Building Regulations For Replacement Sash Windows

On the 1st April 2002 replacement windows came within the scope of building regulations for window companies London and the rest of the UK.

This was one of a number of changes designed to improve the thermal efficiency of homes in the UK and to assist the government in meeting its commitment to reduce C02 emissions under the Kyoto Agreement. It will also mean that are homes are warmer and use less energy.

One of the bigger changes to the building regulations is that the windows should be double glazed and are required to meet a certain level of thermal efficiency. The building regulations previously did not affect the replacement of windows. However, having double glazing in homes means that they are about 3 times more energy-efficient than single glazed windows, these changes will have an effect on the homes energy efficiency.

It is important when replacing windows you use a FENSA regulated company. (FENSA is the self-accreditation scheme for replacement doors and windows). If you sell your home you will be asked to provide a FENSA certificate by the purchasers’ solicitor to prove your replacement windows have met the regulations. If you are unable to provide a FENSA certificate you could have a problem with selling your home.

As a FENSA regulated company we have had to comply with a number of requirements. We have to prove we have adequate employers liability and public liability insurance and the ability to offer our clients an insurance backed guarantee policy for the new windows.

Get in touch today to speak to a member of our team on 020 8017 1632 for more information about building regulations and replacement windows.


Want To Know More About Sash Windows?

Just click one of the boxes below to get some answers.

Book a FREE Survey & Quote with
London’s #1 Sash Window Specialist.

Give us a call now on
020 8017 1632

Download Our FREE Brochure

No email required
  • Browse dozens of case studies at your leisure
  • Be inspired with our range of stunning, authentic sash windows
  • Discover why The London Sash Window Company is London’s #1 sash window specialist


020 8017 1632

Your information is secure with our

Privacy Policy




Your enquiry has been received and one of our team will call from 020 8017 1632 shortly.


Our office hours are 9am - 5:30pm, Monday to Friday. We aim to respond immediately to all enquiries submitted during office hours, or within two hours of opening for all other enquiries.


When we call, one of our team will clarify your requirements, answer any immediate questions you have, and arrange a convenient time for an expert to visit you for a no obligation survey and quote.


While you wait for our call, why not continue to browse our site? Check the FAQs for answer to the most common questions, or be inspired with our sash window gallery!