The lipped casement window style is quite different, possessing unequal sightlines (due to the absence of dummy sashes in non-opening panes as standard) and an overall asymmetric appearance.
Fortunately, most uPVC manufacturers now offer flush casement uPVC windows alongside their standard lipped casement offerings.
The quality and look of uPVC flush casement windows does, however, vary and there are several features to look out for if you want to achieve a true period look (or save money and opt for a compromise).
Our approved supplier network is familiar with conservation area requirements in London and around Surrey.
The difference between lipped casement and flush casement windows is this: on a lipped casement window the opening sash protrudes forward of the window frame, while flush casements have no protruding lip, so visually the frames and sashes on flush casement windows are perfectly flat and symmetrical with one another.
The reason uPVC flush casement windows are symmetrical (as opposed to asymmetrical lipped casements) is because they have dummy sashes fitted to the non-opening panes – whereas lipped casement windows do not.
This means that the glass panes are exactly the same size in both opening and non-opening sections of flush casement windows. With lipped casement windows dummy sashes can be added as an optional extra as seen in the lipped casement photograph which creates a more period appearance.
These are called ‘equal sight lines’ in the trade.
Period timber flush casement windows are typically butt jointed with a visible single horizontal or vertical line at the corner joints. uPVC windows, however, typically have a visible diagonal or V-shaped grooved joint where the frames are welded together with a hot knife. Traditional butt joints can now be added as a feature to uPVC flush casement windows to maintain an authentic period look.
Redwood frames have a smooth surface when painted where as with hardwood windows the grain is prominent and shows through the paint. This woodgrain look can be replicated onto uPVC in all colours, including varnished oak and mahogany. Dual colour is also an option, with smooth grey on the outside and white on the inside being particularly popular among contemporary homes.
The R9 100mm uPVC flush casement window, by Eclectic Systems, offers optional working butt hinges and working peg stays with matching handles. Most manufacturers, however, stick to high-compression security friction hinges and multipoint locking. That said, many do offer dummy peg stays and matching handles if required, along with black, white or gold dummy butt hinges fitted to the external frames.
When we provide you with a quote, we’ll take you through all the options and associated price implications.
Unlike standard uPVC lipped casement windows, which have a back-to-front frame depth of 70mm, flush casement windows can possess a depth of up to 100mm in 10mm increments. This is because pre-1950’s flush casement window styles were designed to create richer deep contours and rebates.
As a rule of thumb, we recommend replacing like for like. In other words, if you’re taking out 70mm frames, replace them with 70mm frames. This will prevent you from having to chip away 30mm of internal plaster to fit 100mm frames into a 70mm gap, or being left with an unsightly mastic line on the outside.
Nowadays, most double-glazed windows are premium ‘A’ rated, and gas-filled with warm edge spacer bars as standard. However, there are still around a dozen variations of glass and coatings to choose from. Different specifications will be suited to different rooms, depending on whether security, soundproofing, anti-UV, condensation, heat retention or heat rejection are priorities.
As a rule of thumb, we recommend using UltraClear low-iron glass for the outer pane and a premium low-e soft coat on a standard iron pane for the inner pane. This combination will give the appearance of clear glass from all angles (rather than a distorted cloudy look that some lower cost low-e hard coats on standard iron can create).
We will guide you through your glazing options during the quotation process.
In the past, when glass could only be produced as smaller panes, larger window panes were made up of timber astragal bars or lead strips, which joined the smaller panes up into one large pane.
These period features are still popular today and can even be created with double glazing. If you wish to retain your existing stained glass features, these can either be faithfully replicated using period colours, or the existing stained glass can be refurbished and inserted as the central pane within a triple-glazed unit.
A ‘no-salesperson’, no-obligation emailed quote
A free home visit, if required (for those in London and Surrey)
CAD drawings with detailed specifications for each quoted product
Realistic before & after photo simulations, if required