London Penthouse: Unlocking the Rooftop Landbank

Case: Town Center Rooftop
Start of Build:
Build Duration:
Units: 4 units – 27 m² living room, master suite, second bedroom/office, family shower room.


In 2013 we were contacted by Rachele who works for a London based property developer. She had planning permission and architect’s drawings for 2 flats in a vertical extension above an existing 1960’s 3 storey block in Camden. The company could not afford to develop this project using traditional building methods – the build would be slow and site costs high; 12 months of scaffolding, complications getting materials in, high costs of storing and getting refuse out, H&S restrictions, traffic disruption, obstructing pavements and parking spaces, noise, dust, local resident’s complaints etc etc. Rachele had decided to look into off-site construction and found Boutique Modern.

As we worked up the design and assessed cost Rachele’s brief changed – access from one of the staircases was denied by a tenant so we quickly adapted two small flats into one luxurious Penthouse apartment – our Structural Engineers designed a steel frame that would support the apartment using only the outside and party walls of the existing building, spanning the roof deck and keeping enabling works to a minimum.

We complied in every way with the architect’s drawings we were supplied. Window reveals were matched to the permitted elevations and finishes were replicated to comply with planning permission. The only difference being the interiors which were now more spacious than the original floorplan and the floor to ceiling windows surrounding the cramped second stair well became the central feature of the ‘loft’ like main space. The flat was completed with very high spec finishes, a ‘German’ kitchen, a jacuzzi bath and walk in wardrobe in the master suite, the family shower room features a huge skylight above a waterfall shower head as well as a vast range of technology throughout the apartment.

The exterior is finished in a Monocouche Render and the apartment has the only sedum roof in the area. PV panels and our usual super-insulated structure help limit the property’s energy use dramatically.

The 4 units were transported in the usual way deep into Central London, the street outside the building was closed from 10.00 in the morning until 5.00 in the evening and we suspended 4 parking spaces for a day so we could position the crane. After a few issues with the enabling works we located the first unit at 2:00 in the afternoon – the street was open and Penthouse complete at 5.00 that same day!

This project was an enourmous challenge and we thank Rachele for her lateral thought in finding and working with us. Boutique Modern have become one of the few companies in the UK with experience of applying volumetric prefabricated roof top extensions and the resulting Penthouse has been valued in 7 figures.

Projects of a similar nature: If you are considering a vertical extension of your own our team are happy to discuss, assist and advise on the best route forward.

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