What to Check When Viewing a Flat: Buyer's Checklist

Technical aspects and basic services in the property

Service installations are the backbone of any property. Identifying faults in utility networks before making an offer will allow you to calculate accurately the actual renovation budget required for the property.

Plumbing and water pipework

Turn on the bathroom and kitchen taps simultaneously to check both water pressure and flow rate. See how long it takes for hot water to arrive and verify that the flow does not drop suddenly. If the water has a reddish or yellowish tint when you open the tap, the building or flat likely still has galvanised iron or lead pipes, which means they will need replacing with modern materials such as copper or multilayer pipework.

Inspect the space beneath basins, sinks and toilets for damp marks, leaks or mould. Likewise, check the age of the boiler or electric water heater and confirm whether it displays proof of having passed mandatory periodic inspections.

Electrical consumer unit and climate control

Ask to see the main consumer unit (fuse box). In older properties, it is common to find outdated units lacking a residual current device (RCD) or a main automatic switch (IGA), or installed without proper circuit separation for appliances, lighting and power sockets. An old electrical system without earthing on sockets fails to comply with current regulations, poses a safety hazard, and will require a complete overhaul.

Regarding climate control, test the air conditioning units and switch on the radiators if the viewing allows. Pay special attention to the condition of the radiators, ensuring there are no leaks from the bleed valves or obvious signs of rust around the connections.

Insulation and exterior joinery

Windows and enclosures determine the thermal and acoustic comfort level of the property. When assessing what to look for when viewing a flat, examine the window frame materials (timber, standard aluminium, or thermal break aluminium and PVC) and the glazing system. Double glazing with an air gap significantly reduces heating and air conditioning costs.

Open and close several windows to check that they operate smoothly without looseness. If the property is located on a busy road or commercial street, close all windows fully to assess the soundproofing performance against outside noise.

Structural condition, preservation and lighting

Beyond the surface aesthetics of walls and paintwork, it is vital to examine the structural elements that guarantee the habitability and long-term durability of the home.

Walls, ceilings and dampness

It is important to distinguish between superficial hairline cracks in plaster or paint and structural cracks. Fine, horizontal cracks are usually caused by thermal movement in finishing materials, whereas diagonal or stepped cracks in partition walls can indicate building settlement that requires specialist technical inspection.

Inspect ceilings, upper wall corners, and surfaces adjoining bathrooms or exterior facades thoroughly. Dark patches, flaking paint or bubbling plaster are clear signs of damp, whether caused by condensation (due to lack of proper ventilation) or water ingress from outside or upper floors.

Aspect, natural light and ventilation

The aspect (orientation) of the property dictates how much direct sunlight it receives throughout the year. A south or south-east aspect provides greater natural light and warmth during winter, benefiting energy efficiency. Check whether the main rooms feature external windows or face inner light wells, which will reduce natural light entry.

Check whether the flat benefits from cross-ventilation, meaning windows located on opposite or adjacent facades. This allows rapid air renewal and helps cool the property during summer months without relying constantly on air conditioning.

Layout and load-bearing walls

Consider whether the layout of the rooms meets your day-to-day needs. If you are considering renovating to create open-plan areas (such as joining the kitchen to the living room), identify which walls are non-structural brick or plasterboard partitions and which are load-bearing walls or contain communal soil stacks. Modifying load-bearing walls requires architectural plans, municipal permits, and formal authorization from the owners' community.

The building, communal areas and local area

The overall condition of the building directly affects property value and the recurring expenses you will assume as an owner.

Lift, accessibility and ITE/IEE

Observe the general condition of the entrance lobby, staircase, landings and internal courtyards. Check that the lift works properly, assess its capacity, and see whether the building features ramps or lifts to ensure step-free access for people with reduced mobility.

In older buildings, it is essential to confirm whether the property has passed the Technical Building Inspection (ITE) or the Building Assessment Report (IEE). An unfavorable ITE inspection highlights defects in the facade, roof or structure that will require the owners' community to undertake costly renovation works.

Communal fees and outstanding special assessments

Ask for the exact monthly communal fee and what services it covers (cleaning, concierge, lift maintenance or central heating). Inquire whether any extraordinary levies or special assessments have been approved or are under discussion for structural repairs to the building. Levies approved before the sale must be settled as agreed between the parties or as stipulated by current law.

Surroundings, local services and noise environment

It is advisable to walk around the neighbourhood at different times of day. An area that seems peaceful on a weekday morning might experience high noise levels at night or over the weekend due to bars, restaurants, outdoor terraces or loading bays. Check proximity to essential amenities such as public transport, healthcare centres, supermarkets and schools.

Documentary checks and legal implications

Before advancing any deposit payment, it is essential to verify the legal status of the flat you have viewed.

Verification of the Nota Simple Informativa

Although a comprehensive land registry check takes place before signing the deposit agreement (contrato de arras), requesting or examining the Nota Simple from the Land Registry allows you to confirm the vendor's legal ownership and check whether the property carries charges, existing mortgages, court encumbrances or easements.

Official Protection Housing (VPO) in the Comunidad de Madrid

In the case of properties subject to public housing protection regimes located in the Comunidad de Madrid, it is compulsory to verify the type of VPO, the years elapsed since its final classification, and the maximum legal sale price fixed by the regional administration. In the Comunidad de Madrid, disqualification procedures (descalificación) or sales at capped prices directly determine buyer eligibility and property transfer options.

Energy Performance Certificate and floor plans

Request the current energy performance certificate. The energy label (ranging from A to G) provides an estimate of annual utility costs. Having a dimensioned floor plan of the property also helps you verify the usable floor area against the gross built area recorded in the Land Registry (Catastro).

Summary checklist: what to check when viewing a flat

To simplify your in-person inspection, you can use this quick checklist during your viewing:

• Plumbing: Water pressure, hot water delivery time, condition of drains and absence of leaks under sinks.
• Electrical system: Consumer unit with RCD and main switch, presence of earthing and condition of sockets and switches.
• Insulation: Window frame materials, double glazing and soundproofing effectiveness against outdoor noise.
• Structure and surfaces: Absence of diagonal cracks, damp patches, wall bubbling or condensation.
• Climate control and lighting: Facade aspect, hours of sunlight, cross-ventilation, and operation of radiators or air conditioning.
• Building: Result of the ITE/IEE inspection, presence of a lift, entrance accessibility and cleanliness of communal areas.
• Communal status: Amount of standard monthly communal fees and verification of any approved extraordinary levies.
• Documentation: Verification of the Nota Simple from the Land Registry and, if applicable to VPO properties in the Comunidad de Madrid, review of the maximum legal price and protection regime.

Secure your purchase with professional advice

Knowing in detail what to look for when viewing a flat requires technical expertise, time to analyse legal documentation, and objectivity so as not to overlook major defects. An incomplete inspection during the viewing can lead to unpleasant surprises or unplanned expenses after completion.

To approach the buying process with total peace of mind, a Personal Shopper Inmobiliario (property buyer's agent) provides dedicated technical and legal representation focused exclusively on protecting the buyer's interests. This professional carries out property searches, meticulously inspects the physical condition of the property, evaluates its land registry and cadastral status, and negotiates the final purchase price.

At Sky Real Estate, we have a multidisciplinary team recognized at international awards such as the Sky Law European Legal Awards (2023-2025) and registered with the Banco de España under code ICI D-286. If you want to make a secure investment and benefit from expert support throughout the entire process, discover how we can assist you through our personal shopper inmobiliario (PSI) service.