and subject, you know, and it’s going to take time, but it’s going to happen eventually, and it’s just nice to be involved in that.

I also would quite like to write a book maybe one day, which I’ve already named, which would be Flora Tecticularis.  Tecticularis born from the Latin word tectum which means roof.  So like Flora Tecticularis.  So you would term invertebrates that live on roofs tecticularus invertebrates if you see my point.  

Interviewer:  Have you got someone to publish it?

Alex:  Yeah, no that’s a bit down the line.  I’m starting to write it now but it’s going to take a bit of time.  

Interviewer:  Great.  Well you’re now committed to doing it because you’ve told millions of people across the world that you’re starting it and they know.

Alex:  Yeah, oh god yes.  Yeah I suppose.  I mean also another to go into is like a tropical environments like really arid, like desertscape environments and do green roofs there.  I mean we do some tropical consultancy I think in Hong Kong, Singapore and places like that, India.  So it’d be nice to concentrate on that afterwards, and it’s moving from country to country looking at the native plants and seeing what you can use them and the way to use them then go to another place and do the same.  So hopefully it’d be nice to travel around.  I’ve got a burning passion to go to Chile one day because that’s another area like I’ve specialist knowledge, of the Chilean temperate rainforest, Mount Pleasant rainforests and, you know, beautiful carved like shrubberies and things like that.  If you think it’s hot, well it’s another side of the Amazon.  It’s almost as diverse as the Amazon but it’s temperate.  So it’s a nice climate, nobody knows about it, you get lots of small mammals and stuff, it could be very interesting that.  One day, one day.

Interviewer:  So my last question is about whether if you’re given a sliding scale between optimist and pessimist, looking to 2020 and looking at the global scale.

Alex:  Yeah.

Interviewer:  Where do you sit on that in terms of whether we’re all going to take environment sustainability seriously enough?

Alex:  Well if humans haven’t perished due to rapid climate change by then I would imagine that everything will move on slowly.  I mean really what you need with things like green roofs and a lot of other things like solar power and stuff like that is more government intervention in, you know, incentive to actually apply these technologies that could be so beneficial.  I mean I think I read a fact, if you cover all of Texas in solar panels there’d be enough power for the whole world.  So I mean, so like green roofs there’s a lot of places you can put solar panels that ascertain energy, and you can implement sometimes with green roofs as well.

So I mean it’s a win-win situation as long as the governments actually act to try and promote these things properly and don’t just do things slowly like they always do.  Yeah, so I think by 2020 we’ll have better regulations about green roofs in England and Britain and I mean Europe’s, I mean Europe have quite good regulations already.  There’ll be a certain standard for plant choice and design, also on roofs that are, you know, like are quite visible.  Yeah, and I think that’s probably going to have, that’ll be how it is.  Whether things remain more expensive or come cheap, I don’t know.  I suppose economies of scale come into it.

Interviewer:  Well I’m never going to look at a green roof in the same way again.

Alex:  Ah thank you very much.

Interviewer:  It’s really wonderful work.

Alex:  That’s very interesting.





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