Plumbing & Water Systems

According to EN 806 (parts 1–5) and Portuguese Decreto Regulamentar 23/95 (RGSPPDADAR), water supply installations must be designed and installed to provide adequate flow rates and pressures at all draw-off points. Minimum static pressure at the most unfavourable draw-off point is 100 kPa (1 bar) per DR 23/95. Pipe materials must comply with relevant EN standards (EN ISO 15875 for PE-X, EN ISO 15874 for PP, EN 1057 for copper). All connections must be accessible for maintenance. Pipe sizing must follow DR 23/95 hydraulic design requirements. Potable water installations must prevent contamination per EN 1717.

1. Verify pipe materials and fittings match the specification and hold valid CE marking per the relevant EN standard

2. Check pipe sizing against DR 23/95 hydraulic design — verify diameters match the calculated flow rates for each section

3. Measure static water pressure at the most unfavourable draw-off point — minimum 100 kPa (1 bar) per DR 23/95

4. Inspect all connections, joints and fittings for leaks and correct assembly — no solvent cement overflow, correct compression fitting torque

5. Confirm isolation valves are installed at each riser, branch, apartment entry and appliance connection per DR 23/95

- Water pressure below minimum at upper floors due to undersized mains or insufficient booster capacity

- Incorrect pipe material or non-CE-marked fittings used in the installation

- Missing isolation valves at required locations, preventing maintenance without full system shutdown

- Pipe runs not adequately supported or clipped, causing noise and stress on joints

According to EN 12056 (parts 1–5) and Portuguese DR 23/95, drainage systems must be designed to convey wastewater and rainwater safely and hygienically. Minimum pipe gradients are 1% (1:100) for horizontal branches ≥ 100 mm and 2% (1:50) for branches < 100 mm. All sanitary appliances must be trapped with water seal depth of minimum 50 mm per EN 12056-2. Ventilation must be provided per EN 12056-2 system requirements (primary, secondary or air admittance valves). DR 23/95 defines specific requirements for Portuguese installations including minimum pipe sizes, access chambers and connection to the public sewer.

1. Check pipe gradients using a spirit level or laser — minimum 1% for ≥ 100 mm pipes, 2% for < 100 mm pipes

2. Verify all sanitary appliances have traps with minimum 50 mm water seal depth — inspect trap type and condition

3. Confirm drainage ventilation is provided per EN 12056-2 — check stack termination above roof level and any secondary venting

4. Inspect all joints for correct assembly and watertightness — solvent-welded joints must show even solvent bead, push-fit joints fully inserted

5. Verify access points (rodding eyes, access chambers) are provided at changes of direction and junctions per DR 23/95

- Insufficient pipe gradient causing slow drainage and blockages

- Missing or incorrect traps allowing sewer gas ingress into habitable spaces

- Inadequate ventilation causing trap siphonage and gurgling

- Access points missing at changes of direction, preventing maintenance

- Pipe sizes undersized for the connected appliance load

According to EN 806-2 and Portuguese legislation (D.L. 306/2007 on water quality, and ANQIP technical specifications), hot water systems must be designed to minimise Legionella risk. Hot water must be stored at minimum 60°C and distributed at minimum 50°C at the furthest draw-off point. Dead legs must not exceed 3 litres volume per EN 806-2. Recirculation systems are required for pipe runs exceeding 10 m to the furthest point. Portuguese ANQIP ETA 0701 provides specific Legionella prevention guidance for building water systems. Temperature control devices must limit delivery temperature to maximum 38°C at bidets and 41°C at baths per safety requirements.

1. Measure hot water storage temperature — must be maintained at minimum 60°C to prevent Legionella colonisation

2. Check distribution temperature at the furthest draw-off point — minimum 50°C within 30 seconds of opening the tap

3. Identify and measure dead legs in the system — must not exceed 3 litres volume per EN 806-2

4. Verify recirculation pump operation and return temperature (minimum 50°C return) for systems with long pipe runs

5. Check thermostatic mixing valve (TMV) settings at safety-critical outlets — maximum 38°C at bidets, 41°C at baths

- Hot water storage temperature below 60°C, creating conditions for Legionella growth

- Excessive dead legs from poor pipe layout or abandoned connections

- Missing recirculation on long pipe runs, causing long wait times and stagnation

- Thermostatic mixing valves not installed or incorrectly set at vulnerable user outlets

According to Portuguese REH (Regulamento de Desempenho Energético dos Edifícios Residenciais, D.L. 118/2013 and subsequent updates) and EN ISO 12241, hot and cold water pipes must be insulated to minimise energy losses and prevent condensation. Hot water pipes in unheated spaces must have minimum insulation thickness as specified by REH (typically 20–30 mm for pipes up to 42 mm diameter). Cold water pipes in warm or humid environments must be insulated to prevent condensation. Recirculation loops require full insulation throughout. All insulation must be continuous through wall and floor penetrations with no gaps.

1. Verify insulation material and thickness match the REH specification and project design — check product data sheets and CE marking

2. Measure insulation thickness at representative points including straight runs, bends, valves and fittings

3. Inspect insulation continuity — no gaps at supports, penetrations, valves or fittings; all joints sealed with appropriate tape

4. Check vapour barrier integrity on cold water pipe insulation — continuous and sealed at all joints to prevent condensation

5. Confirm recirculation loop pipes are fully insulated throughout their length including return pipe

- Insulation missing or reduced at bends, valves and fittings, creating thermal bridges

- Gaps in insulation at pipe supports and wall penetrations

- Vapour barrier on cold water insulation damaged or discontinuous, causing condensation

- Insulation thickness below REH minimum requirements

According to EN 806-4 and Portuguese DR 23/95, all water supply pipework must be pressure tested before concealment or commissioning. The test pressure must be 1.5 times the maximum design working pressure, with a minimum of 1000 kPa (10 bar) per DR 23/95. The system must hold the test pressure for a minimum of 2 hours with no visible leaks and pressure drop not exceeding 0.2 bar. All joints, fittings and connections must be visible and accessible during the test. Drainage systems must be tested per EN 12056-5 by air test (minimum 38 mm water gauge for 3 minutes) or water test.

1. Verify the system is filled, vented of air and pressurised to 1.5 times the maximum design working pressure (minimum 10 bar per DR 23/95)

2. Monitor pressure gauge for minimum 2 hours — pressure drop must not exceed 0.2 bar

3. Visually inspect all joints, connections, fittings and valves during the test period for any signs of leakage

4. For drainage systems, conduct air test at 38 mm water gauge maintained for minimum 3 minutes with no drop, or water test to soffit level

5. Record test results including date, test pressure, duration, ambient temperature and test medium — retain for building file

- Pressure test conducted at insufficient pressure or for too short a duration

- Air not fully purged from system before testing, giving false pressure readings

- Joints and connections concealed before testing, preventing visual leak inspection

- Test results not documented or retained for the building completion file

According to EN 1717, potable water supply systems must be protected against backflow contamination by appropriate devices matched to the fluid category risk. Type AA (unrestricted air gap) is required for category 5 fluids (e.g. WC cisterns with submerged inlets). Type BA (verifiable backflow preventer with reduced pressure zone) is required for category 4 fluids. Portuguese DR 23/95 mandates backflow protection at the building entry point and at all cross-connections. All devices must be testable and accessible for maintenance. Hose union taps and garden taps require minimum EA (verifiable single check valve) or higher protection.

1. Verify backflow prevention devices are installed at the building water entry point per DR 23/95 requirements

2. Check each appliance connection for appropriate backflow protection matched to the fluid category per EN 1717 classification

3. Confirm air gaps at WC cisterns, storage tanks and similar — type AA gap must be minimum 20 mm or twice the inlet diameter, whichever is greater

4. Verify RPZ (reduced pressure zone) valves are installed where required for category 4 risks and are accessible for annual testing

5. Check that all hose union and garden taps have minimum single check valve (type EA) protection

- Missing backflow protection at the building entry point or individual appliance connections

- Incorrect device type for the fluid category risk — under-protection creating contamination risk

- Air gaps reduced or eliminated by modifications (e.g. flexible hoses extending below overflow level)

- RPZ valves installed in inaccessible locations, preventing required annual testing

Portuguese Decreto-Lei 521/99 and the associated technical regulations govern gas installations in buildings. All gas installations must be designed and executed by qualified professionals (Técnico Responsável de Gás — TRG) and inspected by an accredited entity. Pipe materials must comply with EN 1057 (copper), EN 10255 (steel) or approved flexible connections. Gas meters must be located in ventilated enclosures accessible from common areas. Ventilation requirements depend on appliance type: open-flue appliances require permanent ventilation openings sized per the regulation. All gas installations require a certificate of conformity (Certificado de Conformidade) issued by the inspector before gas supply is activated.

1. Verify that the installation has been designed and is being supervised by a qualified TRG (Técnico Responsável de Gás)

2. Check pipe materials and fittings for compliance — copper per EN 1057 or steel per EN 10255, with approved joints and supports

3. Confirm gas meter location in a ventilated, accessible enclosure with appropriate signage per D.L. 521/99

4. Inspect ventilation provisions for gas appliances — permanent ventilation openings sized per the regulation for the appliance input rating

5. Verify leak testing has been performed on the complete installation at 1.5 times working pressure (minimum 30 minutes) before commissioning

6. Confirm that a Certificado de Conformidade will be issued by the accredited inspection entity before gas supply activation

- Gas installation executed by unqualified personnel without TRG supervision

- Inadequate ventilation for open-flue gas appliances, creating carbon monoxide risk

- Gas pipes routed through bedrooms or enclosed spaces contrary to regulations

- Missing or inaccessible gas isolation valves at meter and appliance connections

- Installation commissioned without the required Certificado de Conformidade