The application, refused earlier this week by Westminster City Council, had sought permission for the part-redevelopment and part-refurbishment of Dolphin Square in Pimlico, a private estate built in the 1930s. The proposals included the demolition and reconstruction of Rodney House, a rooftop extension to the remainder of the estate, refurbishment and reconfiguration of the existing residential units and the erection of 16 townhouses.
According to a planning report, the plans would see the number of residential units increased from 1,225 to 1,455.
The report said that demolition of Rodney House was "considered to represent ‘less than substantial harm’ to the conservation area under the National Planning Policy Framework tests owing to its lesser design quality".
It said the increase in height of the proposed replacement building and rooftop extensions would "increase the buildings dominance". However, it added that, "given the scale of the existing building, and the simplicity of the proposed architecture, it is considered that the architectural character of the conservation area will be preserved".
The report said the proposed extensions were also "considered to have a satisfactory relationship with surrounding residential properties in terms of amenity".
Planners also said the proposal "represents the opportunity to secure the delivery of 230 new residential units, including 57 on-site affordable housing units; improved public access to the internal courtyard garden and the extension of the Thames path", and these were "considered to represent significant public benefits".
Overall, the report said the proposals were "considered acceptable in design, conservation, land use, amenity and highway terms in accordance with the Core Strategy and Unitary Development Plan (UDP) policies".
But the council’s planning committee went on to refuse the application.
Westminster City Council chairman of planning Gotz Mohindra said: "Dolphin Square clearly needs refurbishment but this scheme provides too much temporary lettable accommodation at the expense of permanent housing, especially for families, or wider public benefit to justify the harm that the extensive works would do to the conservation area.
"The increase in short term let properties, which the council and residents fiercely oppose, left us with little choice but to refuse the application."
In April, the council called on the government to introduce tougher legislation to help it stop illegal online lettings, after an investigation by the local authority discovered a ten-flat residential building operating as a "virtual hotel".
In July last year, the local authority said it had issued ten enforcement notices and 75 planning contravention notices against suspected unauthorised short-term lets since setting up a task force to tackle the issue.