What hidden costs arise from specific Spanish building regulations?

When purchasing property on the Costa del Sol, particularly new builds or recently renovated properties, hidden costs can emerge from specific Spanish building regulations that differ significantly from Northern European standards. For instance, the **Decennial Insurance (Seguro Decenal)**, mandatory for new constructions, protects against foundational and structural defects for ten years. While essential, the cost of this insurance is typically incorporated into the developer's price, but verifying its existence and coverage is crucial, as some older or improperly registered properties might lack it, exposing buyers to future liabilities. Furthermore, changes to technical building codes (Código Técnico de la Edificación - CTE) can lead to unexpected expenses during renovations. If a renovation significantly alters the structure or use of a property, it may trigger requirements to upgrade to current CTE standards, which could involve costly improvements for energy efficiency, sound insulation, or accessibility that were not factored into the initial budget. Additionally, the **Licencia de Primera Ocupación** (First Occupancy License) is vital for new builds or extensive renovations; without it, connecting utilities can be difficult, and its delay can incur holding costs or even make a property unsellable. Buyers should also be aware of potential costs related to legalizing older structures that might predate current planning permissions or have been built without proper licenses. Remedying these situations can involve substantial legal fees and construction costs to bring the property into compliance, all of which are 'hidden' if not thoroughly investigated through due diligence.