The building is currently arranged as 16 studio flats, and after the extension is complete the total number of flats will be reduced to 14 due to the creation of larger flats – with five two-bed apartments, a single one bed flat and eight studios in the completed product. While losing on the total number of units, the scheme does add to the total residential floor space and increases the potential number of people living here so is a net positive for density.

Seven similar villas exist in the area, many of them have been converted into flats. Each consists of a lower ground, ground and two upper floors.

The designs have been drawn up by Squire and Partners, who have chosen to echo the surrounding warehouse architecture of Linton House in their design for the two buildings.

The new buildings are on the edge of the Gospel Oak and Kentish Town industrial area, but as the former office building to the north has already been converted to residential and part of the site already has permission for a residential scheme, this context is gradually changing.

The scheme, however, provides more employment floorspace than the current site, with the self-storage facility over doubling in size, as well as on-site office space also over doubling, although the day centre is being lost as it already has plans to move to a nearby site. In addition to the employment floorspace, 60 flats are planned, 8 of which will be for social rent and for assisted living accommodation.

The current building looks like many other north London mansion blocks, except it isn’t what it looks like. The mass of the building betrays that the use was something different – in this case, the Metropolitan Police used it for storage for stolen cars. The police sold this to the current owner for £2m in July 2014 – not a great deal considering that the ground floor retail units brought in an annual income of over £100,000.

The new designs, drawn up by Piercy & Co, break up the bulk of the current building by effectively splitting the new building into two blocks, one facing Haverstock Hill while the other fronts Adelaide Road. In between the two will be a courtyard.

Retail is provided on the ground floor, and 17 of the 77 flats are planned to be sub-market, 9 for social rent, 8 for intermediate tenure.

An application was previously submitted for seven flats, although thanks to a slight enlargement of the plot this has now been increased to nine. These will be two one bed flats, two two bed flats, four three bed flats and one four bed apartment.

The design, from Box Architects, matches the height of the existing terrace of houses along York Way, but thanks to a slope in the road is able to support four storeys rather than three.

Maryon House dates back to the 1960s, and provides six two bed maisonettes on what was a bomb impact site from the Second World War. The current design is rather out of keeping with the Victorian era housing stock but not uncommon for bomb-blast sites across London.

KSR Architects were drafted in to produce the replacement building’s design. They’ve opted for a building of similar height to the existing block, extended only slightly to match the roof line of the neighbouring houses. The additional residential space has been created by echoing a design feature found in the neighbouring buildings – rear extensions.

In total the new building will provide four more apartments than the original, with a greater mix of unit sizes: two one bed flats, five two bed apartments and three three-bed units. Like the original, all are private. Given this is a conservation area, it’s unlikely anything larger would get through planning.