Speaking on 'This Morning', he said: "It's amazing it's a wonderful hobby, 23 years I was building the layout, it's massive, and every detail - some of the sky scrapers are 6ft high.
"A lot of it was made on the road, I take big flight cases and the hotels would give me a special room and special fans to get rid of the paint smells and the glues, I'd be in there working and they'd be like 'Showtime in two hours'.
"It's wonderful - well, it was, it's finished now."
The 'Maggie May' hitmaker feels lucky now he's able to fit his work round his young sons because he couldn't do the same when his older children were growing up.
He admitted: "I was hugely in debt to the IRS so I had to go out and work, the two eldest ones, Kimberly and Sean, did complain about it but I said I wasn't having a party, I had to go out and work, pay the IRS off, but now I see the kids calendars and work around it because I can afford to do it."