CESBA tool indicators
As part of the CEC5 project, 23 CEC5 model assessments on public buildings throughout Europe are being conducted using the transnational CESBA tool indicators or CESBA generic tool indicators. The CESBA tool follows the ENERBUILD tool
- 1 How the CESBA generic tool works
- 2 Indicators of the CESBA tool: New Buildings
- 3 Indicators of the CESBA generic tools: existing buildings (refurbishment)
- 4 CESBA tool: Refurbishment of cultural heritage buildings
- 5 Source/ Download
How the CESBA generic tool works
The CEC5 criteria catalogue promotes the documentation and evaluation of the energetic and ecologic quality for newly erected public buildings (schools, kindergartens, gymnasiums, administrative buildings). Buildings, which can’t become comprehensively modernized due to requirements of monument protection, are evaluated on the basis of a separate criteria catalogue. The evaluation of the buildings is based up on a point-scheme with a max. of 1.000 points to achieve.
These points are distributed among five evaluation categories:
- Quality of location and equipment (80 points)
- Process and planning quality (240 points)
- Energy demand and supply (450 points)
- Health and Comfort (200 points)
- Building materials and construction (200 points)
The criteria within these subcategories are characterized by weighted averages and differentiated by “compulsory” and “additional” criteria The sum of points achieved of all single criteria within a subcategory can be higher than the above mentioned max. points.
Indicators of the CESBA tool: New Buildings
Indicators of the CESBA generic tools: existing buildings (refurbishment)
These indicators apply only to existing buildings that are not heritage-protected
CESBA tool: Refurbishment of cultural heritage buildings
For heritage-protected objects respectively objects that are worth to being preserved as well as for assembly halls with a capacity of more than 300 people, an assessment within the framework of an examination board can be conducted.
C1 to C5: Examination board on heritage-protected buildings
For heritage-protected buildings, this can be explained by two reasons: On the one hand, input data that can be used for calculations are often not available when it comes to heritage-protected buildings. On the other hand, restrictions concerning energetic measures may arise due to the necessity of protecting the building. This means that partially, energetic useful measures are not undertaken since for example, the appearance of the building may change. Therefore, the energetic characteristics are higher than it would be technically feasible and within the scope of CESBA (Vorarlberg KGA), this would lead to a lower score. These buildings can be assessed in the context of an examination board within the CESBA area of “Energy Demand and Supply, indicators C1 to C6“ in order not to play off the eligible architectonic meaning of the building against its energy efficiency.
Constitution of the examination board commission
The examination board commission consists of at least three persons, whereby one of the persons is not allowed to be involved in the project (execution, planning, and consultation). Experiences have proven a commission constitution of one building physicist, one engineer for building technology and one architect to be the ideal choice. This is due to the fact that through this constitution, all energy relevant areas are covered by professionals. In case it the commission not able to do a conclusive assessment and evaluation itself, it can consult further experts.
Assessment by degree of performance
The allocation of credits of the block “Energy Demand and Supply” of CESBA (with a maximum 500 credits for refurbished buildings) proceeds as follows:
- It is specifically checked for each project if the evaluation areas and their subdivisions showed in the table below apply. If necessary, they are adjusted or changed. Thus, changing the assessment categories themselves should stay an exception due to comparability reasons.
- The next step is to award the percentage of the main categories to the energy efficiency of the building as well as the achieved credits (see also 37% for “winter thermal protection” in the table below). The examination board evaluates, which proportions the categories „winter thermal protection“ „summer thermal protection“, “energy efficient building technology“ as well as “execution quality“ have for the specific building. Adding together all percentages for the four main categories, you get 105% for a maximum amount of credits (this example: 500 credits). On the one hand, the regular assessment process of CESBA itself is based on over-scoring, too. On the other hand, we have to presume that some measures contradict each other, so it is never possible to get the maximum amount of credits within all fields. Consequently, achieving the overall maximum amount of credits is not possible at all.
- The third preparatory task of the commission is the individual scoring of the sub-categories which can be allocated to the respective main categories. The sum of the percentage proportions of the sub-categories has to make up 100% for each main category (see the example of the sub-categories for the main indicator “winter thermal protection“).
- After the preparatory tasks, the actual examination board takes place. The degree to which each indicator is fulfilled is defined individually for each sub-indicator and then, the sub-indicators are scored (see the grey column in the following example). A high fulfilled indicator makes up 5 credits, a low fulfilled indicator 1 credit. If the indicator is not fulfilled at all, it is scored with 0 credits. The assignment logic is the following: for each sub-indicator, the commission defines what would have been possible under the existing circumstances and what has actually been implemented.
- When filling in the excel table, sub-credits for each assessment category are calculated automatically by multiplied the percentage of the main category, the sub-category as well as the degrees of fulfilment. Looking at the example of the heating demand, you have 37% for the category thermal protection winter multiplied with 25% for the heating demand multiplied with 4.5 credits for the degree of fulfilment. The sum of this sub-credits is then multiplied with the maximum total score – for refurbishment projects 500 credits – and this results in the final outcome of the examination board (this example: 498 points).
Example: Thermal insulation
Due to heritage-protecting reasons, only an exterior insulation thickness of 10cm is possible, although for energetic reasons and technical feasibility, an insulation thickness of 20cm or more would be doable, too. For the evaluation, the commission expects that the maximum insulation thickness in this case is 10cm, since otherwise, the building would be changed too much which cannot be reconciled with the preservation of this heritage-protected building. Therefore, an actually executed insulation thickness of 10cm is the highest respectively very good fulfilled indicator and is assessed with 5 credits. If the insulation was not implemented at all, it would be assessed with 0 credits and insulation thicknesses between 0 and 10cm are assessed with credits between 0 and 5. Thus, each sub-category gets an individual degree of fulfilment. Hereby, each member of the commission assigns his or her own degree of fulfilment; the final degree of fulfilment is calculated from the arithmetic mean of the points awarded by the members of the commission.
|Refurbishment – heritage-protected; Efficiency determined on building envelope||degree of fulfilment: 1=low; 5=high|
|Winter thermal insulation||37%'|
|LEK value (line of European indicators)||60%||5||111|
|Heat recovery and allowance for usability||10%||5||18,5|
|Summer thermal insulation||26%'|
|Proportion of window surfaces and allocation of windows||0%||0||0|
|Solar protection measures||20%||4||20,8|
|Available storage mass||20%||4,5||23,4|
|Free night cooling||20%||4,5||23,4|
|Externally induced demand for cooling||40%||5||52|
|Energy efficient building technology||37%'|
|ventilation system (heat recovery)||10%||4,5||16,7|
|Ventilation system regulation and dimensioning||5%||4||7,4|
|Minimization of low-pressure losses||5%||3||5,6|
|Heat supply for heating||8%||5||14,8|
|Usage of renewable energy for heating||15%||5||27,8|
|Heat distribution heating||5%||5||9,3|
|Heat dissipation heating/controller||6%||5||11,1|
|Heat supply/ warm water||3%||3||3,3|
|Heat dissipation, warm water buffer||3%||3||3,3|
|Usage of renewable energies for warm water||3%||3||3,3|
|Heat dissipation of warm water||2%||3||2,2|
|No technical cooling (active and passive systems)||5%||5||9,3|
|Usage of renewable energies for cooling||2%||5||3,7|
|Utility-oriented monitoring; user training||10%||4||14,8|
|Light and illumination||9%||3||10|
|Auxiliary power building technology||5%||3||5,6|
|Energy efficiency elevator||1%||3||1,1|
|Final energy demand||3%||4||4,4|
|Quality of performance||5%'|
|Sum (overscoring possible)||105%||497,5|