Extra costs at end of building project -is this normal?

[MsSampson]

We have just completed large building project, loft conversion and extension. Basically every room in the house was affected at some point. Project ran over massively. Our builders quote was pretty reasonable. There were always lots of workmen on site, so the overrun was not down to them as such, they were all hard workers, worked weekends etc.
Various things came up during the build that were beyond the original spec, and we knew they would be additional costs (altering size of window opemis for example, and material costs for new steels). We never got costs for these despite asking, but we're reassured by the builder who we had a good relationship with that they were going to be approx £1k, and there were a few bits we removed from the spec that we were told would balance it out.
Project finally finished and we were presented with a bill for £6k, approximately 10% of total costs. A lot of the items listed were for things that had never been discussed. For example fitting a laminate flooring upstairs. The spec our architect put together was astonishingly detailed, and to be fair, it doesn't specify that particular floor. But they just fitted it! They didn't ask if we wanted it done, and then provide a cost. They just fitted it. If I had known I would have told them not to, as I'm more than capable. Ditto some "additional painting". If I had ever been told they were painting things that were outside the spec, and that it was going to cost me £600, I would have told them not to.
Our architect was paid to administer the contract, but he's now working on another project with the builder, and I think is keen to not rock the boat with him (not my problem obviously).
Anyway, stupidly long post, sorry. I am pretty sure the builder made a loss because of the overrun, and this is his way of trying to recoup. And as a small business owner I have some sympathy. How normal is this kind of thing? Our architect seems to be suggesting it's our fault for being too informal, and that it's normal, and we should pay
Is it?

Sorry, on phone with no glasses, but no excuse for typos and no paragraphs!

I would pay all the things that you did agree and ask the builder to come round to discuss the rest of it to try to find a compromise but consider telling him to take up the flooring.

Oh I could have written the exact same post although ours is more like 5%, including for things specifically told him I didn't want to pay extra for. He was very keen to do extras presumably as a way to make back some money.
When I showed his list to the architect he said it's all either overpriced or not needed, but I've yet to have that discussion with the builder.
We were told to get a detailed breakdown of the costs that seem high, and only pay the ones we legit agreed to.
Needles to say we spent money and time getting an online contract which states he has to agree extras including cost before incurring them, which really annoys me as it's coming straight out of our kitchen money.
Anyway we're intending to pay the reasonable costs (mainly extra work supporting the inadequate spine walls after the chimney was demolished) and not the ones that are unjustified, although we may pay some of it anyway as a bonus for good work. But either way it's out of our kitchen money.
Good luck, and make sure your architect gets a proper breakdown and ask them to undo anything you didn't ask for .

I think you have to take some responsibility here - its down to you to know what is in the spec and therefore covered in the price. If you knew that the flooring wasn't included, presumably you were there when he started to put it down and you should have stopped him / queried it? That is quite a lot of extras at a cost of £6k that you didn't notice he was doing!

If, on the other hand, you mean you asked him for every item that he's now billed you for what the cost was, and he said it would be covered by an additional £1k, then I think you have some comeback.

I agree however that you need to have a discussion with him, but recognise that you are at fault here too, not just the builder.

If your architect was paid to administer the project, what were you paying him for? He seems to be culpable too. Doesn't matter that he is now on another project with the same builder and doesn't want to "rock the boat": he has a duty both to explain why/where the spec wasn't followed and to manage your budget.

I agree about paying that part of the bill that they had quoted for, those extras that you had agreed and say you'll meet with them to come to some accommodation for those elements that you didn't agree.

Your architect should support you in this but I have my doubts

If you've not already paid your architect, I would withhold a small part of their fee as they didn't administer the project as you paid them to do.

I disagree with the idea that you are responsible for not stopping him, especially given you are not the contract administrator.
He has written instructions to say what to do, to take an extreme example how about he decides to fit gold plated insulation he's got spare. It's his job to follow the spec and if he does extras without asking, how are you to know it's not standard.
To be honest I've picked up on many things they did wrong and turned a bling eye to just as many others. But if they want more money for things they did themselves, I'm not going to be impressed.

Thanks all, useful to see others perspectives. I think overall, given the length of the build, the overall quality (we're really happy), and the efforts put in by the builder and his team during the last month or so (working very long days, evenings/every weekend), the actual overall cost is probably fair.

What I am really annoyed about is the way it was communicated, or rather not communicated. I am swinging around to the idea that a lot of this should have been the architect's responsibility, as he was administering the contract. Unfortunately he's been paid in full

We've paid the undisputed amount in full already, will hopefully come to an agreement about the rest soon.

Some definite lessons learned about being more business like in future.

You're thinking of doing More building work already? We're seriously going to need to forget all this before we think about doing it again!

Haha, you're right Johnd. Never again!