Thermal Insulation and Energy Efficiency

According to the EPBD, the REH (DL 118/2013) and national energy regulations, external walls must achieve the required U-value (typically 0.35–0.50 W/m2K for new buildings in Portugal, varying by climate zone I1, I2, I3). Insulation products must comply with EN 13162–EN 13171. Insulation must be continuous to minimise thermal bridges according to EN ISO 10211.

1. Check that the insulation material and thickness match the energy calculation (ETICS data sheet or thermal design)

2. Confirm that insulation is continuous — no gaps at junctions, corners or around openings

3. Inspect for thermal bridges at structural elements (columns, beams, balconies)

4. Check that insulation is properly fixed (mechanical fixings, adhesive or both)

5. Use thermography to detect missing insulation or thermal bridges

- Gaps in insulation at wall-floor junctions creating thermal bridges

- Balcony connections without thermal break elements

- Insulation compressed or displaced during installation

- Insulation type unsuitable for the application (moisture sensitivity)

According to the EPBD and the REH, roofs typically require U-values of 0.30–0.40 W/m2K and ground floors 0.30–0.50 W/m2K in Portugal (varies by climate zone and national regulations). Vapour barriers must be placed on the warm side of insulation according to EN ISO 13788 to prevent interstitial condensation.

1. Check the thickness and material of roof insulation against the design

2. Confirm that the vapour barrier is installed on the warm side and is continuous

3. Inspect insulation at eaves, gable ends and around roof penetrations

4. Check that floor insulation is correctly positioned (above or below the slab)

5. Check for thermal bridges at wall-roof and wall-floor junctions

- Insulation missing or at reduced thickness at eaves and roof edges

- Vapour barrier punctured by services or fixings

- Floor insulation crushed under heavy loads before slab casting

- Thermal bridge at parapet or roof wall plate

According to the EPBD and EN 13829, building airtightness must be verified by blower door test. Typical requirement: air change rate <=3.0 h-1 at 50 Pa (n50) for new buildings, <=0.6 h-1 for passive houses. Controlled ventilation must be provided according to EN 15251 to ensure indoor air quality while maintaining energy efficiency. The REH (DL 118/2013) defines the minimum ventilation requirements for residential buildings in Portugal.

1. Check that the air barrier membrane is continuous across the entire building envelope

2. Confirm sealing at all penetrations (pipes, cables, ducts) through the air barrier

3. Inspect sealing at window and door frames

4. Carry out a blower door test according to EN 13829 — the result must meet the target n50 value

5. Check that mechanical ventilation with heat recovery (MVHR) is installed and commissioned

- Air barrier not continuous — gaps at junctions and service penetrations

- Window and door frames not properly sealed to the air barrier

- Blower door test failure due to unsealed penetrations

- MVHR not commissioned or filters without maintenance access