Skip to main content
Delivery / post-retrofit

6. Maintenance


The final stage of a retrofit project is about making sure that the retrofit systems deliver as expected and that any issues are quickly identified and addressed. This involves a combination of effective use by residents and maintenance by the housing provider.


    Why it matters

    Well-maintained and operated energy systems will be more likely to deliver the reductions in energy demand and carbon emissions that your retrofit project aimed to achieve. More importantly, good maintenance and operation of these systems will help support your residents’ health and wellbeing and assure their safety in their homes.

    Key steps to take

    1. Plan for maintenance: As you identified and designed your retrofit measures, you should document the maintenance requirements that each will need into a clear plan for how each property needs to be maintained. This will help you understand what resources are needed and how you will communicate with contractors and residents during and after the retrofit.

    2. Develop capacity: You may not have specialist in-house maintenance services for renewable energy systems and other retrofit equipment. The more retrofits you carry out, the more these systems will become business-as-usual for your organisation, so consider how much internal capacity should be developed.

    3. Make sure your contracts support effective maintenance: During procurement, you will have set out the contractual expectations of system providers and installers. These should include maintenance and repair responsibilities.

    4. Set out clear expectations with residents: Your organisation will be the first port of call for residents who have faults or issues with their energy systems. Make sure that residents know who is responsible for fixing which system and that your customer service and maintenance teams have clear information on who will be contacting residents and when this will happen.

    Success factors

    Think about maintenance from the start: As you develop your retrofit project, make sure that someone with maintenance responsibility is part of your team and that you consider the maintenance implications of all measures and technologies.

    Build knowledge and skills within the organisation: Heat pumps, solar PV and solid wall insulation may be new to your organisation now, but will become increasingly common in the coming years. Developing in-house maintenance capacity will help your organisation be fit for the future and reduce reliance on external contractors.

    Deep dive

    Roles and responsibilities

    You need to ensure that appropriate maintenance service is in place, which includes annual inspections. Retrofit systems require maintenance by qualified persons; this means that you may have to procure separately from your existing responsive repairs contract and / or to upskill your in-house maintenance team.

    Advanced controls and remote monitoring of systems’ performance mean that residents should need very little interaction with the operation of their systems, other than to set the temperature controls.

    The table below shows the maintenance and aftercare roles and responsibilities following the handover of the completed retrofit installations:



    Retrofit coordinator

    Ensuring that post-works advice and operating instructions are provided to the resident and that an appropriate maintenance and repair service is in place

    Housing officer

    Ensuring that communication with residents is handled satisfactorily and that any residents’ concerns are addressed to their satisfaction

    Customer service centre

    Receiving the first line enquiries from residents. Handler must be able to understand the resident’s issue and direct the call for action to be taken

    Maintenance contractor/team

    Fixing technical problems within the target response time and conducting service inspections

    Asset management

    Recording completed maintenance and repairs in the Asset management system

    Planning for cyclical replacement of the systems

    Energy advice provider

    Offering residents advice on the best use of their installed systems


    Operating the systems’ controls correctly

    Reporting any system malfunctions

    Delivery models for maintenance

    You have probably already fitted some solar PV and heat pump systems through new build and previous retrofit programmes. As your use of these types of systems scales up, there is an opportunity to set up a specific service for maintenance. To do this you will need to:

    • Understand the opportunity within your stock: audit your stock data for information about the number of systems already installed and the likely number of installations (in both new build and retrofits) over the next ten years

    • Draw up a business case for a purpose-designed maintenance and responsive repair service. Options for delivery of such a service include:

      • A new specialist renewable energy/heating contractor

      • Existing heating/Mechanical and Electrical (M&E) contractors

      • Reskilling of existing DLO

      • Setting up a new, specialist renewable energy installation and maintenance DLO

    Your preferred approach will depend on a number of factors including scale, availability of skills within the organisation or externally, opportunities and appetite for reskilling and management capacity within the organisation.

    Energy performance contracting

    Whole house retrofit projects require a great attention to insulating the building envelope thoroughly and installing the right heat and renewable energy systems. Energy performance contracts with the supplier of the retrofit system guarantee that the expected energy and carbon savings are actually achieved, placing the onus on the supplier to fix performance issues. Although the guarantee of energy performance is still a developing concept, it is a possible model for procuring whole house retrofit projects in the future.

    Maintenance regimes

    You need to ensure that a service regime is in place for system maintenance and responsive repairs. Regular servicing of the retrofit systems must follow the manufacturers’ instructions. This has implications for operational performance, ongoing safety and the validation of warranties and guarantees.

    Your systems should have been specified to make use of automation and remote monitoring as far as possible. This will help you to identify and diagnose issues as soon as they arise.

    The table below sets out broad steps for maintenance and care but is not comprehensive and does not replace manufacturers’ instructions.



    Maintenance regime

    Tenant care


    Remote monitoring

    Air-source heat pumps

    Annual inspection:

    • Remove debris

    • Replace filters

    • Clean coils and fans

    • Check airflow is correct

    • Check refrigerant levels and pressure

    • Check all electrical contacts

    • Check for system leaks

    • Check reverse heating /cooling controls

    • Lubricate belts and motors

    • Check and test thermostat

    The unit may frost over when the outside temperature is below freezing, in which case activate the defrost mode (automated controls ought to prevent this from happening)

    Report any problems to customer services

    Ground-source heat pumps

    Annual inspection:

    • Check the electronics and controls

    • Check the water pump, compressor, above ground pipes and connectors

    • Check the chemical mix of anti-freeze/coolant fluid in the ground array

    • Check the radiators and bleed the system if necessary

    Ensure the temperature setting is not too low, to avoid the auxiliary heater being activated (automated controls ought to prevent this from happening)

    Report any problems to customer services

    Solar PV

    Annual inspection:

    • Checks of the inverter, meter and other components

    • Check current and voltage outputs

    • Inspect the condition of the roof

    Visually check the panels from time to time

    Solar Thermal

    Annual inspection:

    • Check safety values

    • Check the pump fluid pressure

    • Check the PH levels

    • Replace the antifreeze fluid every 4 years

    Visually check the panels for time to time

    Report any problems to customer services

    Mechanical Ventilation with Heat Recovery (MVHR)

    Annual inspection:

    • Replace filters

    • Clean air valves and grilles of dust and dirt

    • Check all connections are well sealed and that there are no air leaks

    • Check that controls are working properly

    Check the condensation drain is not blocked

    Report any problems to customer services

    External wall insulation

    10-year inspection of watertight seals

    No holes to be made in the wall insulation

    No storage of items on top of loft insulation

    Report any problems such as water ingress to customer services


    Reducing the need for repairs

    The instances of repairs to renewable energy systems will be reduced by:

    • Specifying systems that require very little or no care and maintenance by residents. Operation of the systems should be as automated as possible.

    • Fitting remote monitoring devices which send alerts to the service organisation when a system is not working properly or is in need of preventative maintenance. Heat pumps and solar PV are often fitted with these devices as standard.

    • Setting up an annual service to check that the systems are operating efficiently and safely in compliance with regulations.

    Further resources

    How should I communicate with residents around maintenance and repairs?

    Together with Tenants, National Housing Federation: this charters commits housing providers to ensuring that residents receive timely advice and are given support when things go wrong.

    Visit Website

    The charter for social housing residents (Social Housing White Paper - England): this government white paper focuses on safety and good tenant communications where residents have simple and accessible routes for raising issues, making complaints and seeking redress. A senior person in the organisation is to be responsible for compliance and responsive repairs are to be completed right first time to tenants’ satisfaction.

    Visit Website

    What are the risks of poor maintenance of retrofit installations?

    Planning Responsible Retrofit, Sustainable Traditional Buildings Alliance: Chapter 4 of this guidance sets out key risks of retrofit and can be applied across all building types.

    Visit Website

    Get in touch

    If you would like to discuss planning issues on your retrofit project, please contact the SHRA Support team.

    We would love to hear about your experiences. What has worked for your organisation? What lessons have you learned? What documents, reports or tools have you found most helpful? Please contact us if you would like to share your experiences.

    Related Documents

    Back to top