The Royal Institution of Chartered Surveyors (RICS) has labelled a new tax on windfall gains from development land as “seriously flawed.” The RICS said the proposed tax, which would be levied on the rise in value of both commercial and residential land once planning permission has been granted, was based on a “misunderstanding about how land is valued, how planning gains arise and how the property market operates.” RICS added: “The key problem with the proposals is that planning permission is only one stage of development and the tax would be paid when the permission is granted, rather than on the actual and eventual gain in value.” The tax would be used to fund new schools and hospitals.