It is though, a very good idea to rent before you buy as you may well find an area that you never thought of which will suit you perfectly, and this will give you time to settle in, look around and decide whether a permanent move is for you.
Moving abroad is a major step for anyone and buying a property is a huge investment, so instead of immediate purchase, consider renting for a while. You will find longer term rentals in almost every part of Spain, and this will be substantially cheaper than say, a 2 week holiday let; spending 3 months or more in your chosen area will help you to decide what you really want to buy and where, or like many before you, you might end up just renting on a permanent basis.
Even if you have spent many holidays in a certain part of Spain, living there is a very different experience. What seemed perfect for your week or 2 with the family may not be the best place to buy a property as many resorts close down partially or completely in winter. If the idea of living in an urbanisation appeals to you, rent a place in one, and you will quickly find if it really suits you as inevitably some driving will be involved even to get basic things. The Sierra Nevada or the Pyrenees provide wonderful skiing, but is a chalet what you really want? Will you be running it as a business? Will you be there full or part time? Spending a few weeks out of season up in the mountains will help you to decide on what is best for you.
Most holiday lets are for up to a month and are based on seasonal tariffs. A longer term let of 3 - 6 months or even up to a year will be considerably less expensive, and will be a good base from where to do your house hunting. You will probably already have an area in mind, so have a look at Spanish websites to see what sort of property is available there. www.idealista.com and www.fotocasa.com both have sites in English for long-term and short-term rentals and cover all of Spain.
You may be able to find unfurnished accommodation to rent if you want to bring your belongings with you, but most short-term rentals are furnished to some extent. Try to find a rental similar to the property you are hoping to buy - you will soon find out if it’s right for your lifestyle. You should be aware that short-term rentals give less protection to the tenant than full-term 3 year rental contracts, (they used to be for a minimum of 5 years, but the government changed the law recently to a minimum of 3 years) but even if you are renting for just one month you should have a proper rental contract. It is worth having the contract checked out by a lawyer before you sign, despite the cost which shouldn’t be more than 70€.
Many expats who began renting with the intention of buying find that they no longer want to buy and opt to rent permanently. Long-term rentals in Spain are comparatively inexpensive, though coastal areas will always be desirable and therefore cost more. This holds true for short-term lets as well. The advantage of renting is that if something goes wrong, it is the landlord who must fix it and since mortgages can be hard to come by, it is the answer for many who want to live in Spain. You can let out your home in the UK and rent in Spain.
For most people however, renting is a means to an end - buying your own property. It pays to take your time to decide whether a particular location is good for you, whether you would prefer an urbanisation or a property in a town, how close you really want to be to local amenities, the medical centre and schools. Unless you genuinely know a location extremely well, you would be wise to find a pleasant property to rent. Day-to-day living is quite different from being in “holiday mode.”