Strong rental market triggers boom in "sardine apartment" planning across London

London leaseholders are being forced to live with months of disruption as their landlords try to squeeze a profit out of unused areas in their blocks - such as roof spaces and storage rooms - by turning them into flats to rent out.

The capital’s strong rental market is being blamed for the boom in “sardine apartment” planning applications, which neighbouring residents are often powerless to prevent.

'The only option for owners is to fight sardine schemes through the planning system'

One of the latest cases centres on the Grade II-listed Beaux Arts Building in Holloway, which was modelled on Grand Central Station in New York.

To the horror of its residents, who include Carole Caplin - former lifestyle adviser to Cherie Blair - and theatre director Max Stafford-Clark, the freeholder has won consent to insert a new flat into the ornate lobby. Islington council is now considering a contentious proposal to create a second new flat on the roof.

Meanwhile Wandsworth council recently agreed to the addition of two new flats in the roof space of a building on Abercrombie Road, Battersea, to the fury of the owners of its eight flats. They claimed the project would cause them “unbearable” disruption and the new mansard roof would ruin the look of the building and decrease the value of their homes. Members of the council’s planning committee approved the plans, ruling there was already a precedent for similar works.

And Kensington and Chelsea council approved an identical proposal for a house in Lexham Gardens, Kensington, despite objections, arguing that “the impact of the construction process is not of sufficient weight to inform a recommendation”.

Paul Williams, a director of Savills, said unless protected by a specific clause in the lease, the only option for owners is to fight sardine schemes through the planning system.

Daniel Farrand, head of planning at law firm Mishcon de Reya, said that residents could try to argue that a development would have a negative visual impact on the building, would cause overlooking or put pressure on local parking.

But claims about devaluation of property and building disruption would not help their case. “You are expected to put up with a certain amount of disturbance,” he said. “It is a very, very difficult thing to stop because local planning policy supports it in a lot of cases.”

Converting an average loft into a self-contained flat with access would cost no more than £100,000 and the sale of such a flat would make a handsome profit of several hundred thousand pounds. “Because the freeholder owns the land already it is going to be a very profitable business, which is why they are keen to do it.” said Williams.