How to Add a Glass Extension to a Listed Home

Glass extension to a grade II listed house

Deciding on an extension to a listed home

When wanting to extend or renovate a historic or listed building the integrity of the original building and design is something that must be carefully considered.

A listed home in England is a protected building of particular architectural or historical significance. By being ‘listed’ the property is protected from unrestricted alterations in an effort to maintain the cultural significance of the buildings.

glass extension is an extremely popular option when looking to extend a listed home for many different reasons.

The transparent nature of a structural glass box extension does not hide the original building design, maintaining its architectural design. The clear definition between what is a new extension and an old building helps protect the character of the home.


frameless glass link

So, how to add a glass extension to a listed home?

A cohesive design is important and a listed building consent application is much more likely to be successful if they are led by an architect. But ensuring that your glass extension design is carried out by an experienced glass contractor is an important contributing factor.

Double height glass extension to Grade II* listed home in London
Credit Seacon Ltd.

The use of Low Iron Glass is usually recommended when looking to add a glass extension to a listed building. Low iron glass is a clearer glass product than standard clear glass. It is manufactured with a lower iron oxide content and therefore creates a more transparent glass structure.

These structural glass boxes can then be supported by frameless structural glass beams and fins, made from Low Iron Glass, to ensure a fully glazed and transparent structural glass installation.

If any opening doors are required opt for as slim a frame as possible. If no thermal performance is required to the glazing (when being used as part of a conservatory design rather than extension) the doors needn’t have any frame at all. If a level of weather sealing and thermal performance is required then sliding doors will afford you the slimmest frame, reducing the amount of obscuration between the outside and listed building structure.

Side infill glass extension to Grade II listed house
Credit Archea

In some cases, you might consider the use of non-reflective glass which is made from Low Iron Glass with additional coatings on the glazing to reduce its reflectivity. If this solution can be used the glass is nearly invisible to passers-by and will greatly reduce the impact of any new addition on the character of the listed building.

When looking to extend a listed building with a glass extension precision is the key. Ensure you have the right permissions in place (adding an unauthorised extension to a listed building is a criminal offence), use a suitable architect and seek the advice of an experienced architectural glazier who will design and install.

Asking your architectural glazing company for previous picture examples of extensions to listed buildings might help your planning application

The following two tabs change content below.
Rebecca is Head of Marketing at the IQ Group and has worked in glazing specification for many years. She has a broad range of technical knowledge about all our glazing products and offers technical advice and guidance to architects for specification. Her easy to digest technical advice is often quoted in magazines and publications. You might also recognise her as one of the IQ Glass CPD presenters.