What to Expect from an ECO4 Installation
An ECO4 installation involves more than a tradesperson arriving and fitting a new boiler or adding insulation. Before work begins, the household, property and proposed measures normally need to be assessed. The project may then pass through technical design, funding approval, installation, inspection and handover stages.
The exact process depends on the property, the measures being proposed and the organisations delivering the project. Some households may receive several coordinated improvements, while others may be offered a more limited package based on the assessment and available supplier funding.
This guide explains what to expect before, during and after an ECO4 installation, the questions you should ask and the paperwork you should receive.
ECO4 update for 2026: The scheme has been extended to 31 December 2026. However, the extension allows energy suppliers more time to complete existing obligations and rectify non-compliant work; it does not introduce additional targets or guarantee that funding will be available for every new application. is an ECO4 installation?
An ECO4 installation is a home energy-efficiency or heating improvement delivered through the fourth phase of the Energy Company Obligation.
ECO4 is not a conventional grant that gives a fixed payment directly to every eligible household. Energy companies decide which retrofit projects they will support, how much funding they will provide and which delivery partners they will use. Different providers may therefore offer different measures, funding amounts or customer contributions for the same property. g on the property and project, eligible work may include:
- Loft, wall, floor or roof insulation.
- Heating controls.
- First-time central heating.
- Certain boiler repairs, replacements or heating-system upgrades.
- Renewable heating systems.
- Connections to qualifying district-heating systems.
- Ventilation work required as part of the retrofit design.
ECO4 follows a whole-property approach. The aim is to consider how insulation, heating, ventilation and the building’s condition interact rather than treating every improvement as an isolated job. A pre-retrofit assessment is used to establish the property’s starting energy rating and help determine an appropriate improvement package. installation process at a glance
| Stage | What normally happens | What the household should check |
|---|---|---|
| Initial enquiry | Basic household and property details are collected | Who is collecting the information and why |
| Eligibility check | Benefits, income, referral route, tenure and property information may be checked | Whether this is an initial check or confirmed approval |
| Retrofit assessment | The property is inspected and its energy performance and condition are recorded | Which areas must be accessed and how long the visit may take |
| Improvement proposal | Suitable measures are recommended | What is included, excluded and why each measure is proposed |
| Funding approval | The supplier or delivery partner reviews the project | Whether funding is confirmed and whether a contribution applies |
| Contract and consent | The scope, responsibilities and terms should be provided in writing | Price, cancellation rights, guarantees, exclusions and timescales |
| Pre-installation checks | Technical details, access and existing condition may be checked again | Whether enabling or repair work is required |
| Installation | Approved measures are installed | Daily access, disruption, safety and protection of belongings |
| Commissioning and handover | Systems are tested and instructions are provided | Controls, warranties, certificates and contact details |
| Monitoring or inspection | The property may be selected for a quality check | Who is visiting and which organisation they represent |
1. The initial eligibility check
The process normally begins with questions about the household and property.
You may be asked for information such as:
- The property address.
- Whether you own or rent the home.
- The landlord’s details where applicable.
- Household income or qualifying benefits.
- The current EPC rating.
- The existing heating system.
- The boiler’s age, make and model.
- Existing insulation.
- Health or vulnerability circumstances where relevant.
- Recent energy bills or fuel information.
- Photographs of the boiler, loft, walls or heating system.
This first check does not necessarily mean the household or project has been approved.
A household may meet an ECO4 eligibility route but still not receive an installation. The property assessment, technical design, available supplier funding and proposed measures must also be accepted. Ofgem states that ECO eligibility does not require an energy supplier or installer to proceed with work. lear about who is contacting you
ECO4 projects can involve several organisations, including:
- An obligated energy supplier.
- A managing agent or funding partner.
- A lead-generation company.
- A retrofit assessor.
- A retrofit coordinator.
- One or more installation businesses.
- A certification or guarantee provider.
Ask the person contacting you to explain:
- Their company name.
- Their role in the project.
- Which organisation would carry out the work.
- Which energy supplier is expected to fund it.
- How your personal information will be used.
- Whether the check is preliminary or a confirmed offer.
Do not assume that a website, advertisement or caller represents the government merely because it refers to ECO4.
2. Landlord and property-owner permission
If you own the home, you will normally need to consent to the proposed work.
Private tenants may also qualify, but the landlord’s permission is generally required before measures can be installed. A supplier may request evidence that the landlord or relevant property owner has authorised the work. on may also be needed from:
- A housing association.
- A freeholder.
- A management company.
- Another joint owner.
- A mortgage or leasehold party where the agreement requires it.
The provider should establish the required consent before booking installation work.
3. The retrofit assessment
The retrofit assessment is one of the most important stages of the ECO4 installation process.
The assessor may record:
- The age, type and construction of the property.
- Wall, roof and floor construction.
- Existing insulation.
- Windows and doors.
- Heating and hot-water systems.
- Ventilation.
- Signs of damp, mould or disrepair.
- Room dimensions.
- Access limitations.
- Energy-performance information.
- Occupancy and household requirements.
The assessor may need access to the loft, boiler, meter cupboards, heating controls and every relevant room. Move stored belongings where practical and make sure access points are available.
The assessment is not the installation
An assessor recording a measure does not mean it has been approved.
The findings still need to be reviewed as part of the retrofit design and funding process. Previously unknown property conditions may also mean that:
- A proposed measure is removed.
- A different measure is recommended.
- Repair or enabling work is required.
- Ventilation work is added.
- The expected customer contribution changes.
- The property cannot proceed.
Ask for a clear explanation if the final proposal differs from what was discussed during the first enquiry.
4. The proposed ECO4 measures
Following the assessment, you should be told which improvements are proposed and why they are considered suitable.
ECO4 focuses on improving less energy-efficient homes and encourages a coordinated, multi-measure approach. However, the final package depends on the property’s starting condition, scheme requirements, technical findings and supplier funding. posal might include a combination such as:
- Loft insulation and heating controls.
- Wall insulation and ventilation.
- First-time central heating and insulation.
- A heating-system upgrade alongside fabric improvements.
- Several insulation measures installed as one project.
Do not judge the offer only by the number of measures. Check:
- Which areas of the property will be treated.
- The proposed materials and systems.
- Any areas that are excluded.
- Whether decoration or reinstatement is included.
- Whether ventilation upgrades are required.
- Whether the heating or hot-water supply will be interrupted.
- Who will remove waste.
- What guarantees will apply.
- Whether you must pay anything.
5. Funding approval and customer contributions
ECO4 funding is not automatically the same for every household or provider.
Energy companies determine which projects they will fund and the level of support they will provide. This means one provider may offer a fully funded package while another may request a customer contribution or propose a different scope. bution does not necessarily mean the project offers poor value, but it should be understood before you agree.
Ask for a written breakdown showing:
- The total project value.
- The amount expected to be funded.
- Your contribution.
- When payment becomes due.
- Whether any advance payment is refundable.
- What happens if funding is refused.
- Whether the contribution can change after further checks.
- Which work is included in the price.
- How additional work will be authorised.
Paying a contribution does not by itself guarantee final approval or installation.
6. The contract and written scope
Do not rely only on a telephone conversation or a salesperson’s description.
Before work begins, you should understand:
- The legal name of the business you are contracting with.
- The measures being installed.
- The products or materials being used.
- The rooms or areas included.
- The expected installation period.
- Your responsibilities.
- The installer’s responsibilities.
- The funding arrangement.
- Any customer payment.
- Cancellation terms.
- Guarantees and financial protection.
- Complaints procedures.
- What happens if unexpected work is found.
Check that verbal promises appear in the written documents.
For example, if you have been told that the company will repair plasterwork, move furniture, replace flooring or redecorate, confirm exactly what level of reinstatement is included.
7. Pre-installation checks
A further visit may take place before the main installation.
The installer or technical team may check:
- Measurements.
- Product quantities.
- Scaffold requirements.
- Cable and pipe routes.
- Boiler or radiator locations.
- Ventilation arrangements.
- Electrical capacity.
- Storage and access.
- Parking.
- Waste removal.
- Water, gas or electricity isolation.
- Areas requiring protection.
This is also the time to discuss household needs.
Tell the provider in advance if:
- Someone works from home.
- A resident has mobility or health requirements.
- Young children or pets live in the property.
- Heating or hot water cannot be interrupted for long.
- Access is restricted.
- There are valuable or delicate belongings.
- Parking or scaffold access requires permission.
- An alarm, camera, satellite dish or external fitting may obstruct the work.
8. Preparing your home
The provider should explain what needs to be moved before installation.
Preparation may include:
- Clearing the loft hatch and a safe route to it.
- Moving furniture away from walls.
- Emptying cupboards around the boiler.
- Removing fragile items from work areas.
- Providing access to radiators.
- Clearing driveways or external walls.
- Arranging access to meters and consumer units.
- Protecting belongings from dust.
- Keeping pets away from work areas.
Ask whether the team will supply dust sheets, floor protection and temporary weather protection where needed.
Do not move or disconnect gas, electrical or heating equipment yourself unless a competent person has instructed you to do so.
9. What happens during the installation?
The installation programme depends on the measures and the condition of the property.
A heating-control installation will involve different work from first-time central heating or external wall insulation. A multi-measure project may also involve different teams visiting at separate stages.
At the start of the work, the installer should confirm:
- The planned work areas.
- The expected sequence.
- Which services may be interrupted.
- Working hours.
- Site safety arrangements.
- The person responsible for questions.
- How unexpected problems will be handled.
Potential disruption
Depending on the measures, you may experience:
- Drilling and construction noise.
- Dust.
- Furniture being moved.
- Restricted access to some rooms.
- Scaffold around the property.
- Temporary loss of heating or hot water.
- Contractors entering several rooms.
- Materials being stored outside.
- Vehicles and waste containers near the property.
- Follow-up visits for finishing or inspection.
Ask for an expected daily schedule rather than assuming every measure will be completed during one visit.
10. What to expect from different ECO4 measures
| Stage | What normally happens | What the household should check |
|---|---|---|
| Initial enquiry | Basic household and property details are collected | Who is collecting the information and why |
| Eligibility check | Benefits, income, referral route, tenure and property information may be checked | Whether this is an initial check or confirmed approval |
| Retrofit assessment | The property is inspected and its energy performance and condition are recorded | Which areas must be accessed and how long the visit may take |
| Improvement proposal | Suitable measures are recommended | What is included, excluded and why each measure is proposed |
| Funding approval | The supplier or delivery partner reviews the project | Whether funding is confirmed and whether a contribution applies |
| Contract and consent | The scope, responsibilities and terms should be provided in writing | Price, cancellation rights, guarantees, exclusions and timescales |
| Pre-installation checks | Technical details, access and existing condition may be checked again | Whether enabling or repair work is required |
| Installation | Approved measures are installed | Daily access, disruption, safety and protection of belongings |
| Commissioning and handover | Systems are tested and instructions are provided | Controls, warranties, certificates and contact details |
| Monitoring or inspection | The property may be selected for a quality check | Who is visiting and which organisation they represent |
The table provides a general guide. The actual work should be confirmed in your property-specific design and contract.
11. Changes discovered during the work
Even a detailed survey may not reveal every concealed condition.
For example, installers may uncover:
- Damaged surfaces.
- Unsafe wiring.
- Moisture or decay.
- Blocked cavities.
- Inaccessible pipe routes.
- Asbestos-containing materials.
- Structural defects.
- Previous unsuitable alterations.
Work should not simply continue without explanation where a significant problem affects safety, price or design.
Ask the provider to confirm in writing:
- What has been found.
- Why it affects the installation.
- Whether work must pause.
- Who is responsible for repairs.
- Whether the proposed scope or contribution will change.
- Whether you have a choice about proceeding.
Do not agree to unexplained additional charges at the door.
12. Testing, commissioning and quality checks
After installation, relevant systems should be checked and commissioned before handover.
Depending on the measure, this may include checking:
- Heating operation.
- Hot-water operation.
- Thermostats and heating controls.
- Radiator performance.
- Ventilation airflow.
- Electrical safety.
- Pressure or system settings.
- Insulation coverage.
- Weatherproofing.
- Finishes and reinstatement.
- Waste removal.
ECO4 installers must generally be TrustMark-registered businesses, and projects involving relevant retrofit measures must follow the applicable retrofit and installation requirements. TrustMark quality-assurance arrangements can include audits, inspections and requirements to correct non-compliant work. perty may therefore be selected for a later inspection even when the installation appears complete.
Always verify the identity of anyone requesting access and ask which organisation has arranged the inspection.
13. The ECO4 handover
Handover should explain what has been installed and how to use or maintain it safely.
Do not be afraid to ask the installer to demonstrate equipment more than once.
The handover may include:
- A summary of the completed measures.
- Heating and hot-water instructions.
- Control settings.
- Ventilation instructions.
- Maintenance requirements.
- Product information.
- Emergency or isolation information.
- Warranty and guarantee details.
- Installer and provider contact information.
- Advice about expected drying, curing or settling periods.
- Photographs or installation records where applicable.
For mechanical or electrical systems, ask the installer to show you:
- How to turn the system on and off.
- How to change the temperature or programme.
- What normal operation looks and sounds like.
- Which settings should not normally be changed.
- What to do if a warning or fault appears.
- Who to call for technical support.
14. Paperwork to keep after an ECO4 installation
Keep all documents together for future maintenance, complaints, insurance or property-sale enquiries.
The exact paperwork varies, but you may receive:
- The signed contract.
- The final scope of work.
- Payment receipts.
- Product information.
- Installation and commissioning records.
- Operating instructions.
- Warranty documents.
- Workmanship or measure guarantees.
- Electrical, gas or building-compliance certificates where applicable.
- Handover confirmation.
- Complaints contact details.
- Details of the TrustMark-registered business.
- Details of the relevant scheme or certification provider.
Do not sign a completion or satisfaction declaration until you have had a reasonable opportunity to inspect the work and report visible concerns.
If something is unfinished, record it in writing and take dated photographs.
15. What should you check before the installer leaves?
Use this final check:
- The agreed measures appear to have been completed.
- The property has been left safe.
- Heating, hot water and controls have been demonstrated.
- Ventilation equipment is working and has been explained.
- Visible damage or unfinished work has been recorded.
- Waste and unused materials have been removed or a collection date agreed.
- Important surfaces have been reinstated as agreed.
- You know who to contact with a problem.
- Guarantees and certificates have been explained.
- Any follow-up visit has been confirmed.
- You have copies of the documents you signed.
16. What if there is a problem after installation?
Contact the business responsible for the work as soon as possible.
Describe:
- The problem.
- When you first noticed it.
- Which measure is affected.
- Whether it creates an immediate safety risk.
- What you want the company to do.
Keep:
- Photographs and videos.
- Contracts.
- Quotations.
- Certificates.
- Emails and messages.
- Names of people you speak to.
- Dates of calls and visits.
- Copies of complaints.
TrustMark’s complaints process normally begins by raising the issue with the registered business. If it is not resolved, the complaint may be escalated to the business’s Scheme Provider and, where the relevant conditions are met, to the Dispute Resolution Ombudsman. mmediate gas, electrical, fire or structural safety concern, stop using the affected equipment where safe to do so and contact the appropriate emergency or qualified professional service.
Questions to ask before agreeing to an ECO4 installation
Ask the provider:
- Which organisation is funding the project?
- Has funding been confirmed or is the project still being assessed?
- Which company will carry out each measure?
- Is each installer appropriately registered for the work?
- Which measures are included?
- Why have those measures been recommended?
- Which rooms and areas will be treated?
- What is excluded?
- Will ventilation work be required?
- Is there a customer contribution?
- Could the contribution change?
- How long is the proposed installation programme?
- Will heating, hot water or electricity be interrupted?
- Who handles decoration and reinstatement?
- What guarantees and financial protection apply?
- What paperwork will be provided?
- Who should be contacted if the work is delayed or defective?
- What happens if previously unknown property problems are discovered?
A reputable provider should be willing to explain the proposed work without pressuring you to sign immediately.
Frequently asked questions (FAQs)
Clear answers about ECO4 installation timescales, disruption, customer contributions, survey changes, making good, inspections and what to do if a problem occurs. Speak to Simple Green Energy .
Understand the work before it starts
A good ECO4 installation should begin with a proper property assessment, a clear written scope and an explanation of the costs, measures, disruption, guarantees and aftercare involved.
Discuss your ECO4 installationFinal Thoughts: Which Is the Better Option?
ECO4 funding is normally the better financial route when the household qualifies, funding is available and the recommended package genuinely addresses the property’s needs.
Paying privately may be better when the work is urgent, the customer wants a particular installer or product, or greater control over the scope and timetable is important.
Do not decide based only on words such as “free”, “funded” or “premium”. Compare the total customer cost, work included, technical design, guarantees, timescale and expected result.
The best option is the one that solves the property’s actual problem at an affordable cost—with the scope and responsibilities clearly set out before work begins.
