Start with safe action, before documentation
Discovering a crack can be unsettling, particularly when you are planning a renovation or have only just noticed it. Before taking measurements or searching for similar photographs, consider whether the situation needs immediate attention. If materials are falling, there is significant distortion, a sudden change or other signs of danger, move away and seek an urgent assessment. Contact the appropriate emergency services in an emergency. Do not enter to take photographs or stand beneath elements that could fall.
This guide helps you prepare an enquiry. It cannot establish a home's stability remotely. The shape, width or location of a crack alone cannot establish its cause. Equally, the absence of any one warning sign does not guarantee safety. If you are uncertain whether a space can be occupied, request professional instructions for your particular circumstances before continuing to use it.
Locate the crack within the building
Where it is safe to observe, mark the crack on a simple sketch of the home. Identify the floor, room and wall or ceiling, using recognisable references such as a doorway, corner or adjoining room. A close-up may show an opening clearly while removing the very context the professional needs. Pair it with a wider image and retain the date for both.
Explain what you actually know about the element. If you only know the surface finish, say so. Do not assume a wall is a partition or a loadbearing element from its apparent thickness. Note signs on the opposite face or in adjacent spaces only where you already have safe, authorised access. Do not remove finishes, climb to difficult locations or open ceilings. Any investigation that requires access or opening-up needs to be organized with the appropriate precautions and equipment.
Build a chronology that distinguishes facts from memory
Write down when you first noticed the crack, when you know it was absent and what changes you have observed. “I discovered it today” does not necessarily mean “it appeared today”. Old photographs of the room may help narrow the dates, although their resolution may be insufficient to confirm anything. State that limitation instead of treating an unclear image as proof.
Also record known recent building work, water incidents or changes in how doors and windows operate, without assuming a causal connection. Include earlier repairs where known: approximate date, affected area and available records. If you can safely take comparison photographs, use similar reference points. The professional should decide whether measured monitoring is necessary and how it should be arranged. Do not install tell-tales or attempt repairs yourself to test movement. Improvised monitoring can create misleading readings or unwarranted reassurance.
Gather records and define the enquiry
Collect drawings, an approximate construction date, earlier reports and records of alterations that you legitimately have available. If the structural system is unknown or drawings are missing, say so. Identifying an information gap is more helpful than filling it with an assumption. In a shared building, coordination with the owners' community may be necessary to obtain records or access other areas.
When requesting a visit, describe the locations, the changes you have observed and any immediate concern. Ask what further information is needed, what the assessment will cover and what written document you will receive. An initial inspection, a more extensive structural assessment and the design of a possible intervention are not necessarily the same service. Defining the appointment avoids expecting a complete conclusion from a limited visit or an exchange of photographs. Also establish who will coordinate access and communication between those involved.
Ask what the assessment can establish
An assessment should help determine the next steps using the evidence available. It may identify further inspection needs, missing records or measures that need to be taken. Ask which conclusions are supported and which questions remain open. Recognised uncertainty can guide a proportionate investigation. A categorical explanation without sufficient evidence can lead to the wrong decisions.
Spain's Technical Building Code provides official structural safety documents, but citing a regulation cannot replace assessment of an existing building. The professional must determine the appropriate checks and technical framework. Do not choose a cosmetic repair because a crack resembles one shown online. Nor should you independently commission openings, strengthening, demolition or temporary propping. If intervention is proposed, ask for its scope, how it will be organized and which permissions or coordination it requires. These questions should be resolved before work is undertaken.
Keep instructions and follow-up together
After the visit, retain the report or written advice alongside the photographs and chronology. Record any instructions about occupancy, access or monitoring, who issued them and what review is planned. A conclusion limited to a particular date or area should not become a general guarantee about the entire building. If new changes appear, report the facts and ask whether they affect the previous advice.
Before a renovation, bring unresolved questions into the appointment so that new finishes do not conceal matters still requiring attention. Where common building elements are involved, coordinate communication with the relevant parties. A one-page summary of locations, background and clearly identified photographs is a manageable starting point for an enquiry. The aim is an appropriate professional assessment with understandable next steps. It is not a promise that an image will provide a reliable diagnosis or establish the safety of the home.
Projects and next steps
Sources and references
Published: October 25, 2026. Requirements and documents must be checked for each property and proposed intervention.