The "think pods" that have come to symbolise the architecture of the Scottish Parliament building are leaking and in need of repairs, less than four years after the building was opened.

The parliament's management team has hired a contractor with a cherry-picker to check the sealants on all the iconic windows.

They were created by the late architect Enric Miralles as a place where MSPs can ponder the great issues of the day, and it is claimed their shape was inspired by the Raeburn painting of a minister skating on Duddingston Loch in the capital.

A Parliament spokeswoman stressed yesterday that the problem is not structural, and that any problems can be solved with the use of replacement mastic and silicone sealant. The work began on Monday and is expected to take 10 days. The cost will not be known until the extent of the problem is clear, and it is assumed the bill will be met from Holyrood's annual maintenance budget. That has also been required to meet the cost of sealing other points in the £414m building where heavy rain leads to leaks.

The windows caused problems in the early months of the Parliament's operation at Holyrood, when it was found that paper stuck to them by MSPs to provide shade had the effect of weakening the glass.