Last week, FD attended the topping out ceremony for KPMG's new 'environmental' offices at 15 Canada Square - its purpose-built London home that should be ready in the next couple of years - where I watched the final beam signed and hoisted to the top of the tower.

Riding the green bandwagon, KPMG's new green office is to target a 50% cut in carbon dioxide emissions and the firm has installed 'grey-water' systems for their toilets and hand-basins. Grey-water, you say? That's right - the brightest buttons at one of the Big Four will be showering or washing their hands and recycling the water to flush their toilets!

Other ideas KPMG's eco-warriors say they're working on include a grass roof that cools the building, and some other more conventional ways of saving cash and energy, like lighting controls in daylight hours- they're building a full-height atrium - and energy-efficient air cooling.

And they didn't stop there. The firm has pledged that 90% of the waste from constructing the green offices will avoid the local landfill sites and be recycled, after consulting with The Carbon Trust on a raft of ideas to drive being green. They hope that 4,000 of their people will be enjoying an environmentally friendly workspace by 2010, the year KPMG hopes to have consolidated many of its staff from other London offices into its Canary Wharf bolthole - saving a few quid on rent while reducing their pollutant output.

Rachael Singh, financial director