Fitting windows yourself is a bit scary – you are cutting large holes in the side of your van – but it isn’t actually as difficult as you might think.
The secret, as always, is measure twice, cut once.
Here are a few photos illustrating the process of fitting Seitz motorhome window to my van.
1. Decide where the window is to go and mark out the cutting line.
Check the window positioning on both the inside and the outside of the van before you start to cut. Note where the anti-vibration struts are on the inside of the panels – these are a pain to cut through but can safely be removed:

Positioning the window - using a template on the outside and checking the position with the window frame on the inside
2. Cutting a hole for the window
To do this nicely requires two tools – an electric drill with a hole-cutter drill bit and a jigsaw with a metal cutting blade
.
The installation instructions for your windows should specify the size of the hole cutter you need to make the corners.
Here’s how it goes. Corner holes drilled, lines marked and taped up with masking tape (easily available here
) to prevent the jigsaw guide scratching the paintwork:

Window corner holes cut
Three sides cut now – apply some extra tape to help stop the cutout flapping while the jigsaw cuts the last side. Having a second person to help here is useful – they can hold on to the cutout from the inside to help keep it still:

3 sides now cut - one more to go
Arrghhh! Someone’s cut a whole in the side of the van (remember to paint the newly-cut edges with some red oxide paint to stop them feeling any temptation to rust) .
Remember also to clean the metal filings thoroughly from the outside of your van – otherwise they will embed themselves in the painwork and go rusty, giving your van’s paintwork a rather speckled appearance. Don’t ask how I know this… (if you do make this mistake, the metal particles can be removed with a car valeting product known as ‘detailing clay‘)

3. Building the frame
This stage may differ for different types of window and different types of van body. In this case, the windows are Seitz S4 windows being fitted to a panel van body.
Because they are designed to be fitted to caravan and motorhome bodies, which are of a sandwich construction and approximately 1″ thick, an additional frame is required when fitting these windows to a panel van, whose walls are only a couple of millimetres thick.
What’s required is a wooden frame, fitted to the inside of the van like this (full details come with the window’s installation instructions). The idea is to make the wood plus the wall of the van around 1″ thick:

Fitting a Seitz window - wooden frame
4. Fitting the window
This stage is surprisingly easy. All that should be required is to push the two halves together and then screw them together (see your instructions for specific details).
Remember to use some Sikaflex adhesive under the outer window frame and then to seal around the edge of it after fitting with some more sealant/adhesive.
This is especially important with panel vans as the sides of these vehicles usually have some slight curvature, which you have to fight against – hence the importance of sealing the gaps.

Fit the two halves of the window together - then screw them together
That’s it! The first time I fitted these windows I was nervous about it, but it turned out to be a relatively pain-free job. I would recommend having a DIY-competent friend to do it with if possible.
Once your windows are fitted, you can insulate and panel around them.
Next: Carpet lining and flooring
Back to Conversion Guide Index
Disclaimer: All material is provided for information purposes and is my opinion only. I can take no responsibility for the accuracy, suitability, reliability or safety of the information in this guide.




very informative , i have a fiat ducato swift kontiki, some toerag has broken the windows ,my question is can i use caravan windows on this vehicle , any help greatly appreciated,,,,jon
Bad luck… you may well be able to use caravan windows – they are the same in design and fitting as most motorhome windows. It will be a question of whether you can get the right sizes, colours (frame and the window itself – these vary) and fittings. Some motorhome converters use bespoke sized windows in their conversions. If this is the case, then you may have to purchase replacements from Swift.
I would probably contact Swift for a quote for the parts in any case, as at least they should be able to provide exact replacements, even if they cost a little more. They may also advice on fitting, if needed.
hi .. regarding the above. do u wood panel ur van, before fitting the window or do u put the woden window frame in then the window, and then wood panel the whole van?
Hi Phil,
Good question! I think it’s best to fit the window with its wooden spacer frame first, then panel around it. When I bought my van, it was already panelled out as it had been a work van.
So when I fitted the windows I removed the panelling, fitted the window, then cut a hole in the original panel and refitted it.
Hope this helps,
Roland
This was great, thanks so much. Helped me put in two roof vents in a fiberglass roof.