FCA authorised · FRN 724952 0117 325 0027Quote & buy →
Retrofit and energy consultants
Yes. If you assess homes for retrofit, coordinate PAS 2035 projects, design insulation or advise on U-values and condensation risk, you need professional indemnity insurance. Insulation that is specified or detailed badly can trap moisture, cause mould and rot, and cost far more to take out than it did to put in. Those losses come from advice and design, not accidents, so public liability will not usually respond. Retrofit coordinators registered through the TrustMark framework are also expected to hold PI.
Part of: Professional indemnity for consultants
In short
Insulation consultants are judged on whether their assessment, design and advice keep a building dry as well as warm. PAS 2035:2023 sets out the roles of retrofit assessor, coordinator, designer and evaluator and is required on many government schemes. Random audits published by DESNZ and Ofgem in October 2025 found that 92% of external and 27% of internal wall insulation installations under ECO4 and the Great British Insulation Scheme had at least one major technical non-compliance. In England, Approved Document L sets U-values for renovated walls, roofs and floors, and BS 5250 covers moisture risk. PI covers negligent assessment and design, subject to the policy terms.
Last reviewed 5 October 2026 by the Apex professional indemnity team.
Insulation consultants rarely install anything, but their decisions settle what gets installed and how. You might carry out retrofit assessments, coordinate projects under PAS 2035, design and detail wall, roof and floor insulation, calculate U-values or judge whether a build-up will suffer from condensation. Homeowners, landlords, housing providers and installers all act on that work.
Public liability (PL) covers accidental injury and accidental damage, such as a ladder put through a conservatory roof during a survey. It is not designed for what goes wrong with insulation advice, where nothing was damaged by accident but moisture became trapped, mould appeared or a wall had to be stripped back because the specification or detailing was wrong. Professional indemnity (PI) insurance covers your liability for that kind of loss, and the cost of defending the claim, subject to the policy terms.
The scrutiny has also increased. After widespread failings in solid wall insulation on government schemes, DESNZ is tightening the rules for retrofit coordinators and designers, and clients are reading appointments and insurance schedules more closely.
The examples below are illustrative, not real claims. They show allegations insulation consultants and retrofit professionals can face.
None of these is an accident. Each alleges that your assessment, design, coordination or calculation fell below the standard of a competent insulation consultant.
An expert reviewing your work will compare it with the retrofit process standard, the Building Regulations and the moisture guidance that applied when you gave your advice.
| Standard or rule | What it says | Why it matters to your PI |
|---|---|---|
| PAS 2035:2023 (BSI) | The current specification for retrofitting dwellings: assessment, evaluation of improvement options, design and specification of measures, and monitoring and evaluation. DESNZ says it defines the roles of retrofit assessor, designer, coordinator and evaluator, that one person can hold more than one role, and that it is required on many DESNZ schemes. | Your PAS 2035 role defines what you were responsible for when something fails. |
| TrustMark framework | DESNZ says coordinators and assessors registered with scheme providers under the TrustMark framework are deemed qualified for their roles. The Retrofit Coordinator scheme requirements on TrustMark’s site require PI and public liability from a regulated insurer, with a defined minimum of £250k per property or as required by the client. | Your scheme provider records your insurance as part of its audits. |
| Approved Document L, volume 1, 2021 edition (England) | Where more than 50% of a thermal element is renovated, including by cavity fill or by insulating a wall internally or externally, the whole element should reach the improved U-values in Table 4.3, such as 0.30 W/m²K for a wall with internal or external insulation, unless that is not technically or functionally feasible or would not pay back within 15 years. A lesser standard may be acceptable to protect against condensation under Part C. | Your U-value and moisture advice must satisfy building control as well as the client. A 2026 edition takes effect on 24 March 2027 for most work. |
| BS 5250:2021 | Code of practice for managing moisture in buildings: where moisture comes from, how it moves and is deposited, and how to manage the risks through assessment, design, construction and operation. | The benchmark for whether you thought about moisture properly. |
| BS EN ISO 13788:2012 | Simplified methods for assessing mould and surface condensation risk and interstitial condensation. BSI notes the method ignores effects such as liquid moisture transfer, air movement and moisture-dependent material properties, so it applies only where those effects are negligible. | Where those effects matter, an expert may say a simple calculation was the wrong tool. |
In October 2025 DESNZ and Ofgem published random audits of solid wall insulation installed under ECO4 and the Great British Insulation Scheme. The audits, carried out by chartered surveyors against PAS 2035, found that 92% of external wall insulation installations and 27% of internal wall insulation installations had at least one major technical non-compliance that will affect the performance of the system, and some had health and safety risks to occupants. Every household that had external wall insulation under those schemes is being offered an audit, faults are to be fixed by the original installer, and DESNZ says ECO4 will end in December 2026.
Most of the remediation falls on installers, but PAS 2035 roles surround every installation: someone assessed the home, someone designed the measure and someone coordinated the project. When costs mount, installers, and guarantee providers where an installer has stopped trading, may ask whether the design or coordination contributed. If you worked on these schemes:
| Usually covered by PI | Often excluded or limited | Needs a different policy |
|---|---|---|
| Negligent retrofit assessments and coordination | Promises that products are fit for purpose, and guaranteed energy savings | Accidental damage during a site survey (public liability) |
| Errors in insulation design, detailing and specification | Claims involving mould or fungi, under some wordings | Injury to your own staff in lofts and on scaffolds (employers’ liability) |
| Wrong U-value and condensation risk calculations | Installation work by you or your own operatives | Defective installation by contractors (their own liability cover and guarantees) |
| Unsuitable advice on cavity, internal or external wall insulation | Circumstances you knew about before the policy began, including unreported audit findings | Insurance-backed guarantees on installed measures (guarantee providers) |
| Defence costs and expert evidence | Asbestos disturbed during intrusive surveys | Loss of client data held on retrofit portals (cyber insurance) |
Cover depends on the insurer accepting the risk and on the wording. Make sure the business description names every PAS 2035 role you take on: a policy for “energy assessment” may not stretch to design or coordination.
For coordinators working through the TrustMark framework, the scheme requirements set a floor of £250k PI and public liability per property, or as required by the client, from a regulated insurer. Many clients ask for more. Housing associations, local authorities running grant schemes and main contractors set limits in contracts and frameworks, sometimes with collateral warranties. Programme work across hundreds of homes can produce many similar claims from one design error, so check how your policy treats related claims and whether the limit applies to each claim or in total; see aggregate vs each and every claim.
Insulation failures are slow. Moisture can take several winters to show, and a fault repeated across a housing programme may not be traced for years. PI is claims-made, so the policy in force when the claim arrives is the one that responds. Keep cover continuous, notify circumstances promptly and arrange run-off if you retire or close the business; read run-off cover explained.
A complete proposal gets better terms than a bare one, and a broker can only present what you tell us. Have these ready:
Speak to a broker
PI for insulation consultants, placed by a named broker
Start the online proposal and save it as you go, or leave your number and a named broker will call you back, usually the same working day.
Apex Insurance Brokers is an independent insurance broker based in Bristol, established in 2009 and authorised and regulated by the Financial Conduct Authority. We are not tied to one insurer: we work with over 30 markets, including Lloyd’s syndicates through wholesale brokers, and every client has a named broker who handles the placement, mid-term changes, certificates for clients and the renewal.
Yes, if you assess homes, design or specify insulation, coordinate retrofit projects or advise on U-values and condensation risk. Mistakes lead to damp, mould and costly removal rather than accidental damage, so public liability usually won’t respond. PI covers your liability for negligent advice and design, subject to the policy terms.
No law requires it. Retrofit coordinators working through the TrustMark framework are expected to hold it: the coordinator scheme requirements on TrustMark’s site require PI and public liability from a regulated insurer, with a defined minimum of £250k per property or as required by the client. Other clients set their own limits in contracts.
It can, if a claim alleges your assessment, design or coordination was negligent and the policy covers that role, subject to its terms. Timing matters: report audit findings that involve your projects promptly, because a new policy usually excludes matters you already knew about.
DESNZ describes the designer as designing appropriate retrofit solutions and the coordinator as coordinating delivery of the works; PAS 2035 also has assessors and evaluators. One person can hold several roles. Tell your insurer every role you take on, because each brings different responsibilities and a different exposure.
It can, where the claim alleges your design or advice was negligent, subject to the policy terms. Watch for mould or fungus exclusions: a wording that removes those claims leaves an insulation consultant exposed on the issue most likely to arise. Record how you assessed moisture risk, for example against BS 5250.
Often years later. Moisture problems can take several winters to appear, and a design fault repeated across a programme may surface long after the work. Because PI is claims-made, the policy in force when the claim arrives is the one that responds, so keep cover continuous, keep your PAS 2035 records and arrange run-off.
Apex arranges professional indemnity insurance for insulation consultants across the UK. Tell us about your work and we’ll find cover that fits. Or call 0117 325 0027.
Start your PI proposal Call 0117 325 0027Apex Insurance Brokers Limited is authorised and regulated by the Financial Conduct Authority. Registered in England and Wales, company number 07014570. This page is general information, not advice on your individual circumstances. Cover is always subject to the insurer’s acceptance and the policy terms, and this page does not guarantee that cover will be available or on what terms.
