Really difficult without a picture, but it could be what's known as a Wolf Spider. They can have a body up to about 2cm across, but don't tend to have stripy legs, although it can sometimes look like it because of their different coloured "knees". With their legs at full stretch (possibly while trying to escape from a cat !!) they can be around 10cm across.
Here's the chap:
The bite from a wolf spider can be very painful although not dangerous (unless you are allergic). Not much reassurance at 3.00am in the morning I know !!
Alternatively, the only other "nasty" spider in Spain is the Brown Recluse Spider or Fiddleback (because it has a mark on it's back that looks like a violin. Although once again, I guess you weren't really investigating it that closely at 3.00am !! It probably wasn't this one as they are generally a lot smaller and definately single colour.
Neither spider are fatal, but both can be quite painful.
Next time (!) go and get your camera, and take a picture with it on your hand to get a sense of scale !!........ only joking.... Wolf Spiders can be quite aggressive if provoked.
Regards