The best advice I was given when we first came here was "would you try and do what you want to do her as if it was in England".

The answer is of course ....... yes because we are all led to believe that everything here is a bed of roses and no-one would ever try and con you.

Sadly the reverse is true and I have heard so many stories of people having their finger well and truly burnt and having no recourse because they didn't consult an architect etc. However .... there are as many so called respectable businesses out there as there are dodgy ones so who the hell do you trust?

Get a quote for work, not just from one or two firms but from 3 or 4. And ALWAYS ask your friends if they know this or that company.

Stop being so naive .. strap on a pair and ask for written quotations, stick to a budget but before anything has been agreed go to the town hall with your builder and get approval. If the builder doesn't want to go to the town hall with  you then it is a sure sign that they have something to hide.

In my experience the town halls (ajuntaments) are on YOUR side.

Good luck