advanced building skins 14 | 15 June 2012 - lamp.tugraz.at - Graz ...

2.1.4 SBTool
Advanced Building Skins
The SBTool 5 is based on the philosophy that a rating system must be adapted to local conditions
before its results can become meaningful. The system is therefore designed as a generic framework,
with local non-commercial organizations being expected to define local context conditions and to
develop appropriate weights and benchmarks. The system has been designed to facilitate such a
regional calibration; in fact, the system requires the insertion of regionally meaningful benchmarks.
SBTool covers a wide range of sustainable building issues, not just green building concerns, but the
scope of the system can be modified to be as narrow or as broad as desired, ranging from 120 criteria
to half a dozen;
The system allows third parties to establish parameter weights that reflect the varying importance of
issues in the region, and to establish relevant benchmarks by occupancy type, in local languages. Thus,
many versions can be developed in different regions that look quite different, while sharing a common
methodology and set of terms. The main advantage, however, is that an SBTool version developed
with local knowledge is likely to be much more relevant to local needs and values than other systems;
The system provides separate modules for Site and Building assessments, with Site assessments
carried out in the Pre-design phase and Building assessments carried out in Design, Construction or
Operations phases;
SBTool takes into account region-specific and site-specific context factors, and these are used to
switch off or reduce certain weights, as well as providing background information for all parties.
Weights for criteria that remain active are re-distributed, so that the total always remains 100%.
There is a capacity to carry out assessments at four distinct stages of the life-cycle and the system
provides default benchmarks suited to each phase.
2.2 National Building Vertification Systems in Austria
2.2.1 Klima:aktiv (Building and Refurbishment)
The klima:aktiv building and refurbishment certification system for New Construction Office [30] is
divided into four assessment categories according to a system of 1000 points. The categories are
design and construction (Category A maximum 120 points), energy (Category B, maximum 600
points), building materials and construction (Category C, maximum 160 points) and comfort and
indoor air quality (Category D, maximum 120 points).
Klima:aktiv assessment allows LCA to be carried out in two different ways. On the one hand, category
C 2.1a (ecological benchmark of the whole building) and alternative category C 2.1b (ecological
benchmark of building envelope). The assessment considers three environmental impact categories
GWP, AP and PEI.n.e. (or CEDnr). For the final assessment these three environmental impact
categories are aggregated into one ecological benchmark (OI 3).
In the first case, the assessment goes only partly in line with the CEN/TC 350 approach. The Use
phase only focuses on environmental impacts. Due to the fact that the construction and maintenance
processes are considered by the assessment, environmental impacts caused by energy demand during
use phase are not included in the aggregated results. Environmental impacts are partly embedded in
category B 2.2 (CO2 emissions) and B 2.3 (cumulative energy demand).
In the second case, due to time-related focus of the before use phase and the spatial-related focus of
the building envelope as well as the declaration of environmental impacts in CO2-emissions, the
environmental assessment concept does not correspond to the CEN/TC 350 concept, which is based on
a holistic approach. The influence of neglecting spatial and/or time related aspects is shown in detail in
[5].
At most, 100 points (or 10%) can be achieved by using case one, and 75 points can be reached by
accomplishing LCA in case two. Taking into account the previously mentioned categories B 2.2 (125
points) and B 2.3 (125 points), a total of 350 points using case one, and 325 points using case two, can
be achieved.
5 Overview of the SBTool assessment framework, Nils Larsson, iiSBE and Manuel Macias, UPM Spain, April 2012
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