So, Do All Window Installers Have to Be FENSA Approved?
When replacing windows in a property, many homeowners hear about FENSA approval and assume that every installer must be registered. In reality, the situation is slightly more complex. While FENSA approval is common and often preferred, it is not the only legal route for replacing windows. What matters most is that the installation complies with building regulations and is properly certified.
Understanding how FENSA works, when it is required, and what alternatives exist helps homeowners avoid costly mistakes and delays. We explain whether all window installers have to be FENSA approved, what the rules are, and how homeowners can make sure their window replacement is compliant.
What FENSA Is and Why It Exists
FENSA stands for the Fenestration Self Assessment Scheme. It is a government authorised scheme that allows registered window installers to certify their own work as compliant with building regulations.
When a FENSA registered installer replaces windows or doors in an existing property, they notify FENSA after the work is completed. The homeowner then receives a certificate confirming that the installation meets current standards for safety, energy efficiency, ventilation, and glazing requirements.
This certificate is important because it proves the work was carried out legally. It is often requested during the sale of a property and can help avoid delays or questions from buyers.
Do All Window Installers Have to Be FENSA Approved?
No, not all window installers have to be FENSA approved. However, every replacement window installation must still comply with building regulations, regardless of who carries out the work.
FENSA approval is one method of compliance, but it is not the only one. If an installer is not registered with FENSA, the work can still be legal as long as it is inspected and approved by building control.
The key requirement is not FENSA membership itself, but proper certification of the installation.
What Happens If an Installer Is Not FENSA Registered?
If a window installer is not FENSA registered, the homeowner must notify building control before the work begins. This usually involves contacting the local authority and paying an inspection fee.
A building control officer may inspect the installation during or after the work to confirm that it meets regulations. Once the officer is satisfied, a completion certificate is issued. This certificate serves the same legal purpose as a FENSA certificate.
While this route is valid, it often involves more paperwork and coordination. Many homeowners prefer to avoid this extra step by using a registered installer.
Why Many Homeowners Prefer FENSA Registered Installers
Many homeowners choose FENSA registered installers because the process is simpler and more straightforward. Certification is handled automatically, and there is no need to contact building control separately.
Using a registered installer also reduces the risk of missing documentation, which can cause problems later. When selling a property, buyers often ask for proof that replacement windows were installed correctly.
Homeowners commonly check installer status using the FENSA installer checker before booking work.
What Building Regulations Cover for Window Replacement
Building regulations apply to most replacement window installations. These rules are in place to ensure safety, comfort, and energy efficiency.
Energy Efficiency Requirements
Replacement windows must meet minimum thermal performance standards. This helps reduce heat loss and supports lower energy use in the home.
Safety Glass Regulations
Windows installed in certain locations, such as near doors or at low levels, must use safety glass. This reduces the risk of injury if the glass breaks.
Ventilation Standards
Replacement windows must provide adequate ventilation. This often includes trickle vents or other approved ventilation solutions to allow fresh air into the property.
Fire Escape Requirements
In some rooms, especially bedrooms, windows must meet escape requirements. This ensures occupants can exit safely in an emergency.
Whether the work is certified through FENSA or approved by building control, these standards must always be met.
Does FENSA Apply to All Types of Window Work?
FENSA certification mainly applies to replacement windows and doors fitted into existing openings. It does not usually apply to windows installed as part of a new build or an extension.
In those cases, the entire project is already covered by building control approval, so separate FENSA certification is not required.
Understanding this distinction helps homeowners avoid unnecessary confusion about when certification is needed.
Window Styles and Compliance
All window styles must comply with building regulations when replaced. The design does not change the legal requirement.
Many homeowners replace older units with casement windows because they provide strong seals and reliable ventilation. Period properties often use sash windows to maintain traditional appearance while improving insulation.
Homes with modern designs may prefer flush windows for their clean look, while larger properties sometimes include bay windows. Regardless of the style chosen, the same regulatory standards apply.
What Happens If You Do Not Have Certification?
Replacing windows without proper certification can lead to problems later. The most common issue arises when selling the property, as buyers or solicitors may request proof that the work was completed legally.
If certification is missing, homeowners may need to apply for retrospective approval. This can involve inspections, additional costs, and potential delays.
In some cases, remedial work may be required if the installation does not meet current standards. Keeping certification from the start avoids these risks.
DIY Window Installation and FENSA
Homeowners are allowed to install their own windows, but DIY work cannot be certified through FENSA. In this case, building control must be notified, and inspections are required.
DIY installations carry additional risk because incorrect fitting can affect insulation, security, and safety. Even if the windows themselves meet standards, poor installation can lead to non compliance.
For this reason, many homeowners decide that professional installation is the safer option.
Other Organisations That Support Compliance
While FENSA focuses on certification, other organisations provide useful information for homeowners.
Energy performance ratings are explained by the BFRC, which helps homeowners understand how window efficiency is measured. Guidance on inspections and regulatory compliance is also available through LABC, which covers building control requirements across the UK.
These resources help homeowners understand the wider framework around window replacement.
Choosing the Right Installer
When choosing an installer, homeowners should ask how certification will be handled. A reputable installer should clearly explain whether they are FENSA registered or how building control approval will be arranged.
Clear communication at the start of the project helps avoid confusion later. Installers should also provide documentation once the work is complete. If you would like advice before replacing your windows, you can contact us here to discuss your options and ensure everything is handled correctly.
Long Term Value of Proper Certification
Proper certification protects the value of the property. Buyers want reassurance that improvements were completed legally and to the correct standard.
Certified installations also give homeowners confidence that their windows meet safety, insulation, and ventilation requirements.
Conclusion
Not all window installers have to be FENSA approved, but all replacement window installations must comply with building regulations and be properly certified. Using a FENSA registered installer is often the simplest route, but building control approval is a valid alternative. What matters most is that the work is completed correctly and documented. If you would like guidance on window replacement or installer requirements, our team at Skyway Windows LTD will be happy to help.
