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Everything you need to know about replacing historic windows

January 16, 2023

Windows aren’t just for flooding your home with natural light and enjoying picturesque views. 

They are an eye-catching focal point that give your property a distinct style, look and feel.

On older properties, historic windows take on an even greater significance because the style, design, and craftsmanship are part and parcel of your home’s period character.

When choosing whether to refurbish or replace, it’s vital to understand replacement requirements between the modern and the more traditional window.

Falling foul of planning laws, listed building consents, or conservation area restrictions can be costly – not to mention the lasting impact that poorly thought-out work can have on your home.

Here’s everything you need to know before you get started:

 

How do you know when is best to repair versus replace? 

Historic England advises that original period windows should be retained and preserved wherever possible.

The organisation, which champions British heritage, says old windows are usually “durable, functional and repairable if looked after”, and even those in poor condition can be salvaged with the proper skills.

Replacement should really be a last resort once you have exhausted all other options to restore them.

 

When it comes to deciding whether to repair or replace, there are several factors to consider:

Condition: If the window is in good condition with only minor issues such as peeling paint or a broken sash cord, repair may be the best option. However, if the window is significantly deteriorated or has major structural issues, wood decay, or rot, installing replacements may be necessary. Left unchecked, rot can spread beyond the window and cause problems with the integrity of the wall. A good joiner, metal worker, or window expert can help advise you.

Cost: Repairing historic windows can often be less expensive than replacing them, especially if the windows are still in good condition. However, if the repairs are extensive or the windows are severely damaged, replacement may be more cost-effective in the long run.

Energy efficiency: If the cost of heating your home is a concern, replacement may be the better option, as modern windows are typically more energy efficient than historic windows. 

 

Pros of repairing historic windows:

  • Repair can be less expensive than replacement
  • Preserves the historical character of the building
  • Can be a good option if the windows are still in good condition
  • Better for the environment and can continue to have a long lifespan if well cared for

 

Cons of repairing historic windows:

  • May not be as energy efficient as modern windows
  • May not address structural issues or significant deterioration
  • May take significant time and effort to properly restore

 

Pros of replacing historic windows:

  • Can improve energy efficiency
  • Can address structural issues or significant deterioration
  • Can provide a lower maintenance option if modern materials are used

 

Cons of replacing historic windows:

  • More expensive than repair
  • May alter the historical character of the building
  • May require changes to the window opening that could impact the architectural integrity of the building.

 

What is the historic window replacement process like? 

Replacing windows in listed buildings or properties in a conservation area isn’t straightforward, as there are often additional planning controls and considerations in place to preserve the historical character of the property or area.

If your property is listed or located in a conservation area with Article 4 direction, you will likely need consent to make any alterations to the windows.

Historic England advises that you should always consult with your local planning authority and conservation officer first. The process for obtaining permission can vary between local authorities, but it typically involves submitting a written application along with supporting documentation, such as drawings and photographs. 

If you carry out works on a listed building or conservation area property without the correct planning permission, it is considered a criminal offence under law. Heavy fines and even prison sentences can be handed out for anyone carrying out unauthorised work.

It’s most likely that you will be made to pay a fine and incur further costs with remedial work to make the alterations compliant with planning laws. 

That’s why it’s always cheaper and less hassle to go down the correct path, making sure you secure the necessary permissions before undertaking any work. 

However, it doesn’t mean that historic windows cannot be replaced when necessary. Historic England says that windows in a listed building should only be replaced if it’s agreed with a conservation officer that they are legitimately beyond repair.

The process of replacing historic windows can be complex and time-consuming, and it is advisable to allow plenty of time for research, planning, and installation.

 

Is it okay to change the style and size of the window with a modern upgrade?  

When upgrading a historic window to a modern window, it is generally not appropriate to change the style or size of the window unless there is a compelling reason to do so. 

The purpose of upgrading a historic window is typically to improve energy efficiency and functionality while preserving the character of the building. Changing the style or size of the window can significantly alter the appearance of the building and may not be in keeping with its historical character.

In some cases, it may be possible to use a modern version of the same style of window as the historic window. For example, if the historic window is a double-hung sash window, it may be possible to use a modern version of a double-hung sash window that incorporates energy-efficient features such as multiple panes of glass and low-emissivity coatings.

However, if the window has significantly deteriorated or has structural issues that cannot be addressed through repair or the use of a modern version of the same style of window, it may be necessary to replace the window with a different type. In this case, it is important to choose a window that is appropriate for the age and style of the building and that meets the necessary energy efficiency standards.

Homeowners should be aware that replacing a historic window with a new type of window can significantly alter the appearance of the building and may not be in keeping with its historical character. It is important to carefully consider the impact on the building’s appearance and to obtain the necessary permission from the local planning authority if required. It is also worth considering whether it may impact the resale value of your property, for better or worse. It may be worth consulting an estate agent beforehand.

 

Why is extensive research and planning so important in the replacement process? 

Extensive research and planning are important in the replacement process because it helps to ensure that any new windows you choose are appropriate for the age and style of the building, and that they meet the necessary energy efficiency standards. 

It is also important to consider any designations that may apply to the building, such as listed building status, and to ensure that the necessary permission is obtained from the local planning authority if required.

If planning is not carried out effectively, there is a risk that the new windows may not be appropriate for the building and may not meet the necessary standards. This could result in problems such as poor energy efficiency, damage to the building, or even legal issues if the work is carried out without the necessary permission.

If the process is rushed, it is more likely that mistakes will be made and important details may be overlooked. This could result in problems that are costly to fix and may have a negative impact on the building. It is important to allow sufficient time for research and planning to ensure that the replacement process is carried out effectively and that the new windows are appropriate for the building.

 

Take your time weighing up the pros and cons 

It is important to understand the differences between replacement requirements for modern and historic windows, as falling foul of planning laws, listed building consents, or conservation area restrictions can be costly and have a lasting impact on a property.

When deciding whether to repair or replace historic windows, factors to consider include the condition of the window, cost, and energy efficiency. Going down the repair route can often be less expensive, while preserving the historical character of the building. However, it may not be the best option from an energy efficient standpoint. 

Replacing historic windows will almost definitely improve energy efficiency, and may also address structural issues or significant deterioration. Cost will also need to be taken into consideration though, as will any potential alterations to the historic character of the building. 

Time is another factor that shouldn’t be overlooked either, with the process of replacing historic windows often requiring planning permission.