Generally planning permission would not be required if the window enlargement is fairly modest. But if you are within a conservation area or the building is listed then the appropriate consent would be required.

You should also be careful not to introduce clear glass where there may have been obscure or frosted particularly above ground level, as there may have been planning reasons for having this in the first place (eg overlooking issues).

In making the apertures wider you will more than likely need to replace the lintel above to maintain the structure above the window. Dropping the cill level shouldn’t be an issue.

The windows of a home play a major part of the character of the property so be careful in selecting the right material, style and colour. PVCu is the most cost-effective option, but the large frames and white appearance doesn’t suit everyone’s tastes. You can get coloured and wood grain effects but you’ll still know it’s PVCu.

Timber windows enable great subtle details in the frame and beading, so they suit traditional properties very well. A lot of new houses we’re designing or major refurbishments are incorporating hybrid systems (such as powder coated aluminium external frames and timber inside) or pure aluminium, which allows for very elegant and slim frames.

Dressing around the window can add character; examples include soldier brick coursing or dressed stone. You should also consider the cill detail which could have a sub cill below the main window cill.

Not every property will support the look of large expanses of glass. Older buildings usually have smaller casements, as when they were built glass couldn’t be produced in large sheets. As we’ve developed more modern architecture has moved to larger expanses of glass and these days structural glazing is becoming viable in domestic situations.

Have a look at companies like Kloeber, Velfac, IQ Glass, Mumford & Wood for examples of window types used in different settings and ultimately pick what you like. Make sure you see a sample in the right colour in daylight and adjacent to the wall material of your home before ordering, as you don’t want to repaint pre-finished items for your project.

Opinder Liddar, lapd architects