You can't miss the Marlborough Group's new massive outdoor advertisement adorning three buildings at the bottom of Grafton Street. It is a poster that measures 18 metres long and six metres in depth - and it is covering the scaffolding that fronts numbers 111 to 113 while renovation work is in progress. "Poster" isn't really the correct word to use - in the industry, these are called mesh wraps because they're made of PVC netting and can be made large enough to wrap around an entire building.

They're also available in digitally printed full colour, making them particular appealing to the advertising industry, which is increasingly using them as a high-profile launch medium for campaigns.

Further up Grafton Street, the Marathon Sports shop has a shop-sign to rooftop advertising wrap in vibrant colour showing just how effective buildings can be as temporary ad sites.

For safety reasons, scaffolding has to be covered in mesh - so the theory behind building site wraps is that businesses may as well hop on the back of the regulations and get some public attention. The giant, cleverly designed wrap at the Trinity end of Grafton Street is a smart PR move by Marlborough, which has yet to move into the building.

The scale of the wrap gives the passing impression that the recruitment company has taken over the entire building from top to bottom. In fact, its street level presence is only 868 sq feet at number 111, while it has 13,500 sq ft on the upper floors of the two other buildings.

So, although it is good news for The Marlborough Group, the other tenants in the Irish Estates-managed group of buildings are not so happy. Seamus Breslin, manager of Specsavers Opticians on the ground floor, is less than pleased. In the past, he has tried to get planning permission for a small horizontal sign for his premises but was turned down. "That's one of the reasons why it was particularly maddening to see the massive sign," says Mr Breslin. "But the real reason is that it totally obscures our shop front."

He is getting together with Irish Nationwide, the other ground floor tenant affected by the wrap, to see if they can get it either taken down or at least amended to include signage for their businesses.

According to Marlborough, the wrap will be in place for the next month or longer, depending on the progress of the building work. As these wraps become more evident around the city, they are bound to become a planning issue. According to Dublin Corporation, planning permission has not generally been applied for when wraps are being erected, despite their presence being very much a planning issue.

The rule of thumb is that any material alteration to the facade of a building needs planning permission. The corporation takes a lenient line when a company is renovating and scaffolding obscures their business sign. In order to facilitate the company to continue doing business during their renovations, they usually turn a blind eye to a small wrap or sign bearing the company's name. In the past, complaints - usually from the public about the visual clutter created by advertising wraps - have been forwarded to the corporation's planning enforcement office.

However because these wraps are most often used as launch ads for campaigns, they have usually been taken down by the time the planning office catches up with them.

In any case, some advertisers don't use this medium as a semi-permanent one, seeing it more in opportunist terms - for example Coors Light guaranteed maximum exposure by erecting a massive wrap at a building on O'Connell Bridge for the duration of the St Patrick's Day Parade. The appeal of reprinting a 48sheet poster on to a PVC wrap and hanging it on your building is obvious - while the printing costs are slightly higher, the site is free, presuming you own the building. Putting your poster up on an official 48-sheet poster site in a good location in the city costs from £300 for a two-week period.

"It's a mistake to see these wraps solely in terms of their use in advertising," says Cliona Conway, business display manager at Print and Display Digital, the company who printed the Marlborough wrap.

She points to the example of Italy were wraps are used by civic authorities to camouflage historic buildings under renovation. "The Colosseum is a prime example," she says, "When they were renovating that, they had a print of the building on a mesh to make the whole area more pleasing to look at, especially to tourists' eyes." While there is no doubting the aesthetic value in covering unsightly sites, the commercial reality is that advertisers, such as Marathon Sports, are likely to maximise the situation.