FAQ

The data relating to the dismantling capacity applies to all construction elements of the building envelope as well as to the internal structure (walls, ceilings):

·                roof

·                external wall

·                windows

·                floor slabs

·                intermediate slabs

·                internal partitions.

The greater part of a construction element, i.e. more than 50% of its surface area, must be easily removable or separable.

The following are exempt from this dismantling condition:

• the coating layer;
• buried elements.

For the dismantling capacity, all layers of the construction element used for calculation of the U-value must be taken into consideration, including seals and membranes. All buried elements are excluded; wall, floor and ceiling coverings (e.g. wallpaper, paint and flooring, etc.) are not taken into account. A list of materials should be drawn up, corresponding to the majority of buildings present . This list must cover the location, construction and nature of the assembly of materials. A model can be found in the LENOZ File template.

Calculation of the environmental indicators is directly linked to calculation of the thermal transmittance U and its inherent calculation rules. However, the layers of membranes and seals, which are negligible when calculating the thermal transmission coefficient given their low impact in terms of their insulation capacity, should be taken into consideration for calculation of the predicted environmental indicators.

For a new building, the construction elements of the thermal envelope (= external structure) as well as internal walls and slabs are taken into account.

For the elements of the external structure, all the layers taken into consideration for calculation of the U value are also taken into consideration for calculation of the I _env and I_prim indicators.

Party walls and partition walls between different units in a block of flats should be considered internal walls (within the building envelope).

For existing buildings, only new insulating materials used during the retrofitting works are taken into consideration.

For existing buildings, only the primary energy requirement of the technical installations for conditioning the building should be considered for the I_prim indicator (Chapter 4.2). The primary energy expenditure of the existing building is not taken into account. 

In the case of a LENOZ certificate for a new building, the I_prime indicator is calculated based on the primary energy requirement for the construction of the residential building and the primary energy requirement for the heating of the building over a period of 30 years.

If the environmental impact data is not available, it is impossible to calculate the environmental indicators of the construction material.

An expert may use building material data other than that in the LuxEeB-H software, namely: 

•  Ökobau.dat 2016 in accordance with standard EN 15804 (edition of 18.05.2016)
• or the manufacturer's EPD (Environmental Product Declaration) in accordance with standard EN 15804 

Should it prove advantageous to use an EPD for a specific product, experts can use the Icalc calculator provided by the Ministry of Sustainable Development and Infrastructure, which can be downloaded from www.Klima-Agence.lu. 

In the case of individual calculations made by the expert, the values required for calculation of the environmental indicators must be filled in on sheet no. 4 of the Icalc calculator.

Then the environmental indicators of the specific product must be manually transcribed into the U-value calculation sheet in the LuxEeb-H software. 

General reminder: Any constituent layer (insulation, membranes, wood, blocks, panels) may optionally be calculated using this method. However, using an EPD for a specific product is not the primary method to be used by experts. In order to make the calculation of environmental indicators as simple as possible, a database is available in the Lux-Eeb-H software and all the values entered therein can be used for the calculation of environmental indicators. 

In general, the environmental indicators I_env and I_prim are calculated automatically (from the database implemented in the Lux-Eeb-H software) when filling in the calculation sheet for the thermal transmission coefficients of the different layers making up the thermal envelope (U value).

Section 7.3 of the Annex to the Grand Ducal Regulation on housing sustainability certification uses the I_env indicator for different constructions. Current data on building materials, recorded in the LuxEeB-H software, can be viewed in the Materialdaten LENOZ 2016 document on the website http://www.ml.public.lu/fr/lenoz/Experts/index.html.