How these pages are researched, written and checked
There is no named expert reviewer behind this site, and saying so is part of the method rather than a gap in it. What stands in place of a signature is checkable: a closed registry of sources, official documents behind anything regulatory, no figure that a cited source does not carry, and a review date and a list of explicit limits on every page.
Advice in English usually describes a different country
Search in English for condensation, damp or home ventilation and much of what comes back was written for a house somewhere else: a colder and drier winter, a different way of arranging rooms, a different set of building rules. Most of it is sound where it was written. Applied to a flat in Barcelona it can be quietly wrong — not in the physics, which travels, but in everything the physics has to work with.
So the first rule behind these pages is that nothing gets in merely because it is repeated often in English. Anything describing how a dwelling in Spain is supposed to renew its air comes from Spanish and Catalan documents; English is where it gets explained, not where it gets decided. Where the rules turn on a distinction that English treats loosely — dry rooms and wet rooms, and the transfer air that has to move between them — the terms keep the meaning the Spanish code gives them.
That principle also settles which pages exist in English at all: this section is not the Catalan section translated, and its topics were chosen during research rather than filled in to complete a grid.
What a citation on this site actually is
The editorial pages carry no links dropped into the middle of a paragraph. They cite by identifier against a closed registry that lives inside the project's own code, and every entry in that registry names the real publisher, the real address of the document, and a short note on what that document may legitimately support.
The practical consequence is that an invented reference here is not difficult, it is unpublishable. A page citing an identifier the registry does not contain fails the pre-publication check, and the whole page stops. Behind that sits a second and narrower gate: each topic carries its own approved shortlist, so citing a source that does exist in the registry but has no bearing on the topic stops the page as well.
The sources were gathered and verified during the research phase, before any text was written. None is added mid-draft to prop up a sentence that has drifted. When a claim turns out to have nothing behind it, the claim is what changes — narrowed to what the source actually says, or removed.
Regulation comes from the regulation, not from a catalogue
Everything stated here in regulatory terms rests on official documents: the Código Técnico de la Edificación and its Documento Básico HS 3 on indoor air quality; the RITE, Royal Decree 1027/2007, together with its 2021 amendment; the royal decree on fluorinated gases; the guide to controlled mechanical ventilation published by the housing department of the Generalitat de Catalunya; and the DB-HS3 application guide from the Col·legi d'Arquitectes de Catalunya. For dampness, mould and health, the World Health Organization. For climate, AEMET.
The registry records what kind of authority each source carries, and that classification decides what the source is allowed to hold up:
| Source type | Example | What it may hold up |
|---|---|---|
| Official | DB-HS3, RITE, Generalitat de Catalunya | Regulatory and legal statements |
| Institutional | COAC, a university, a public broadcaster | Professional interpretation, terminology |
| Research | Peer-reviewed literature | Measured effects and quantities |
| Industry | Manufacturer or trade material | Terminology and market context only |
A manufacturer's document can settle what a component is called in Spanish or in Catalan. It never converts anything into a legal duty. No source of that last kind is cited anywhere in this first set of pages; the category exists so that if one ever enters, it enters labelled for what it is rather than promoted in silence.
One habit matters more than it looks. Duties are written exactly as narrowly as the document writes them. A requirement the regulation places on companies that carry out a certain kind of work stays a requirement about those companies, and is not rewritten into an obligation resting on whoever is reading. A threshold the source sets is not dropped because the sentence reads more smoothly without it. Either edit would be small, and either would change what the law says.
A number appears only when a source is carrying it
There are no prices here, no local statistics, no invented airflow figures, no savings percentages. Where a number appears it keeps both its source and its evidence type. The 104-location Spanish heat-recovery study is a model using manufacturer-declared efficiencies of 86 to 91%; the heritage retrofit study is a field observation with mean apparent thermal effectiveness around 74%. They are not merged into a universal range or turned into a promise for one particular flat.
The same restraint governs the housing stock. Describing how a construction detail behaves is physics, and can be done freely: an old aluminium frame with no thermal break runs cold, and a cold surface is where condensation lands. Saying how common such frames are, or dating them, with no source that ever counted them, is a fabricated statistic wearing the costume of local knowledge.
Nothing is asserted about the people reading, either. The optional, consent-based analytics records aggregate page use; it does not justify a line such as “the question everyone asks.” A value measured in another market is not carried over to fill a gap: a measurement taken elsewhere does not become evidence about Catalonia by appearing on a page about it.
Every page shows when it was reviewed and what it does not solve
Each editorial page displays the date of its last review and a list of explicit limits — what the measure just explained does not fix. That list is content, not fine print at the foot. A page on correcting condensation has to say as well that better air renewal lowers the risk but does not guarantee that mould will not return, and that a damp patch is not automatically condensation: a leak, rising damp and rain penetration are different mechanisms, and separating them reliably takes an on-site inspection.
The date is not moved to look recent. Touching it while nothing of substance has changed would be inventing a review, and a false review date is as fabricated as a false number. When a source changes and the page changes with it, the date follows. When a comma is corrected, it does not.
There is no named reviewer here
The publisher is Aleksandr Prokofyev, identified in the legal notice. That editorial responsibility does not make him a technical reviewer. There is no editorial board, no named reviewer with a professional registration number and signature, no peer review, and no certification or accreditation standing behind these pages.
What exists in its place is traceability. Every page declares the sources it rests on, all of them are public, and all of them can be opened. Nothing here asks to be believed because it appears on a web page: the Documento Básico HS 3, the RITE and the World Health Organization guidance can each be read directly, and the last of those was written in English to begin with.
A limit follows from that, and it should be said in full. Explaining a general mechanism is not ruling on a particular case. No page here substitutes for an on-site inspection, or for the technical assessment of one specific dwelling by a qualified professional standing in front of the building.
Where the text stops on purpose
This portal is informational. There is no installation service behind it, no design, commissioning, legalisation or maintenance work, no pricing, no appointments, no lead capture. Where a page describes work that belongs to a qualified company, it describes it as something that exists in the world rather than something that can be ordered here — and that boundary shapes sentences, not just the footer.
Air conditioning appears only where it clarifies something about ventilation. Work on a refrigerant circuit is reserved to certified personnel and companies under Royal Decree 115/2017 and the European F-Gas framework, and writing about it as though it were a domestic task would steer a reader somewhere they have no business being steered.
None of this is medical advice. On indoor dampness, mould and health these pages stop exactly where the World Health Organization stops: there is evidence linking persistent dampness and mould with respiratory symptoms, and the text goes no further than that. No page diagnoses anyone, and none promises a health outcome.
How to flag an error, and what happens next
If a sentence here looks wrong, the report that can genuinely be checked has three parts: which page, the exact sentence, and — where you have it — the document that says otherwise. With those three, a correction can be verified the same day. Without them, the sentence in question is often impossible even to find. The route for sending one is set out on the contact page of this site.
From there the procedure does not vary. The source the sentence rests on is opened and compared word by word. If it does not support what was written, the sentence is narrowed to what the source does support, or it goes. If the source does support it but the wording could be read two ways, it is changed anyway: an ambiguous sentence about a regulation is an error even when it is technically true. Where the correction touches substance, the review date moves with it.
No response time is promised. Announcing one that nobody has guaranteed would be exactly the kind of promise this page exists in order not to make.