DIY made to measure windows are ordinary made-to-measure windows. The difference is that measuring, unloading and fitting are your job, so the order has to be complete from the start: correct sizes, the right frame, shutters and fitting materials. With us you build these windows in the configurator and see the price immediately. We do not offer fitting, so you only pay for the product. Below is the whole route from measuring to fitting day.
Is every window suitable for DIY fitting?
Technically, yes: a window you fit yourself is no different from one fitted by a company. Size and weight are what decide. Standard tilt and turn windows in a family house are a reasonable job for someone with tools and building experience. Large lift and slide doors and heavy aluminium units are better left to a crew that fits them regularly. For years we did not only manufacture and export windows, we fitted them as well, so we know where problems usually arise.
DIY made to measure windows: buying them step by step
1. Measure the openings. Width and height in three places, take the smallest figure, then deduct the fitting gap given in the instructions for your fitting method. You order the frame size, not the opening size. 2. Choose the frame type. A standard frame for normal fitting in the opening, a renovation frame over the old frame without breaking out the plaster, or a Dutch-style (NL) frame, with or without a fin. Availability depends on the system. 3. Describe the opening. Note the opening side as seen from inside. An opening sash must be at least 450 mm wide and a door sash at most 2300 mm high. 4. Decide on shutters and fly screens now. A top-mounted roller shutter adds a box and makes the window taller. With a wired motor, your electrician connects the cable; we do not sell switches. A Somfy io radio motor needs no control wiring. 5. Add fitting materials. The configurator suggests foam, tapes, fixings and wedges. As a guide: fixings roughly every 70 cm, at least two per side, and one can of foam per about 6 m of perimeter, depending on the system and the wall. You can add aluminium external sills in the same place. 6. Check the drawing before paying. Before production you receive a drawing and specification to approve. The order means paying 100%, and after that the sizes cannot be changed. Made-to-measure windows cannot be returned within 14 days (Directive 2011/83/EU, Article 16(c)). 7. Plan the delivery. Production takes 3–8 weeks, and you get photos of the finished windows before they ship. They arrive on racks, and unloading is up to you: a forklift or 2–3 people. Check the delivery with the driver, note any damage on the consignment note and photograph it. 8. Store the windows until fitting. Upright, under cover, away from sun and moisture. Remove the protective film no later than 4 weeks after delivery. 9. Fit according to the instructions. The window is fixed mechanically with frame fixings or anchors; foam only insulates. Seal the joint to the wall in three layers: airtight on the inside, insulation in the middle, vapour-open on the outside. Do not cover the drainage holes in the bottom frame. Details depend on the system and the wall, so follow the manufacturer's instructions.
The most common mistakes with DIY windows
We have been working with windows since 1997, have completed more than 5,000 orders, and with every quote we check the sizes, opening sides and descriptions. Most corrections come from the same mistakes:
- the opening size entered instead of the frame size;
- the opening side described from outside, so the window arrives mirrored;
- a top-mounted shutter added after measuring, when the sizes have to be worked out again;
- no people or equipment for unloading on delivery day;
- protective film left on the windows in full sun for weeks.
Keep the warranty in mind too. GALI gives a 2-year warranty on profiles, hardware, sealed units, shutters and motors, but it does not cover damage caused by incorrect fitting. That makes the manufacturer's instructions a condition, not a suggestion.
What comes with the windows
The declaration of performance and CE documentation come with the delivery, so you have the window specifications on paper, including for building control. Our article on the declaration of performance explains how to read it. The whole process from order to delivery is on our how it works page. Build your windows in the configurator, where the price updates after every change; we prepare a quote including delivery within 3 working days.
Frequently asked questions
How to fit a window?
A window is fixed mechanically with frame fixings or anchors, and the gap is filled with insulation and sealed in three layers. The exact method depends on the system and the wall, so check the manufacturer's instructions.
How to install a window frame?
The frame is set level and plumb in the opening, packed with wedges and fixed mechanically before the joint is insulated and sealed. Follow the manufacturer's instructions for your system and wall type.