May 5, 2015
Securing permission to carry out alterations, such as replacing windows in a listed building, can often feel like a complex and time-consuming process. However, with the right approach and a clear understanding of the rules, it is certainly achievable.
At George Barnsdale, we have many years of experience supporting Conservation Officers, architects, and homeowners with both Grade 2 listed windows replacement and listed building window repairs. In this blog, we’ll share key insights from our past projects to help bring clarity to what is often a confusing area.
We’ll cover:
- Building Regulations and Conservation Law
- Guidelines on Replacement and Repair
- Sympathetic Replacement Approaches
Before we begin, it’s important to stress that undertaking unauthorised work on a listed building is a criminal offence, and individuals can be prosecuted. Seeking professional advice and securing the correct permissions is essential.
Building Regulations and Conservation Law
Regardless of the grade, all listed buildings are covered by the same degree of statutory protection. Listed Building Consent applications relating to Grade I* will usually mean a higher level of consultation between the Planning Department, English Heritage and the Secretary of State. The majority of listed buildings fall within the Grade II category (approx. 94%) and will not require any high-level consultation.
For all grades of listed buildings, the listing status covers the entire internal and external physical evidence of the property, including objects fixed to it and curtilage buildings or other structures.
For the replacement of timber windows, we strongly recommend that you check with your local authority Conservation Officer to see if consent will be needed for your planned works. Checking with your local Conservation Officer in the early stages of your renovation means that you will have an outline of what will be acceptable to them and how your aspirations fit with this.
When you are ready to apply for planning permission, we recommend that you visit the planning portal – for listed properties or the planning portal – for conservation areas
* Grade I: These are buildings of exceptional special interest, although they are not necessarily the most ‘splendid’ or prestigious. Grade I listed buildings make up approximately 1.4% of listed buildings nationwide.
** Grade II: These are high-quality buildings, mostly unaltered, and often with an interior of special interest. Nationwide, these comprise 4.1% of all listed buildings.
What choice do you have regarding replacing or repairing
You will find that Conservation Officers and public bodies such as Historic England (officially the Historic Buildings and Monuments Commission for England)tend to have a preference for repair to protect the appearance of the façade and maintain the character of the building. However, this does not mean that consent for replacement is impossible. On the contrary, we are finding that more Conservation Officers want to work with the owners of listed properties to jointly solve problems, and ensure that the property is fit for purpose whilst remaining authentic to preserve the character of the building.
Advice on repair and replacement is provided by Historic England which has produced a document detailing Conservation Principles, Policies and Guidance. Within this document, when it comes to features such as windows, they have taken the stance that “repair is preferable to replacement“. However, they do outline that the cause of the problem should be fully understood before repair is carried out, because ineffective repair can be detrimental in the long term.
If the windows need replacing, then you should piece together a plan that is sympathetic to the building’s heritage by using original materials, designs that accurately match existing detailing and physical properties.
Sympathetic Replacement
As authenticity is key from a planning perspective, in the design of the George Barnsdale Historic Range methods and techniques have been developed to closely replicate the aesthetics and the production methods of the original windows.
- Putty is used to replicate the traditional look of older windows; this can be painted to match the colour of the windows.
- Single glazing or slim fit double glazing can be used with machine or hand-drawn glass to preserve traditional manufacturing methods and mimic the optics of older windows.
- Internal sash profiles can be matched to any existing detail to preserve character; these can also be matched to the structural bars.
- V-Grooves can be removed to provide both the frame and sash with the flat finish often found in Listed Properties.
- In addition to this, authentic hardware is used to ensure a precise and sympathetic match to the existing windows.
External Putty System (Right) & Standard Internally Beaded System (Left)
The images below highlight the aesthetic detailing of the external putty system compared with our standard internally beaded system.
Glazing techniques such as machine and hand drawn glass have been produced with traditional manufacturing methods to mimic the optics of older windows. The images below highlight the restoration authenticity of both machine and hand drawn glass when compared with modern float glass.
Example of Float Glass
Example of Machine-Drawn Glass
Example of Hand Drawn Glass
As you can see, the optical quality of the machine and hand-drawn glass is sympathetic to older methods of glassmaking. You can still obtain good thermal performance through incorporating either hand-drawn or machine-drawn glass in narrow double-glazed units.
Contact George Barnsdale Today
To see some examples of previous projects we have been involved with, view our Project Types page, which will give you examples of a few of our recent Retained Facades, Commercial Developments and Residential Developments projects that we have undertaken.
To learn more about our services, visit:
If you have a specific project in mind or would like personalised advice, don’t hesitate to get in touch with us. Our experienced team is always happy to help.
Repairing & replacing windows in a listed building FAQs
Can I replace windows in a Grade 2 listed building without permission?
No, any significant changes to a listed building, including windows, require Listed Building Consent from your local planning authority. Even if you intend to use like-for-like materials, it’s essential to gain approval first.
While Grade 2 listed windows replacement is possible, the design, materials, and glazing must usually match the original as closely as possible to preserve the historic character of the property.
Is it better to repair or replace windows in a listed building?
Generally, repair is preferred over replacement when dealing with heritage windows. Planning authorities typically expect homeowners to retain as much original fabric as possible.
However, if windows are beyond repair, due to rot, warping, or damage, replacing windows in a listed building may be approved, provided the new units replicate the original in terms of appearance and material.
What types of glazing are allowed in listed building window replacements?
While modern glazing options like double or triple glazing are often restricted in listed buildings, specialist slimline or vacuum-insulated glazing can sometimes be approved if they closely resemble the original glass. These solutions allow for thermal efficiency improvements while complying with conservation guidelines.
