Her honesty is disarming. "This area's not the nicest. There's no natural light here and that's so beneficial for children and their families."

I have just arrived in the lift lobby, on level four of the John Radcliffe Hospital and Lynn Kawik, head nurse for children's surgery, has already started pointing out faults.

She is showing me round the paediatric department so I can relay to Oxford Mail readers how the wards compare with the new £20m children's hospital, which is slowly rising from the ground outside.

The lift lobby is the first place children see when they arrive in the paediatric department. It's bright enough, with colourful pictures to welcome young patients, but Mrs Kawik is still not impressed.

She said: "The children's hospital entrance will have an atrium with a lot of light and air, which will make it very child friendly. Just the entrance can make a huge difference."

Mrs Kawik is all smiles, full of energy, and knows the name of all the children she sees, greeting them with as much love and care as a mother.

All the nurses, play specialists, physiotherapists and teachers who work here are the same.

But while the treatment is second to none, the wards they work in were not designed with children in mind - and now they are old and too small.

Walking through surgical ward 4C, you can see space is at a premium, as pushchairs, toys, equipment - and beds - compete for room.

Mrs Kawik said: "The main problem is our lack of space - we're desperately short of it. The beds are so close together, there's no space for parents to sleep next to their children and that's really important.

"The bays are very open and there's very little privacy - they're almost in the corridor. The new hospital has more space, meaning more privacy which is again very important. It's particularly important for toddlers who like their mums there all the time rather than in a room far away.

"In the new hospital, there'll be a special place for pushchairs behind a lovely screen, but here storage is very poor."

Similar problems can be found on every children's ward at the JR, including the Doris Field Day Unit, where it is humbling to meet the children.

Many are regular visitors and the tiny ward is their second home, where they undergo treatment like blood transfusions to keep them alive. The new hospital will increase the day unit from five to 16 beds.

The space issue is not just a problem on the "shop-floor", Mrs Kawik explains.

"We have no space for clinical supplies like intravenous fluids, but in the new hospital this has all been planned into the building. It will not only have more storage space, but safer storage space.

"At present, there's stuff here, stuff there, and we have to run between two areas.

"Also, it's almost impossible to talk confidentially. If doctors have to give sensitive information to parents they need to go to a quieter area, but at the moment tearful parents have to go to the sister's office, and that's not comfortable for them.

"Soon we'll have an interview room and seminar rooms."

Mrs Kawik has just as much concern for parents as for her young charges. She knows the children benefit if their mums and dads are cared for, kept comfortable and stress-free.

But on level four, that's difficult.

She said: "There's no coffee shop and I think that kind of facility makes all the difference to parents. It helps them relax straight away and makes it more homely for them.

"At the moment they have to leave their children and go to a different floor for a break.

"We don't have many facilities for parents and we don't allow hot drinks on the ward. As a result, parents don't want to leave their children and don't eat and sleep as much as they should do.

"The new hospital will have beverage bays, so parents can have a few moments away while still being able to see their children.

"Also, our parents' accommodation is not the quality we'd like to provide. The new accommodation, I have to say, is fantastic."

We walk into the parents' quarters, which is as homely as possible, with pictures on the walls.

But the two bunk-bedded bedrooms are for men and women respectively, and the thought of sharing with strangers at one of the most anxious times of your life is not appealing.

Boasting about the new facilities, Mrs Kawik said: "There'll be a huge family room, so families can eat together. It's much better. It will be on the top level, so they can have a break, which is important for them. Some parents really need to be encouraged to take a break from their children because of their stress levels. If they have a nice area to relax, it makes a huge difference to them."

Mrs Kawik is so enthusiastic about the children's hospital that she rushes after me as I prepared to leave.

She added: "It's really important our patients come to an area that's child friendly and that they can relate to, because some are here all the time."