Does the 2028 deadline apply to your property?
DL 97/2017 introduced a transitional compliance calendar based on installation age. Gas installations fitted before 2018 must complete their first mandatory inspection by 26 August 2028. Properties inspected after 2018 run on a standard five-year cycle from the date of that inspection.
If your installation predates 2018 and has no inspection certificate, the 2028 deadline is not far off, and with accredited technician capacity shrinking (see APEG dissolution below), booking delays are already being reported in Lisbon and Porto.
| Installation year | Deadline |
|---|---|
| Before 2003 | Already overdue; inspect immediately |
| 2003–2017 | By 26 August 2028 |
| 2018 or later | Every 5 years from last inspection |
What does DL 97/2017 require?
DL 97/2017 (Decreto-Lei n.º 97/2017, de 10 de agosto) replaced the previous voluntary inspection regime with a mandatory five-year cycle for all residential gas installations in Portugal.
Before DL 97/2017 came into force, inspections were voluntary and informal. No standardised certificate existed. Technicians had no obligation to register findings with DGEG (Direção-Geral de Energia e Geologia). Property owners carried liability without knowing it.
The law changed three things:
Mandatory periodicity
Inspection every five years for residential buildings, every three years for commercial premises.
Certified technician requirement
Only DGEG-accredited technicians (EIG, Entidade Inspetora de Gás) can issue a legally valid certificate. Certificates from non-accredited parties have no legal standing.
DGEG registration
Every certificate must carry a valid DGEG registration number. Without that number, the document cannot be used for insurance claims, property sales, or regulatory compliance.
Gas inspection certificate validity
The gas inspection certificate (boletim de inspeção de gás) issued by a DGEG-accredited EIG technician is valid for five years for residential properties and three years for commercial premises. After expiry, a new full inspection by an accredited technician is required before a replacement certificate can be issued. The new inspection typically takes 60–90 minutes for a standard residential installation. The certificate validity date is printed on the boletim and is also registered in DGEG's central database; insurers and notaries can cross-check it independently.
Who is legally required to get a gas inspection in Portugal?
The obligation falls on the property owner, not the tenant.
Owners
Owners of any residential property with a natural gas or LPG installation must maintain a valid inspection certificate at all times.
Landlords
Landlords retain full responsibility regardless of the rental agreement. If a tenant's claim triggers an insurance investigation and the certificate is expired, the insurer can refuse the claim and pursue the landlord for damages.
Buyers
Buyers should verify the certificate before signing the promissory purchase contract (CPCV, Contrato-Promessa de Compra e Venda). If the certificate is expired at the escritura (deed), the liability for any existing defect transfers to the buyer. DL 10/2024 (Decreto-Lei n.º 10/2024, de 8 de janeiro) removed the mandatory municipal licence check at notary, which means buyers now bear more due diligence responsibility than ever. Negotiate inspection as a purchase condition, or book a pre-purchase inspection (€595) that covers gas alongside all other major systems.
What are the most common gas installation defects found in Portuguese properties?
InspectOS technicians flag defects in the majority of inspections on pre-1990 installations. The table below shows the most frequent issues and their frequency across InspectOS inspections.
| Defect | Frequency | Severity |
|---|---|---|
| Expired certificate (>5 years) | Very common | Critical: legal non-compliance |
| Non-compliant pressure regulators | ~20% of installations | Critical: safety risk |
| Corroded or poorly supported piping | ~25% in pre-1990 properties | Significant |
| Inadequate ventilation in appliance rooms | ~15% of inspections | Significant: CO risk |
| Faulty shut-off valve or flexible hose | ~10% of inspections | Significant |
| Undetected CO accumulation risk | 2–3% of inspections | Critical: life safety |
Source: InspectOS inspection data, 2024–2026.
Carbon monoxide is odourless and colourless. A boiler, hob, or water heater with a blocked flue can produce lethal concentrations in a closed room without any visible sign. InspectOS technicians use calibrated CO detectors as part of every gas inspection; it is not a standard part of all third-party inspections in Portugal.
What happened to APEG, and does it affect your gas inspection?
APEG (Associação Portuguesa dos Engenheiros de Gás) dissolved on 31 December 2025. This is the single biggest structural change to Portugal's gas inspection market since DL 97/2017 came into force.
APEG provided credentialing, training, and professional oversight for a large share of Portugal's accredited gas technicians. Its dissolution does not invalidate existing DGEG credentials, but it removes the professional body responsible for renewals, dispute resolution, and new technician accreditation.
The practical effect: the pool of available DGEG-accredited technicians is contracting at exactly the moment demand is rising ahead of the 2028 transitional deadline. In Lisbon and the Algarve, booking lead times that were two to four days in 2024 are now stretching to two weeks or more in peak months.
InspectOS maintains active relationships with DGEG-accredited EIG technicians across Portugal. All credentials are verified before every assignment. If you are in a high-demand area, booking ahead is practical, not precautionary.
What are the fines for failing to comply with DL 97/2017?
Under DL 97/2017, Artigo 29.º, penalties for non-compliance are:
| Violation | Fine (individuals) | Fine (companies) |
|---|---|---|
| Expired or absent inspection certificate | €250–€3,500 | €450–€40,000 |
| Use of non-accredited technician | €500–€5,000 | €1,000–€60,000 |
| Obstructing a DGEG inspection | €1,000–€10,000 | €2,000–€80,000 |
Beyond fines, the more significant risk is insurance. Most Portuguese home insurers include a standard clause that voids gas damage cover when the inspection certificate has lapsed. This applies to claims for fire, explosion, and CO incidents. The insurer does not need to demonstrate causal connection between the lapsed certificate and the incident; a lapsed certificate alone is grounds for refusal in most standard policies.
After a formal DGEG notification, property owners have a three-month grace period to regularise. After that, gas supply can be permanently disconnected to the property.
If you also need an electrical inspection (€250) and energy performance certificate (€400), all three can be booked in one coordinated visit.
Book your gas inspectionHow does the InspectOS gas inspection work?
A DGEG-accredited InspectOS technician visits the property and conducts a full inspection of the gas installation. The inspection covers:
- Full visual check of all accessible pipework, fittings, and supports
- Tightness test across the entire installation
- Pressure regulator check and compliance verification
- Combustion appliance inspection (boiler, hob, water heater, fireplace)
- Mandatory ventilation verification in all rooms with gas appliances
- Shut-off valve and emergency isolation check
- CO concentration test using a calibrated detector
- Issuance of the official DGEG-registered inspection certificate
The certificate is issued the same day. On request, InspectOS notifies your home insurer directly.
Price: €110 (incl. 23% VAT)
Available in Lisbon, Porto, Algarve, and nationwide.
If you also need an electrical inspection (€250) and energy performance certificate (EPC, €400), all three can be booked in one coordinated visit. Most landlords renewing an AL licence or preparing a property for sale need all three in any case.
Gas compliance checklist
Run through this before booking or before a property transaction:
- Check the date of the last gas inspection: must not be more than five years old
- Confirm the technician holds a valid, current DGEG credential (ask for the EIG number)
- Verify the inspection certificate includes a DGEG registration number
- Confirm all combustion appliances operate correctly (boiler, hob, water heater)
- Check ventilation in every room with a gas appliance
- Confirm flexible hoses are within their marked replacement date
- Notify your home insurer once the renewed certificate is issued
- If buying: request the certificate before signing the CPCV, not after