Fensa Certification for Windows

Sunil Radia • 11 November 2021

Fensa - a government authorised scheme for the regulation of window installations

What is FENSA?

 

FENSA is a government-authorised scheme that monitors building regulation compliance for replacement windows and doors. Each FENSA Approved Installer, from large national brands to small local companies, is assessed regularly by to ensure its compliance to building regulations is continually maintained.

 

Windows and FENSA Regulations

 

The FENSA scheme allows window and door installation companies that meet certain criteria to self-certify that their work complies with the Building Regulations.  

 

This certificate is a guarantee that the installer who fitted your new windows and doors has abided by Building Regulations and local requirements also. It also means that your installation has been registered with your local council by the installation company, which is a legal requirement especially when you are selling your home.

 

FENSA was first initiated on 1st April 2002 by the government. That’s why, as of 1st April 2002, you need a Fensa certificate or Building Regulation Completion Certificate if 50% or more of the window is made from glass panels.

 

What are the Regulations?

 

All replacement windows in both domestic and commercial buildings come within the scope of the Building Regulations. Anyone who installs replacement windows, doors, roof lights and roof windows will have to comply with strict thermal performance standards.

 

Any installation by a firm which is not registered by FENSA, including work done as a DIY project by a householder, needs full local authority approval under the Building Regulations. You should note that you, as the house owner, are ultimately responsible for ensuring the work complies with the Building Regulations

 

Window Company/Homeowner Requirements

 

Window companies have to meet certain criteria to self-certify that their work complies with the Building Regulations.

 

A sample of the work of every installer is inspected by FENSA appointed inspectors to ensure standards are maintained and installers who fail to perform can be suspended or even excluded from the scheme.

 

There are two ways to prove compliance:

 

·  a certificate showing that the work has been done by an installer who is registered under the FENSA Scheme.

·  a certificate from the local authority saying that the installation has approval under the Building Regulations.

 

What will happen if you don’t have a FENSA Certificate (fensa.org.uk)

 

When you work with a window fitter who is FENSA Approved, you will get a FENSA Certificate when the job has been completed. This is all the proof you need that your installation has been carried out compliantly, and this document will be hugely important when you come to sell or mortgage your home - and for your own peace of mind. You would find it difficult to sell your property because a buyer will require a FENSA certificate and also if you are remortgaging your property your solicitor will want to see that certificate.

Case Study – Building Without Insurance

by Niket Kapur • 20 March 2026
A homeowner commenced building works on their property without arranging appropriate site insurance. This is not uncommon. There is often an assumption that either the contractor’s insurance will be sufficient, or that an existing household policy will continue to provide cover. In this case, neither applied. Partway through the project, it became clear that there was no valid insurance in place. At that stage, the position became significantly more difficult. Insurers were unwilling to provide cover retrospectively. From their perspective, the risk had already begun without protection, and they were being asked to step into an unknown position. The property was effectively uninsured during an active construction project. We were instructed to review the situation. A structured approach was taken, including: Clearly defining the scope and stage of the works Presenting the risk in a transparent and credible way Engaging directly with specialist insurers Following extensive discussions, we were able to: Secure appropriate site insurance cover Bring the project back within an insurable and protected framework This was not straightforward. It required persistence and a clear understanding of how insurers assess risk. On a construction project, the absence of insurance is not a minor oversight. It is a significant exposure. If you are planning a build, it is worth ensuring that the right cover is in place before work begins. 

Case Study – Council Tax, Planning Delays and Structural Issues

by Niket Kapur • 20 March 2026
A homeowner commenced a significant renovation project with the intention of improving and extending their property. The project did not proceed as expected. There were delays with planning, and during the course of the works, structural issues emerged which required a reassessment of the build. Ultimately, a substantial part of the property had to be demolished mid-project. At this stage, the property was clearly uninhabitable. However, the local authority took a different view. They imposed double council tax on the basis that the property was empty, applying the standard premium used to discourage long-term vacant properties. Representations were made to explain the position. These were rejected. The authority maintained a rigid stance and would not accept that the condition of the property and the nature of the works justified relief. The charges continued to accrue. We were instructed to review the situation. A detailed and structured approach was taken, including assembling the appropriate evidence, reframing the basis of the claim, and engaging with the local authority in a more targeted way. The outcome was clear: Full council tax waiver achieved Over £10,000 recovered for the client Ongoing liability removed This is not an uncommon scenario. Local authorities will often apply standard rules without properly considering the specific circumstances of a construction project. Initial refusals are frequent, but they are not always correct. A properly prepared and presented case can materially change the outcome. Situations like this arise regularly on construction projects. Addressing them correctly can make a significant financial difference. Sunil K Radia The Building Guidance Partnership Telephone (020) 8076 3110 WhatsApp +44 7507 705376 www.theBGP.co.uk

Regulatory Compliance Oversights That Could Sink Your Construction Project

by Niket Kapur • 20 March 2026
Most homeowners focus on design, finishes and cost when undertaking a building project. Very few focus on compliance. That is where serious problems arise. This note sets out the key regulatory and risk areas that are frequently overlooked. These are not minor technicalities. They are issues that can expose you to financial loss, uninsured risk and legal liability. 1. Notifying Your Mortgage Lender If your property is subject to a mortgage, your lender has a legal charge over it. That property is their security. Most mortgage terms require you to notify the lender before carrying out structural works Some lenders require formal consent Failure to notify can place you in breach of your mortgage conditions This is often ignored. It should not be. 2. Insurance During Construction Standard household insurance is usually not valid during major renovation or structural works. Many policies specifically exclude properties under construction Continuing without appropriate cover can leave you completely exposed You should: Notify your existing insurer before works commence Arrange specialist renovation insurance where required Ensure cover includes fire, flood, theft, vandalism and public liability Do not assume you are covered. Check. 3. Contractor Insurance Is Not a Substitute Many homeowners assume the contractor’s insurance will protect them. That assumption is dangerous. You must verify: The level of cover is sufficient for the scale of the project The policy includes public liability, employer’s liability and contract works Cover extends to damage to neighbouring properties Liability includes injury to third parties, including trespassers Do not accept a certificate at face value. Review the detail. 4. VAT: Getting It Wrong Is Expensive VAT treatment in construction is complex but critical. New builds may qualify for 0 percent VAT Properties empty for two years or more may qualify for 5 percent VAT on renovation works Evidence of vacancy is essential and must be properly assembled Failure to structure this correctly can cost many thousands of pounds. 5. Council Tax on Uninhabitable Properties Where a property is genuinely uninhabitable, relief or exemption from council tax may be available. In practice: Applications are often rejected at first instance Local authorities do not always guide applicants through the correct route A structured and informed approach is required to secure the correct outcome We regularly assist clients in securing substantial savings, including backdated recoveries where appropriate. 6. Site Safety and Residual Liability Even when a contractor is in possession of the site, the homeowner can still carry risk. If someone is injured on site, including a passer-by or trespasser, liability may arise Simply appointing a contractor does not remove your exposure You should ensure: Proper site security is in place Risk assessments and method statements are being followed Insurance arrangements align with the actual risks on site This is not theoretical. Claims do arise in these circumstances. Final Thought These issues are rarely considered at the outset, yet they carry real consequences. Getting them right early avoids problems later. Contact us today so that we can review your arrangements.  Sunil K Radia The Building Guidance Partnership Telephone (020) 8076 3110 WhatsApp +44 7507 705376 www.theBGP.co.uk