Mr Thomson said the major aim of finding a permanent home was to provide public access to railway layouts so people could see what the club was all about.
"There's always plenty of people at Fergusson Park, it's a win-win situation."
The bonus of the 200sq m extension was that there would be enough room underneath to create a basement garage for equipment and trailer storage by other park users.
Mr Thomson said club members' ages started in their 30s. "But it's not just older guys that enjoy model railways, the kids absolutely love it."
Children's faces lit up at their annual show when they were given the dial to operate a train.
He was confident that funding could be found for the project because of its community benefits, particularly to young people who could learn many modelling and electronics skills from tinkering with railway layouts.
Sports and recreation chairman Richard Kluit was optimistic they would be able to raise the estimated $200,000 to $300,000 for the extensions and other improvements.
He said the model railway club's contribution would be to fit out their section of the building although they could be asked to contribute to building costs if there was a shortfall.
Mr Kluit anticipated the railway layouts would be popular with children after their football games.
Members of the Otumoetai Sports and Recreation Club
* Otumoetai Football Club
* Matua Scouts
* Tauranga Astronomical Club
* Albion Cricket Club
* Tauranga Model Railway Club