Replacement uPVC windows
Replacement uPVC windows come in four steps: measure, order, take the old windows out and put the new ones in. We make your uPVC or aluminium windows to measure and deliver them to your door. You fit them yourself or have an installer of your choice do it.
uPVC windows supplied and fitted?
We don't offer that combination: we supply and don't install. That's why you pay us the factory price plus delivery, and arrange fitting directly with a local window installer.
Whole window or just the glass?
We always replace the whole window: frame, sashes, glass and hardware come as one unit. We don't supply sashes on their own for an existing frame. If the frame is still sound and you only want new glass, that's a job for a glazier: we only supply glass in a new window.
uPVC windows fitted by your installer
Any installer who fits windows can fit ours: they arrive complete, in the size you gave us. Send the installer the drawing from your quote, so they know in advance what's coming. Replacing windows is notifiable work in England and Wales: an installer registered with a competent person scheme such as FENSA or Certass notifies it, or you notify building control beforehand.
Fitting uPVC windows: how it's done
The old window comes out, the opening is cleaned and made true, and the new window is set on packers: level, square and plumb. It's then fixed into the wall, the joint all round is insulated and made airtight, and weathertight on the outside. The work is mostly in that joint, not in the window itself.
Replacement casement windows in an existing opening
Choose a window with an outer flange in the configurator: a 15 to 25 mm lip on the outside that laps over the reveal or the old subframe. The joint is then out of sight and out of the rain, and fitting is simpler. The flange counts in the overall size you order. Note that our casements open inwards, not outwards as most British casements do.
Aluminium replacement windows: measuring up
Whether uPVC or aluminium, you order on the overall size of the frame, not on the size of the opening or of a subframe. Measure the width at the top, middle and bottom and the height on the left and right, and take the smallest figure each time. How to get from the opening to the order size is explained step by step on our measuring page.
What we guarantee, and what we don't
We make the window to ±2 mm up to a metre and ±3 mm above that, and measure it before dispatch. If it's out, we remake it free of charge to the size you ordered. A measuring mistake in the size you gave us is not covered; for that we offer a remake at cost price.
Frequently asked questions
When do uPVC windows need replacing?
When they let draughts in or stick although the hardware is fine, when there's damp or damage in the frame, or when the glass mists up between the panes. A renovation or an energy upgrade is also a good moment.
How long does it take to replace windows?
That depends on the number of windows, their size and the joint; ask your installer. Making the windows takes longer than fitting them: the lead time is in your quote, which you get within three working days.
Can I fit uPVC windows myself?
Yes, if you're handy and work in pairs: a window with its glass is heavy. Pay most attention to setting it true and to the joint all round. In England and Wales you then notify building control before you start; an installer registered with FENSA or Certass does that for you. Scotland and Northern Ireland have their own rules.
How are uPVC windows fitted?
Old window out, opening cleaned, new window on packers, set level and square, fixed, the joint insulated and sealed all round, then finished inside. Check before fixing that the sashes close properly: after that, nothing gets adjusted.
How do you fit uPVC windows so they last?
uPVC expands in the heat. Don't fix it too tight, and leave a joint all round as wide as your installer prescribes, so the frame can move without the seal tearing.
How do I measure my windows for replacement?
On the overall size of the new window. Measure the opening across at three heights and up at two points, take the smallest figure and subtract the fitting gap you want to keep. If there's a subframe, the size you see is its inside size, which isn't the order size.
Can you replace window frames only, or just the glass?
No: we supply the complete window, frame and glass together, and no glass on its own. For new glass in a sound frame, ask a glazier. Your old windows are removed by you or your installer; we don't install, so we don't take anything away.
Know what you want? Put it together.
No form first: you watch your window take shape as you choose. The price follows in the quote, within three working days.
Configure your window or door
Where we have a guide price, it is on the page, not behind a form — not a quote and not a final price; the amount for your sizes is in the made-to-measure quote.
Request a quote