The proposed installation of timber boarding to the existing staircase would seek to perpetuate the retention of an existing unauthorised modern staircase and the associated unauthorised alterations to the original floor plan of the dwelling, both of which are considered to be seriously detrimental to the historic fabric and character of this Grade II Listed Building. The proposal is therefore considered to be contrary to Core Policy G and Development Policy 5 of the North York Moors Local Development Framework which seek to ensure that proposals for the alteration of Listed Buildings will only be permitted where there is no unacceptable impact on the special historic or architectural interest of the building.