Almost every contractor, heating engineer or electrician displays a logo of some kind: on the van, in the footer of the quote or on the website. For clients, it is hard to see exactly what such a quality mark is worth. Some quality marks offer you a disputes procedure and a financial guarantee if the company goes bankrupt; others only say something about a product or about working safely and nothing about the quality of the work in your home. And one "quality mark" is not a quality mark at all but a legal obligation: the CO certification for work on gas installations. This article goes through the best-known logos with the same three questions each time: who awards it and what is assessed, what does it give you, and what does it not mean. Finally, you will read how to check each quality mark yourself.
BouwGarant: quality mark for contractors with a disputes procedure
BouwGarant calls itself "the quality mark in construction" and is aimed at contractors in renovation and new build. A company may only use the quality mark once it meets the admission requirements. According to the pages for contractors, the company must have been registered with the KvK (Chamber of Commerce) in its current legal form for at least two and a half years and be demonstrably active, must have filed annual accounts for the last two calendar years, and the management must hold the professional diploma of contractor for building and civil engineering (aannemer B&U); in addition, BouwGarant mentions the right insurance, a creditworthiness check and periodic assessment by independent bodies. The full requirements are in BouwGarant's assessment guideline.
What it gives you. BouwGarant contractors are affiliated with the independent Geschillencommissie Verbouwingen en Nieuwbouw (Disputes Committee for Renovations and New Build), set up by the Consumentenbond (Dutch Consumers' Association), Vereniging Eigen Huis (Dutch homeowners' association) and BouwGarant. If you cannot reach agreement with the contractor, you can turn to it for a binding ruling without going to court. In addition, for a larger job you can take out a separate Verbouwgarantie (renovation guarantee): an insurance that you apply for before the work starts and that covers the extra completion costs if the contractor goes bankrupt during the work, plus hidden defects after completion. Note: this guarantee is not automatically included with every BouwGarant contractor; you have to apply for it per project. You can read how the guarantee relates to your statutory rights in Guarantee after a renovation: how long, on what and from whom.
What it does not mean. The quality mark assesses the organisation of the company, not your individual job. An affiliated contractor can still produce a poor quote or finish late; the difference is that you then have an accessible route for disputes.
Woningborg and SWK: guarantee for new build
Woningborg and SWK (Stichting Waarborgfonds Koopwoningen, the guarantee fund for owner-occupied homes, since 1978) are best known for the guarantee and warranty scheme for newly built owner-occupied homes. Both organisations assess construction companies before registering them as participants and issue a guarantee certificate per home. According to Woningborg's page for buyers, the scheme provides cover if the contractor goes bankrupt during construction, and from three months after completion a guaranteed warranty on parts of the home. If the contractor does not comply with an arbitration ruling on guaranteed defects, or is bankrupt after completion, you can call on the repair guarantee; in a dispute you can first ask for mediation. SWK works with a comparable scheme for its participants.
What it does not mean. These schemes are linked to a home and a project, not to a company as such. The fact that a contractor is a participant with Woningborg or SWK therefore says nothing about your private bathroom renovation: the scheme generally does not apply to that, unless a separate certificate has been issued for your project. So ask about it and ask to see it.
Techniek Nederland: trade association, not a certificate
Techniek Nederland is the employers' association for installation companies and technical service providers. The logo means the company is a member; it is membership of a trade association, not a certificate issued by an independent body. Even so, that membership has concrete value for you. Members work with the Algemene Voorwaarden voor Installatiewerk voor Consumenten (AVIC, general terms and conditions for installation work for consumers), drawn up in consultation with consumer organisations within the SER (Social and Economic Council), which include a guarantee scheme. In a dispute you can turn to the Geschillencommissie Installerende Bedrijven (Disputes Committee for Installation Companies), which handles complaints about, among other things, the installation or repair of heating, gas and water pipes, electrics, drains and sanitary ware in your home. The condition is that the company is a member of Techniek Nederland; if it is not a member, this route is not open to you. You can check whether a company is a member via the "Find a specialist company" search on the association's website.
What it does not mean. Membership is not proof that a specific engineer is certified for gas work or refrigerants; those obligations are set out separately below. So for gas or heat pump work, always ask about those certificates too.
Erkend Installateur (InstallQ): professional competence per discipline
The term "erkend installateur" (recognised installer) in the Netherlands usually refers to a recognition from InstallQ, an independent foundation that manages recognition schemes for, among others, electrical engineering, gas, water, heating, solar power and heat pumps. A recognised company has demonstrated that it has the required professional knowledge and company equipment and is checked periodically. For you, this is the quality mark that comes closest to the quality of the technical work, because it is granted per discipline. You can find recognised companies in the public register echteinstallateur.nl, searchable by postcode and company name.
What it does not mean. A recognition for solar power says nothing about gas work, and vice versa. Check in the register exactly which recognition the company has and whether it suits your job. A recognition is also not a financial guarantee in the event of bankruptcy, nor a disputes procedure.
KOMO: product and process, not your job
KOMO is the Dutch quality mark for building products, building processes and services. A KOMO certificate or attestation is issued by an accredited certification body, such as Kiwa or SKG-IKOB, on the basis of an assessment guideline (BRL). It says that a product or process has been objectively assessed and meets requirements for, among other things, safety, suitability and durability; it goes further than the statutory CE marking. So if your roofing, window frames or insulation material are KOMO-certified, that is a good sign for the material.
What it does not mean. A KOMO logo on a contractor's quote usually means that they use KOMO-certified products or work according to a certified process, not that their company or your job has been inspected. KOMO process certificates do exist for contracting companies, for example for applying roofing or insulation; you can check whether a company has one via the search function on komo.nl, where certificates can be found by company and by subject. Always ask for the certificate itself.
VCA: working safely, not a judgement of quality
VCA stands for Veiligheid, Gezondheid en Milieu Checklist Aannemers (Safety, Health and Environment Checklist for Contractors) and is managed by the Stichting Samenwerken Voor Veiligheid (SSVV). A VCA company certificate shows that the company's safety management system has been assessed: risk control, training, information, inspections and incident registration. There are levels (VCA*, VCA** and VCA Petrochemie) and, in addition, personal diplomas such as Basisveiligheid (B-VCA, basic safety) and VOL-VCA (for operational supervisors). VCA is intended for companies doing high-risk work, often because business clients require it; it is not a legal obligation for work in homes.
What it does not mean. VCA says something about safety in the workplace, not about the quality of brickwork, tiling or pipework. It is a plus, especially for work at height or with heavy equipment, but no substitute for references and professional diplomas. Company certificates can be checked in SSVV's Centraal Certificaten Register (Central Certificates Register) (ccr.ssvv.nl), personal diplomas in the Centraal Diploma Register (Central Diploma Register).
CO certification for gas work: not a quality mark, but the law
Since 1 April 2023, installing, repairing, servicing and commissioning gas-fired appliances, such as a central heating boiler, gas water heater or gas fire, and the associated air supply and flue gas outlet, may only be carried out by a certified company. The legal basis is article 6.45 of the Besluit bouwwerken leefomgeving (Bbl, the Dutch Building Decree). The company must have a certificate based on a recognised assessment guideline, such as InstallQ BRL 6000-25 or Kiwa BRL K25000, and the engineer must hold a Bewijs van Vakmanschap Koolmonoxide (carbon monoxide certificate of competence). The rule is also aimed at you as the client: if you have the work carried out by a non-certified company, you are acting in breach of the Bbl. So this is not an optional quality mark but a legal requirement for being allowed to touch the boiler at all.
Checking is simple: in the national register of gas combustion installations of the Toelatingsorganisatie Kwaliteitsborging Bouw (TloKB, the admissions body for quality assurance in construction), you search by company name or town to see whether an installer is certified and for which work. If the company is not listed, do not let it do any gas work. Similar certification obligations apply to work with refrigerants in heat pumps and air conditioning units (F-gas certificate for the company and the engineer). For electrics in homes there is no statutory certification obligation; there, NEN 1010 (the Dutch standard for low-voltage installations) and the requirements of the grid operator apply, as explained in May I install electrics myself?.
How to check a quality mark in five minutes
- KvK. Look the company up via kvk.nl. Do the trading name, the address and the activity (SBI code) match what is on the quote? How long has the company existed, and has it not just changed its legal form?
- The quality mark itself. Look the company up in the register of the organisation that awards the quality mark: the "Find a contractor" search at BouwGarant, Woningborg's company register or the SWK list of participants, the "Find a specialist company" search at Techniek Nederland, echteinstallateur.nl for InstallQ, komo.nl for KOMO, ccr.ssvv.nl for VCA and register.tlokb.nl for CO certification. A logo on a website is not proof; only the register entry is.
- Scope and validity. Does the recognition fit your job (gas is not solar power, a new-build guarantee is not a renovation guarantee) and is it still valid?
- What does it give me? Ask the company directly: which disputes committee are you affiliated with, which terms and conditions do you use and do I need to apply separately for a guarantee? A company that takes its quality mark seriously can answer that straight away.
- Record it. Note the register entry and the certificate number with your quote. Should a dispute arise later, you will have the evidence to hand.
Quality marks are useful filters, but no substitute for the basics: several quotes, verifiable references, clear arrangements on paper and a payment schedule that follows progress. You can read how to lay those foundations in 5 tips for choosing the right contractor.