Revisiting Sefton House: A Home That Has Grown Into Itself

20.07.26

There is something particularly rewarding about returning to a completed project years after the builders have left. The architecture has settled, the landscape has matured, and the spaces have become woven into everyday family life. Our recent visit to Sefton House in south-west London gave us the opportunity to do just that.

Originally designed as a deep retrofit and extension of a late-Victorian house, Sefton House was conceived as a careful balance between preserving the character of a historic home and radically improving its environmental performance. Rather than replacing what existed, we focused on unlocking the potential already embedded within the building through thoughtful intervention, low-carbon design principles and a fabric-first retrofit strategy.

Returning to photograph the house, we felt we were stepping into a welcoming family home rather than simply revisiting a project that performs well technically. The new images capture a home filled with natural light, warmth and everyday life. Spaces that were once disconnected now flow effortlessly into one another and out towards the garden, creating an environment that feels calm, generous and connected to nature.

The project's environmental strategy combines a fabric-first retrofit with passive design and natural ventilation significantly reduce energy demand while improving comfort. Low embodied carbon materials and biodiversity-led landscaping further reduce the building's environmental impact.

These strategies are integrated into the design rather than expressed as visible features. Improved daylight, framed views of the garden and a stronger connection between inside and outside create bright, comfortable living spaces.

Projects like Sefton House highlight the potential of retrofit to reduce the environmental impact of our built environment. Existing buildings already hold significant value, not only in their embodied carbon but also in their history, character and place within our communities. Sensitive, performance-led interventions enable these buildings to serve future generations while significantly reducing their environmental impact.

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Revisiting a Deep Retrofit of a Grade II Listed Townhouse

16.07.26

We recently came across this article by Historic England revisiting one of Arboreal Architecture's earlier deep retrofit projects: the transformation of a 170-year-old Grade II listed Victorian townhouse in Clapham.

The project explored how a historic building could achieve a high level of energy performance while carefully conserving its architectural character. Through detailed building analysis, sensitive repairs and the use of natural, vapour-permeable materials, the home's space heating demand was reduced by more than 75%, while its long-term performance continues to be monitored through an embedded network of environmental sensors.

Completed in 2016, the project received the CIBSE Building Performance Award for Residential Building of the Year and remains an important example of how thoughtful retrofit can extend the life of existing buildings while significantly reducing their environmental impact.

Many of the principles developed through this work continue to inform our practice today. We continue to deliver ambitious retrofit and conservation projects, applying the same research-led approach to create buildings that combine heritage, low-energy performance and long-term resilience.

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One Tree at a Time, Guerrilla Tree Planting Architects

24.06.26

As temperatures rise across London this week, a guerrilla-planted olive tree near our office which we planted a few years ago is being watered to help it continue growing.

The tree forms part of a small, ongoing planting initiative that members of our architectural practice have undertaken over the past several years. During that time, a number of trees and plants have been introduced into overlooked and underused spaces in the surrounding area as a modest contribution to local urban greening.

The olive tree was chosen for its resilience and adaptability. With deep root systems, drought tolerance, and the ability to store carbon throughout its lifetime, it has increasingly come to symbolise the need for cities to adapt to changing climatic conditions. A symbol of climate action, resilience, and sustainability, the olive tree reminds us that adapting to a changing climate starts with nurturing nature.

The practice intends to continue planting and maintaining trees where opportunities arise and hopes that others will consider similar actions in their own neighbourhoods. As cities face increasing environmental challenges, local efforts to expand urban greenery can play a role in improving biodiversity, reducing heat, and strengthening connections between people and place.

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