Private Client


This secluded, detached post-war house, originally designed by Burns-Guthrie around 1969-1970 in a mid-century modernist style is reminiscent of Casa de Vidro by Lina Bo Barda. A hidden gem at the edge of a conservation area in Tunbridge Wells the partially cantilevered, partially buried house sits on a steeply sloped site within a generous plot surrounded by mature trees, some of which are protected with TPOs,  forming part of a historical woodland. The house is totally concealed from the main road, accessed via a steeply sloping driveway. Upon arrival one is met by the gleaming white rendered example of later modernism.


Tasked with expanding the house to accommodate the client’s wider family we sought to optimise the most of a large flat roof that provides breath-taking views out across the valley below. In order to facilitate the vertical expansion, the whole interior on the ground floor is to be fully reconfigured to enable each space to function more efficiently and as per the client’s brief, is to reflect their lifestyle for open entertaining Other external alterations to the existing house are required to rectify unsympathetic modifications and to better reinforce and restore the underlying modernist principles of simplicity, clean lines and a clear composition of forms.


In order to help minimise the impact of the originally proposed rooftop addition and to retain the strong geometry of the cantilevered upper level, any new structure was to be set back on all sides except within the internal courtyard where the use of double-height glazing connects the old and the new. A couple of elements, including the chimney and new cylindrical staircase enclosure, were to be accentuated by increasing their height providing a counterbalance to each other as well as variation across the façade. These elements would be mainly visible on the south elevation where the visual scale of the property is reduced, due to the change in levels across the site. The tall glazing on this aspect is limited to 4m with the upper portion set back to again reduce the impact on the courtyard.


Although a clearly contemporary addition the proposed rooftop was to be a combination of slimline glazed windows with the external façade, clad in black-stained timber allowing it to remain subtly nestled among the mature trees, allowing the strong, white geometry of the house to retain its clear dominance and appeal.

Following the pandemic and the subsequent rise in construction costs the full roof extension has not been feasible and the roof works have been limited to the insertion of two angular periscopes that pierce the roofscape serving as lightwells, framing key views out as one enters and moves internally. This articulation of the ceiling heights enhances the ‘compression and release’ to enhance the user experience by defining and lighting circulation routes and creating a central kitchen / entertaining foyer flooded with natural light. This space opens onto an inset central patio allowing the mature garden to creep up to the threshold.


A reduced roof terrace is now accessed via a bold external spiral stair that sits on its own to the approach elevation linking to a continuous balustrade that enfolds the terrace. The extended ramped chimney sits a strong stepped, geometric sculptural rising as the focus for an external living room.


Forming a strong base on which the larger, cantilevered white render box sits the lower floor is to be clad in tiles reminiscent in shape and colours of many mid-century properties. Existing windows and doors are being replaced with black slimline aluminium sliders to provide a coherent appearance to modernise and improve the overall aesthetic of the house.


Due to its original cantilevered upper level, the proposed scheme requires some clever planning to prevent overloading the hard-working structure. The insertion of new concealed internal columns and bridging structures are required to transfer loads where they can be dissipated to the ground below.



Project services provided – 

Feasibility Study

Concept Design

Planning Submission

Discharge Planning Conditions

Detailed / Technical Design

Manage Tender Process

Construction Drawings

Site Attendance during Construction



Design Team.

Foster Structures – Structural

Compliance BC – Approved Inspector


Silvabak Construction – Main Contractor


Under Construction. October 2023