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In the frame – window defects and what to look out for

22/03/21In the frame – window defects and what to look out for

Windows are an intrinsic part of every residential building’s design, whether they are Velux roof lights, dormer windows, panelled patio doors, or just plain old wooden or UPVC casements. Dormer roof windows, shutters or other designs can form eye-catching architectural features in a house, especially in older properties. You can see iron framed windows set in stone, or the distinctive diamonds of leaded lights, which always look interesting, whatever the vintage of the building. Whichever style of window your property possesses, they can be problematic too – as they face the rigours of the every-changing British climate on a daily basis.

Weathering the storm

Probably the biggest problem with timber windows is their longevity. Due to the extremes of weather experienced in the UK, the paintwork and timber will become damaged, if they are not maintained. Protective paint can crack and peel in the sun, water can get between the glass and putty, frost can prise gaps and over time the timber will rot. Usually this affects the lower parts of a window but can cause problems in other areas.

Keeping your windows well maintained with paint or varnish/stain can help slow the process, but timber is a natural resource that isn’t indestructible. This has resulted in many properties having their timber windows replaced with double glazed UPVC alternatives –including the fascias and soffits to match.

You must check to see if planning permission is required to replace windows and doors. If your property is listed or in a conservation area, planning permission will always be required and you run the risk of having to remove them if you do not seek approval. Even if your property is not listed or in a conservation area you should still seek approval. In all cases they will need to be signed off by the local authorities building control unless they are installed by a FENSA certified installer, who will issue you a certificate of approved installation.

Do not despair- what about repair?

Timber windows can be easily repaired, provided they are not too far gone with rot. Any decent carpenter/joiner should be able to do this and it is often a cost-effective remedy, in particular when it comes to listed buildings.

Alternatively, you could consider installing secondary glazing. These are glazed units that are fixed in front of the existing windows internally. This is a popular alternative to replacing windows that are single glazed and are still in good condition or for conservation areas and listed buildings. You also do not need any approval.

Adequate support for windows

Another aspect of windows that can be problematic is where they are loadbearing and have been altered or replaced. Surveyors commonly find that when a traditional timber framed window that was load bearing has been replaced, this causes problems with the new window and the wall’s brick work above. It is not uncommon to see the head of a upvc window head bowing, this in turn can make it difficult, if not impossible, to open the sash. In worst cases the brick work above drops slightly, creating cracks in the wall. Lintels then have to be inserted to take the weight from above.

Lintels can be timber, stone, reinforced concrete and steel. In older properties, the timber or stone lintels are sometimes visible, as a feature. If a replacement lintel is needed then a structural engineer might be needed to calculate the loads and determine what type of lintel is required.

Health and safety with windows

Older properties often have glass that does not meet the current building regulations. This doesn’t mean it needs changing but if you are renovating a property then the glass should be of a certain thickness and conform to British Standards. Special safety glass, which shatters but doesn’t break into large shards, may also be required in certain situations. Single glazing is now being phased out for double glazing as it becomes the norm, for safety reasons but also for economic and environmental issues too. A great deal of money can be saved with adequate double-glazing being fitted, to retain heat and make your central heating system more economical. It will reduce thermal heat loss and can also mitigate noise from outside too.  

In a jam

One of the most common problems with old properties is where they have sliding sash windows. Some owners screw these shut, for safety or security reasons, especially if the room is being used as a children’s bedroom or playroom. Others are painted closed over time and can take quite a lot of effort to get them free again. Sash windows tend to require regular maintenance, as they have a mechanism, a pulley and cord with weights, which need to be working easily for the window to rise and fall. Any moisture in the frame could cause it to warp and jam, while the cord can become mildewed and rotten over time. They are however a nice feature of old properties and should be retained if possible.


Our surveyors offer a full RCIS home survey service, to help you identify potential structural, age-related and aesthetic issues with your property. Contact us today for an expert appraisal.

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