thats a difficult one and will depend on whether you have a governing body when qualified,it also depends on it what form your qualifications come.
As a general rule you may not be able to use your qualifications here but can list them if working privately(if that makes sense?)
If working for a Spanish company you will almost certain to be asked to be fluent in at least two languages one obviously being Spanish.
For example,my governing body was the NAEA (national association of estate agents)in the UK but at this moment in time i cannot use my qualifications in an official capacity as their legislation only covers the UK.
Although i have the qualifications they actually mean nothing here because people have no regress or no complaints procedure for members practising in Spain,a shame but true.
Again in saying that i have seen some Spanish agents dispaying the logo on their websites!? so here lies the confusion!
I would say the best route you could take is to ask your examinig body where your qualifications are permitted to be used and if they are European then you should be half way there.
Also whether the regulations you are using in the UK affect the spanish system(thermal calcs etc.....)
I hope everything works out for you and good luck.