Has anyone replaced their own double glazing?

[Thingsthatgo]

We have one small blown double glazed window with condensation in it. We also have a couple of upvc doors with the leaf pattern obscured glass that I really dislike.
We don't really want to replace the whole doors... maybe some time in the future, but not yet.
It doesn't look that tricky to pop off the trim and switch over the glass. If I watch enough YouTube tutorials can I do it myself? Obviously I'll need to source the sealed units, and measure very carefully. Anything else I haven't thought of?
(Not too worried about the FENSA certificates, I have the certificates for nearly all of the other windows).

Not ourselves but have had the glass replaced in a blown window. It's was a really big one and did not cost as much as I thought.

The risk with doing it yourself is that if not sealed properly then they will just blow again.

Personally I would leave to the experts. Are there are local companies near you as normally cheaper.

I’ve done it in timber windows where it’s easier to take out putty and replace it. I’d be wary of upvc because if you break the trim as you take it out, you’re without a door or window until you can get a matching replacement. But in theory it’s as simple as you make it sound.

Sourcing the double glazed units is pretty easy, though - we ordered from a small local glazier with slightly vague measurements and they were ready in a couple of days.

Thank you. I don't think the fitting of the units has much to do with how sealed they are. You buy them already sealed and the frames are just to hold them in place.
Yes, breaking the trim would be a problem. I expect I could buy some lengths of it in advance just in case and cut them to size. it's not expensive.

My dh changed ours in our holiday home. You take out the old one, get the new unit the exact same size, put it in place, and use long stick thing with bubble in to make sure it is straight, bolt it to the sides of the window and fill it with foam stuff. Then when set and dry you trim off excess foam and put seals into place. It was far easier than he expected.

As others have said, getting a company out to replace the glass is cheaper than you think and a lot less hassle than replacing the entire into

It sounds like you’re more than capable of doing it yourself, like I was. We recently had some new windows fitted and one small dg unit replaced in another window, and that unit cost £80. I paid less than £30 for the last one I replaced in the timber windows, so I think if you’re confident, you could do it yourself for less than it would cost for a window fitter, adding in their costs and labour.

Please update once you have done. I have replaced glass with putty but have never done a sealed unit into a uPVC fitting and would love to know of it is similarly easy.