Okay, this is good, but it is still a bit awkward to advise properly without knowing the complete ins and outs. (that and there is a reason why people charge to look at these sorts of things in depth...)
The quote. (call it this from now on please)
This is pretty clear in so far as it is laid out clearly defining what the prices have included. You will note that there are some things in there which will allow for variations... for instance he notes that the electrical figure is a "provisional sum". This means that it is subject to change - for one reason or another - and that this is simply an allowance that he has made towards the final figure.
It doesn't look like he has asked for any extras here though.
Things that I do note his quote allows for;
1. constructing an internal block wall. If this is the same wall as you talked about earlier (the one he claimed he only allowed to make out of stud) then he can't return to you saying he did not allow for it as there is a figure there to make a block wall and it is clearly specified.
2. works to a shower room. "as discussed". You need to know what you discussed with him really. Because his extras include works to the shower room. If this work was originally discussed then it should have been quoted for in this figure. If you changed your mind about things later on, or site conditions required a change - then they could be legitimate additions.
3. drainage. He makes a very clear allowance for drainage, but also requests more money as part of the additions... what "extra" drainage work was necessary?
To help yourself answer things you need to ask yourself;
After you received the quote, did you change your mind or ask him to do ANYTHING else? for example, we know that you asked him to add a roof light - well this is an extra. did you ask for any sinks / wc etc to be repositioned while he was working, or for any new walls or openings to be made?
What we are trying to establish is where your chap has a legitimate claim for extra work and where he is just trying to recoup costs from mis-quoted items?
Then you will be able to discuss with him and accept any of the reasonable additions whilst ignoring any of the cost re-couping. Ultimately, if you have paid 20k, then you expect 20k worth of work to be completed. If he has not completed the original 20k worth of work then he has no business saying that he will not complete it. However, from his point of view - he does not want to come and complete that 20k (plus the extra 7k of work) only to be told he will not be paid the full and final amount.
A final question I have is what terms were agreed for payment?
The quote. (call it this from now on please)
This is pretty clear in so far as it is laid out clearly defining what the prices have included. You will note that there are some things in there which will allow for variations... for instance he notes that the electrical figure is a "provisional sum". This means that it is subject to change - for one reason or another - and that this is simply an allowance that he has made towards the final figure.
It doesn't look like he has asked for any extras here though.
Things that I do note his quote allows for;
1. constructing an internal block wall. If this is the same wall as you talked about earlier (the one he claimed he only allowed to make out of stud) then he can't return to you saying he did not allow for it as there is a figure there to make a block wall and it is clearly specified.
2. works to a shower room. "as discussed". You need to know what you discussed with him really. Because his extras include works to the shower room. If this work was originally discussed then it should have been quoted for in this figure. If you changed your mind about things later on, or site conditions required a change - then they could be legitimate additions.
3. drainage. He makes a very clear allowance for drainage, but also requests more money as part of the additions... what "extra" drainage work was necessary?
To help yourself answer things you need to ask yourself;
After you received the quote, did you change your mind or ask him to do ANYTHING else? for example, we know that you asked him to add a roof light - well this is an extra. did you ask for any sinks / wc etc to be repositioned while he was working, or for any new walls or openings to be made?
What we are trying to establish is where your chap has a legitimate claim for extra work and where he is just trying to recoup costs from mis-quoted items?
Then you will be able to discuss with him and accept any of the reasonable additions whilst ignoring any of the cost re-couping. Ultimately, if you have paid 20k, then you expect 20k worth of work to be completed. If he has not completed the original 20k worth of work then he has no business saying that he will not complete it. However, from his point of view - he does not want to come and complete that 20k (plus the extra 7k of work) only to be told he will not be paid the full and final amount.
A final question I have is what terms were agreed for payment?