The national context
We work with older and traditionally constructed buildings, and our approach combines respect for longevity and heritage – whether a building is listed or not – with rigorous building physics.
The UK has made foundational commitments to address climate change through the Climate Change Act 2008. Adding to the challenge is that our housing stock is the oldest in Europe: around 20% of the total – 6 million homes – were built before 1919, a period when solid wall construction predominated.
It would not be physically possible or culturally acceptable to replace these old houses wholesale. Equally, it’s not tenable to leave their thermal performance unaddressed, in terms of environmental impact and the comfort of the people who have made their homes in them.
Retrofit is therefore unavoidable. The practical challenge is how heritage and decarbonisation are reconciled, and how measures are prioritised and sequenced.
The importance of longevity
We recognise the value of longevity in buildings as a good in itself and from a practical, environmental and economic standpoint. As Dr Robyn Pender has written, the French word for “sustainability” is “durability”:
“The most durable building will be the one with the longest usable lifespan, requiring the least energy input for ongoing maintenance and operation.”
A house which already lasted 150 or 200 years has proven something important – but the purely practical achievement of its persistence should be given greater weight. Retrofit is best understood as an opportunity to extend the life of an old building, and the process should never lead to fabric – proven as durable – being prematurely discarded.
Comfort (just) before carbon
Carbon reduction is essential. The most reliable way to achieve it in older houses is to make them genuinely more comfortable. Sustained carbon reduction typically follows from careful, well-judged interventions aimed first at improving comfort and performance. This approach is informed by John Kay’s argument in Obliquity – that complex goals are often best achieved indirectly – and by UK Green Building Council research into homeowner motivations.
Repair, then retrofit – and repair before replace
Pre-retrofit repairs are foundational, not ancillary, hence our principle: repair, then retrofit. This recognises that the fundamentals of good maintenance are inseparable from the long-term stewardship of historic buildings.
If a typical late-Victorian house, now around 150 years old, can be expected to remain in use for another century or more, this lends environmental and economic weight to the SPAB’s advice: “stave off decay with daily care”. The perspective that there is critical cultural and environmental value in the basic care of old houses is further strengthened when considering that RIBA uses a span of only 60 years in its life cycle calculations for new buildings.
We support the long-term persistence of historically intact, comfortable and energy efficient buildings, with longevity, repair and retrofit acting together in mutual reinforcement.
Beyond adversarial thinking – and reconciling environmental and heritage concerns
Graeme’s research revealed a paradox. While there was some resistance to solid wall insulation, nearly 90% of respondents expressed a desire to improve the energy efficiency of their homes, motivated by reducing heating costs, improving thermal comfort and a strong concern for the environment.
Rather than discarding aesthetic concerns, we advocate for an approach which integrates heritage values and the practical need for warmth with financial and environmental concerns. Redstart’s work is grounded in striking this balance.
A pragmatic approach
Poor techniques in the construction industry are widespread, and Prof Gavin Killip has pointed out that knowledge about building performance is rarely contextualised across trades. Damaging materials also continue to be used in the repair and retrofit of old houses.
Addressing this landscape requires careful diagnosis, moisture awareness and clear sequencing of measures. As Stewart Brand writes in How Buildings Learn:
“Besides gaining the loyalty of their occupants and visitors, old buildings that stay in use rise to other freedoms. By spanning generations, they transcend style and turn it into history. By showing a tangible deep history, the building proposes an equally deep future and summons the taking of long-term responsibility from its occupants.”
The practical task is to improve energy performance, and ensure that these buildings remain well-used and durable for centuries to come.
Redstart Projects 