The generation op EPDs for activities related to building maintenance Laure Itard1, Inge Blom1, David Anink2
1
Delft University of Technology, Research Institute OTB, PO Box 5030, 2600 GA Delft, The Netherlands, L.C.M.Itard@TUDelft.nl, I.Blom@TUdelft.nl
2
W/E adviseurs, Mariaplaats 21E, PO Box 227, 3500 AE Utrecht
Introduction
In comparison to goods to which LCA is conventionally applied, buildings have a very long service life. During this service life, the building and its equipment are subject to maintenance and to renovations. Very little is known about the environmental effects of maintenance and renovation. Maintenance firms and housing associations that are interested in the
sustainability aspects of maintenance have too little environmental information on their own activities. This is because environmental profiles of materials that are accessible from LCA databases are not suitable for direct use by maintenance firms, because this data are not related to the activities that are really performed by these companies. EPDs at material level could be a solution for maintenance companies, but nor for housing associations that want to label the environmental quality of the maintenance. This is because housing associations (and therefore their maintenance contractors) are interested in the environmental quality of the maintenance of, for instance, window frames but not in the environmental quality of one kilogram paint. EPDs at activity level could offer a possible solution to this problem. The research described in this paper aims to define at which level EPDs are needed and which technical information is necessary to produce EPDs that can support sustainable
maintenance options. This paper focuses on the maintenance aspects of openings in
facades (windows) in dwellings located in The Netherlands. Owner occupied houses are not taken into account because in most cases owners do not use standardized maintenance by specialized companies. They are do-it-yourselfer from which information is difficult to gather. Housing associations use maintenance contractors in an organized way, which simplifies the gathering of information. Besides, housing associations cover about 35 % of the total
housing stock in the Netherlands and should be therefore a main target of environmental building policies.
Methodology
First, existing environmental databases used in Life Cycle Analysis were analysed to find out which data concerning maintenance activities are already included and which data should be added – if existing. To do this, common maintenance activities where divided into main categories: ground, finishing, glass, locks and hinges and tightness components. Studied databases are Ecoinvent and the EcoQuantum Database. Data obtained directly from material producers could also be taken into account. The environmental impacts of the separate components are saved in a database using the usual functional unit (kg material). Second, maintenance companies and housing associations were consulted and their working patterns were analysed in order to find out which functional units could be suitable and at which levels EPDs could be used.
Third, the discrepancies between the functional units in the database and the functional units suitable for maintenance activities were analysed. The way environmental profiles should be defined at the desired levels was investigated.
Forth, several maintenance scenarios were be investigated in order to determine their relative environmental effects. From this a bandwidth of result for different scenario’s and activities could be determined. This is of importance in determining to which extend the use of EPD’s for maintenance could be relevant. The differences between scenarios must be large enough to be translated in terms of environmental declaration. In this paper the choice of relevant scenarios is discussed.
Elaboration
From interviews with maintenance companies and from the analysis of their working patters two interesting levels for EPD’s were identified. These levels are scenarios and activities. A maintenance scenario describes the way maintenance will be organized during a certain period of time. The description is made based on a consistent set of maintenance activities and sub-activities that take place in a suitable sequence and frequency. Figure 1shows the model used to calculate the environmental effects at the level of scenarios.
Figure 1: Structure of the information needed to calculate EPDs at the level of maintenance scenarios.
A structured database is being developed, where maintenance activities are described. For each unit of activity, an environmental profile is determined. An activity is expressed in a unit that is useful to maintenance firms. The functional units needed to calculate the
environmental effect at the level of activities and sub-activities have been determined using data known from literature or from maintenance companies. These functional units are shown in Table 1 for several activities related to the replacement of window frames. An activity can be for instance the application of paint per linear meter window frame. Another activity may be the replacement of a building part. This activity consists then in two sub-activities: the removal of the old component, which includes waste treatment, and the application of the new component, which includes its production and the needed by-processes. Activities and sub-activities consist of material and by-processes. For each unit of material and process an environmental profile is set up. These environmental profiles result from a life cycle analysis conducted with Simapro and the database described in the first part of the paragraph “Methodology”.
A material is for instance one kilogram paint. In this environmental profile, the production of the material is taken into account, including waste and waste processing at manufacture
Materials & Processes (LCA databases) Sub-activities
Activities Object of
maintenance For instance all windows of an apartment
Table 1: Functional unit for several activities
Activities Functional Unit
Removal window-frames m2 per window Placement new
window-frames
m2 per window Removal glass m2 per window Placement new glass m2 per window
Removal lute m per window
Placement new lute m per window Removal old paint m per window Bringing up new paint (3
layers)
m per window
level. For waste processing when the product is removed from the building, a separate environmental profile is used.
A process may be the energy use for burning paint away or for transporting paint to the building.
Standard values about the thickness of the glass or of one layer paint are used to translate the environmental profiles at the material level (kg) to environmental profiles at the level of activities and sub-activities.
The environmental profiles at the level of material and processes do not need to be used by maintenance companies. Only the data aggregated at the level of activity and scenarios are useful to them.
As mentioned above, a scenario is an organized collection of activities. A scenario could for instance be defined by:
• An initial curative operation (for instance repairs to wooden window frame or replacement of glass) followed by
• 25 years preventive maintenance. The preventive maintenance itself could be: • painting the window frames each 5 years with a conventional paint.
A specific problem arises when the scenario includes an activity that has consequences for the energy use of the building. Maintaining single glass in a building produces less
environmental effect in itself than replacing it by double glass, which has also less environmental impact than replacing it by high-performance glass. In such cases it is not responsible to consider only maintenance. The effect of the reduced energy use during the considered maintenance contract (25 years in above mentioned example) must be included into the environmental calculation.
To test the sensitivity of the environmental impacts to differences in scenarios, four extreme scenarios were considered for the maintenance of windows. These scenarios are described hereafter.
Scenario A
• Year 0: initial painting, including removal of paint layers and carrying out small repairs
• Year 5, 15, 25, 35 and 45: scouring and painting
• Year 10, 20, 30 and 40: scouring, painting and lute replacement Scenario B
• Year 0: Removal of double glass and replacement by high insulation glass; initial painting, including removal of paint layers and carrying out small repairs
• Year 5, 15, 25, 35 and 45: scouring and painting
• Year 10, 20, 30 and 40: scouring, painting and lute replacement Scenario C
• Year 0: Removal of double glass and replacement by high insulation glass; Window frames are replaced by high quality wooden frames.
• Year 7.5, 22.5 and 37.5: scouring and painting
• Year 15, 30 and 45: scouring, painting and lute replacement Scenario D
• Year 0: Removal of double glass and replacement by high insulation glass; Window frames are replaced by synthetic frames.
• Year 15, 30 and 45: lute replacement
Scenario A is a conventional maintenance scenario. In scenario B, the effect of a better insulation is tested (more material use but less energy use). In scenario C and D, the effect of using maintenance-free materials to a certain extend is tested. For scenarios A and B, the effect of using harmless paint instead of conventional paint will be studied too, as well as the effect of varying the time interval between painting activities. This is of importance because of the emergence of performance-based maintenance contracts. In this kind of contracts, the maintenance activities are not carried out at fixed time intervals, but only when these
activities are needed. Whether an activity is needed or not is determined by means of regular inspections. This generates generally cost-savings and may have a positive environmental effect.
Conclusions and recommendations
In this paper, a method was presented to quantify the environmental effects of maintenance activities on a way that is useful to maintenance companies and housing associations. The first results of this research show that this could be an interesting way to generate EPDs for the maintenance sector. However, more research and detailed calculations are necessary if one wants to translate this calculation method to useful environmental product declarations.
