The site for this renovation and extension of a 1960s house is on the edge of an historic Buckinghamshire village and has far-ranging views over the Chiltern Hills.


The brief was to add space to the house so the members of the family could feel connected but not on top of each other.

The design intent was to echo the simple construction of the 1960s house while achieving excellent environmental performance. To achieve this the structure has been split with two exposed layers of steel and timber frameworks internally separated by a thick layer of insulation from exterior brick columns. These are designed to be deeper than they need be structurally, in order to give a sense of robust protection internally, while strongly framing and connecting the internal spaces out to the far-reaching views beyond.


The interior was entirely rebuilt, with a two-storey extension on the side and single-storey extension on rear, and new windows installed throughout. The front wall of the original house was retained in order to maintain the consistent character of the street, while on the garden side a lap-pool has been added.

The new interior layout is designed to provide an interconnected sequence of both communal and more defined spaces for the family to use, each with its own distinct character and hidden corners.


Materials and finishes such as the local aggregate concrete floor, clay plaster walls and limewash paints have been chosen to create light, calm spaces and improve internal air quality.

A covered terrace at the rear is designed as an inbetween space where a cup of coffee in the fresh air can be enjoyed while feeling protected from the weather – with the thickness of the brick columns intended to feel ‘sturdy and companionable’.


Architect’s view  

The clients loved the view and the site, but there were a number of issues with the existing 1960s house. Rather than demolish it and start from scratch, we tried to expand the house in a way that increased visibility of the qualities that the client did like, while minimising those qualities they were not keen on. For example, we were very explicit with the new timber and steel structural frames, drawing attention in turn to the honesty of the original house’s construction.

We wanted to make the most of the view, although a glass box extension didn’t feel right. The broad horizontals of the outlook are instead framed in the vertical openings between deep brick columns. This is particularly successful from the covered terrace. The intention was for the interior to feel both open to the landscape and protected by the depth of brickwork from the wind and rain that sweeps across the site. The roof is separated from the columns by dark, projecting rafters. Architect Peter Aldington lives locally and his detailing was a recurring point of reference for us. The two-storey side extension was treated in a simple way that we hope mediates between the columns of the rear extension and the relaxed windows-in-brick-walls of the original house.

We found there was a lovely changing quality of light throughout the day on the site. The internal materials were chosen to emphasise this without being too reflective. The local aggregate in the concrete floors has a fantastic honey tone when the sun hits it, which works well with the clay plaster walls and ply woodwork. We collaborated with excellent interior designer Anna Chipperfield on the fittings, finishes and bespoke ply furniture.

Spaces are organised to support the client’s way of life. The plan offers a flexible combination of private space and areas for the family to come together. The small external lap-pool is oriented across the fields towards the horizon.

Kieran Hawkins, director, Cairn


Client’s View

Working with Cairn felt collaborative from the beginning. They worked really hard to understand how we really wanted to live in the house individually and as a family both now and in the future. The finished house enables us all to live within the space well. With the project we tried to retain key elements of the original house like the asymmetric roof line and an area of exposed brickwork and we are delighted with the end result and all of the care, attention and expertise Cairn demonstrated throughout the project.


Project data

Start on site April 2019
Completion March 2020
Gross internal floor area 252m2 (75m2 extension, 177m2 refurbishment)
Form of contract JCT Intermediate Contract
Construction cost Undisclosed
Architect Cairn
Client Private
Structural engineer Ingealtor
Principal designer Butler & Young
Approved building inspector Assure Building Control
Main contractor Link Groundworks
Software used Revit