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ONLINE BRUSSELS HERITAGE - ONE-DAY SEMINAR - 11/12/2014
THE EPB REQUIREMENTS FOR INSULATION AND VENTILATION
For all EPB units that are extensively or simply renovated, only two requirements have to be satisfied: insulation and ventilation. The insulation requirement solely concerns the modified walls of the envelope, namely (where appropriate) the walls, floor, roof or windows. Where a window is added or replaced there is also a ventilation requirement for the premises in question. In fact, the EPB is not only connected with energy consumption; it is also aimed at improving the quality of the internal air. These two requirements, insulation and ventilation, exist in an identical form in the three Regions of the country. As regards the insulation requirement, the Regions have (with the support of the Belgian Building Research Institute (BBRI)) set the heat transmission values that every project, including any modification of walls, must satisfy when applying for planning permission as of 1st January 2014. For walls and roofs, the maximum U-value is 0.24 W/m2K. This value gives the following indicative thicknesses (tables 2 and 3), which vary depending on the type of insulation. In this way, the thickness of the insulation for a wall will vary from 9 to 17 cm. While these thicknesses seem significant, the requirements are cost optimal, as required by the European Directive. When carrying out works it is important to keep in mind that they are generally not repeated for at least thirty years and it is therefore important to have a long term vision and reflect on the irreversibility of the changes made and what impacts they will have on energy over time. For windows, the maximum U-values are 1.8 W/m2K (including frame) and 1.1 W/m2K for the glass. This is what is traditionally available on the market.
The ventilation required when a window is replaced or added ensures a healthy climate by removing waste air (humidity, domestic pollutants, etc.) There are four systems of ventilation: natural ventilation; mechanical ventilation; and hybrid versions of the two systems. The EPB does not require a particular system but simply sets down the rates of ventilation which, for housing, are well known by the sector (those of the NBN50001 standard, in force since 1991). Added to this requirement for healthy ventilation is (in the
| Structural element | Umax (W/m2K) | Rmin (m2K/W) |
| 1. WALL DELINEATING THE PROTECTED VOLUME excluding walls forming the separation with an adjacent protected volume | ||
| 1.1. TRANSPARENT/TRANSLUCENT WALLS excluding doors and garage doors (see 1.3), curtain walls (see 1.4) and glass bricks (see 1.5) | Uw max = 1.8 and Ug max = 1.1 | |
| 1.2. OPAQUE WALLS excluding doors and garage doors (see 1.3) and curtain walls (see 1.4) | ||
| 1.2.1 Roofs and ceilings | Umax = 0.24 | |
| 1.2.2. Walls not in contact with the ground excluding walls referred to in 1.2.4 | Umax = 0.24 | |
| 1.2.3. Walls in contact with the ground | Rmin = 1.5 | |
| 1.2.4. Vertical and sloping walls in contact with crawl spaces or with a cellar outside the protected volume | Rmin = 1.4 | |
| 1.2.5. Floors in contact with the outside environment | Umax = 0.3 | |
| 1.2.6. Other floors | Umax = 0.3 or | Rmin = 1.75 |
| 1.3. DOORS AND GARAGE DOORS (including frame) | Ud max = 2.0 | |
| 1.4. CURTAIN WALLS (according to prEN 13947) | Ucw max = 2.0 and Ug max = 1.1 | |
| 1.5. GLASS BRICK WALLS | Umax = 2.0 | |
| 2. Walls between two protected volumes situated on adjacent plots | Umax = 1.0 | |
| 4. Opaque walls inside the protected volume or adjacent to a protected volume on the same plot excluding doors and garage doors | Umax = 1.0 |
Table 2
Insulation requirements. U/R-values (since 1st January 2014) (source: BE).
| Type of wall | Umax since 01/01/2014 (W/m2.K) | Thickness in cm of mineral wool type insulation (λ= 0.045 W/mK) | Thickness in cm of plant wool type insulation (λ= 0.04 W/mK) | Thickness in cm of synthetic foam type insulation (λ= 0.035 W/mK) (3) | Thickness in cm of PIR foam type insulation (λ= 0.023 W/mK) |
| Lambda value of the insulation | 0.045 | 0.04 | 0.035 | 0.023 | |
| Sloping (or flat) roof, 80%/20% insulation between rafters | 0.24 | 26 | 25 | 24 | 20 |
| Flat (or sloping) roof, continuous insulation on wooden structure | 0.24 | 16 | 15 | 13 | 9 |
| Flat (or sloping) roof, continuous insulation on concrete structure | 0.24 | 17 | 15 | 13 | 9 |
| Exterior wall (29 cm bricks), external insulation | 0.24 | 17 | 15 | 13 | 9 |
| Exterior wall (14 cm blocks), external insulation | 0.24 | 17 | 15 | 13 | 9 |
| Exterior wall wooden framework | 0.24 | 20 | 19 | 17 | 14 |
| Heavy floor in contact with exterior | 12 | 11 | 10 | 7 | |
| Heavy floor on ground | 9 | 8 | 7 | 5 | |
| Heavy floor over cellar with door and window | 9 | 8 | 7 | 5 |
Table 3
Insulation requirements. U/R-values (since 1st January 2014). Example of indicative insulation thicknesses that comply with the EPB regulation (source: BE).
12 | What are the requirements for the energy performance of buildings when renovating?
