Forget the voting system, let's have a new seat of Parliament

If the Coalition were to commission the greenest government building in the world, it would inspire a new spirit of governance.

If the last election demonstrated anything, it was the suspicion and alienation felt by the British people towards their parliamentary representatives.

Now we are about to decide on which of two imperfect systems we should adopt for the next election, and polls demonstrate ambivalence and confusion.

The Coalition government itself is a new experiment in British politics - an attempt to forge alliances where they have not previously existed.

Right from the start, it proclaimed that it would be "the greenest government ever", in an attempt to win back public trust and rebuild the battered economy.

There is one thing that it could do, right now, to tackle all of these problems at once - and that is to commission a new seat of Parliament, and perhaps even move in by the next election.

The new building would make a bold and courageous statement. It would be built to the highest standards of sustainability, demonstrating in practice what the government is preaching.

The standard could be Passivhaus or close. It could generate its own power and perhaps export the surplus. It would be constructed with a very low ecological footprint. Above all, it would be a democratic and accessible structure.

The building itself would inspire and be fit for the twenty-first century and beyond.

Like the Reichstag dome, designed for the German government by the British architectural practice of Norman Foster; the Welsh Assembly Government building by the British Richard Rogers; and the Scottish Parliament building at Holyrood by Enric Miralles, it would let the public see the activities of their representatives from above and in the round, and thereby engender the sense of a new kind of relationship.

The feeling you get when visiting these places to watch the practice of government is one of greater proximity and access - the politicians feel more approachable and accountable, the decision making process more transparent. Greater trust will result.

Moreover, the effect of architectural space on the psychology and behaviour of its inhabitants is profound.

The current Palace of Westminster was designed for a different age. Its maze of dark, narrow corridors and stairs, lobby rooms in the Perpendicular Gothic style, and the very antagonistic arrangement of the government and opposition benches in the main hall lend themselves to the creation of conflict, the gathering of cabals in dark corners, and whispering campaigns, where whips can lie in wait for unsuspecting MPs to ambush and drag them into whatever conspiracy they have in mind.

By contrast, the light, circular and open styles, and the human scale of the above three buildings, are much more likely to encourage cooperation and partnership - the very requirements for a coalition. The propensity for animosity and retrenchment is reduced. Just ask anyone who works in the Welsh or Scottish national seats.

Moreover, Westminster Palace is impossible to make energy efficient. It is draughty and dark - and of course a listed building. To replace the windows with energy efficient ones is impossible!

Miralles' plans for Holyrood made sustainability a central element of the design. An independent environmental audit of the entire building was conducted by the Building Research Establishment. It was rated as "Excellent" for environmental performance in the areas of health & well being, energy, transport, material selection and water usage.

The National Assembly for Wales' oversailing timber-clad roof is beautifully striated with wood boarding. It swells into steep forms which allow the spaces below to be viewed and provide welcoming drama. At the corners of the cantilevered roof the canopy flips up at the corners in a delicate and sensual way.

These and the Reichstag Dome attract thousands of visitors a year and are popular icons.

The idea of a new, inspirational Parliament building has been mooted several times. Richard Rogers and Norman Foster have both tendered designs.

In 2009 the Royal Institute of British Architects(RIBA) invited 175 schools to design a 'Parliament for the future'. The winning design, by Eastbourne College, was commended for its consideration of sustainability issues, including the use of local building materials, energy efficiency (through techniques such as the use of natural light and water collection, ease of access and for its potential to regenerate and bring new potential to a previously abandoned area.)

If David Cameron and Nick Clegg are truly serious about their green credentials, about encouraging MPs of different ideologies to cooperate, and about recreating a bond of trust between the public and Parliament, what better symbolic and practical legacy could they give to the future than a new Parliament House that is truly sustainable, democratic and inspiring?

Britain has some of the best architects in the world - several practices are, for example, even now helping China construct sustainable, awe-inspiring cities. There is no shortage of skills, experience and imagination raring to go. We are good at large projects, like the Olympic village, Crossrail or the London Array.

Innovation happens in a recession, not a time of plenty when business rests on its laurels. This project would stimulate the most cost-effective inventiveness, the best of British design - and the economy.

Let the Coalition begin now by announcing a competition, open to everyone, for both the most appropriate site and the best design, and create the greenest government building in the world.