German Plant Experience (GPE) group deals with manufacturing and distribution of different construction equipments including concrete batching plant, cement terminals, cement silo, pugmills and pallets which can be used in the production of concrete, concrete products and asphalt.

The sale of more than 300 Sydney carpark spaces in a weekend is a timely reminder of the growing attractiveness of car parking as a property investment, with parking availability under pressure from increasing car numbers.

The spaces in the Mascot car park near the airport sold to local and overseas investors, with some buying several double spaces at $104,500.

In Melbourne agents say car parking buildings are an increasingly lucrative sector of the market, while individual car spaces, unlikely to reap enormous capital growth, provide a consistent, low maintenance income stream.

Geoff White, of Elders Real Estate, says most parking spaces in the CBD sell for $35,000-$60,000 and can be leased for up to $9000 a year.  "And it's not as if you have to worry about the tenant damaging the property."

But he warned, " from the agent's point of view they do not bring a lot of commission."

However management of leased car parking could be worthwhile for agents, as could management of storage sheds, now in demand as families and couples downsized.  This was so in regional centres such as Mildura, as well as Melbourne.

Nick Peden, a divisional director at Savills, says it has sold most of the large carparks which have changed hands in Melbourne since 2010.  "It is a sector of the market that is pretty lucrative because there are not many of them."

Existing carparks, usually up to eight levels, was not optimal use of land on which a building of up to 100 levels could be permitted.  So they were being sold for development.

Earlier this year, Savills sold a five level, 445 bay carpark plus a small office at 380 Lonsdale Street for $43.8 million.  The purchaser, a Singaporean publicly listed company, will demolish it and build apartments.

Nick says for agents it is much like selling at any other well-located CBD building, but one needing minimal maintenance.  The properties are marketed locally, but all Savills' recent sales have been to offshore investors in Melbourne shopping for property.

"There are not a lot of outgoings and really good income growth potential," he says.  "Numbers (of carparks) are dropping, so rates per bay of people wanting to park there are going up and will continue to do so the next decade and beyond."

In the past 12 months the yield has reduced, compressing by at least one point he says.  Last year Savills sold a 427 bay strata car park below a hotel at 222 Russell Street, for $16.88 million – a 7.36 per cent return.

But this year a two level, 106 bay strata car park at 517-537 Flinders Lane was bought by a Malaysia-based private investor for $6 million, a 6.4 per cent yield.

Geoff says the influx of apartments to Melbourne city creates more demand for car parking, with not all new apartments sold with a car space, yet many households having several cars. Some could not be sold because they were attached to an apartment's title.  Others were sold off market – a notice to building owners, for example.  Those sold by real estate agents were commonly marketed online.

"Most people would not know where to start, that's why they should go with an agent who can take it to the marketplace and get the best price and knows the processes and the contracts they need."

Geoff predicted demand for car parking would increase: "So that would push prices – people are still going to drive cars."