If you’re thinking of revamping your property, adding value or simply aesthetic intrigue, then perhaps installing new sash windows has crossed your mind? Well, here’s the thing; we know it has crossed your mind, since you’ve alighted on this article. Welcome.

But embarking on such an installation into any type of property isn’t as straightforward as you might think. Aside from the cost, you have to take into consideration the time involved, whether it will add to or detract value from the property, and if you are legally permitted to actually install the windows in the first place. 

That said, we wouldn’t want to put you off. Sash windows can contribute so much to a property. With the help of Repair A Sash company, here are your IDEAL questions answered on sash window installation.


Aside from the cost, one of the questions we are asked most frequently from our customers relates to the time involved in installing a sash window. Which is understandable, as everyone has their own daily schedule to follow and once you know how long it takes to install then you can make arrangements to work around the time slot.

Without knowing the specifics of a particular job, such as the size, access points and how many windows are being replaced, it is difficult to pin down an exact time frame. However, in most cases, we would estimate a minimum of one day for a single window that allows for easy access and no other unexpected complications. In some instances, that prediction can be reduced if additional windows are also being installed onsite. 

Of course, this is only an estimation to give you a general idea. Once a job is confirmed with a customer and the full specifications are known, then a more accurate estimate can be made.

It’s generally recommended that customers factor in a little extra time in case there are any unexpected complications.


One of the primary reasons to install new sash windows into a property is to increase its aesthetic and financial value on the property market. 

If you are thinking of selling your home, then new windows help make an impression of the overall strength of the property on potential buyers. Not only will they help increase the kerb appeal of the property from the outside, but perhaps more importantly, it will enhance the buyer’s living experience inside the home. 

What’s more, as with most modern window installations, new sash windows will enhance the energy efficiency of a property, enabling it to retain heat for longer periods of time, reducing heating bills and the building’s carbon footprint, too. 

As of April 1 2020, all rental properties – domestic and commercial – have been required to have a minimum Energy Performance Certificate of “E” to comply with the law. Installing new sash windows will ensure you exceed this rating, which adds more value to the property before it is let or sold.


Grade Listed buildings, which are given special levels of legal protection as they are deemed to be of historical interest, have particular interest to planners and permission givers. Grade I listed buildings are classified as being of ‘exceptional interest’ which means installing new sash windows into them will only be granted on very rare occasions.

Which begs the question, can you put new sash windows in a Grade II listed building? 92% of listed buildings are classified as Grade II, with around 376,000 properties in England included, and in order to get consent, there is an official procedure which has to be followed via your local council. In most cases you will be granted consent if the planned works do not have an impact on the historical interest or special architectural design of the building or surroundings. 

To keep within the normal legal parameters here, the installation must also be appropriate in terms of the detailing, scale and materials used, while minimising the potential loss of the building’s historic fabric. 

Although each request is assessed on a case-by-case basis, you are more likely to be granted consent to install new sash windows in a Grade II listed building than you are a Grade I listed building, that’s for sure. 

When considering renovation for a period building, always consult legal professionals before undertaking any work.


Repair A Sash company are experts in the repair, maintenance and installation of sash windows in the capital and are available for jobs of any scale and size. As a FENSA and GGFI-accredited company, they offer a fair and transparent service that customers can trust in.