The building steadily emerging as a multi-million pound state-of-the-art gallery is still very much a construction site but it has an air of something other than concrete, builders and vast open rooms about it.

Excitability in the voices of the two people showing me around might be partly responsible: marketing manager Natalie Creary and assistant site manager John Pickering are oozing enthusiasm.

This is billed as a major new contemporary art centre for the South East, leading the way in developing Eastbourne's Cultural Quarter in situ on the side of the Congress Theatre.

And it has reached a tangible state, with floors going down, windows about to go in and the roof nearly ready to go on.

I stepped into the downstairs conference space, busy with some of the 40+ workers on site, wearing a hard hat and heavy boots.

But in the spring the first visitors will be walking into an exhibition area lit by a 'shaft of light' through the front glazing, hitting the feature staircase which will look like it is 'hanging in the air'.

John Pickering is excited that the hydraulics for the lift have arrived – as we step over them, I get the point. It's a massive lift shaft.

The lift will be big enough to carry a class of schoolchildren (and with a safe working load of ten tonnes), and glazed from top to bottom, it gives views over the Downs.

For now we have to take the stairs up the scaffolding to the second floor. Here, space and views and the 'urban' feel of downstairs make way for a heavyweight community and education aspect.

The specification of the first floor rooms is immense. The protective environment of the collection room and the collection store mean the Towner collection will get the utmost care.

Lighting and air controls are particularly important and set the building far ahead of the facilities the collection is soon to leave behind, at the Towner Art Gallery in Old Town.

The art research room is an extension of this – the atmosphere can be controlled to allow works to be removed from behind glass for closer inspection.

These are the rooms the public can book to use, with the collection store perusable via sliding storage.

The education room was designed with input from schoolchildren. They will have a view to the rear of the two-storey building and all features can be pushed aside for – the all important word in this gallery – space.

A final education area is tucked into a nook and makes a feature of the building's curves and lines.

On the top floor the serious ambition of the Cultural Centre is captured in one massive contemporary exhibition space.

A 5.5metre high gallery to rival the Tate Modern's turbine hall, with load bearing walls to take virtually any work: painting, sculpture or installation.

At each end of the room the ceiling has a glazed strip to allow natural light through the roof.

Taking up the most part of this floor, the cafe and office space take up the rest. For me, it's here the shape and position of the building are most striking.

The square front of the building works round into a curve that has earned the cafe part of the building the name 'the grand piano' from those working on it – a very human touch to what is expected become Eastbourne's new iconic building.

With the exterior giving away little, the new zinc panels in place at the front create the best impression yet of how it will be seen from 2008 onwards.

The render will be put on the outside of the walls in the next few weeks.

By Claire Watson