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St Mary Street, Cardiff

Local Authority: Cardiff County Council 


Proposed Development

Change of use from office to residential with the internal reconfiguration, plus first and second floor rear extensions, and a single storey rooftop extension to provide a total of 12no. residential flats on the upper floors of 117-118 St Mary Street. The planning and listed building consent applications included the creation of a new residential entrance and external alterations to 118 St Mary Street, which was a listed building by virtue of it adjoining 117 St Mary Street (Grade II Listed Building). 


Planning Issues

The application site was last in use as office space occupied by NatWest Bank (Use Class B1). Although the floors had been vacant for 3+ years, a robust justification was required to support the change of use from office to residential. KEW Planning provided marketing information for the application site and an analysis of other available offices within the city centre to demonstrate the loss of employment floorspace would not impact on the available quantum in the wider city centre. 


We also demonstrated that the refurbishment of the building would reintroduce an active frontage to no.118 due to the internal amenity space provided on ground floor level, with residents entering and exiting the building. 


KEW Planning advised the client at the outset that a viability report would be required to support no provision of affordable housing, as the proposed development was over the threshold by which planning policy stipulated.  This resulted in having a response from the District Valuer within a 3 month time period, whist the application was being determined and the result was zero contributions and no legal agreement necessary.


Due to the application site being a Grade II listed building and within the St Mary Street Conservation Area, the listed building consent application required a Heritage Impact Assessment, to demonstrate that there would be no adverse impact on the heritage assets, which KEW Planning prepared. We also successfully negotiated with the conservation officer to achieve the client’s goal of incorporating a garden roof terrace with the rooftop extension.


Due to the constraints of the existing building within this urban location, the distances between windows within the proposed extension were below the general privacy distance of 21 metres. We therefore advised the design team to use alternative design measures, such as screening and careful window positioning, to secure privacy for all units. 



Following successful negotiation and liaison with officers, the application was approved via delegated powers in April 2022. 

This was the first time working with KEW Planning, which came via a recommendation. I have been absolutely thrilled and by the regular communication keeping me up to date on the status of the applications, the professional and technically capable skills that Kathryn in particular demonstrated, and I would have no hesitation in working with KEW Planning again.

Jahan Abedi, Aram Investments Ltd, Property Consultant.