In theory the government is about to start retrofitting 2,700 homes every day. Really, asks Julia Park

No doubt I’m not the only person to have been cold-called and urged to take advantage of the grant available under the government’s green homes retrofitting initiative. On both occasions the caller made it sound dead easy until I explained that, like many others in our village, our house has an exposed timber frame with brick infill. By the time I’d mentioned that the village is in a conservation area and that most of the houses are at least 200 years old and some are listed, they’d lost interest. But the calls forced me to confront some fundamental realities.

Julia Park

For practical and aesthetic reasons, it feels very unlikely that the insulation needed to bring our home up to scratch could be applied externally, though that’s generally preferable in terms of performance. With solid walls, the only alternative is to insulate internally.

I’m no expert but I imagine we would need at least 200mm of insulation to make a real difference. Like the majority of homes here, our house is detached. As most rooms have two outside walls, ‘the shrinkage’ would be as painful as the upheaval. The shower room would no longer function and the kitchen would have to be taken out, shortened and put back. We would need to excavate the ground floor to install insulation and that would probably require underpinning. We would have to take down all the ceilings on the top floor (again…) to increase the roof insulation and replace all of the windows and external doors.

At least £80k later, I can guarantee that however hard we’d tried, we’d be left with gaps, cold bridges and lots of messy bits. And probably still trying to get the local conservation officer to allow us to install an external power pod to charge our electric car.

Don’t get me wrong, I absolutely understand that this needs to happen and I’m not seeking sympathy. I’m just trying to understand how it might work – not only in the home I know best, but also in the other 20 million homes in England that need upgrading. Most will be less challenging than ours, but the majority won’t be easy or cheap. £10k (the maximum grant) doesn’t go far when you start to work through the process; it already feels as though homeowners and landlords would need to make a substantial contribution to the cost of a ‘proper job’. And, of course, it must be a proper job if we are to succeed in the mission and avoid the well-documented failures of previous retrofitting attempts.

Given that we need to be upgrading about 2,700 homes every day from now to 2050, this surely needs to be tackled in a much more intelligent, comprehensive and coordinated way

The questions keep coming. Given the severity of the climate emergency, how much individual and collective choice should we have? Are we allowed to mind that terraced streets could be changed forever because individual owners decide to overclad at random? Should we be lobbying for planning permission to instil some consistency and, if not, how do you manage dips in the roofline and the eaves gutter when some homes have got fatter and others haven’t? Should the owners of semi-detached homes have a ‘duty to co-operate’? Should someone insist that it’s done street by street – it ought to be cheaper? And what are the sanctions for not playing ball? It’s not as though we can confine our emissions to our own back yard, after all.

Concerning then, that the retrofitting programme is due to be up and running within weeks and, as far as I can see, without a plan or a monitoring regime. Given that we need to be upgrading about 2,700 homes every day from now to 2050, this surely needs to be tackled in a much more intelligent, comprehensive and coordinated way?

Our housing stock is the oldest in Europe. Based on recent performance, up to 85% of today’s homes will still exist in 2050. Perhaps many of them shouldn’t? How should we weigh the personal trauma and embodied carbon caused by demolition against the operational energy and other advantages of rebuilding for a 200-year life?

Before sleepwalking into something we have barely begun to think about, someone needs to do a cost/benefit analysis to determine which homes (or perhaps which streets and neighbourhoods) are, and aren’t, worth the investment. My guess is that it’s probably not worth spending more than £10k on a building that might only last another 25 years, even supposing the owners were able to meet the additional cost. But I have no idea where the tipping point is and, anyway, it’s much more complicated than that.

The targeted, but significant, demolition of tired suburban housing could triple density. Scaled up, that has the potential to avoid building on any more greenfield sites and might even release land for food growing, recreation and/or re-wilding. At what point do those benefits outweigh the release of embodied carbon and who should make that decision? What guarantees will be offered to those who choose to retrofit – it should surely involve an independent assessment and ‘before and after’ thermal imaging and airtightness testing?

And let’s not forget that climate change is only one casualty of our failure to build better housing. Only 9% of existing homes provide even the four basic accessibility elements that make a home ‘visitable’. Over the last decade, the number of households with one or more adaptations for a person with a disability has risen by just 1% (to 10%). Given the cost and disruption of a comprehensive green retrofit, it would be madness not to address other serious pre-existing shortcomings, such as poor accessibility, unsafe wiring and potential fire risks, at the same time – but who would pay for those?

Spending £10bn on improving all of the ‘poor housing’ in England would save the NHS £1.4bn a year

In my search for answers I came across a report published in July by the New Economics Foundation: A Green Stimulus for Housing: The macroeconomic impacts of a UK whole house retrofit programme. Calling for a ‘comprehensive policy approach’ (there’s a radical thought…), a new suite of regulations and new funding instruments, it sensibly advocates a ‘whole house approach’; explicitly mentioning wrapping-in age-related adaptions and fire safety improvements. It recommends the creation of a ‘National Retrofit Taskforce’ and suggests that local authorities should play a key role in creating demand and growing local supply chains’.

In the best-case scenarios, the economic forecasts are upbeat. The authors estimate that every £1 spent on retrofitting ‘fuel-poor homes’ would save £0.42 in NHS spending, and cites evidence that spending £10bn on improving all of the ‘poor housing’ in England would save the NHS £1.4bn a year – paying for itself in just over seven years. A no-brainer if it works.

Understandably, it leaves the practicalities of retrofitting to others. The RIBA perhaps? Impressive though it is, rather than tread on the economists’ toes with a list of recommendations to Treasury, we might have expected the new RIBA report to address some of the more tangible elephants in the room that I’ve touched on: how to ensure that every home is upgraded in the most effective way while managing the visual impacts of piecemeal interventions on streets and neighbourhoods – and when to advocate renewal.

Fortunately, LETI (London Energy Transformation Initiative) is on the case with at least some of this.

Following the success of the Climate Emergency Design Guide published at the start of the year, an even larger group of dedicated experts is putting together a set of generic case studies comprising different housing typologies to help everyone understand the principles and the best approach to take. No quick-fix-vaccine for decarbonisation; just a lot of hard, but vital, work.

Interested in Net Zero?


On November 18 and 19 Building is hosting Net Zero Live. On the agenda of the two-day programme are: delivering net zero from construction techniques through to operational use, designing for embodied carbon from material specification through to repair and maintenance and what clients want from costs to impacts and understanding planners’ agendas.

Highlights include three live panel discussions and the exclusive release of the first three parts of Building Boardroom’s nine-part report on net zero, which includes insight from six leading clients.

For more information and to register click here.