Retrofit - We Need to Talk About... Defects in Homes & PAS2035

One of the biggest challenges in retrofit delivery isn’t just installing energy efficiency measures, it’s making sure the home is ready for them. And that’s where defects in homes become a critical issue. In Devon and Cornwall, this is a constant problem with our rural and old housing stock that has lacked maintenance for decades.

With the Warmer Homes Plan Local and Warmer Homes Plan Social now rolling out, we need to ask... are we tackling existing defects before retrofit, or are we ignoring them in the rush to get measures installed?

What Do We Mean by 'Defects' in Retrofit?

It’s not just damp and mould, although those are major issues. We’re talking about:

Poor roof conditions: including poor flashing, slipped tiles, ripped felt, and chimneys in disrepair, all of which can lead to water ingress.
Deteriorated soffits and fascias
Structural problems: subsidence, degraded masonry, failed pointing, wall tie failure.
Deteriorated window & door frames and units
Condensation & ventilation issues
Unstable or poorly constructed loft spaces and DIY conversions
Defective or outdated electrical systems: which could impact heat pump or PV installations.
Compromised cavity walls: where existing insulation has failed or where cavities are unsuitable for refilling.
Blocked or failing rainwater goods: gutters, downpipes, and drainage systems that are not directing water away from the property properly.
Missing or inadequate fire breaks in loft spaces: posing a major safety risk.
Failing historic solid wall insulation: including EWI with failed beads, trapped moisture, or detaching render.

Why Does This Matter?

Because installing retrofit measures on top of an unresolved defect is like putting a fresh coat of paint on damp plaster. It looks good for a while, but the problems won’t go away. In fact, retrofit can sometimes make defects worse if they aren’t identified and addressed first.

How Does PAS2035 Help?

Done properly, PAS2035 ensures defects are caught and resolved before energy measures go in:

✅ Retrofit Assessments identify defects before planning measures.

✅ Risk-based approach ensures high-risk homes aren’t fast-tracked.

✅ Technical Surveys and PIBIs flag issues that could compromise the retrofit.

✅ Independent and trusted Retrofit Coordination ensures measures are installed only when homes are ready.

Stock Condition Assessments – Picking the Right Homes from the Start

One of the biggest mistakes in large-scale retrofit schemes we have seen is selecting properties before understanding their condition. Too often, properties are chosen based on funding criteria alone, without fully assessing whether they are viable for retrofit. The result? Homes that drop out of the scheme at later stages due to defects that should have been identified earlier.

A proper stock condition assessment before properties are selected helps to:

Avoid late-stage dropouts that waste time, resources, and frustrate occupants.
Identify homes that need remedial work first, before retrofit measures are considered.
Ensure funding is allocated efficiently, targeting homes that will benefit the most.

But Are We Really Tackling Defects Properly?

One of the biggest issues we hear from installers is: “We’re not builders, we are insulation installers.” A fair point! Many contractors simply aren’t set up to deal with construction defects like leaking roofs or water ingress. PAS2035 states that any defect allowing water ingress must be fixed before retrofit, but that raises some difficult questions:

Is the supply chain equipped to handle these issues? Do we have enough skilled contractors who can deal with roofing, drainage, and structural problems before energy measures go in?
Is the funding there to cover it? If budgets are tight, does this mean defects get overlooked or passed down the line?
Are we making the right decisions early enough? If a property isn’t fit for retrofit, who makes the call on what happens next?

At Dartmoor Energy, we believe that identifying defects early is critical. The sooner issues are flagged, the sooner the right decisions can be made. Whether that means repairs before retrofit or rethinking the best measures for a property, stock condition assessments should be a key part of any funding strategy, not an afterthought.

With Warmer Homes Plan funding now live, we have a huge opportunity to get this right. But that starts with ensuring we aren’t just retrofitting, we’re fixing homes properly!