Environmental Impacts of Multi-Storey Buildings Using Different ...

- 81 -6.4.3.2 Green Star Recycling ScenarioThe Green Star Recycling Scenario takes recycling in all buildings into account. In order toprovide a fair comparison, the maximum points for each material were applied. This meansfor example that concrete in the Timber building has been recycled, but on the other hand thatthe timber in the Concrete building was FSC certified. However, if less than 1 % of the totalproject value is due to the cost of steel or concrete materials respectively, the option ‘notapplicable’ is available. The cut off rule for timber is 0.1 %.In details the following assumptions and choices in Green Star were made:Timber building• Concrete recycling was taken into account. The N/A option can only be ticked if thecontribution of concrete is less than 1 % of the project’s total contract value. For theTimber building, concrete is required in the foundations. Although detailed data on thecost contribution of specific materials was not available, the contribution in terms ofmass was > 1%. The recycling option was therefore assumed.• The N/A option for steel can only be ticked if it is less than 1% of the project’s totalcontract value. Because the cost contribution was not available, the decision was basedon the material contribution which was less than 1 % and N/A was ticked.• Operational energy figures specific to the Timber building were included(73 kWh/m 2 /yr metered electricity and 15 kWh/m 2 /yr metered natural gas).s• All other assumptions were identical with the TimberPlus, Steel and Concretebuilding.TimberPlus• The same assumptions as for the Timber building were applied. The additional amountof timber in the TimberPlus building cannot be accounted for in the Green Star tool.• Operational energy figures specific to the TimberPlus building were included(70 kWh/m 2 /yr metered electricity and 16 kWh/m 2 /yr metered natural gas).• All other assumptions were identical with the Timber, Steel and Concrete building.Concrete building• The steel contribution was less than 0.5 % and consequently the N/A option waschosen.• The cut off criteria for timber is 0.1 % and more than this value of timber was used.FSC certified was therefore taken into account for the Steel building.• Operational energy figure specific to the Steel building were included (68 kWh/m 2 /yrmetered electricity and 16 kWh/m 2 /yr metered natural gas).• All other assumptions were identical with the Timber, TimberPlus and Steel building.Steel building• The cut off criteria for FSC certified timber is 0.1 % and more than this value oftimber was used. FSC certified was therefore taken into account for the Steel building.• The concrete contribution was > 1 % and recycled concrete was chosen for thisscenario.• Operational energy figure specific to the Steel building were included (70 kWh/m 2 /yrmetered electricity and 16 kWh/m 2 /yr metered natural gas).• All other assumptions were identical with the Timber, TimberPlus and Concretebuilding.