Article taken from Wharf. To view the article, click here. Taking shape on the Olympic site next to the main stadium are two buildings. They are of similar size and appearance.
But to the man charged with monitoring sustainability for the Games there's a huge difference.
This is because the Aquatic Centre has a 3,000-tonne roof, while that of the Velodrome only weighs 500 tonnes, resulting in a vastly disproportionate carbon footprint.
For Shaun McCarthy, the chairman of the Commission For A Sustainable London 2012, which was launched at the start of 2007 as a result of the Olympic bid team's promise to monitor the sustainable legacy of the London Games, this provides "a lesson" in building design.
He said: "It's a perfect example of two buildings of similar size but one that uses a small amount of material and one that uses a lot.
"The Aquatic Centre has got a wonderful sweeping design that was the brief.
"It was an iconic part of the bid, but it's a bete noire of mine.
"It will look fantastic but the Velodrome will also look fantastic and was sustainable to build. The Aquatic Centre will be energy efficient in the end but in the build stage it's not."
In defence of the Olympic Delivery Authority, which is building the venues, Mr McCarthy said the problem was due to the optimistic imagination of the bid team which wanted the Aquatic Centre to look iconic and it was this ambition which ultimately won over the judges.
That disparity is one of the lessons he wants developers to learn in future years.
As chairman of the commission, Mr McCarthy reports to the Olympic Board, which includes the Mayor of London and the Secretary of State for the Olympics, as well as Locog chairman Lord Coe and the British Olympic Association's Lord Moynihan.
The commission looks at how the delivery teams are meeting sustainability pledges.
Last week it released an annual report stating it was a "critical" year for the project.
Mr McCarthy leads a team of 14 experts in scrutinising the work being undertaken by the Olympic delivery bodies, such as the ODA.
He said: "The ODA has done fantastic job of sustainable construction. It set big targets and made it happen. I've also been impressed with its flexibility."
It has not always been plain sailing and the commission once had to call on political weight to secure one key target - that of making the Olympic site free of HFC refrigerants - a chemical composite frowned upon by environmentalists.
After early reticence from the ODA with regard to the commission's concerns, Tessa Jowell, who was Olympic minister at the time, leant her weight and backed the supervising group against the stadium constructor.
As well as monitoring the bodies, the commission also has the role of making sure the Games' message of sustainability is not lost.
It is responsible for ensuring that message goes on to inspire similar good practice for future projects throughout the capital.
Mr McCarthy said: "We need people to be taking on these new standards. We want the ODA to be the norm for building and what Locog does during the Games to be the norm for how events are staged.
"The amount of waste in the event management industry desperately needs to be cut - so it can learn from this.
"The private sector and the Government need to raise their game in procurement as a result of the work already being done here."
The commission next sets its sights on the Olympic Park Legacy Company, which is responsible for the aftermath of the Games site.
The OPLC is tasked with making a new, detailed plan by autumn and Mr McCarthy's team is meeting with the group later this month to discuss progress so far.
He is hoping for real detail - pinning down the practical meaning of well-rehearsed phrases such as "sustainable housing".
He said: "We need to know what that means. Specifically what it will mean for developers. It's not clear and we, and the developers, need some definition."
Overall, the commission is pleased with the development's management to date.
Mr McCarthy said the fact the commission is an independent body is useful for the public looking for a barometer on sustainability of the London Olympics.
He said: "From what I have seen so far I believe London will be better than Vancouver and Sydney - another two good sustainable Games - and I hope we will do as well as Barcelona."
Mr McCarthy was full of praise for the Spanish operation.
He said: "It got a run-down closed off district and opened it up to the sea areas to create a legacy.
"It has also made good use of the Olympic Stadium with football matches and concerts. It's very impressive. Athens is at the opposite end with stadiums unused. It's Barcelona we have to aim for."