Assessment systems for environmental sustainable building and structural materials

2.4 Environmental sustainability and Structural materials selection

2.4.2 Assessment systems for environmental sustainable building and structural materials

An environmental building assessment method reflects the significance of the concept of sustainability in the context of building design and subsequent construction work on-site. The primary role of an environmental building assessment method is to provide a comprehensive assessment of the environmental characteristics of a building (Cole, 1999) using a common and verifiable set of criteria and targets for building owners and designers to achieve higher environmental standards. It also enhances environmental awareness of building practices and lays down the fundamental direction for the building industry to move towards environmental protection and achieving the goal of sustainability (Ding, 2008).

Building environmental assessment is, in and of itself, a defined realm of

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enquiry with more rigorous explorations into weighting protocols, performance indicators, and so on (Cole, 2004). Environmental assessment methods have done the following: given focus to green building practices;

enabled building performances to be described comprehensively; assisted in redefining progress. Improving the environmental performance of buildings within current cost and time constraints requires a different approach to the design process (Cole, 2004).

Sustainable building rating systems come in a variety of shapes and sizes.

They are local, regional, national and international. Three of the most popular and widely accepted international systems (BREEAM and LEED) were reviewed. In addition, the Singapore local system, Green Mark, was reviewed as well.

2.4.2.1 UK BREEAM

The Building Research Establishment Environment Assessment Method (BREEAM) was developed by the UK Building Research Establishment (BRE) over two decades ago as a widely used environment assessment method for buildings.

BREEAM addresses wide-ranging environmental and sustainability issues and enables developers and designers to prove the environmental credentials of their buildings to planners and clients. According to a statement by BRE (2011b), BREEAM provides clients, developers, designers and others with: 1) market recognition for buildings with low environmental impact; 2) assurance that the best environmental practice is incorporated into a building; 3) inspiration to find innovative solutions that minimize environmental impact ; 4) a benchmark that is higher than current regulations; 5) a tool to help reduce running costs, improve working and living environments; and 6) a standard that demonstrates progress towards corporate and organizational environmental objectives. The family of BREEAM includes BREEAM Courts, BREEAM Data Centres, BREEAM Education, BREEAM Healthcare, BREEAM Industrial, BREEAM Multi-residential, BREEAM Offices, BREEAM Retail, BREEAM Prisons, and BREEAM Other Buildings, which

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enable BREEAM to be applied in all types of buildings.

In BREEAM, credits are awarded in ten categories according to performance.

The percentage of credits achieved in each category is then multiplied by the corresponding BREEAM section weighting. These credits are then added together to produce a single overall score on a scale of Pass, Good, Very Good, Excellent and Outstanding.

The latest version of BREEAM schemes for assessing buildings was updated in 2011 by adding in BREEAM New Construction UK 2011(BRE, 2011a).

Table 2.1 outlines the weightings for each of the nine environmental sections included in the BREEAM New Construction Scheme. It can be seen that those items affected by structural materials are worth about 1/3 of the total points.

Table 2.1 Point allocations in BREEAM New Construction (2011)

(Source: BRE, 2011)

Categories Available points Applied structural materials

Management 12% Yes

Sustainable procurement 8 Yes

Responsible construction practices 2 Yes

Construction site impacts 5 Yes

Stakeholder participation 4 Yes

Service life planning and costing 3 Yes

Health and Wellbeing 15% No

Energy 19% No

Transport 8% No

Water 6% No

Materials 12.5% Yes

Life Cycle Impacts 2-6 Yes

Hard landscaping and boundary

protection 1 Yes

Responsible sourcing of materials 3 Yes

Insulation 2 Yes

Designing for robustness 1 Yes

Waste 7.5% Yes

Construction waste management 4 Yes

Recycled aggregates 1 Yes

Operational waste 1 No

Speculative floor and ceiling finishes 0-1 No

Land Use and Ecology 10% No

Pollution 10% Yes

Innovation (additional) 10% Yes

28 2.4.2.2 US LEED

The Leadership in Energy and Environmental Design (LEED) Green Building Rating System™ was developed by the US Green Building Council (USGBC) and officially launched in the US in 1998. Rating system Version 2.0 was released in March 2000, with LEED Version 2.1 following in 2002, Version 2.2 following in 2005, and Version 3 following in 2009. The scheme was inspired by other schemes, including BREEAM. Unless a country-specific LEED system is in place, the LEED US Criteria is used for any country in the world. LEED provides building owners and operators with a concise framework for identifying and implementing practical and measurable green building design, construction, operations and maintenance solutions. It is a voluntary certification program that can be applied to any building type and any building lifecycle phase.

The LEED systems evaluate environmental performance from a whole- building perspective over a building‘s life cycle. They promote a whole- building approach to sustainability by recognizing performance in seven key areas shown in table 2.2.

The current version, LEED 2009, uses the U.S. Environmental Protection Agency‘s Tools for the Reduction and Assessment of Chemical and Other Environmental impact‘s (TRACI) categories (USEPA, 2009) as the basis for weighting each credit. It also takes into consideration the weightings developed by the National Institute of Standard and Technology (NIST);

Together, the two approaches provide a solid foundation for determining the point value of each credit. All certified projects receive a LEED plaque and a certificate, with ratings such as Certified, Silver, Gold or Platinum.

According to the guidebook of LEED for new construction v2009 (USGBC, 2009a, 2009b), those items affected by the applied structural materials are identified in table 2.2. About 43 points out of the total possible score of 110 are associated with structural material selection.

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Table 2.2 Point allocations in LEED for new construction v2009

Categories

Available points

Applied structural materials

Sustainable Sites 26/110

Credit 3 Brownfield Redevelopment 1 Yes

Credit 5.1 Site development- protect or restore habitat 2 Yes Credit 5.2 Site development- Maximize open space 3 Yes

Water Efficiency 10/110 No

Energy and Atmosphere 35

Prerequisite 2 Minimum energy performance required Yes

Credit 1 Optimize energy performance 1-19 Yes

Material and Resources 14/110 Prerequisite 1 Storage and collection of recyclables required Yes Credit 1.1 Building reuse--maintain existing walls,

floors and roof 1-3

Yes

Credit 2 Construction waste management 1-2 Yes

Credit 3 Material reuse 1-2 Yes

Credit 4 Recycle content 1-2 Yes

Credit 5 Regional material 1-2 Yes

Credit 6 Rapidly renewable material 1 Yes

Credit 7 Certified wood 1 Yes

Indoor Air Quality 15/110

Credit 3.1 Construction IAQ mgmt plan--during

construction 1

Yes Credit 4.3 Low emitting materials--floor systems 1 Yes Credit 4.4 Low emitting materials--composite wood

and agrifiber products 1

Yes

Credit 8.1 Daylight and views--daylight 1 Yes

Credit 8.1 Daylight and views--views 1 Yes

Innovation in Design 6/110 No

Regional Priority 4/110 No

Sustainable Sites 26/110

Credit 3 Brownfield Redevelopment 1 Yes

Credit 5.1 site development- protect or restore habitat 2 Yes Credit 5.2 site development- Maximize open space 3 Yes

Water Efficiency 10/110 No

Energy and Atmosphere 35

Prerequisite 2 minimum energy performance required Yes

Credit 1 optimize energy performance 1-19 Yes

Material and Resources 14/110

30 (Source: USGBC, 2009)

2.4.2.3 Singapore GM

The Singapore Green Mark (GM) scheme was launched in January 2005 as an initiative to drive Singapore's construction industry towards more environmentally-friendly buildings (BCA, 2013). It was aimed at promoting sustainability in the built environment and to raise environmental awareness among developers, designers and builders when they start project conceptualization and design, as well as during construction.

BCA GM is a benchmarking scheme that incorporates internationally recognized best practices in environmental design and performance. It rates buildings according to five key criteria -- energy efficiency, water efficiency, environmental protection, indoor environmental quality, and other green and innovative features (BCA, 2012c). Based on an overall assessment, a building may be awarded one of four GM ratings: the GM certified, Gold, Goldplus or Platinum award.

Categories

Available points

Applied structural materials Prerequisite 1 storage and collection of recyclables required Yes Credit 1.1 building reuse--maintain existing walls,

floors and roof 1-3

Yes

Credit 2 construction waste management 1-2 Yes

Credit 3 material reuse 1-2 Yes

Credit 4 recycle content 1-2 Yes

Credit 5 regional material 1-2 Yes

Credit 6 rapidly renewable material 1 Yes

Credit 7 certified wood 1 Yes

Indoor Air Quality 15/110

Credit 3.1 construction IAQ mgmt plan--during

construction 1

Yes Credit 4.3 Low emitting materials--floor systems 1 Yes Credit 4.4 Low emitting materials--composite wood

and agrifiber products 1

Yes

Credit 8.1 daylight and views--daylight 1 Yes

Credit 8.1 daylight and views--views 1 Yes

Innovation in Design 6/110 No

Regional Priority 4/110 No

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Based on the current version of BCA GM for new non-residential buildings (Version NRB 4.1) (BCA, 2012a), those items affected by structural materials are identified in table 2.3. About 42 points out of the total possible score of 190 are associated with structural material selection.

Table 2.3 Point allocations in BCA GM for new non-residential buildings (VNRB 4.1)

Categories

Available points

Applied structural materials

Part 1 - Energy Efficiency 116 /190

1-1 Building Envelope - ETTV 12 Yes

1-2 Air-Conditioning System 30 No

1-3 Building Envelope – Design/Thermal

Parameters 35 No

1-4 Natural Ventilation / Mechanical Ventilation 20 No

1-5 Daylighting 6 Yes

1-6 Artificial Lighting 12 No

1-7 Ventilation in Carparks 4 No

1-8 Ventilation in Common Areas 5 No

1-9 Lifts and Escalators 2 No

1-10 Energy Efficient Practices and Features 12 No

1-11 Renewable Energy 20 No

Part 2 - Water Efficiency 17/190

2-1 Water Efficient Fittings 10 No

2-2 Water Usage and Leak Detection 2 No

2-3 Irrigation System 3 No

2-4 Water Consumption of Cooling Tower 2 No

Part 3 – Environmental Protection 42/190

3-1 Sustainable Construction 10 Yes

3-2 Sustainable Products 8 Yes

3-3 Greenery Provision 8 No

3-4 Environmental Management Practice 7 No

3-5 Green Transport 4 No

3-6 Refrigerants 2 No

3-7 Stormwater Management 3 No

Part 4 - Indoor Environmental Quality 8/190

4-1 Thermal Comfort 1 No

4-2 Noise Level 1 No

4-3 Indoor Air Pollutants 2 No

32 Categories

Available points

Applied structural materials

4-4 Indoor Air Quality (IAQ) Management 2 No

4-5 High Frequency Ballasts 2 No

Part 5 – Other Green Features 7/190

5-1 Green Features and Innovations 7 Yes

(Source: BCA, 2013)