Coastal Building Restrictions in Castellón: What Ley de Costas Means for Buyers

Spain's coastline is treated as public property along a strip nearest the sea, and the Ley de Costas (Coastal Law) sets out how far that public domain reaches and what can be built near it. For a buyer looking at Castellón, this is not abstract legal theory: it can determine whether a house can be extended, whether a terrace built decades ago is fully legal, and, in rare cases involving older constructions close to the shoreline, whether a property's long-term future is secure.

None of this means buying near the sea in Castellón is unwise. Thousands of coastal homes are bought, renovated and enjoyed every year. It simply means the checks need to happen before you commit, not after, and that a local lawyer who reviews the land registry entry, the cadastral file and any municipal coastal certificate is essential rather than optional for this type of purchase.

Castellón province lies along the northern Costa del Azahar, offering a coastline with towns such as Peñíscola alongside inland mountainous areas. It tends to appeal to buyers seeking a quieter, less developed coastal environment compared to areas further south, including those interested in traditional Spanish towns and countryside.

The region is generally accessed via Valencia or Castellón airports, with more limited direct international flight options than larger hubs. Property types include coastal apartments, traditional village houses, and rural fincas, with activity increasing during the summer tourist season.

What follows are measured, dated figures for Castellón (province) — who lives there, what homes are advertised for, how to get there and the climate — each one sourced. They help you form a realistic picture of Castellón (province) before deciding whether to buy there, to live, for holidays or to let out.

Castellón province, taken as a whole rather than just its capital, counted 627,620 registered residents on 1 January 2025 in the INE census. The number reflects the full territory, large and small municipalities alike, that makes up the province. The province of Castellón registers 118,810 residents of foreign nationality, about 19 out of every 100 people. That share is notable yet far from dominant, and it varies widely between towns within the province.

On 1 January 2025, the province of Castellón had just 1,423 British nationals on its register, a modest figure. Because registration only counts year-round residents, it leaves out second-home owners who spend part of the year in the province. The table below lists the largest foreign nationalities registered in Castellón (province) on 1 January 2025, among those INE publishes for every municipality.

Beyond the main nationalities listed above, the INE also registers smaller groups, Germans, Italians, Dutch, Belgians or Scandinavians among them, across Castellón province. This breakdown reflects 1 January 2022, the last edition counting every nationality individually, a different year from the table above.

Of the 3,955 homes for sale across the province of Castellón, the median works out at €1,740/m², with a median ticket of €179,000 in our data. That is below the €3,135/m² median across the 130 towns we track, making the province one of the more affordable among them. Among current adverts, the central half cluster between €1,230 and €2,370 per square metre; some properties are listed well below this band, others well above it.

Taking €179,000 as the median asking price in Castellón (province), the resale transfer tax at 9 % amounts to about €16,100, and notary, land registry and gestoría costs add a further €2,100. The combined figure, close to €18,300, is what a buyer needs ready in savings, separate from any mortgage funds. These are asking prices taken from adverts active on 2026-11-01, not confirmed sale prices. What a buyer actually pays is negotiated, and depends on the condition, exact location and orientation of each home.

This table sets out population, foreign residents per 100 people and median price per square metre for the towns we track in Castellón (province), highlighting how much local markets can vary.

According to INE's experimental estimate from holiday-rental platform listings, Castellón (province) had 6,990 tourist dwellings in 05/2026, offering 37,362 bed places and close to 11 per 1,000 residents. The presence is moderate overall, but a regional licence remains necessary for tourist letting. In 2024, 29,530 tax-declared long-term tenancies in Castellón (province) produced a median rent of €440 a month, according to the Ministry of Housing's reference system. It is historical data for long-term contracts, unrelated to holiday-let income, and rents can fall as well as rise. According to the same official data, the middle half of long-term rental flats cost between €350 and €550 a month.

Castellón has a single commercial airport, Aeropuerto de Castellón (CDT); depending on where exactly in the province your property is located, an airport in a neighbouring province may actually sit closer to your door. The figures that follow reflect conditions in or around Castellón de la Plana, the provincial capital; elsewhere in the province, particularly inland, at altitude or on other islands, the climate can vary considerably. The mean temperature in January is 10.6 °C (average daily minimum 5.8 °C) and in August 25.6 °C (average daily maximum 30.3 °C), a cool-mild winter pattern. It is worth confirming how any property is heated before buying. With about 467 mm of rain a year on roughly 46 days, rain is neither scarce nor abundant here. On average, 2,755 hours of sunshine are recorded each year. Climate data come from AEMET's 1981-2010 normals, recorded at its Castelló - Almassora station around 4 km away; the actual spot may vary a little, particularly further inland or higher up.

The province of Castellón saw 14,098 registered home sales in the year to 07/2026, per INE. A busier market like this generally offers more comparable transactions and greater choice. Bear in mind that these numbers reflect the province of Castellón overall; they shift a great deal between towns and between individual properties. Let us know what you have in mind so we can look at your case.

The transfer tax on a resale home is set by each Spanish region. In Castellón the general rate is 9 %, and on top of it come notary, land registry and gestoría (roughly one more percent). On a new build you pay 10 % VAT plus stamp duty instead of the transfer tax. This money is not lent by the bank.

The law divides the coast into zones. Closest to the water is the public maritime-terrestrial domain, which belongs to the State and cannot be privately built on. Behind that sits a protection zone, where new construction is generally barred and existing buildings may face limits on how much they can be reformed or enlarged. Further back is a wider influence zone, where building is allowed but under stricter local planning rules than inland plots.

Many homes in Castellón sit comfortably outside any restricted strip and are unaffected in practice. Others, particularly older houses built before current rules were tightened, may hold a special legal status that allows the existing building to remain but limits what can be added to it. This is exactly the kind of detail a buyer needs clarified property by property, not assumed from a listing description.

For a property in Castellón that sits anywhere near the water, the paperwork trail matters as much as the view. A lawyer can request the coastal demarcation (deslinde) status from the relevant authority, confirm whether the specific plot or building falls inside a protected strip, and check whether any existing concession or special authorisation applies to it.

These checks take time, so build them into your timeline before exchanging. A property that looks straightforward on a portal listing can turn out to carry conditions that affect a future extension, a pool, or even routine maintenance work near the boundary.

Spain is a relatively short flight away from most UK airports, making regular visits to a Spanish property straightforward for owners based in Britain. Many British buyers are drawn to Spain for its climate, coastal lifestyle and established expatriate communities. One practical point to bear in mind is that Spanish inheritance law differs from UK rules, so it is worth taking specific advice on how it may affect the property and one's estate. Currency movements between sterling and the euro can also affect the overall cost of purchase and ongoing expenses.

Spain and the United Kingdom have a double taxation agreement in place, and a local tax adviser should confirm how rental income or gains from Spanish property must be declared and reported to HMRC.

As the United Kingdom is no longer an EU member state, British citizens may stay in Spain for up to 90 days in any 180-day period without a visa, and must apply for a visa or residence permit for longer stays.

Since the United Kingdom uses the pound sterling (GBP) rather than the euro, buyers should factor in exchange-rate movements and currency conversion costs when paying for a property or transferring funds to Spain.