What a retrofit assessment actually involves

A retrofit assessment is more than a standard building survey or a quick energy audit. It's a detailed, whole-house evaluation designed to understand how your property performs as a system - where heat is escaping, what condition the building fabric is in, and what improvements would make the biggest difference.

The assessment covers walls, roof, floors, windows, doors, heating systems, ventilation and overall heat loss. It also looks at how the building has been maintained and how the household uses the property day to day. The goal is to build a complete picture that a retrofit coordinator can then use to design a plan tailored to your home and your circumstances.

This is distinct from an EPC survey, which produces a rating but doesn't go into the same depth about building condition, occupant habits or the risks associated with specific improvements.

Why the assessment starts with you, not the building

Before looking at the property itself, the first conversation is about understanding what's driving you to act. The trigger is usually something specific - energy bills that are higher than expected, rooms that never feel warm, or a renovation that presents an opportunity to get the energy performance right at the same time.

I need to understand what problem you're trying to solve, what your budget looks like, how long you plan to stay in the house, and whether comfort, value or carbon reduction is the priority. Do you have a budget for a whole-house plan, or can you only afford one or two things right now? Are you planning to stay five years, ten, twenty?

These questions matter because they shape what's realistic. The assessment has to be grounded in your priorities and motivations, not just what the building needs in theory. There's no point recommending a comprehensive package to someone planning to move in two years, and no point suggesting one measure at a time to someone who wants to do everything while they're already renovating.

The on-site survey: what I look for

The physical survey is primarily visual - systematic and detailed, but non-invasive by default. I'm reading the building through what I can see and measure without opening up walls or floors.

I start with the basics: wall thickness and construction type, signs of mould and damp, and the general state of the house. How it's been maintained over the years tells me a lot about what I'm likely to find.

The exterior is just as important as the interior. I'm checking whether the pointing (the mortar between bricks or stones) has been maintained, whether there's evidence of water ingress, and whether timbers or windows are deteriorating. The outside of a building often reveals problems that aren't visible from inside.

In some cases, where there's a specific reason to check what's inside a wall cavity, a borescope (a small camera on a flexible tube) can be used through a minimal drill hole. But that's not standard practice - the default assessment is visual.

A home that looks well-maintained on the surface can still be losing heat through the walls, roof and floors in ways that only a proper assessment will identify.

Identifying red flags and existing problems

Experience teaches you to read a property quickly. Mould and damp are the most obvious red flags, along with staining on walls and ceilings and wear beyond what you'd expect for the age of the building.

Then there are the signs of previous work that's caused problems rather than solving them. I've walked into properties where cement render has been applied to an old building that needs to breathe. Spray foam used on a floor where there's a moisture issue underneath. Cupboards pushed against exterior walls, trapping moisture behind them. These indicators tell me someone has tried to improve the building without understanding how it works as a system.

The reasons vary. Sometimes it's a lack of budget, sometimes circumstances have changed and the homeowner hasn't been able to afford upkeep. Buildings need ventilation. Cooking without extraction, showering without opening a window, keeping trickle vents closed - these habits trap moisture and cause damage over time. Identifying these issues during the assessment is essential because they affect which retrofit measures are appropriate and which could make things worse.

How occupancy and lifestyle factor in

A retrofit assessment covers the physical structure, but how you live in the property directly affects how it performs and what needs to change.

Ventilation is the most common issue. Properties were designed to breathe, to be open. Older buildings in particular weren't built for the weather patterns we now experience - hot summers, cold and wet winters. When you improve the airtightness of a building through insulation and draught-proofing, adequate ventilation has to be maintained. Otherwise you trap moisture and create the exact problems you were trying to avoid.

I look at whether trickle vents (the small ventilation slots built into window frames) are being used, whether there's extraction in kitchens and bathrooms, and whether the household has habits that contribute to moisture buildup. I've been in homes where the homeowner says they're cold and the thermostat is set to 15 degrees - well below the recommended 18-degree minimum. That's a difficult conversation when someone is on a tight budget, but the reality is that properties need heating and ventilating properly to function well.

Understanding this balance between what the building technically needs and what the homeowner can realistically do is one of the harder parts of the assessment. Every household is different.

Risk assessment: why it matters

Part of the assessment is identifying risks that specific retrofit measures could introduce. Adding insulation to an older property without addressing ventilation can trap moisture and cause mould. Using inappropriate materials on a building that needs to breathe can create damp problems. Insulating a floor with moisture issues underneath can make those issues significantly worse.

The assessment considers these risks so that the eventual plan accounts for them. What could go wrong matters as much as what could be improved, and the order of work matters as much as the work itself. Customers need to understand that adding more insulation isn't always the solution. Sometimes changing habits is more important than changing the building.

What happens after the assessment

The findings from the assessment go to a retrofit coordinator, who uses them to design a plan. At Furbnow, this becomes a Home Energy Plan - a document that includes modelled costs for each recommended measure, projected energy savings, and a recommended sequence for the work based on your goals and budget.

The plan reflects the whole-house picture: which measures to prioritise, what order to do them in so that each improvement supports the next, and how to phase the work if you can't do everything at once. Some measures interact with each other - walls and windows, for example, share junctions that need to be detailed properly if both are being improved. The assessment captures all of this so the plan starts from reality rather than assumptions.

If you're thinking about retrofit and want to understand what an assessment would reveal about your home, a good first step is talking through your situation.

Book a free call to talk through your situation and work out the right next step.