Directory data sources
The Vert.lu directory contains two kinds of company listings. This page explains where the information comes from, how to tell them apart and how to request a correction.
Partner companies
A partner company created or claimed its own listing, confirmed its contact details and agreed to receive quote requests through Vert.lu. Only those listings offer direct contact and a quote request button.
Listings compiled from public sources
All other listings are compiled from registers and public sources (trade register, professional registers, official publications). Those companies are not Vert.lu partners, have not confirmed this information and receive no requests through our site. We display no contact persons, no unverified email address and no quote request button on them.
Correction or removal
Any company can request a correction or the complete removal of its listing. Requests are handled as quickly as possible, after which the listing is removed from the directory and from search engines.
The sources used
Company profiles on vert.lu draw on several combined sources. Public registers accessible in Luxembourg establish a company's legal existence and its declared activity. The official register of authorised installers provides information specific to regulated building and energy trades, such as photovoltaics or heat pumps.
These are supplemented by information companies supply themselves when they claim or create a profile, along with publicly available material from their own websites, such as a list of their services or photos of completed work.
How the data is normalised
Raw information from different sources does not always look the same: an address may be spelt differently, a locality abbreviated, a trade described with source-specific wording. Before publication, these elements are brought into a common format: a normalised address, a locality matched to its municipality, and an activity matched to a standard trade category used across the directory.
This normalisation allows companies to be compared against each other and lets the search and filter functions by trade or locality work reliably, without changing the meaning of the original information.
How often it is refreshed
Data drawn from public registers is reconciled at regular intervals to reflect known changes: a new permit, a change of address, or the end of an activity. Information a company supplies directly after claiming its profile is updated as soon as the company changes it.
Between two reconciliations, a profile may not yet reflect a very recent change in a public register. Companies and homeowners who notice outdated information are therefore invited to report it.
Correcting an error
A company that spots an inaccuracy on its own profile can claim it to correct it directly, or report the error through the site's contact channels. A homeowner who notices clearly wrong information on a profile can report it the same way.
Reports about contact details or a company's authorisation status are handled first, since these are the most sensitive elements for a homeowner about to contact a professional.
What is never published
vert.lu does not publish personal data about a company's managers or staff beyond what is needed for professional contact, nor internal financial information, nor content from sources whose reliability cannot be established. Information that cannot be traced to an identifiable public source or to the company's own statement is not added to a profile.
Ratings and reviews
Where ratings or reviews from homeowners are shown on a profile, they come from identified users who genuinely used the company concerned through vert.lu or reported a verifiable experience. A review that is clearly abusive, off-topic, or breaches the site's usage rules can be removed once reported.
The absence of reviews on a profile is neither a positive nor a negative judgement of the company: it simply means no usable review has been collected yet.