James Parker speaks to Nick Whant, sustainability manager at the NSBRC, about the viability, performance and sustainability of retrofitting properties.
IS RETROFIT A VIABLE OPTION FOR ANY TYPE OF PROPERTY?
In short, yes! Depending on your budget, you may be looking for low-cost solutions to increase comfort and reduce running costs of your home, or you may be considering a ‘deep retrofit’, which represents a larger investment and a more disruptive project.
We generally encourage a ‘fabric first’ approach, focused on reducing heat-loss and improving airtightness before investing in heat and energy solutions. Reducing your ‘space heating demand’ will generally offer greater long-lasting benefits than heat and energy upgrades alone, which can be a fantastic next step.
In a more modern home, you might choose to skip ahead and focus on distributing heat around your home more economically, or reducing your reliance on the grid by integrating solar and battery storage.
In the Retrofit Zone educational exhibit at the National Self Build & Renovation Centre (NSBRC), we explore how your approach and priorities may vary depending on the type or age of your home.
WHAT ARE THE MAIN BENEFITS OF DOING A RETROFIT?
Retrofit projects come in all shapes and sizes, and so do the benefits. Keeping warm in winter and cool in summer makes for a more comfortable home. A balanced environment with consistent temperatures and fresh air comes with health benefits too. Indoor air pollution can be more harmful than we tend to realise.
More efficient homes aren’t just better for the planet. You can drastically reduce running costs, which is especially appealing for those thinking about their forever home. Shorter term benefits can be achieved, and your property value can increase too but most significant retrofit solutions are a long-term investment. Crucially, reducing gas and energy usage – or moving away from fossil fuels – futureproofs against rising costs in an increasingly volatile market.
For some, creating a more sustainable home, or sensitively updating an older property can be rewards of their own, and a legacy to leave for future generations.
WHAT ARE SOME MISCONCEPTIONS PEOPLE HAVE ABOUT RETROFIT?
Cavity wall insulation has long had a mixed reputation. It was often promoted as a quick fix for older buildings with narrow cavities, but in many cases the insulation later became damp and ineffective. Repairs can be disruptive and expensive. More recently, similar concerns have emerged around external wall insulation upgrades, a decade or so on from this non-intrusive solution being widely recommended and subsidised. While external systems are generally easier to remove, failures still create serious problems for homeowners and tenants.
Importantly, these issues don’t mean the systems themselves are inherently flawed. Many failures stem from poor assessment of building suitability, existing moisture or debris in cavities, incompatible materials and inadequate detailing that attracts or traps moisture. This is especially critical in older solid-wall homes where breathable, vapour-open materials and good ventilation are essential. Effective moisture management is key. Addressing knowledge gaps among tradespeople remains vital, and is something the NSBRC is actively supporting.
WHAT ARE THE KEY AREAS TO CONSIDER WHEN PLANNING?
Knowing where to start can be tricky, so we recommend deciding how far you want to go, and working backwards from there to create a plan – even if you end up staggering the work itself. It can be tempting to start making upgrades before having a whole house plan. The danger is having to undo work further down the line, or wishing you had factored in how upgrades interact with one another. Effective prioritisation is important, as is balancing the eco-system of your home, cost-effective scheduling and ensuring longevity of upgrades.
That’s exactly why we’ve built the Retrofit Zone. You can explore life-size cross-sections of housing commonly found in the UK, to help you navigate challenges and solutions associated with your type and age of property. We demystify retrofit standards, jargon, planning permission, financing and schemes to equip you with a strong base level of understanding and identify your next steps.
HOW SUSTAINABLE CAN I BE?
It really comes down to budget. If sustainability is your main objective, then a carbon-neutral house without bills is genuinely achievable – as long as you can afford the initial investment. Some retrofitters even manage to create carbon-negative homes, producing more energy than they use, and selling clean energy back to the grid.
Most of us aren’t in a position to fund such a project and have to balance our priorities. It’s all about weighing up the expense of the project vs the long-term benefits and savings. Of course, not all these benefits are financial.
Perfection shouldn’t be the enemy of progress though. There are many ways to curb our gas and electricity usage without achieving a fully self-sufficient home. Some retrofitters also choose building materials with less ‘embodied carbon’ in their production methods. Reducing water usage and harvesting rainwater, supporting biodiversity, being conscious consumers and managing waste effectively, all make a difference too.
WHAT ARE THE MOST COMMON MISTAKES PEOPLE MAKE WHEN RETROFITTING?
While the Boiler Upgrade Scheme offers homeowners up to £7,500 for switching to low-carbon heating systems like air source heat pumps, these should not be seen purely as cost-saving measures. Heat pumps allow us to move away from fossil fuels more efficiently than ever before but typically run at lower temperatures than gas boilers. This means homes could become less comfortable or less affordable to run
if we don’t reduce heat loss and upgrade radiators. A ‘fabric first’ approach helps maximise efficiency, and underfloor heating is a common solution which pairs well with a heat pump. Grants are valuable, but should support well informed decisions, rather than drive them.
High-spec products or materials are no guarantee of success without proper installation and detailing. For instance, triple-glazing reduces heat loss through the glass but poor airtightness around the frame allows heat to escape. Likewise, insulation on the internal or external surface of walls must continue along window reveals and onto the frame to prevent cold spots and condensation. Ventilation is also crucial. Blocking airflow beneath suspended timber floors can trap moisture, so clear paths between airbricks should always be maintained.
Examples of all these scenarios are demonstrated in the NSBRC’s Retrofit Zone. Visit nsbrc.co.uk to find out more and plan your free visit.
To listen to the full podcast and hear more of what Nick has to say about the potential of retrofitting your home, scan the QR code
