Forward-thinking architects are coming around to the view that inner-city tower blocks and woodland can be combined and are incorporating both in their latest designs. Plans for "vertical forests" - 25-floor buildings, flecked with balconies full of bushes and small trees - are sprouting up in several European countries. Fittingly, Milan, the continent's design capital but also one of Western Europe's most polluted cities, is leading the way with the construction of two green towers. The Bosco Verticale (vertical wood) project, due to be completed in 2015, consists of two residential blocks, 110m and 76m in height, set in the Isola neighbourhood just north of the city centre. The towers will house 900 trees, ranging from 3m to 9m in height, plus thousands of shrubs and flowering plants. Stefano Boeri, the architect responsible for the design, says the buildings will together provide the city with the equivalent of a further 10,000sq m of
woodland. The layer of foliage around the apartments is supposed to produce humidity, absorb CO2 and dust particles, produce oxygen and shield the building from traffic noise. Energy recycling systems that generate power from sunlight and wind should produce dramatic energy savings. The designers say the plants provide shade in the summer and allow more light through during winter after they have shed their leaves. But all that environmental technology doesn't come cheap. Prices at the exclusive development will start at €750,000 ($1.3 million) for 100sq m, near the ground, rising to €1.2 million for flats with spectacular views. "The towers may well be beautiful, but they are not something everyone can afford," said Damiano di Simine, regional president of the environmental campaign group Legambiente. "The real answers to Milan's pollution problems lie with sorting out the traffic problems and improving public transport." And Milan's residents know that new ideas are needed: thick smog regularly envelops the city and its levels of toxic soot frequently breach EU safety levels. But the problem of how to keep the foliage looking good - and doing its job - has yet to be resolved. Brunello said plans for gardeners to descend, like window cleaners, on rigs outside the Bosco Verticale are being ditched in favour of "garden-freeclimbers" - think Spiderman armed with clippers and green-fly spray.