Should we have our builder fit our new bifold windows?

[DeeLite]

Our builder has offered to supply and fit bi-folds for our extension and the cost is £1,500 less than a local window company we've also had a quote from.

Our builder is reputable but a small company so I'm worried about what will happen if we have problems with the windows five years down the line. Will our builder be still around and, even if he is, will he duck it by saying it's a manufacturing defect and will the manufacturer duck it by saying it's a fitting defect so we're left in no-mans land.

We're on a very tight budget so are really tempted by the builder's offer. Am I wrong to be worrying about problems in the future or are bifolds fairly reliable?

I homestly dont know this but think he would need to be fensa approved so that you get the appropriate guarantees

I wouldn't. If something goes wrong they'll blame each other.

I wouldn't.

I wouldn't but I would use his quote to negotiate with the specialists!

The specialists won't budge on their quote. I'm thinking that if we'd bought this house with the bifolds in situ, we wouldn't have given this a thought. In reality, is anything likely to go wrong that will cost more than £1,500 to fix (being the difference between the two quotes)?