Hobsons Bay council has voted to start detailed design and development of an $18.5million four-court extension of the Altona Sports Centre.

Home to more than 30 clubs and 6000-plus registered users, the centre at HD Graham Reserve in Altona Meadows currently has six indoor basketball/netball courts and two outdoor netball courts.

Mayor Angela Altair said the council would seek funding from state and federal governments and other sources, including $3million from the state government’s better indoor stadium fund.

Cr Michael Grech said the four new indoor courts would include a “show court” with retractable seating for up to 1000 spectators.

“These additional four courts will also allow the centre to host state and regional tournaments,” he said.

Cr Peter Hemphill said netball and basketball were two of the municipality’s fastest-growing sports, and the centre was currently running three courts short of requirements.

“Not too long ago, there were 42 byes each week … that’s about 80 teams that were not getting a game,” he said.

Based on registrations at the centre in 2016, 54 per cent of basketballers and 44 per cent of netballers were Hobsons Bay residents.

Most remaining users came from adjoining municipalities, including 35 per cent from Wyndham and 10 per cent from Maribyrnong.

Hobsons Bay has a current population provision of 11,595 people per indoor court.

Basketball Victoria and Netball Victoria advise that a population provision per court of 5000 for basketball and 8000 for netball represents current best practice.