Infrastructure&Development Property prices in parts of Dublin could rise by up to 20 per cent as a result of the State transport plan, "Transport 21".

The highest increases are expected in the south Dublin areas of Cherrywood, Cabinteely, Foxrock and Cornelscourt where the arrival of Luas will lift some severe restrictions on development.

But the extension of Luas to Swords, Citywest and the Docklands, along with the opening of phase one of the Navan line which goes as far as Dunboyne, will also ensure high appreciation for homeowners.

In a more long term strategy, the development of the orbital metro from Tallaght to Clondalkin by 2010; to Lucan by 2012; Blanchardstown by 2014 - and the link to Swords via the airport - will all provide a boost for property values in these areas.

According to Martin Gilmartin of south Dublin agency Daphne L Kaye and Associates, the greatest appreciation in property values may be felt, somewhat ironically, in the areas where land and property prices are among the State's highest. Mr Gilmartin told The Irish Times that a virtual ban on commercial development has been in place in Cherrywood - a vast undeveloped area between the recently opened section of the M50 and the N11 - because of the absence of public transport and access.

Now with access already in place through the Lehaunstown Carrickmines and Loughlinstown junctions, Mr Gilmartin expects property values to rise by at least 20 per cent on the opening of the Cherrywood Luas which will underpin public transport and lift planning restrictions. "That is going to open up high density," he says, adding that it would also have knock-on increases in places from Rathmichael to Deansgrange and Cornelscourt.

On its way to Cherrywood, Luas will also pass close to Ballyogan and Stepaside - no doubt sprinkling its magic on house prices and development land values there too.

Property speculators will also be expressing keen interest in the Dunboyne area, which by 2009 will have a new rail link to Dublin city centre, encouraging the development of commuter housing and a keen interest in park and ride.

According to local auctioneer Joe Fox, there had been so much hope and campaigning for the proposed rail link in the area that even the sight of fellows with picks and shovels working on the line will start an upward momentum in house prices.

Dunboyne currently has a population of about 7,000, Fox estimates, with the cheapest homes starting at about €300,000.

However, he points out that newer housing in the area is of better-than-average quality, with large four-beds in well maintained estates. "It will be a big help when it comes," he says.

A third area where "Transport 21" is likely to transform house prices is the Docklands, which will be one of the first new areas to link into the transport network in 2008.

The East Wall area, which is between Harry Crosbie's proposed Point Village and the IFSC, is particularly well placed to exploit the advantages of Luas. Already only a mile from O'Connell Street, the Luas extension will then bring direct access to the Red and Green lines. The new Spencer Dock railway station should also help raise the popularity of the area.

While "Transport 21" will undoubtedly help property values, the director of the Dublin Transportation Office, John Henry, has yet a few more surprises up his sleeve for the coming years.

With transport links at last being put into already developed areas, Henry told The Irish Times this week that he is planning to turn the process on its head and put forward plans for development along strategic "cross over points" on the public transport map.

"Essentially what we propose is that at crossover points (such as the Liffey Junction where Luas meets the Maynooth line) there would be major development, because it could be supported."

Another point where the lines cross is on the Kildare/metro west route near Clondalkin.

Henry says he also wants to develop new local hubs for bus services, such as routes emanating from the Dundrum Luas stop, serving surrounding areas and linking them into the rail network.