Green dream... Jubilee Wharf in Penryn, Cornwall. Photographs: Christine Sullivan  The old Cornish port of Penryn, straddling two creeks and lined with streets that rise and fall like breakers, was once at the heart of the local granite trade. Ships would set sail from here laden with stone for great building projects around the world, from Singapore to Buenos Aires and beyond.  Penryn never boasted architecture to match these far-flung, grandiose cities, although it has a vernacular charm and touches of Georgian virtuosity. Now, though, it could become a magnet for anyone and everyone - architects, builders, developers, politicians and perhaps the Duke of Cornwall himself - interested in genuine low-energy design. In fact, the brand new Jubilee Wharf, a creek-side development comprising flats for local people to rent, 12 craft workshops, a public hall, a nursery and shops, might well be the greenest British building to date. Its carbon emissions seem to be a happy zero. It has been built as far as possible from local materials, including red cedar and larch, using local labour. And it fits, in an appropriately ramshackle way, into the higgledy-piggledy fabric of Penryn.  From a strictly aesthetic point of view, this cluster of buildings seems curious and even questionable at first. Planners were originally unsure, but saw the light and wisely approved the design. It grew on me quickly, for two reasons. First, this is obviously a very thoughtful project, its look based, although not slavishly, on the happy mess of old nautical buildings beside it. There are boats moored alongside, a few of them gleaming, but mostly battered old sea creatures seemingly held together by thick layers of muddy paint; somehow, it all fits together.  Secondly, although new, it is already a welcoming place. The two blocks of the development - one four storeys high, comprising studio workshops with maisonettes above; the other over two storeys, housing a nursery, public hall and cafe - enclose a courtyard, protected from the occasionally fierce coastal wind.  People have already moved into the maisonettes, including Andrew Marston, whose development company Robotmother dreamed up Jubilee Wharf, and his wife Alice, who runs the cafe. Marston's master touch was to commission ZEDfactory (formerly Bill Dunster architects), established in 1998 with a mission to produce intelligent, low-energy buildings; ZED stands for zero energy development. Bill Dunster has long practiced what he preaches. His family home, Hope House in Surrey, is an experiment in green design, while the BedZED flats he designed for the Peabody Trust at Beddington, Surrey, are, despite teething troubles, an important step towards truly sustainable homes.  Dunster would like houses to be responsible for their own energy demands. At Jubilee Wharf, four 6kw wind turbines and one 75kw wood-pellet biomass boiler (burning cleanly and efficiently what is effectively compacted rubbish) provide pretty much all the power needed for the development. Solar cells will be added to provide essentially free electricity throughout Penryn's riviera-like summer, while all parts of the building are highly insulated. The turbines seem quiet when compared with those giants whining on fields and downs around the country, and complement the array of masts rising from boats along the Penryn wharves.  The maisonettes are a delight. Warm and cosy, each boasts what would once have been called a "sun lounge", an enclosed suntrap that retains whatever heat comes in through the living room windows looking out over the estuary. Wind cowls on the maisonette roofs provide ventilation when windows are shut, ushering in fresh air with the prevailing wind. Similar cowls on the roofs of flats at BedZED have seized up over time; the solution here has been wheel hub bearings from Ford Mondeos, designed to spin around for a quarter of a million miles or more.  The flats also face into the courtyard, already quietly bustling. A craft fair and a farmers' market are in the offing, while a bike shop has opened, and the cafe, with its warm recycled timber interior, is buzzing. The big public hall has a timber roof shaped like the upturned hull of a boat, and is clad in cheap, hard-wearing zinc. The curved roof is not just there for show; it's a means of sweeping, or deflecting, sea winds up and over both the courtyard and the block of studio workshops and maisonettes.  With so much experimental ingenuity at work, it might be assumed that the cost of Jubilee Wharf has been on the high side. Not so: Andrew Marston's development has cost £3.6m. Of this, £470,000 was raised by Carrick district council through Objective One, an EU fund aimed at developing areas where prosperity is 25% below the EU average. A further £350,000 was provided for the 30-place nursery by SureStart, the government childcare programme. And the cost would have been at least half a million pounds less if the ground beneath the derelict sheds that stood on the site hadn't been laced with forgotten sewers, and other pitfalls.  Jubilee Wharf should prove exceptionally cheap to run. More than this, Andrew Marston and Bill Dunster have shown an intelligent way for small towns to develop, economically and socially. Too many councils give in to the bullying demands of supermarket chains, as if these unsustainable land monsters were the only means of boosting employment and local income. How about a few, or more than a few, variations on the theme of Jubilee Wharf, reflecting the topography, style, local production, sentiments and ambitions of people in different parts of the country? Let's hope for more developments with the intelligence - if not always the creekside look - of Jubilee Wharf.
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