It is understood that Dashwood is suing Moorgate Investment Partnership for £250,000 for breach of statutory duty, nuisance, negligence and trespass, and for breach of rights to light.
The writ claims that Moorgate's contractor, Laing O'Rourke, had trespassed on Dashwood's property, which neighbours the scheme, at 63 Coleman Street.
The writ attributes the trespass to unlawful structures placed on the roof of 63 Coleman Street without permission. It also stated that debris and building masonry had been dropped on Dashwood's property during the works.
The writ said: "Dashwood argues scaffolding cantilevered over airspace of its property was a trespass and a nuisance, and says that dust and debris fell onto its building for two years, damaging a boardroom rooflight four times in 2001 and 2002." Dashwood is also seeking an order redrawing the boundary to take account of the new building. It is seeking an inquiry into the value of any strips of land transferred by Dashwood.
Scaffolding cantilevered over its property was a trespass and a nuisance
High Court writ
The writ said that the rooflight had been repaired by taping over several broken panes of glass, that a gutter was left blocked for months and that rubble had been found in an air-conditioning cooling tower.
Dashwood claims that the boundary infringement has reduced the amount of light available to its offices.
The company has also complained that a new wall, built further west than the original, encroaches on its land, and that a northern wall is over the boundary by six inches.