The 2005 World Sustainable Building Conference, Tokyo, 27-29 September 2005 (SB05Tokyo)

04-024

ENVIRONMENTAL ASESSMENT OF SCHOOL BUILDINGS IN NORWAY AND POLAND

Inger ANDRESEN senior researcher1 Aleksander PANEK professor2 1

SINTEF Technology and Society, Architecture and Building Technology, N-7465 Trondheim, Norway, [email protected] 2

Warsaw University of Technology, Institute of Heating and Ventilation, Faculty of Environmental Engineering, 00-653 Warsaw, [email protected]

Keywords: environment, assessment, redevelopment, schools.

Summary SURE-BUILD – Sustainable Redevelopment of Buildings in Poland – is a joint project between the Norwegian University of Science and Technology and Warsaw University of Technology, http://www.ab.ntnu.no/sure-build/. The project is focusing on rehabilitation of polish schools based on the experiences gained by the work on sustainable buildings in Norway. A part of this project focuses on using environmental assessment tools of school buildings as a background for determining the most beneficial measures for their re-development. This paper briefly describes the Norwegian work on adaptation and testing of the EcoProfile model for school buildings in Norway. Further, the application of the model to a school building in Poland is described. The case study school building is located in Zgierz, Poland, and is part of the re-development work in the SURE-BUILD project. The paper also discusses the importance of focusing on different environmental criteria when re-developing school buildings in Poland and Norway, and the opportunities for further adaptations of the Norwegian EcoProfile and the Polish E-Audit methods for use in such processes.

1.

The Norwegian EcoProfile Method

EcoProfile is a method for simplistic environmental assessment of buildings (Pettersen 2000). The method is intended to be quick and easy to use in order to reach a wide-spread application in the building community. Three versions have been developed; one for evaluating existing office buildings, one for evaluating existing dwellings, and one for use in the design of dwellings. The method assesses the buildings in three main criteria; ”External environment”, ”Resources” and ”Indoor climate”. These main criteria are divided into subcriteria (see figure 1), and several of these are again divided into sub-sub-criteria. Each sub-criterion contains a number of parameters, or indicators, at the lowest level. These parameters are used to assess the actual performance of the building, using an input sheet (in Excel). Figure 2 shows the parameters for the sub-criterion “Emissions to air”. There are currently 82 parameters included in the method. Each of the parameters is given a grade. The grading scale ranges from 1 to 3 where: Class 1 = Lesser environmental impact Class 2 = Medium environmental impact Class 3 = Greater environmental impact Eventually a class 0 is going to be included that will represent a sustainable construction, but there is currently no basis for defining such a level. The grading is based on judgments by the assessor. The final result of the EcoProfile assessment is presented in a bar diagram showing the 3 main criteria, see figure 3 (left diagram). For a closer view on the performance with respect to the sub-criteria, star-diagrams like the one to the right in figure 3, are provided.

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The 2005 World Sustainable Building Conference, Tokyo, 27-29 September 2005 (SB05Tokyo)

Figure 1.

The main criteria and sub-criteria of the EcoProfile Method.

Y.1.1

Heating source

Y.1.2

Maintenance of heating system

Y.1.3

Cooling medium

Figure 2.

District heating, solar, heat pump Electricity, combined oil/el, or bio Oil or gas Not necessary Established routines Not established routines Ammonia, CO2, or no cooling HFK (R134a) KFK (R11, R12, R500, R502) or HKFK (R22, R123)

2

2 1

The input sheet for the parameters to be assessed for the sub-criterion “Emissions to air”. water use land

3,0

3,0

heating

2,5

re-use

2,0

ventilation

1,5

2,0

1,0

operation (materials)

0,5

cooling

0,0

1,0

construction

lights

building properties

0,0 Ytre miljø

External environment

Ressurser

Resource use

outdoor energy use

Inneklima

Indoor climate

calculated energy

operation (energy) flexibility

Figure 3.

Examples of results of an EcoProfile evaluation.

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The 2005 World Sustainable Building Conference, Tokyo, 27-29 September 2005 (SB05Tokyo)

2.

The EcoProfile Method Applied to 2 Norwegian School Buildings

In order to apply the EcoProfile Method to the design of school buildings, some adjustments were made. The adjustments involved using some parameters from the “EcoProfile for Dwellings” and some parameters from the “EcoProfile for Office Buildings” method. For example, the EcoProfile for Office Buildings does not contain any parameters related to material and land use, so for these issues, the parameters from the EcoProfile for Dwellings were used. Also, some parameters were slightly changed, and a few were left out, i.e. parameters related to the operation of the school that cannot be affected at the design stage. The weighting of the parameters was not altered, but this may be done in a later revision. This adjusted “EcoProfile for Schools” method was used during the design of two Norwegian Schools: Kvernhuset Secondary School and Borgen Community Center. This is documented in (Andresen 2001a) and (Andresen 2001b). Since the results of the EcoProfile assessments were to be used in the further design of the buildings, the assessment had to produce very specific guidance to the design group. The results of the EcoProfile assessments were therefore presented as an OBS-list, i.e. a list of matters that needed special attention in the further design work. The OBS-list contained the following specifications (generalized): 1) Energy issues •

Ensure good air tightness by careful detailing of building envelope

•

Minimum thermal insulation requirements for roof, walls, floor, and windows. Careful design to avoid thermal bridges.

•

Demand controlled services: minimization of lighting needs based on occupancy and daylight control, minimization of ventilation control based on low-emitting materials and controls based on occupancy, CO2, temperature and moisture.

•

Avoidance of cooling installations by minimizing internal gains, using exterior shading, thermal mass, night free-cooling.

•

High efficiency heat-recovery

•

Clean and efficient energy supply systems

2) Indoor environment issues: •

Good daylight distribution (design of windows and surfaces)

•

Avoid moisture (detailing, drying)

•

Low-emitting materials for indoor surfaces

•

Easy to clean (smoothness, avoid dust collectors)

3) Equipment and materials use:

3.

•

Minimize amount and size (multifunctionality, area-efficiency, flexibility)

•

Use robust solutions (minimize moving parts, durable materials)

•

Easy maintenance (access)

•

Reuse

•

Recycle

•

Renewable

•

Minimize hazardous waste/effluents

The EcoProfile Method Applied to a Polish School Building

The Primary School #1 in Zgierz was built in 1963, its construction is traditional masonry silica brick technology. The usable area is approximately 5970 m2, of which 3110 m2 is classrooms and 780 m2 is gym area.

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The 2005 World Sustainable Building Conference, Tokyo, 27-29 September 2005 (SB05Tokyo)

Figure 4.

Primary School #1 in Zgierz.

Figures 5, 6, 7 and 8 show the results of the EcoProfile evaluation for the school building. The evaluation has been based on drawings and a visit to the site in October 2004.

Emissions to air 3,0 2,5 2,0

Transport

1,5

Pollution in ground

1,0 0,5 0,0

Outdoor space

Emissions to water

Waste management

Figure 5.

The EcoProfile star diagram for ”External Environment”.

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The 2005 World Sustainable Building Conference, Tokyo, 27-29 September 2005 (SB05Tokyo)

Water consumption Land Re-useable materials

3,0 2,5

Heating

2,0

Ventilation

1,5 1,0

Materials O&M

Cooling

0,5 0,0

Construction materials

Lights

Building properties

Outdoor energy use

Calculated energy

O&M Energy flexibility

Figure 6.

The EcoProfile star diagram for ”Resource Use” (O&M is Operation and Maintenance).

Thermal climate 3,0 2,5 2,0

Transverse factors

1,5

Atmospheric

1,0 0,5 0,0

Mechanical

Acoustic

Actinic

Figure 7.

The EcoProfile star diagram for ”Indoor Climate”.

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The 2005 World Sustainable Building Conference, Tokyo, 27-29 September 2005 (SB05Tokyo)

Large environmental load Medium environmental load Little environmental load

Environment

Figure 8.

Resources

Indoor climate

The overall result of the EcoProfile evaluation.

Looking at the star diagrams, one can easily sort out the factors that need special attention. Special attention should be given to the criteria with a score higher than 2, which means that they represent a rather high environmental load. Concerning the external environmental loadings, figure 5 shows that it is only “emissions to air” and “waste management” that have a score higher than 2. The waste management is poor because there is no segregation of waste and there is no special procedure for the handing of hazardous waste. The emissions to air are high because the building has a heating system consisting of coal fired boilers that are over 15 years old. In the heating season of 2002/2003, 135 t of coal and 108 t of cinder coke were combusted. Looking at the star diagram in figure 6 “Resource Use”, there are several items that receives a score higher than 2. The energy consumption for heating is high due to no thermal insulation, large air infiltration, and lowefficient heating system. However, there are no ventilation or cooling systems, which saves energy for running fans and pumps. The energy consumption for lights is high; gas discharge tubes and mercury discharge lamps are used, and there is no lighting control system. The building also receives a poor score on operation and maintenance (O&M), because there are no formalized procedures for energy management or the operation of the technical equipment. The criterion entitled “Building properties” represents overall design and construction issues related to energy use, such as flexibility of space and effective use of space. These issues are judged to be poorly handled as the building has fixed partitions and quite specialized spaces. However, the school is very spacious and offers a big potential for improvement. The building also scores poorly on construction materials, which means that the materials which were used for constructing the building were not re-used or recycled, nor did they have any environmental label. The silica used as main construction material is quite deteriorated due to poor maintenance during the building life. Finally, the building scores poorly with respect to water consumption; because there are no measures taken to conserve water (e.g. water saving equipment). The last star diagram, figure 7, shows the result of the indoor climate evaluation. The figure shows that three issues require special attention; the thermal climate, the atmospheric climate, and the indoor climate. The thermal climate is poor due to poor ventilation, no exterior shading, and draft/cold radiation from windows. The atmospheric climate also suffers from poor ventilation, but the score is somewhat improved by the fact that the building has low-emitting interior surfaces. The actinic climate is quite poor due to insufficient electrical lighting, but this is somewhat counteracted by an ample provision of daylight. Based on the preliminary EcoProfile evaluation, the following OBS-list of issues that needs special attention in the upcoming redevelopment process is produced: •

Reduction of heating energy needs. This includes adding thermal insulation to the building envelope and replacing the windows with better insulating windows. The amount and type of insulation is to be decided based on technical/economical and architectural considerations. This will reduce the thermal

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The 2005 World Sustainable Building Conference, Tokyo, 27-29 September 2005 (SB05Tokyo)

losses through the envelope, reduce draft, and improve the thermal comfort. Care needs to be taken in order to avoid moisture in the construction and to ensure sufficient ventilation. Also, the heating system needs to be improved by using more efficient equipment, cleaner fuel, and efficient controls.

4.

•

Improved ventilation. This involves designing a ventilation system with improved air exchange. The system may be based on mechanical or hybrid/natural ventilation principles. Utilization of natural driving forces, as well as easy operation, maintenance and use, should be emphasized.

•

Improved thermal comfort. This involves preventing high indoor temperatures by applying effective solar shading (e.g. exterior movable) and nighttime free cooling.

•

Improved lighting. This includes using high efficient lighting for energy savings and improved visual qualities. It also involves utilizing daylight to replace artificial lighting for energy saving and improved indoor environment, as well as occupancy controls.

•

Improved waste management. This involves having a strategy for collecting, sorting, and disposal of waste, including the provision of space and information programs.

•

Water saving measures. This includes installing water saving equipment such as low flush toilets and reduced flow showerheads. It may also include reuse of grey water for irrigation, etc.

•

Visible environmental design and installations. The Norwegian environmental school projects show that using environmental design as a means for expressing and teaching the students and the general public about the environment, is an important success factor.

The Polish Eaudit Method

The E-Audit method (Panek 2002) of environmental performance assessment of buildings has been created as a result of analyses of existing methods, works of GBC and ISO, as experts’ proposal. The E-Audit method could be a prototype of an official method for assessing environmental impact of buildings at the country scale. The method relies on building comparison in relation to a chosen standard. The standard is defined as a hypothetical building, a so-called reference building, designed and erected according to existing norms and local best practices, which is characterised by the same shape, volume, number of rooms, functions, number of users and location as the building assessed. The assessment is a three stage hierarchical process. The lowest one is the sub-criteria, followed by criteria, and category which at the end forms the assessment of the issue. Features of one level are input to the higher level. Detailed description of issues, categories and their components criteria and sub-criteria are provided in (Panek 2002). Sub-criteria are related to the assessment on the lowest level, and after normalisation and weighting their sum present the assessment of higher level – the criteria. Within the criteria the founding sub-criteria can have the same units, but sometimes it happens that they have different units (like different kind of emissions for Environmental Loadings). In the case, a normalisation is performed in relation to some artificial scale. In case a feature is not relevant to the building being assessed, for example when there is no energy demand for cooling (because the building has no air conditioning system), the criteria is not considered and marked as non applicable - N/A. Every component of the assessment system is assigned a value from the relative scale, which allows objectivity and uniformity of the assessment at every level. The scale should have agreed graduation according to current building norms, and to demands beyond the existing norms and commonly used technologies. The range of the relative scale is from -2 to 5, where -2 represents building below the existing demands, and 5 reflects the best available solution. All buildings are assessed with respect to 0 on a relative scale, which represents the reference building. It should be noted that some of the features are simple to assess (these are called direct). These direct elements, like for example the composting organic wastes feature, are assessed in a two value process where -2 denotes non existence of the feature whereas 5 indicates its presence. Assignment of values from the range of scale is performed on the level of sub-criteria or on a level of criteria for some simple features. The value assigned reflects the distance of the assessed building feature to the same feature of the reference building. For example, assessing seasonal heat demand, the reference building of some shape factor requires 283 MJ/m3, and the case study building has 193 MJ/m3, which is 32% less than the reference. The assigned value from the scale is 4, which means that the case study requires 30% less energy than the reference (0 on the scale). The resulting values are weighted (in order to reflect their internal importance) and summed. The definition of weights has been performed on the basis of the analytical hierarchy method (Saaty 1990).

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The 2005 World Sustainable Building Conference, Tokyo, 27-29 September 2005 (SB05Tokyo)

The framework of the E-Audit system is the same as the framework of recent systems under development by ISO TC59 SC17 WG4, however for some of the features there are not reliable data in Poland. This includes for example the embodied energy in relation to materials and building components as it is required in Life Cycle Analysis. The E-Audit system is general and it can be applied to new and existing buildings of different types. Main and obligatory issues of the framework are: Resources Use, Environmental Loadings, Health and Indoor Environment. The method does not provide benchmarks itself; it provides a list of issues of concern whereas the assessment methods are left for the assessor. The total number of criteria is more than 120 and depends on building type. E-audit is a comprehensive method which requires an adequate data base, which for many criteria does not exist in Poland.

5.

Discussion of the applicability and relevance of the EcoProfile method in Poland.

Although different in many ways, Poland and Norway face many similar challenges with respect to sustainable building. Energy use is a main issue in both countries, and although the energy systems are very different, energy conservation stands out as the prime emphasis in both countries. Also, indoor environment is a prime issue in both countries. Schools in Norway suffer from bad indoor air quality and overheating, and so do Polish schools. Acoustics, however, seems to be a somewhat larger problem in Poland than in Norway. The quality of building materials is good in both countries, but their application and use need further attention. Water and waste management seems to be more advanced in Norway. The Norwegian EcoProfile method and the Polish E-Audit method contain many similar environmental criteria. The strength of the EcoProfile method lies in that it is very quick and easy to use, the E Audit is complex and requires a lot of environmental data. Therefore, the combination of these features and the proposal of a framework adequate for school buildings is one of the tasks for future research in the SUREBUILD project. Some of the criteria in EcoProfile seem to be too superficially treated, considering their importance for the overall environmental performance of school buildings in Poland. Ventilation, daylighting and quality of space probably need to be elaborated, their high importance taken into account. Also, some criteria may probably be left out. The weights need further consideration. However, at this stage in the project, there is insufficient experience in order to draw any final conclusions about these issues. Nevertheless, it is clear that an EcoProfile/E-Audit analysis is very useful as a basis for setting specific goals for the re-development work, and for following up the goals throughout the process. Matusiak et al. (2004) lists a number of technologies for sustainable re-development and their strengths and weaknesses with respect to application in Polish schools. The SWOT (Strengths Weaknesses Opportunities and Threats) analysis includes considerations about cost-efficiency, energy-saving potential, technical compatibility, skill and knowledge requirements, etc. Together with the EcoProfile/E-Audit analyses, this makes a valuable basis for sustainable re-development of Polish schools.

References Andresen, I. 2001a. Miljøvurderinger i prosjekteringen av Borgen Lokalmiljøsenter. SINTEF Report STF22 A01018, SINTEF Civil and Environmental Engineering, Trondheim, Norway. Andresen, I. 2001b. Miljøvurdering av Kvernhuset Ungdomsskole. SINTEF Report STF22 A01502, Trondheim, Norway. Matusiak et al. 2004. Sustainable re-development of school buildings in Poland. A state-of-the-art. Report from the SURE-BUILD-project, Trondheim/Warsaw. Panek, A. 2002. Environmental Assessment Method of Buildings Sustainability E-Audit. State Inspectorate of Environment Protection, Warsaw, (in Polish). Pettersen, T.D., 2000. EcoProfile for Commercial Buildings. Norwegian Building Research Institute, Oslo, Norway. Saaty, T. L. (1990). Analytical Hierarchy Process. New York, McGraw-Hill.

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