Tell me about being longlisted for the Ashden Awards.

AW: It’s nice to be recognised, and we were pleased that it’s an indication of how, within the city council portfolio, we’re recognised as one of the buildings that’s ahead of the curve. Catriona is responsible for visitor services, while I’m responsible for aspects of collection care and management, so one of the reasons our greening strategy has been so successful is because we’ve worked together.

What is the biggest sustainability challenge for an organisation such as this?

AW: This is an enormous complicated building. In 2002 we came out of a £35m investment with a building with full air-conditioning, and incredibly complicated systems that were reliant on external consultants to be able to manage.

CM: There was just an acceptance about what was needed to run the building, and saying our energy bills will be half a million pounds a year and there’s nothing we can do about it – rather than going back to basics and seeing what we could get away with.

AW: [The investment came] just before that big move towards environmental sustainability, so it was taken as a given from the outset that there would be museum standards, ie 55 degrees, plus or minus 5%, relative humidity. We needed our plant to be able to deliver that.
They massively underestimated it and didn’t take into account that the costs of gas and electricity would go up. It was idealistic projection. We had complex building, and we were conscious that things were starting to fail.

So in 2009 we began our sustainability drive. At that point we had just received a G rating on our Display Energy Certificate – that’s the same as the Tate and other large galleries. Since then, we’ve achieved a 37% reduction in energy consumption. In real terms it’s actually 43% because over that period of time we’ve increased our opening hours.

How did you achieve that?

AW: The starting point was looking at lighting. As well as direct energy consumption, it also had an impact on the plant; the major thing in reducing running costs of the plant was the heat load from the old lighting. We had council funding to replace all the lighting with gallery-specific LED lighting. How the light looks and how it makes things look is very important. Then we looked at changes to the way the plant operated. We started turning the air-conditioning off overnight, which is a complete no-no for galleries!

How did it go?

CM: We did a week’s trial run. Everything deteriorated overnight but then came back on. The following week we left the plant on, and compared consumption. Then we decided to switch it off from then on – and that was it, we’ve never looked back.

AW: Everything we do is about stability. So we implemented a much wider set of controls so there wasn’t a big spike in humidity when the plant came back on in the morning. Everything became more gradual and that stabilised gallery conditions. The theory is that most artworks are perfectly happy in 30 to 70% relative humidity, it’s the stability that’s important.

We had to be quite confident that there wasn’t going to be an impact on the collection, but almost all of our paintings are glazed and back-boarded, so it’s like a little micro-climate for the painting. This means that if we do have changes in gallery conditions, the paintings are buffered and protected.

Inevitably there can be a problem with other people’s materials, so negotiations with lenders to our exhibitions can be quite difficult because a lot of people will still stick to 55 degrees relative humidity. But we are able to show them the [safe] conditions that their artwork is exposed to. We also have had a very clear steer from Maria [Balshaw, gallery director], who from the outset said that the bottom line is we won’t borrow from people who insist on narrow environmental parameters, because we don’t believe they’re necessary in most cases.

It’s not that we’re being relaxed and we don’t care, it’s that we’ve decided – and we have the evidence to demonstrate – that actually it’s not that important. Before that we were spending vast amounts of money on maintaining systems, to meet very narrow parameters and it wasn’t even as if the systems were achieving that. If anything, our conditions are more stable now than they were before. So those [strict] conditions are neither necessary nor achievable and yet consume massive amounts of resources.

Tell me about other aspects of greening the gallery.

AW: We were [initially] focussing on the plant and the building because that was one of the big areas of consumption. One of the problems at that point was it was quite difficult to engage staff with turning their lights or monitors off when the building was so obviously profligate in its consumption. We had to start with big changes, and staff engagement became part of that. Using smart meters for energy monitoring, we were able to show staff what their lift usage was consuming, for example.

Other initiatives include having Bromptons that staff can use instead of taxis. There are pockets of staff enthusiasm also surrounding biodiversity, so we have the bee hives on the roof. The honey is sold, so the money from the bees actually sustains them.

We’ve just entered a partnership with the National Trust’s gardener-in-residence; he’s going to develop the gardens around the outside of the building. It’s about reclaiming the small urban gardens across the city.

It’s quite a difficult building to make green; it doesn’t feel like a green building because it’s metal and glass and stone, it’s a bit of a blingy building. so we’ve always looked for opportunities to soften it and green it, but it was quite a challenge. It’ll be really exciting to see how it develops. We want this generally to be a proper garden.

Find out more about Manchester Art Gallery here.