When the M2 opened, the prices across Seven Hills for existing warehouses and new developments jumped 20 per cent.

The same thing occurred around the Kingsford Smith Airport in Sydney, albeit at a slower pace, when that land was gradually developed.

But the plans for the second airport come as areas in the west are already well established with industrial property.

Andrew Maher, JLL national director of corporate industrial solutions, says it would transform the western Sydney area. While rents and land values have already been increasing, Maher said it will be a boom for developers.

A drive down the M7 and M4 and it's warehouses everywhere. The demand for space in the area, near Erskine Park, is high and rents have been solid for some time.

That area is at one end of the proposed new airport, with Hoxton Park for residential and Prestons for industrial property at the other.

So any spare land, some of which is still zoned farming, closer to Badgerys Creek will no doubt be looked at in coming months.

But bear in mind land values historically don't tend to rise until the road is built.

Investors like to take and ''wait and see'' approach, unless cash runs out and it stops half way.

Property agents have said the ancillary industries that traditionally hug airports, such as food caterers, courier bays, freight forwarding companies, hire car business and local aircraft parts storage will all be lining up for space at the new site.

Groups such as Goodman, DEXUS, Stockland, GPT and Charter Hall's industrial funds, will all be looking at snapping up available land on which to build a warehouse.

These are the dominant players around the existing motorways and they will be keen to replicate what they have around Mascot and Botany.

The new airport will also be a winner for centres such as Liverpool and that will certainly flow through to Parramatta, with hotels for airport staff and cabin crews in higher demand.

Knight Frank associate director, sales and leasing at Liverpool, Terry Hassan says the new airport would be very positive for the western districts. It would provide not only jobs, but the opportunity for new residential master-planned communities and for the industrial and commercial sectors, he said.

The shift of industries away from Sydney Airport to the west, and the subsequent conversion of the warehouses to residential, had also led to low supply of properties for airport-related businesses.

That could see these industries relocating to the new airport, causing a pull on demand for the land.

ccummins@fairfaxmedia.com.au