The other day I was alerted to a great project in Baltimore, MD, USA. This project aims to install the first green roof specifically designed for honeybees. One of the people behind the project is Jorg Breunig. He has promised me an article on the project and also a review of the early studies on green roofs and bees by Dr. Gunther Mann in Germany. Joerg used to work with Dr. Mann for Optigreen [UK partner Flag] in Germany and now fronts up Green Roof Service LLC in the US.

I have never met Joerg,  but have been communicating with him now for a number of years. He had some great comments to a recent blog I did on my personal website. However lets get back to point here. I like this project and it addresses an issue I think is really important in London. Hives and habitat on roofs not just hives.

The honeybee features in all my seminars and talks. It's plight is of grave concern, but also the honeybee has a resonance - connecting people with habitat -economics with biodiversity. It  also highlights the industrial, product approach to pollination, which in my experience is similar to the approach of building professionals to designing our cities.

Over the last two years there has been a real increase in people promoting hives on roofs. Don't get me wrong I think this is a great idea. However there has been little coming out of the various bodies promoting this about actually creating habitat for bees as well as homes for hives at roof level.  What the 'foodies' often miss is that the honeybee is also a 'flagship' species for all of our bees, whether they be bumblebees,  sand bees, solitary wasps and also other rare invertebrates so often forgotten about.. It was only a month ago that  the first observations of a rare bumblebee on a green roof in London was announced. So hives and habitats will not just benefit us and our appetite for honey.

I think there is another point here. There is a minor fixation with objects/things. It is the sort of IKEA approach to solving problems. I have put up a bird box - problem solved. I have put up a hive problem solved. When I was first involved in black redstart nature conservation architects and ecologists went 'we will put up 50 bird boxes for them'!!!!! ' 'Job done' The fact that black redstarts don't need nest boxes -there are more than enough places for them to nest on a building without our help, was neither here nor there. They had donee something. But the point was what they needed was/is habitat replacement for that taken by the building footprint.

Of all of the hives that have been put in London I know of only 4 roofs that actually have both hives and green roofs and another where a green roof was installed to help the hive at ground level. One is in Hackney,  installed on an extension 4 years ago by a guy who keeps bees, another is on the architect practice, Bere Associates office, a green roof I helped design. The third is on Eversheds Ltd, a green roof that I was also involved in (there are 3 hives on this roof) and on a school in Golders Green. There is also a hive at the Museum of London on a semi-intensive green roof.

When I was on the London Food Board a year ago, there was a lot of talk about London becoming sustainable in honey production. Again it was all about hives and not about habitat. When I asked about how much honey was actually produced in London per hectare - I was met with a wall of silence. It was if there would need to a  be serious research project to find out!!!

So I did a little research myself. A bit like the research I did 10 years ago on biodiversity and green roofs (I track down someone in the know - got on a plane to Basel, CH and…). In this case I spoke to Justin Bere of Bere Associates,  who has a hive on his roof. He put me in touch with a beekeeper in Sussex  I asked the apparent $million - 'how much honey is produced in a city like London compared to the Sussex countryside.'   Some figures were given to me and, to the surprise of a number of people, I came up with some interesting figures. What was also interesting was that when the beekeeper in question saw some pictures of roofs that I had designed they were really excited.

The Figures for Potential Honey Production in London

According to the report I wrote for London 32% of the land area of central London could be converted to green roofs.  Therefore taking 6km circle with its centre at Nelson's Column, Trafalgar Square = 716.6 acres (290 Hectares) of which 228.5  acres (92.5 Hectares)  is grey roofs that could be green.

Now according to the beekeeper 30 - 50 lbw can be produced in rural areas per acre [lets call it  40 lbs]  compared to approximately 100 lbs in London per acre.

So the current  6km circle can potentially produce 71,660 lbs of honey.

Now if the roofs could be greened up in the area we will get an additional 22,850 lbw [personally I think it would be more as the roofs would be really flower rich if I have my way) meaning that Central London could produce potentially a grand total of just under 95,000 lbs (19200 kg)  of honey. Now that sounds like a lot of honey to me and a lot of habitat!!! And we would need a lot of hives. I feel a real burgeoning cottage industry happening above the West End and the City!

By all means put hives up but please please can we put habitat up as well. And in doing so we might create a burgeoning cottage industry high above the West End and the City.

Finally I want to wish Joerg Breuning and his team the best of luck at the Ice Storage House in Baltimore. I look forward to hearing about it

Bring on the bees!

Please note I failed my maths exams so the calculations are as good as my calculator. Also for US readers I have used UK lbs not US lbs.

Next column will be on the issue of substrates and brown roofs - refining the issue.