Who signs your reports
A small building-surveying and engineering practice in Barcelona with twenty years of its own archive. Here is who we are and what qualifies us — in case you are comparing.
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Twenty years in the same place, doing the same thing
SINLUZ is the trading name of SLZ, Ingeniería y Arquitectura, S.L.U., a multidisciplinary team — building surveying, engineering, structures and land surveying — working in Barcelona and its metropolitan area since 2004.
Technical direction is by Raúl Heras, chartered technical architect, CAATEEB registration no. 10385. Every report that leaves this office is signed by a chartered professional: that is what makes it valid before a bank, a court or a local authority.
A note on titles, because it confuses people arriving from abroad: an arquitecto técnico (technical architect, formerly aparejador) is the regulated profession in Spain responsible for building surveys, structural condition, site supervision and expert reports — the closest equivalent to a chartered building surveyor in the UK.
We are not a large consultancy and we do not want to be. We are the practice you call when you need someone to go, look, measure and tell you the truth in writing.
We do not opine: we measure, document and sign.
What qualifies us
The details clients usually ask for before commissioning an expert report or a building inspection.
Chartered building engineer, licence no. 10385. Raúl Heras is registered with CAATEEB, the professional body for building engineers and surveyors of Barcelona, and has been since the practice began.
University teaching in building engineering. Raúl Heras teaches at the Department of Architectural Technology of the Universitat Politècnica de Catalunya (UPC), at the Barcelona School of Building Construction, where he lectures on artificial intelligence applied to building engineering in the Building Engineering degree from the 2026-2027 academic year.
Court-appointed expert witness since 2013. Raúl Heras is member no. 428 of the Catalan Association of Judicial and Forensic Experts working with the Administration of Justice, registered in December 2013.
Published research on high-alumina cement. Lead author of the chapter «Application of Machine Learning Approaches to Predict Calcium-Aluminate Cement», published by Springer in Building Engineering Facing the Challenges of the 21st Century (Lecture Notes in Civil Engineering 345, 2023). The research, carried out with the UPC on 533 samples from our own archive, identified high-alumina cement from photographs with 96.5% accuracy.
Over 12,000 case files studied. Our own technical archive since 2004: more than 3,000 commissions completed and a series of over 1,000 laboratory-backed high-alumina cement tests.
Three things we always do the same way
Fixed price before we start. We tell you what it costs and there are no surprise extras. If the scope changes because of something that appears during the work, we ask you before doing it.
Deadlines in writing. The timescales published on each page go into the quotation. If a case does not allow that timescale, we say so in the first conversation instead of accepting it and running late.
If it is not our field, we say so. There are things we do not do — standalone habitability or energy certificates, for instance — and when asked we refer you to someone who does them well.
We work in English, Spanish and Catalan, and a good share of our pre-purchase surveys are for buyers who are not based in Spain: we are used to reporting remotely, in plain language and with photographs.
5.0 out of 5 on Google, from 122 reviews
Real, public reviews from our Google listing — exactly as they were written.
«Hace años que trabajamos con Raúl, nos ha hecho varios proyectos. Estamos encantadas con su trabajo, siempre rápido y profesional. Además, el trato personal es impecable: una persona clara y honesta. Recomiendo 100%»
«Excellent service from start to finish. The inspection was carried out professionally, with samples taken carefully and neatly, and we received clear, practical advice on the repairs needed. The report was delivered incredibly quickly. Highly recommended!»
«100% Recomendable! Raúl es un 10, y se merece la ovación del público en pie…»
Read all 122 reviews on Google → Have we worked for you? Leave a review
What clients ask us most
Who exactly signs the reports?
A chartered technical architect. Technical direction is by Raúl Heras, CAATEEB registration no. 10385; depending on the type of commission, he signs or the competent member of the team for that speciality does. The report always states the name and registration number of whoever signs it.
Are your reports valid for a Spanish bank or court?
Yes. A report signed by a chartered technical architect is the document banks, courts and local authorities accept. For court proceedings we also attend to ratify the report when required.
Can you work with buyers who are not in Spain?
Routinely. We visit the property, report with photographs and talk you through it by video call or WhatsApp. You do not need to be in Barcelona for the survey — only your seller's permission to access the property.
Do you work for private individuals or only companies?
Both. In the same month we may have a public-sector contract and an aluminosis test on a sixty-square-metre flat. The technical standard and the way we work are identical.
Comparing practices?
Tell us about your case and we will tell you what we would do, what it costs and how long it takes — no obligation.