The sun peeked through the rain clouds yesterday for the topping-off ceremony at the John Radcliffe Hospital's new £105m west wing.

NHS managers and staff climbed to the roof of the 142-bed building for a ceremony marking the halfway stage of work on the development, which will house services transferred from the city's Radcliffe Infirmary.

The construction includes 2,250km of cabling, 100km of pipework and 45km of ducting.

Sir William Stubbs, chairman of the Oxford Radcliffe Hospitals NHS Trust, which oversees the site, said patients would be able to enjoy state-of-the-art facilities once the wing was opened.

He said: "It will provide the best standard of medical services to replace a much loved, but antiquated building, and it's of enormous importance. We're delighted to see it on target and next year the first patients will be treated here.

"The inside of the building has been influenced by our staff at the RI. The clinicians, including doctors and nurses, have all helped to shape it and, in doing so, they have helped enhance the quality of their work in the future."

Together with ORH chief executive Trevor Campbell Davis, Sir William laid the final concrete on the building's roof, before being presented with silver trowels by developer Carillion to mark the occasion. Work will now continue on the inside of the building, which is part of a £135m development which includes the neighbouring children's hospital. When it is finished, in December 2006, the west wing will house neurosciences, specialist surgery, critical care, a day surgery unit and Oxford University research.

Mr Campbell-Davis said: "At the moment, RI staff find it almost impossible to provide clinical services at their present site. Here we have a chance to change the facilities to not just the best in Britain, but I think, in the world."