The legal, technical and financial mistakes it helps you avoid
This article is written with technical support from the cost and budgeting guidance prepared by architect José Manuel Garrido R. (The Villas Architect):
https://www.thevillasarchitect.com
Building a villa in Spain is an exciting project — but the most expensive mistakes usually happen before construction begins.
Many buyers focus almost exclusively on construction cost per square metre. While this figure is important, it represents only one part of the total investment. In practice, insufficient preliminary work is one of the main reasons why budgets are exceeded, timelines are missed and legal problems arise later.
A proper preliminary due diligence phase, carried out before committing to a property purchase or final design, is what separates a controlled project from a risky one.
Buying to build: where most problems actually start
When the intention is to build, the legal risks do not begin on site. They begin at the moment of purchase.
Plots, houses to demolish or properties acquired with a future construction project in mind must be analysed not only from a title and ownership perspective, but also from the standpoint of what can realistically and legally be built.
This is why, when buying to build in Spain, due diligence must go beyond standard conveyancing checks.
Mistake 1: Assuming you can build what you have in mind
One of the most common and costly errors is purchasing a property based on assumptions about buildability.
Urban planning regulations vary by municipality and determine:
- Maximum buildable area
- Permitted occupancy
- Height limits and setbacks
- Whether basements, terraces or additional volumes are allowed
Without verifying these parameters before purchase, buyers often discover too late that their project must be reduced, redesigned or restructured, with direct financial consequences.
Mistake 2: Underestimating the real total investment
Another frequent mistake is calculating the budget based solely on construction cost per square metre.
In reality, construction is only one part of the overall investment. A realistic assessment must also include:
- Architect and technical direction fees
- Mandatory technical roles and preliminary studies
- Municipal licence costs
- Applicable VAT on construction and services
- A contingency margin for unforeseen costs
Failing to consider these elements early leads to budget overruns and difficult decisions once the project is already underway.
Mistake 3: Discovering legal and technical constraints too late
Even when a plot is technically buildable, missing early coordination between legal, planning and technical aspects can cause:
- Delays in licensing
- Costly design adjustments
- Unclear allocation of responsibilities
These issues are rarely construction problems — they are planning and sequencing problems.
Mistake 4: Misunderstanding licence costs and timing
Municipal building licences are not uniform across Spain. The cost and structure of these fees vary by municipality and can represent a significant percentage of the construction budget.
Without early clarity, licence costs often appear as an unexpected financial burden at a critical stage of the project.
Mistake 5: No contingency planning
Even well-prepared projects face variables: price fluctuations, technical refinements or administrative requirements.
Projects that start without a contingency margin are far more vulnerable to disruption when small issues arise.
Why preliminary due diligence makes the difference
When preliminary due diligence is done properly, buyers gain:
- Legal certainty about what can be built
- A realistic view of the total investment
- Fewer surprises during licensing and construction
- Greater control over the project from the outset
In Spain, successful villa projects are not defined by what happens on site, but by the decisions made before the purchase is completed.
How this fits into property purchase in Spain
Buying to build requires more than standard conveyancing.
When a property is acquired in Spain with a construction project in mind, legal due diligence must extend beyond title and charges.This approach is integrated into our property purchase service for clients who intend to build.
👉 https://costaluzlawyers.es/property-purchase-spain
Contact us today to tell us about your project. We’ll be delighted to support you from the very beginning with our preventive, risk-focused legal approach.
Reviewed by María de Castro, Abogado no. 2745, Ilustre Colegio de Abogados de Cádiz. CostaLuz Lawyers has supported international buyers since 2006 on EyeonSpain with guidance and advice on the legal aspects of life in Spain. Included in the lawyers lists of the UK and Ireland embassies. Updated 22 Nov 2025.
María Luisa de Castro’s work, founder of CostaLuz Lawyers, is backed by a strong presence in specialist media and professional directories. Her track record as a Property Law and Consumer Real Estate Law (Derecho de Consumo Inmobiliario) specialist can be seen in her guides for international audiences on Expatra, in her long-running blogs on Spanish off-plan protection and Ley 57/1968 on EyeOnSpain , in her legal analysis for Confilegal and Legal Today, and in her contributions for the Spanish Bar Council (Consejo General de la Abogacía Española) and the Centre for Consumer Studies at the University of Castilla-La Mancha.
Her work is also profiled on international retirement and expat platforms such as Retirement Abroad, and has been highlighted by expat media including The Olive Press News Spain and The Local Spain among other specialist expat and legal forums.
Her legal work has also been featured or referenced in respected international and Spanish media, including The Telegraph, The Times, the BBC, El País and El País English, The Local Spain, The Olive Press and other reputable outlets, particularly in connection with landmark court rulings on Ley 57/1968 and Spanish consumer protection.
CostaLuz Lawyers is also included in the official lists of English-speaking legal professionals for British and Irish nationals in Spain, as compiled by the UK government’s “Spain: list of lawyers” and by the Embassy of Ireland in Spain and its honorary consular network.
Legal Notice: The content on this page is provided for general informational and educational purposes only. It does not constitute legal advice and should not be relied upon as such. No action should be taken based solely on this content without first seeking independent professional legal counsel. Each case requires individual assessment based on its specific circumstances. CostaLuz Lawyers accepts no liability for actions taken or not taken based on this content.
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This content has been prepared with the assistance of artificial intelligence and reviewed by María Luisa de Castro, a lawyer specialising in Real Estate Law and founder of CostaLuz Lawyers.
The information provided is general and indicative in nature. It should not be used as the sole basis for making professional, legal or investment decisions, and CostaLuz Lawyers assumes no responsibility for decisions taken solely on the basis of this content.
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