It is perfectly normal to get some settlement cracking on new properties as they settle onto their fondations plus the abnormally large amount of rain that we have had this year has certainly increased the amount and wre have also seen this on some of the newer properties that we have seen
What is not acceptable is for the developer to simply dismiss this as a defect but a lot depends on how long you have lived in the property
Your 10 year guarntee is actually not drectly related to the builder but, as in the UK, is an insurance policy and the details of who thye cover is with will be with your completion paperwork and the next thing to do is contact them requesting a professional assement by a Spanish surveyor as it may may, given where the cracking is happening, that the top corse of brickwork is not tied in
Again if you are unhappy you could always fill in a complaints form and have OMIC investigate this
I have just had a run in with this developer, a certain individual onsite, regarding snagging repairs where he stated that onlñy one list was allowed which is not correct according to law and the lawyer is dealing with this but you shouldn´t just accept their word