Buying an older house can be rewarding, but it’s vital to thoroughly check its structural integrity before purchase. This guide covers key physical inspections, a step-by-step inspection process, expected costs/timescales, and legal/regulatory considerations to help you make an informed decision.

1. Key Physical Inspections

Before buying, have experts inspect all critical aspects of the house’s structure and systems. Focus on the following areas:

Structural Soundness (Foundation, Walls, Cracks, Beams)

• Foundations & Settlement: Verify the foundation is solid and not undermined by soil movement. If the house is on a slope or hill, ensure it sits entirely on undisturbed (“cut”) ground rather than fill – an older house partially built on fill without proper reinforcement is a red flag (Buying property in Spain, is a structural survey recommend - Andalucia.com). Look for signs of subsidence or settling, such as uneven floors or gaps between walls and ceilings.
• Walls & Load-Bearing Elements: Examine load-bearing walls for cracks and bulges. Minor hairline or vertical cracks can be due to normal settling and aren’t always serious, but large diagonal cracks often indicate significant structural movement (Buying property in Spain, is a structural survey recommend - Andalucia.com). Diagonal or stepped cracks radiating from corners of windows/doors suggest foundation issues or seismic stress and should be evaluated by a structural professional. Walls that lean or bulge outward could signal structural failure.
• Door/Window Alignment: Open and close doors and windows; if frames have shifted out of square or doors stick badly, it may mean the building has moved (Buying an old house in Spain: All you need to know). In a sound structure, door and window openings should remain square and not distorted (Buying property in Spain, is a structural survey recommend - Andalucia.com). Misaligned frames or cracked arches/lintels above openings are signs of past movement.
• Beams, Columns & Floors: If accessible, inspect any exposed beams or columns (many 1930s houses have wooden roof beams or floor joists). Probe wood for softness that could indicate rot or insect damage. Check if floors are level; a slope or sag might mean a weakened joist or foundation settlement. While some unevenness can occur in old houses, be skeptical if told “old houses just have uneven floors” – investigate the cause (e.g. go into any crawlspace to check for rot or water damage on sill beams). Any sagging roof ridge or bouncy floor is a concern (Buying property in Spain, is a structural survey recommend - Andalucia.com).
• Red Flags: Significant structural red flags include wide diagonal cracks, a visibly sagging roofline, or ongoing settlement (e.g. freshly plastered-over cracks that have re-opened). These issues may require costly foundation underpinning or structural repairs and could be deal-breakers if severe (Buying property in Spain, is a structural survey recommend - Andalucia.com).

Roof Condition (Tiles, Leaks, Insulation, Structure)

• Roof Covering: Examine the roof’s surface (use binoculars or have an inspector go up). In southern Spain, many older homes have terracotta tile roofs. Missing, cracked, or slipped tiles can allow water in. Ensure the tiles are intact and properly overlapped. As clay tiles age they become brittle, so damaged sections should be noted (Guide to building and other types of surveys in Spain) (Surveying issues to consider when buying an old property in Spain). On flat roofs or roof terraces, look for patched or painted areas – a fresh bitumen or paint patch often indicates past leaks (Surveying issues to consider when buying an old property in Spain).
• Leaks & Damp Signs: Check ceilings and upper walls indoors for water stains or peeling paint, especially after rains. In attic spaces (if any), look for dark stains on rafters or damp insulation. Any sign of leakage means the roof’s waterproof membrane or tiles might be compromised (Surveying issues to consider when buying an old property in Spain). Also note if there is no guttering; many Spanish homes lack gutters (Guide to building and other types of surveys in Spain), which can lead to water running down walls and causing damp at the base.
• Roof Structure: Determine the roof structure type. A 1930s house might have a timber-framed roof. Inspect the attic or eaves for sagging rafters, rotted wood, or termite damage. A sagging roofline visible from outside is a serious warning sign (Buying property in Spain, is a structural survey recommend - Andalucia.com). If the roof structure is concrete (less common in 1930s homes, but some have concrete beams), check for cracks in the concrete or corrosion in any exposed rebar.
• Insulation & Ventilation: Older houses often lack proper insulation. If accessible, have the inspector check the attic for insulation condition and adequacy (Cómo Prepararte Para Una Inspección Técnica De Viviendas Antiguas | Hausum). Poor insulation can be upgraded later, but be aware it affects comfort and energy usage. Also ensure there’s ventilation in the roof space to prevent humidity buildup.
• Expected Condition: Many old houses will eventually need roof overhaul. If the roof is 80-90 years old with only patch repairs done, assume it may require re-roofing. However, if a recent roof renovation was done, get documentation (building permit, contractor warranty) and have the quality verified. A solid roof is crucial; ongoing leaks can rot timber and weaken the entire structure over time (Cómo Prepararte Para Una Inspección Técnica De Viviendas Antiguas | Hausum).

Ground Stability (Soil Condition, Subsidence Risk, Landslides)

• Soil & Terrain: Research the soil conditions of the site. Granada’s suburbs can have mixed soil types (clays that shrink/swell, or rocky soils). If the house is on flat ground, check for any history of sinkholes or underground water issues. If on a hillside, assess the slope stability. Look at retaining walls or terrace levels on the property: cracks or bowing in retaining walls, or soil pulling away from foundations, can indicate movement.
• Site Inspection: Walk around the house’s exterior. Look for signs of ground movement such as tilted fences, cracked paving, or depressions in the yard. Pay special attention to any hillside directly above or below the house for signs of landslides (slipped earth, fallen rocks) (Cómo Prepararte Para Una Inspección Técnica De Viviendas Antiguas | Hausum). Also check if any large trees are very close to the house; tree roots can undermine foundations or, if the tree has been removed, the soil can settle (Surveying issues to consider when buying an old property in Spain).
• Foundation Exposure: If the foundation edge is visible, inspect it for cracks or differential settlement. In one reported case, a poorly planned development led to a retaining wall collapse that left a house’s foundation partly exposed and unsupported (Guide to building and other types of surveys in Spain). While extreme, it underscores the need to ensure surrounding ground supports the structure.
• History of Issues: Ask the seller and neighbors if there have been any previous landslides or flooding in the area. Granada province has seen landslides in certain zones (Desprendimientos, hundimientos y socavones: la historia negra de …), so local knowledge is valuable. Also verify if the area is seismic; Granada is in a seismically active region (historically affected by tremors). A 1930s house was not built to modern earthquake codes, so check for earthquake retrofitting (unlikely in most homes, but some owners may have added reinforcements). If serious ground instability or seismic weakness is suspected, consider having a structural engineer or geotechnical engineer evaluate it. Modern builds in the area undergo rigorous seismic foundation studies (borehole soil tests, etc.) – older homes lack this, so you must rely on visual clues and expert opinion (Buying property in Spain, is a structural survey recommend - Andalucia.com).
• Drainage: Ensure the site drains properly. Water pooling near the foundation can cause erosion or subsidence. Look for drainage channels, and check that downspouts (if present) lead water away from the house. Poor drainage might manifest as damp soil against walls or algae growth on exterior walls. Simple landscaping fixes can sometimes solve drainage issues, but if you see evidence of major past water damage or earth movement, that’s costlier to address.

Electrical and Plumbing Systems

• Electrical System: Many Spanish homes built in the early 20th century have had piecemeal electrical upgrades. Check the main electrical panel (“cuadro eléctrico”) – is it modern with circuit breakers, or old with ceramic fuses? A modern-looking fuse panel and new outlets could hide old wiring behind the walls (Surveying issues to consider when buying an old property in Spain). Look for a mix of outlet styles or old cloth-insulated wires in the attic; a mixture often means only partial re-wiring was done (Surveying issues to consider when buying an old property in Spain). Houses from before the 1970s might even have aluminum wiring, which is less safe than copper and now obsolete (Cómo Prepararte Para Una Inspección Técnica De Viviendas Antiguas | Hausum). If the wiring is outdated, plan for a full rewire to meet current safety standards (with grounding and sufficient circuit capacity). Always ask the seller for the Boletín Eléctrico (electrical safety certificate) if they have one, which confirms the installation meets code (Surveying issues to consider when buying an old property in Spain). If they cannot provide it, anticipate needing an electrician’s inspection and upgrades.
• Plumbing System: Old plumbing can be equally problematic. Determine if the water pipes are copper, galvanized steel, or even lead. In very old houses, lead pipes might exist and should be replaced for safety (Cómo Prepararte Para Una Inspección Técnica De Viviendas Antiguas | Hausum). Galvanized steel pipes (common mid-20th century) corrode internally, causing low pressure and rusty water – replacement with copper or PEX is often needed. Check water pressure at various taps and see if the water runs clear. Inspect for leaks or damp spots under sinks and around the base of walls; persistent damp near a bathroom could mean a hidden pipe leak (Surveying issues to consider when buying an old property in Spain). Because many Spanish homes have pipes buried in walls or floors, leaks can go unnoticed for years and cause structural damage (Surveying issues to consider when buying an old property in Spain). A thermal camera or moisture meter can help detect moisture behind tiles or plaster.
• Waste System: Confirm whether the house is connected to the municipal sewer or using a septic tank (Surveying issues to consider when buying an old property in Spain). Many old houses in small towns had cesspits or septic systems. An inspector should locate the septic tank (if any) and assess its condition – an old brick cesspit might need an update to meet today’s standards. If on a sewer, you might consider a video inspection of the sewer line (to check for tree root intrusion or collapse, especially if clay pipes were used decades ago). One buyer reported a sewer scope saved them thousands by revealing broken sewer pipes before purchase, allowing negotiation on price. Always flush toilets and run all taps during the inspection to see if drainage is smooth (Surveying issues to consider when buying an old property in Spain).
• Water Heater/Boiler: If the house has a hot water boiler or heating boiler, check its age and ask for maintenance records. An old unit might need replacement for efficiency and safety. If there’s gas service, ensure there’s a recent inspection sticker for the gas installation.
• Upgrades Needed: Keep in mind that completely renewing electrical and plumbing systems is common in 50+ year-old houses. It’s often considered essential in a renovation (Buying an old house in Spain: All you need to know). Neglecting to update these can lead to frequent breakdowns – e.g. an expert recounted a case where not changing old pipes led to 12 pipe bursts in 10 years (Buying an old house in Spain: All you need to know). Budget for these upgrades in an old house purchase unless it’s proven they were recently done properly.

Pest and Damp Inspection (Woodworm, Termites, Humidity)

• Damp (Humedades): Older Spanish houses often lack a damp-proof course in walls, so rising damp is a frequent issue (Surveying issues to consider when buying an old property in Spain). Inspect lower sections of walls for salt efflorescence (white powdery deposits) or bubbled/blistering paint – these indicate chronic damp where water is wicking up the wall and evaporating, leaving salts behind (Surveying issues to consider when buying an old property in Spain). Also look for black mold spots in corners, musty odors, or dehumidifiers in use (sign the home has moisture issues). External walls: check if plaster is flaking or if there are algae on the wall, suggesting persistent moisture. In Granada’s climate, damp can result from rainwater, groundwater, or plumbing leaks, so identifying the source is key. Minor damp can often be managed with improved ventilation, adding a damp-proof membrane, or injection damp-proofing, but severe structural damp might require more extensive work.
• Timber Pests (Carcoma, Termites): Termites (termitas) and wood-boring beetles (carcoma) are a serious threat in old houses with wooden elements. Even if a house is mostly stone or brick, it will likely have wood roof beams, window frames, doors, or floorboards that are susceptible (Surveying issues to consider when buying an old property in Spain). Termites can silently chew through wood; one expert noted a case in northern Spain where a 20x20 cm timber beam was reduced to 5x5 cm in cross section by termites, nearly hollowed out (Buying an old house in Spain: All you need to know). Look for signs of infestation: small exit holes in wood, tiny piles of wood dust, blistered or warped wood, or shed insect wings near windows. Tapping wood beams to hear if they sound hollow can also hint at internal damage. In many village homes, woodworm beetles (which leave pinholes) are common; extensive powderpost beetle damage can weaken timbers over decades.
• Pest Inspection: It’s wise to have a professional pest inspection for wood-destroying organisms. Many pest control companies in Spain offer a free or low-cost termite inspection (Inspección Gratuita de Termitas - Anticimex), knowing that treatment (if needed) is expensive. If termites are found, get a quote for treatment – typically ranging from €900 to €2,300 for an average house depending on severity (¿Cuánto cuesta un tratamiento contra las termitas? Precios en 2025). Treatments may involve chemical barriers or bait systems. Ensure any existing wood is treated and structurally sound; severely damaged beams must be reinforced or replaced.
• Other Pests: Check for signs of rodents or bats in the attic, and for wood rot (fungus) in any chronically damp timber. While not “pests,” mold and dry rot fungi can eat through wood like pests do. If the house has an enclosed crawlspace, definitely inspect underneath (or have a specialist do so) for dry rot, mold, or termite mud tubes on foundation walls.
• Damp Proofing History: Ask if any damp-proofing work has been done (injections, new damp course, etc.) and if there are guarantees. Also check if the exterior ground level is higher than the interior floors – if so, that can cause damp seeping through walls. This might require re-grading outside or adding drainage.
• Takeaway: Damp and pests are often “hidden problems” that a casual viewing might miss but can lead to huge repair costs if ignored (Buying an old house in Spain: All you need to know). Since Spanish law makes it hard to claim these as seller’s hidden defects later, you want to catch them now. A thorough inspection with moisture meters and pest experts will help avoid nasty surprises.

Neighboring Buildings in Terraced Houses (Shared Walls & Risks)

If the house is terraced or shares party walls (paredes medianeras) with neighbors – common in Spanish townhouses – you must consider the condition of those adjoining structures as well: