The interior brings to mind the Guggenheim Museum

Designed by Lord Foster, the architect behind London's Millennium Bridge and the Reichstag in Berlin, the �43m City Hall will accommodate 440 staff and members. At its heart is a showpiece debating chamber, above which rises a spiral staircase.

Those keen to view government in action - or simply soak up the city skyline - will be welcome. As well as 250-seat viewing gallery in the chamber, the top floor of the 45m-high building is an open public space.

City Hall uses a quarter of the energy of a conventional office building, yet some of its high-tech touches have suffered teething troubles.

Much of the building will be open to the public

Glitches that have had to be remedied include roof vents controlled by weather sensors that stayed open during a storm; glare inside the offices; and high humidity in summer and sudden chills in winter.

Its fans say that City Hall is one of the most inspired buildings in Europe in years, and a bold statement on transparent government.

Its detractors say that the building has cramped offices, is prone to leaks and is "disappointingly dumpy". Judge for yourself.

Spectacular views are to be had from the tenth floor

Your comments so far:

Having moved into my office on the 6th floor, the telephones do not work, neither do the computers and staff wait up to 10 minutes for the lift. My office has no natural light. Frankly it's a triumph of style over substance.
Brian Coleman, GLA, UK

I've lived and worked in "futuristic" buildings before and they are splendid, eye-catching places... until the heating packs up, the windows refuse to close and the roof springs a leak. Will we still love this "crystal maze" in 30 years time, or be desperate to have it pulled down before it gets listed?
Bob

Norman Foster does it again. An excellent example of light and space which will assist the city's modern look, while not drawing too much attention away from the old classical pieces. Look forward to seeing a session in his similar design for the German Bundestag.
Adam, UK

I am looking forward to my next trip to London to see this new City Hall. The silhouette against the skyline is imaginative yet does not detract from nearby historical areas.
Martha, US

I love it, but you can't help thinking something has to go wrong somewhere. Did they make sure they built an athletics track somewhere in there?
Max Eddy, England

It looks a bit like someone has sat on the Post Office Tower. I've always thought Norman Foster's buildings get far too good a press: the Sackler galleries were sweltering this weekend in the sun, and I remember the Sainsbury Centre before they reclad it when all the panels were corroding away.
Gordon, UK

It's a bit rubbish actually. Looks like a car headlight, or a normal building that has slumped somewhat. And I suspect it will look chronically dated in a very short period of time. A missed opportunity.
Gaz, UK

This building is an exquisite gem, a masterpiece of architectural engineering, that is a herald of our times and technologies. Lord Foster has simply outdone himself with this marvellous, yet cost-effective design.
Rev, Austria

I see this building from my train every day. From some angles it looks like a Dalek wearing a flat cap. I can't believe planning permission was given to put this building so close to two of the capital's major tourist attractions. Yuk!
Lems, UK

Q: how do they clean the windows?
Matt, London

It looks stupid and a complete waste of money. Why not just build a normal building that won't look totally out of date in five years like the silly buildings they where building years ago, any one remember concrete?
Karl, England