Begin with the legal boundary, not the distance to the beach
A coastal address does not automatically create a legal problem, but proximity to the shore requires checks that ordinary title information may not resolve. The first question is whether the property or any part of its garden, pool, terrace or access falls within maritime-terrestrial public domain or an associated restriction zone. This must be assessed against the relevant legal boundaries, not an approximate distance measured from today’s waterline.
The Coast Act defines protected coastal assets and establishes the framework for their delimitation and use. The approved deslinde identifies the public-domain boundary through an administrative procedure. Obtain the applicable plans and resolution where the property may be affected. A marketing statement that the house is “100 metres from the sea” does not establish which boundary applies, whether the plot crosses it or what rights the seller is actually entitled to transfer.
Legal framework and sources: BOE · Ley 22/1988, de Costas ↗BOE · Real Decreto 876/2014, Reglamento General de Costas ↗
Separate public domain from restrictions on private land
Public-domain occupation and ownership of private land subject to coastal easements are materially different situations. A plot within public domain cannot be analysed as ordinary unrestricted private freehold merely because a deed or historic Registry entry exists. A concession or other lawful title may be relevant, and its terms can fundamentally change the nature and value of the acquisition.
Private land outside public domain may nevertheless be subject to protection, transit or access restrictions. These do not all have the same purpose or consequence. The review should identify each affected part of the property and explain whether the issue concerns ownership, public passage, permitted works or administrative authorisation. Avoid a single broad statement that the home is “affected by Costas”. The buyer needs to know the legal interest being acquired and how each restriction influences ordinary use, renovation and eventual resale.
Legal framework and sources: BOE · Ley 22/1988, de Costas ↗BOE · Real Decreto 876/2014, Reglamento General de Costas ↗BOE · Ley Hipotecaria ↗
Understand the protection strip and its exceptions
The Coast Act sets a general protection easement of 100 metres inland from the inner boundary of the seashore, with legally defined possibilities of variation. A 20-metre regime can apply in specified transitional circumstances, but should not be assumed simply because an area is built up today. The historic classification and statutory conditions require verification. The appropriate reference line and the exact part of the plot affected are essential to the analysis.
Within the protection zone, uses and works are subject to restrictions and the relevant authorisation regime. Existing buildings can have particular transitional treatment, which must be examined separately from permission to construct something new. A buyer contemplating a pool, extension or replacement house should ask a specific question about that project. Permission to maintain an existing home should not be interpreted as permission to enlarge it or rebuild it with a different footprint.
Legal framework and sources: BOE · Ley 22/1988, de Costas ↗BOE · Real Decreto 876/2014, Reglamento General de Costas ↗
Use official mapping as screening, then obtain precise confirmation
MITECO provides public information on coastal boundary lines, but explains that the displayed data are informative and can be checked with the peripheral coastal services. Use the map to identify a possible issue, record the layer and date and locate the entire parcel, not only a point placed on the house. Where the boundary is close, mapping accuracy and the parcel’s own geometry need technical attention.
Request the appropriate certificate or written information from the competent coastal demarcation or provincial service, identifying Registry and cadastral references and supplying a georeferenced plan where needed. Ask about the approved boundary, pending revision or proceedings and the particular restriction relevant to the purchase. The municipality may also hold important information, but it does not replace the authority competent for the coastal matter. Preserve the response and its scope; a general map screenshot is not equivalent to a formal answer on the specific property.
Legal framework and sources: MITECO · Líneas de deslinde del dominio público marítimo-terrestre ↗BOE · Ley 22/1988, de Costas ↗BOE · Real Decreto 876/2014, Reglamento General de Costas ↗
If there is a concession, value the concession you can acquire
Obtain the complete concession title, amendments, plans and evidence of current compliance. Identify the holder, authorised use, occupied area, duration, charges, transfer conditions and any breach or expiry issue. A concession is not equivalent to perpetual private ownership, and an anticipated extension should not be treated as granted without the corresponding decision. The remaining term can affect financing and the buyer’s investment horizon.
Article 70 of the Coast Act regulates transfers and requires the relevant prior administrative recognition for an inter vivos transfer. The precise process and competent authority must be confirmed for the concession. Ensure the purchase agreement reflects these requirements and explains the outcome if transfer cannot be completed. Check that all marketed facilities fall within the lawful title. A terrace or pool outside the authorised perimeter may create a separate issue even where the principal concession itself is valid.
Legal framework and sources: BOE · Ley 22/1988, de Costas ↗BOE · Real Decreto 876/2014, Reglamento General de Costas ↗
Existing works and future renovations need separate answers
Reconstruct the building history using licences, plans, completion evidence and any coastal authorisations or declarations required. Compare those documents with current reality. Coastal transitional rules can distinguish between types of existing works and the alterations allowed. Do not assume that an old building is fully regularised merely because enforcement has not occurred or because the Cadastre records it.
A planning licence and a coastal permission address different legal interests. Both may be relevant, along with heritage or other sectoral rules. Before buying for renovation, ask what can be repaired, replaced, enlarged or changed and what documentation must be obtained first. A declaration of old works for Registry purposes is not a method of overriding public-domain protection or coastal limitations. If the proposed improvement is essential to the purchase, resolve its feasibility before the deposit becomes an unconditional commitment.
Legal framework and sources: BOE · Ley 22/1988, de Costas ↗BOE · Real Decreto 876/2014, Reglamento General de Costas ↗BOE · Texto refundido de la Ley de Suelo y Rehabilitación Urbana ↗
Review physical coastal risk alongside the legal position
A favourable legal position does not remove exposure to storms, erosion, salt corrosion, coastal flooding or maintenance costs. Ask the surveyor to consider the building’s setting, drainage, exposed structure and repair history. Examine available official risk information and obtain insurance terms suited to the location. A sea view can be an asset while also increasing the need for maintenance and resilience measures.
Keep the conclusions separate: a public-domain boundary is a legal delimitation, while an inundation or erosion study describes a physical hazard under its assumptions. Neither automatically answers the other. Consider access during severe weather and the impact of any protective works or public projects. Where the buyer relies on an existing seawall, determine its ownership, condition, lawful status and maintenance responsibility. The existence of a defence structure should not be treated as a guarantee that damage cannot occur.
Legal framework and sources: BOE · Ley 22/1988, de Costas ↗BOE · Real Decreto 876/2014, Reglamento General de Costas ↗
An example: the house was outside, but the pool was affected
In this fictional transaction, an initial map places the house outside maritime-terrestrial public domain. The buyer interprets that as a complete coastal clearance. A parcel-wide survey shows that the garden and pool occupy a different position relative to the approved lines, and the proposed extension lies within the protection area. The original point-based check did not address these elements.
The buyer obtains the applicable coastal information, reviews the pool’s authorisation and asks whether the extension is permissible. The transaction may remain viable, but the price and contract must reflect the answer rather than the headline result for the main building. A retention cannot create permission for a prohibited extension. The example shows why coastal due diligence must analyse the entire property and the intended project, with each conclusion tied to a clearly identified boundary and source.
Legal framework and sources: BOE · Ley 22/1988, de Costas ↗BOE · Real Decreto 876/2014, Reglamento General de Costas ↗MITECO · Líneas de deslinde del dominio público marítimo-terrestre ↗
Make the final decision on evidence, term and permitted use
The final coastal review should state the property’s relationship with public domain, the applicable easements, any concession and the position of proposed works. Identify the authority consulted, document dates and unresolved proceedings. If the evidence is incomplete, explain what remains unknown and why it matters. An assertion of “no coastal problem” should not conceal an enquiry limited to one map layer or an outdated boundary.
Use that analysis to agree conditions, document delivery and any lawful rectification before completion. Where a concession is involved, align price and finance with the transferable right and remaining term. Where private land is subject to restrictions, explain the practical consequences for occupation, maintenance and resale. The objective is not to discourage every coastal purchase, but to ensure that the buyer understands the specific home being acquired and does not pay for ownership or development possibilities the seller cannot deliver.
Legal framework and sources: BOE · Ley 22/1988, de Costas ↗BOE · Real Decreto 876/2014, Reglamento General de Costas ↗BOE · Ley Hipotecaria ↗
Sources & further reading
BOE · Ley 22/1988, de Costas ↗BOE · Real Decreto 876/2014, Reglamento General de Costas ↗MITECO · Líneas de deslinde del dominio público marítimo-terrestre ↗BOE · Ley Hipotecaria ↗BOE · Texto refundido de la Ley de Suelo y Rehabilitación Urbana ↗Editorial preview: professional legal review is pending. This guide provides general information and does not determine the legal position of a particular property.
Have a property in mind?
Bring the documents and questions from this guide into your property analysis.