You will find a lot of people make or have made the same mistake.
In the UK you buy a house, you use a lawyer and your covered by the law if there are any come backs.
In Spain, even having an escritura or a mortgage does not guarantee that your house is legal. We also know of a Spanish bank manageress who is in an illegal house, with the mortgage through her own bank.
So its not just those emigrating or buying investment property in Spain who are getting caught out
Some people think that because they have a mortgage they are in the clear. But some now have clauses stating that if the house is illegal, the person the money has been lent to, is still liable to pay back all the money. Again can you imagine Barclays or Natwest, saying here have a mortgage on a house and it may be illegal

The web site was and is not designed to put people off buying in Spain. I myself love living here and can not imagine returning to the yUK. It hopefully comes across to warn people of what can go wrong and gives some advice on trying to make a stress free property purchase

No such thing mate ........ anywhere

Another useless bit of information which I have heard from several sources, is how Catral came to be noticed by Valencia.

It goes along the lines of
Some English home owner had a place with good country side views.
A new build was going up that was spoiling their views and they complained to Valencia. The rest is history and so will a lot of our houses

As I say I can not confirm this to be true, but I have heard it from several different sources.

As for buying in Spain being a pain, when is buying any house stress free?
I never booked the lorry to drive my kit to Spain until a few days before completion on my yUK home

Just because a property is resale doesn't guarantee that it's legal!

There are plenty of illegally built resale properties out there (and illegally segregated land), on the market right now, being bought (sometimes unknowingly, sometimes believe it or not, knowingly) by both Spanish and foreign buyers.

Some of these properties are 2 or 3 years old, some of them are 10 or 20 years old. It's buyer beware, regardless of the age of the property.

I guess that if you know it is illegal and the price reflects it, there is no problem buying it (assuming there is no demolition order pending).

You will obviously have to explain the situation when you sell but I think a lot of properties are sold on this basis.

The most common seems to be where the size is underdeclared (2 beds on the escritura but 4 in fact plus the appartment underneath!)

There is a risk but how much of a risk is it?

Perhaps you know Hillybilly?

Well, unfortunately many would-be vendors of illegal resale properties don't declare this fact to would-be purchasers. It's only if the would-be purchaser does their homework or if they have a thorough lawyer that the illegality may be revealed. By which time they've probably already gone to quite a lot of expense, fallen in love with the house etc etc and are so more inclined to take the risk.
IMHO if a property is in any way illegal or has undeclared m2 etc then this should be reflected in the asking price i.e. you can't expect to sell your house as and achieve the price of a 4 bed villa, with roof terrace and pool if one of the bedrooms, the roof terrace and the pool are, strictly speaking, "not there"! But...many people will of course try to do just that, in the hope that the illegality will not be dicovered until it's too late. In fact many buyers don't discover the illegality of their resale property until they come to sell on themselves, which can be years later.
I'm no expert but the chances are that the older the property is, the more likely you are to be able to legalise the anomolies, but even so this will take time and incur expense, stress, so why put yourself through it? I guess it's down to how "risk averse" the person is and how smitten with a particular property they are.

I remember when we were trying to buy a house in Puerto Serano near Algondodonales. We were using an abogado in Jerez, a contact of the agent. However he would not be rushed, even by the agent. He advised not to do a thing until he said it was safe to proceed. The land was correctly registered, but without the house. However he said this was not a problem, and it could be declared and registered before the notary. It fell through for different reasons.