Open-City, formerly Open House, events grow every year and are concerned with creating better places, better cities. I know them mostly for their work on Open House. This year I thought I’d check out their new event, Green Sky Thinking, a nearly week long programme highlighting new thoughts and solutions in incorporating sustainability in architecture. In addition to gaining access to buildings in the way Open House allows, the events also include talks by a number of architecture and design firms. I wanted to go to all of them! But unfortunately I could only narrow it down to one event as most of the sessions were during the working day.

The Angel Building, Islington, was completed in 2010 and cost £72 million to retrofit.

It used to be an ugly environmentally unfriendly 1980s commercial block that BT moved out of with 7 years left on the lease. After Derwent London were done with it 100,000 square feet had been added to the building (an increase of 73% net floor space) by building outward not upward, two roof top terraces, reduced energy consumption thanks to a number of innovative measure such as 6m glazed bays providing natural light, wrapping the existing concrete frame with a highly energy-efficient glazed skin (which also reduced the amount of demolition required), rainwater recovery (used to flush toilets saving 455,000 toilet flushes a year), installation of waterless urinals (saving 87,000 liters of water per year), and passenger lifts which recycle energy as they descend. Yes the lifts are a bit slow but they do use 50% less energy to power. Then there are all the technical things like biomass boilers etc. etc.

Add in some art. Add in communal meeting spaces, breakout areas, cafes and benches (so you can mingle with other tenants in the building rather than just being secluded to your own business.) Add in some trees. And you get quite a beautiful building inside and out that would just be a joy to come to work to.

Current tenants include Cancer Research UK (the first time they have all been in one building allowing them to save 20% on costs), Expedia and Sage.

The environmental/sustainability theme even trickled down to our afternoon tea which included muffins, carrot cake and “Green” tea (as in environment not just green tea …)

The architects were really inspirational. They really sounded like they were into the whole sustainability concept including having the belief that if they can’t walk to a site/building then they won’t buy it and they don’t consider themselves developers but refurbishers. The Angel Building was shortlisted for this year’s RIBA 2011 Stirling Prize. (Update: The prize this year was won by the Evelyn Grace Academy, London by Zaha Hadid Architects)