{"id":2202,"date":"2026-10-06T20:13:08","date_gmt":"2026-10-06T18:13:08","guid":{"rendered":"https:\/\/unitearquitectura.com\/?post_type=unite_proyecto&#038;p=2202"},"modified":"2026-10-06T20:13:08","modified_gmt":"2026-10-06T18:13:08","slug":"estudio-de-viabilidad-antes-de-comprar-terreno-o-casa","status":"publish","type":"unite_proyecto","link":"https:\/\/unitearquitectura.com\/en\/proyectos-unite\/estudio-de-viabilidad-antes-de-comprar-terreno-o-casa\/","title":{"rendered":"Feasibility study: what to check before buying a plot or a house"},"content":{"rendered":"<p class=\"wp-block-paragraph\">A feasibility study answers a very simple question before you sign: <strong>can I do what I want to do here, and how much will it cost me?<\/strong> It works just as well for a plot where you want to build your home as for a house you are thinking of buying and renovating.<\/p>\r\n\r\n\r\n\r\n<p class=\"wp-block-paragraph\">It is one of the jobs we do most, and almost always for the same reason: the advert, the seller or the deeds themselves say one thing, and the local plan (PGOU), the Cadastre or the Land Registry say another. Here we explain what we check, what tends to come up and when it is worth doing.<\/p>\r\n\r\n\r\n\r\n<h2 class=\"wp-block-heading\">When it is worth it<\/h2>\r\n\r\n\r\n\r\n<ul class=\"wp-block-list\">\r\n<li><strong>Before buying a plot to build a house on.<\/strong> This is the clearest case: if you cannot build what you have in mind, it is better to know before you pay.<\/li>\r\n\r\n<li><strong>Before buying a house you want to renovate or extend.<\/strong> Can that window be opened up, a storey added or the porch enclosed? Does what is already built have a licence?<\/li>\r\n\r\n<li><strong>Before buying a country house.<\/strong> This is where almost all the problems come together: rural land (suelo r\u00fastico), unlicensed buildings, floor areas that don't add up, no mains drainage or electricity.<\/li>\r\n\r\n<li><strong>Before investing.<\/strong> To find out how many homes fit on a site, whether commercial premises can become a home or whether a warehouse allows the activity you want to set up.<\/li>\r\n<\/ul>\r\n\r\n\r\n\r\n<p class=\"wp-block-paragraph\">The best time is <strong>before signing the deposit contract (arras)<\/strong>. If you are in a hurry to reserve, ask your notary or lawyer whether you can make the purchase conditional on the outcome of the study. That way, if it goes wrong, you don't lose the deposit.<\/p>\r\n\r\n\r\n\r\n<h2 class=\"wp-block-heading\">What we check<\/h2>\r\n\r\n\r\n\r\n<p class=\"wp-block-paragraph\">A feasibility study is not just \u201clooking at the house\u201d. It has three parts, and the big problems are usually in the first two:<\/p>\r\n\r\n\r\n\r\n<figure class=\"wp-block-table\"><table><thead><tr><th>Part<\/th><th>What we look at<\/th><th>What can go wrong<\/th><\/tr><\/thead><tbody><tr><td><strong>Planning<\/strong><\/td><td>Land classification, zoning regulations, buildability, site coverage, heights, setbacks, permitted uses and constraints (flood risk, roads, watercourses, power lines).<\/td><td>That the plot cannot be built on, that it only allows a much smaller house, or that it does not permit a pool, a second storey or the use you have in mind.<\/td><\/tr><tr><td><strong>Land Registry and Cadastre<\/strong><\/td><td>Land Registry extract (nota simple), deeds, Cadastre, boundaries, easements, charges and old orthophotos to see how the property has changed.<\/td><td>That the area in the deeds does not match the real or cadastral area, that there are undeclared buildings, or that the access track is not yours.<\/td><\/tr><tr><td><strong>Technical<\/strong><\/td><td>For a plot: shape, slope, access, water, electricity, drainage. For a house: structure, roof, damp, services and windows and doors.<\/td><td>That connecting services costs a fortune, that a septic tank is needed, or that the house needs a much bigger renovation than it seems.<\/td><\/tr><\/tbody><\/table><\/figure>\r\n\r\n\r\n\r\n<figure class=\"wp-block-image size-full\"><img fetchpriority=\"high\" decoding=\"async\" width=\"2400\" height=\"1587\" src=\"https:\/\/unitearquitectura.com\/wp-content\/uploads\/2026\/10\/01-vega-baja-huerta-y-pueblos.jpg\" alt=\"Huerta de la Vega Baja con pueblos, urbanizaciones y la sierra al fondo\" class=\"wp-image-2192\" srcset=\"https:\/\/unitearquitectura.com\/wp-content\/uploads\/2026\/10\/01-vega-baja-huerta-y-pueblos.jpg 2400w, https:\/\/unitearquitectura.com\/wp-content\/uploads\/2026\/10\/01-vega-baja-huerta-y-pueblos-1024x677.jpg 1024w, https:\/\/unitearquitectura.com\/wp-content\/uploads\/2026\/10\/01-vega-baja-huerta-y-pueblos-1600x1058.jpg 1600w, https:\/\/unitearquitectura.com\/wp-content\/uploads\/2026\/10\/01-vega-baja-huerta-y-pueblos-300x198.jpg 300w, https:\/\/unitearquitectura.com\/wp-content\/uploads\/2026\/10\/01-vega-baja-huerta-y-pueblos-768x508.jpg 768w, https:\/\/unitearquitectura.com\/wp-content\/uploads\/2026\/10\/01-vega-baja-huerta-y-pueblos-1536x1016.jpg 1536w, https:\/\/unitearquitectura.com\/wp-content\/uploads\/2026\/10\/01-vega-baja-huerta-y-pueblos-2048x1354.jpg 2048w\" sizes=\"(max-width: 2400px) 100vw, 2400px\" \/><figcaption class=\"wp-element-caption\">The Vega Baja from Guardamar castle. Between a town and the farmland next to it there can be a different land classification and completely different rules. Photo: Joanbanjo \u00b7 <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Vista_cap_a_Oriola_i_Callosa_des_del_castell_de_Guardamar_del_Segura.JPG\" target=\"_blank\" rel=\"noopener\">CC BY-SA 4.0<\/a>, via Wikimedia Commons.<\/figcaption><\/figure>\r\n\r\n\r\n\r\n<h3 class=\"wp-block-heading\">1. What the planning rules say<\/h3>\r\n\r\n\r\n\r\n<p class=\"wp-block-paragraph\">The first thing is to find out what type of land the property is on and what the municipality's local plan (PGOU) allows. We check this in the planning drawings and regulations and, whenever necessary, <strong>we speak directly to the town hall's technical officer<\/strong>. Many questions can only be resolved that way.<\/p>\r\n\r\n\r\n\r\n<ul class=\"wp-block-list\">\r\n<li><strong>Urban land.<\/strong> You can build if the plot qualifies as a building plot (solar). Even so, you need to check the minimum plot size, buildability, heights and setbacks.<\/li>\r\n\r\n<li><strong>Developable land.<\/strong> Normally you cannot build until the sector has been developed, which can take years and cost the owners money.<\/li>\r\n\r\n<li><strong>Non-developable or rural land (r\u00fastico).<\/strong> This is where most nasty surprises happen. In the Valencian Community, a detached house on ordinary non-developable land needs at least one hectare and cannot cover more than 2% of the property. On top of that, each municipality's plan can be stricter, and on protected land it is often impossible to build any house at all.<\/li>\r\n<\/ul>\r\n\r\n\r\n\r\n<p class=\"wp-block-paragraph\">We also check the <strong>constraints<\/strong>, which can limit the plot even if the land can be built on. In the Valencian Community, for example, flood risk is checked in PATRICOVA, and in the Vega Baja looking at it is practically a must.<\/p>\r\n\r\n\r\n\r\n<h3 class=\"wp-block-heading\">2. What the Land Registry and the Cadastre say<\/h3>\r\n\r\n\r\n\r\n<p class=\"wp-block-paragraph\">The Land Registry and the Cadastre (Catastro) are two separate databases and they often don't match. With the Land Registry extract (nota simple) and the cadastral record we check who the owner is, how big the property is, whether there are mortgages, seizures or easements, and whether the property is \u201ccoordinated\u201d, that is, whether the Cadastre's drawing is also valid for the Land Registry.<\/p>\r\n\r\n\r\n\r\n<p class=\"wp-block-paragraph\">If the areas don't add up, it can be corrected with a <a href=\"\/en\/servicios\/representacion-grafica-alternativa-gml\/\">georeferenced plan (GML)<\/a>, but it is better to know before buying: the area that counts for working out what you can build is the one you can prove, not the one in the advert.<\/p>\r\n\r\n\r\n\r\n<p class=\"wp-block-paragraph\">A trick we use a lot is <strong>old orthophotos<\/strong>. By comparing aerial photos from different years we can see when each structure appeared, whether the fencing has moved or whether the property has changed shape. It tells us whether an extension or a pool has been there for years or is recent.<\/p>\r\n\r\n\r\n\r\n<figure class=\"wp-block-image size-full\"><img decoding=\"async\" width=\"2000\" height=\"1500\" src=\"https:\/\/unitearquitectura.com\/wp-content\/uploads\/2026\/10\/02-camino-de-acceso-parcela.jpg\" alt=\"Camino de tierra junto al vallado de una parcela r\u00fastica\" class=\"wp-image-2190\" srcset=\"https:\/\/unitearquitectura.com\/wp-content\/uploads\/2026\/10\/02-camino-de-acceso-parcela.jpg 2000w, https:\/\/unitearquitectura.com\/wp-content\/uploads\/2026\/10\/02-camino-de-acceso-parcela-1024x768.jpg 1024w, https:\/\/unitearquitectura.com\/wp-content\/uploads\/2026\/10\/02-camino-de-acceso-parcela-1600x1200.jpg 1600w, https:\/\/unitearquitectura.com\/wp-content\/uploads\/2026\/10\/02-camino-de-acceso-parcela-300x225.jpg 300w, https:\/\/unitearquitectura.com\/wp-content\/uploads\/2026\/10\/02-camino-de-acceso-parcela-768x576.jpg 768w, https:\/\/unitearquitectura.com\/wp-content\/uploads\/2026\/10\/02-camino-de-acceso-parcela-1536x1152.jpg 1536w\" sizes=\"(max-width: 2000px) 100vw, 2000px\" \/><figcaption class=\"wp-element-caption\">Access track to a plot. Is it public, yours or the neighbour's? Does it count towards the property's area? These are questions the study must answer. Photo: Unit\u00e9 Arquitectura.<\/figcaption><\/figure>\r\n\r\n\r\n\r\n<h3 class=\"wp-block-heading\">3. What is (or isn't) on the ground<\/h3>\r\n\r\n\r\n\r\n<p class=\"wp-block-paragraph\">Then we go and see it. On a plot we look at the access, the shape and the slope, and whether water, electricity and drainage reach it. A meter cabinet on the fence does not mean there is enough power for a house, and a sewer running along the track does not mean you can connect to it.<\/p>\r\n\r\n\r\n\r\n<p class=\"wp-block-paragraph\">We have come across country houses whose only supply was around 2 kW of solar panels without batteries, with no internet and no septic tank. None of that stops you buying, but it all has a cost that <strong>needs to go into the price negotiation<\/strong>.<\/p>\r\n\r\n\r\n\r\n<figure class=\"wp-block-image size-full\"><img decoding=\"async\" width=\"2000\" height=\"1500\" src=\"https:\/\/unitearquitectura.com\/wp-content\/uploads\/2026\/10\/03-armario-contador-parcela.jpg\" alt=\"Armario de contador junto al vallado de una parcela en la huerta\" class=\"wp-image-2191\" srcset=\"https:\/\/unitearquitectura.com\/wp-content\/uploads\/2026\/10\/03-armario-contador-parcela.jpg 2000w, https:\/\/unitearquitectura.com\/wp-content\/uploads\/2026\/10\/03-armario-contador-parcela-1024x768.jpg 1024w, https:\/\/unitearquitectura.com\/wp-content\/uploads\/2026\/10\/03-armario-contador-parcela-1600x1200.jpg 1600w, https:\/\/unitearquitectura.com\/wp-content\/uploads\/2026\/10\/03-armario-contador-parcela-300x225.jpg 300w, https:\/\/unitearquitectura.com\/wp-content\/uploads\/2026\/10\/03-armario-contador-parcela-768x576.jpg 768w, https:\/\/unitearquitectura.com\/wp-content\/uploads\/2026\/10\/03-armario-contador-parcela-1536x1152.jpg 1536w\" sizes=\"(max-width: 2000px) 100vw, 2000px\" \/><figcaption class=\"wp-element-caption\">Meter cabinet on the boundary of a plot. You need to check what supply actually arrives and at what power. Photo: Unit\u00e9 Arquitectura.<\/figcaption><\/figure>\r\n\r\n\r\n\r\n<p class=\"wp-block-paragraph\">For a house we carry out a technical inspection: structure and cracks, roof, damp, electrical, water and drainage installations, windows and doors, and insulation. And we check the paperwork: whether it has an <a href=\"\/en\/servicios\/licencia-segunda-ocupacion\/\">occupancy licence<\/a>, <a href=\"\/en\/servicios\/certificado-energetico\/\">energy performance certificate<\/a> and, if the building is old, the <a href=\"\/en\/servicios\/inspeccion-tecnica-de-edificios\/\">building inspection report (IEE\/ITE)<\/a>.<\/p>\r\n\r\n\r\n\r\n<h2 class=\"wp-block-heading\">Two real cases (no names)<\/h2>\r\n\r\n\r\n\r\n<p class=\"wp-block-paragraph\">These are two studies we did in 2024 and 2025. We have removed any details that could identify anyone.<\/p>\r\n\r\n\r\n\r\n<h3 class=\"wp-block-heading\">A plot in the farmland that did not allow a house<\/h3>\r\n\r\n\r\n\r\n<p class=\"wp-block-paragraph\">Some clients had bought a rural property of almost one hectare to build a two-storey house with a pool. They asked us for the study <em>after<\/em> buying. The outcome:<\/p>\r\n\r\n\r\n\r\n<ul class=\"wp-block-list\">\r\n<li>The land was protected agricultural non-developable land. <strong>An ordinary house was not allowed<\/strong>, only one linked to and justified by a farming operation.<\/li>\r\n\r\n<li>Even then, the maximum site coverage was <strong>1% of the property<\/strong>: about 88 m\u00b2, on a single storey and with no pool.<\/li>\r\n\r\n<li>The deeds said more than 10,000 m\u00b2, but the Cadastre recognised about 1,200 m\u00b2 less, and the orthophotos did not reach a hectare either. The property was not coordinated.<\/li>\r\n<\/ul>\r\n\r\n\r\n\r\n<p class=\"wp-block-paragraph\">The conclusion was hard but clear: either look for alternatives, or sell the plot and find another with better conditions. With a study beforehand, that purchase would not have gone ahead.<\/p>\r\n\r\n\r\n\r\n<h3 class=\"wp-block-heading\">A semi-detached house with an unlicensed storeroom<\/h3>\r\n\r\n\r\n\r\n<p class=\"wp-block-paragraph\">A client wanted to buy a semi-detached house on an estate and fully renovate it. The house complied with the local plan, but some storerooms next to the pool had been built without a licence. As the town hall confirmed to us, the deadline for taking action against them had passed, so they could stay, but <strong>they could only be maintained<\/strong>, not extended or rebuilt. We also explained which procedure the renovation would need: a declaraci\u00f3n responsable (works notice) if it did not touch the fa\u00e7ade, and a licence with a project if it opened up new windows or doors.<\/p>\r\n\r\n\r\n\r\n<p class=\"wp-block-paragraph\">Watch the deadlines: in the Valencian Community, the town hall has 15 years to act against unlicensed works, and on protected land or public property there is no time limit. Old works are not automatically legal works. If what you are buying has unlicensed parts, sometimes they can be <a href=\"\/en\/servicios\/legalizacion-de-obras\/\">legalised<\/a> and other times their age can be proven with a <a href=\"\/en\/servicios\/certificado-de-antiguedad\/\">certificate<\/a>.<\/p>\r\n\r\n\r\n\r\n<h2 class=\"wp-block-heading\">What we need and what we give you<\/h2>\r\n\r\n\r\n\r\n<p class=\"wp-block-paragraph\">To get started we need very little:<\/p>\r\n\r\n\r\n\r\n<ul class=\"wp-block-list\">\r\n<li>The <strong>cadastral reference<\/strong> or the exact address.<\/li>\r\n\r\n<li>The <strong>land registry extract (nota simple)<\/strong> (requested from the Land Registry for about \u20ac10) and, if you have them, the deeds.<\/li>\r\n\r\n<li>The advert or whatever the seller has told you, and <strong>what you want to do<\/strong>: what house, how many storeys, whether you want a pool, what renovation.<\/li>\r\n<\/ul>\r\n\r\n\r\n\r\n<p class=\"wp-block-paragraph\">We give you a signed report setting out what can and cannot be done, the problems we have found, how they can be solved and, where needed, an estimate of the cost of the works or repairs. We make it valid for six months, because the rules and the situation of the property can change.<\/p>\r\n\r\n\r\n\r\n<figure class=\"wp-block-table\"><table><thead><tr><th>If the study says\u2026<\/th><th>What you can do<\/th><\/tr><\/thead><tbody><tr><td>What you want can be done<\/td><td>Buy with peace of mind and start the project with the facts already checked.<\/td><\/tr><tr><td>It can be done, but with conditions<\/td><td>Negotiate the price, ask the seller to regularise things before signing, or adjust the project.<\/td><\/tr><tr><td>It cannot be done<\/td><td>Don't buy, or buy knowing exactly what you are getting and for how much.<\/td><\/tr><\/tbody><\/table><\/figure>\r\n\r\n\r\n\r\n<p class=\"wp-block-paragraph\">The study often pays for itself: a problem spotted in time is an argument for lowering the price, and one that isn't spotted is one you pay for later.<\/p>\r\n\r\n\r\n\r\n<h2 class=\"wp-block-heading\">In short<\/h2>\r\n\r\n\r\n\r\n<ol class=\"wp-block-list\">\r\n<li>Do the study <strong>before<\/strong> signing the deposit contract (arras), not after.<\/li>\r\n\r\n<li>Look at all three parts: planning, Land Registry and Cadastre, and technical condition.<\/li>\r\n\r\n<li>Don't trust the area in the advert, or that some building work \u201chas always been there\u201d.<\/li>\r\n\r\n<li>Use whatever comes up to make your decision and to negotiate.<\/li>\r\n<\/ol>\r\n\r\n\r\n\r\n<p class=\"wp-block-paragraph\">If you already have the plot and are thinking about the house, carry on with our article <a href=\"\/en\/proyectos-unite\/hacerse-una-casa-que-mirar-y-cuanto-cuesta\/\">Building a house: what to look at before you start and what it really costs<\/a>. And if you are about to buy in the province of Alicante or the Region of Murcia, write to us via the <a href=\"\/en\/contacto\/\">contact page<\/a> with the cadastral reference.<\/p>\r\n\r\n\r\n\r\n<h3 class=\"wp-block-heading\">Further reading<\/h3>\r\n\r\n\r\n\r\n<ul class=\"wp-block-list\">\r\n<li>Decreto Legislativo 1\/2021, consolidated text of the Valencian Land Use, Urban Planning and Landscape Act (TRLOTUP), Valencian Community.<\/li>\r\n\r\n<li>Mortgage Act (Ley Hipotecaria), articles 9, 10 and 199 (coordination between the Cadastre and the Land Registry).<\/li>\r\n\r\n<li>Generalitat Valenciana, Territorial Action Plan for Flood Risk Prevention (PATRICOVA).<\/li>\r\n\r\n<li><a href=\"https:\/\/www.sedecatastro.gob.es\/\" target=\"_blank\" rel=\"noopener\">Cadastre online portal (Sede electr\u00f3nica del Catastro)<\/a> y <a href=\"https:\/\/www.registradores.org\/\" target=\"_blank\" rel=\"noopener\">Registradores de Espa\u00f1a<\/a> (nota simple).<\/li>\r\n<\/ul>\r\n\r\n\r\n\r\n<p class=\"wp-block-paragraph\"><small>Cover photo: a building plot at the foot of the Sierra de Callosa, in Redov\u00e1n. Photo: Ximonic (Simo R\u00e4s\u00e4nen) \u00b7 <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Residential_under_Sierra_de_Callosa_in_Redov\u00e1n,_Alicante,_Spain,_2022_January_-_2.jpg\" target=\"_blank\" rel=\"noopener\">CC BY-SA 4.0<\/a>, via Wikimedia Commons.<\/small><\/p>","protected":false},"featured_media":2193,"template":"","class_list":["post-2202","unite_proyecto","type-unite_proyecto","status-publish","has-post-thumbnail","hentry"],"_links":{"self":[{"href":"https:\/\/unitearquitectura.com\/en\/wp-json\/wp\/v2\/unite_proyecto\/2202","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/unitearquitectura.com\/en\/wp-json\/wp\/v2\/unite_proyecto"}],"about":[{"href":"https:\/\/unitearquitectura.com\/en\/wp-json\/wp\/v2\/types\/unite_proyecto"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/unitearquitectura.com\/en\/wp-json\/wp\/v2\/media\/2193"}],"wp:attachment":[{"href":"https:\/\/unitearquitectura.com\/en\/wp-json\/wp\/v2\/media?parent=2202"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}