Strategic implementation plan - D ESIGN FOR DECONSTRUCTION

6.8 D ESIGN FOR DECONSTRUCTION

6.8.4 Strategic implementation plan

M.R. Hosseini, et al, [70] studied the work of several researches and presented some

strategic points for consideration in the setting up of a RL strategic implementation plan. Five points are discussed below that have to be considered in the setting up of a strategic

implementation plan.

Minimising RL cost

Building products and building frames have to be designed in a way to allow easy, cost effective deconstruction [70].

Improving the quality of recovered products

The quality of recovered products and building components has to be at least equal to the quality of raw materials (the original product) to improve product salvage values. This will increase organisational income and promote the implementation of RL in the construction sector. The design of products and components has to be done in such a way that it ensures easy and cost effective recoverability [82].

Price optimisation

Recovered items have to be available to the market at lower prices compared to new products. Market conditions and demand have to be considered in determining the selling price of recovered products and components. The price of recovered items could be used as an effective manner to control an organisation’s inventory levels and to increase revenues [83].

Designing an effective RL system structure

The RL system structure will contribute to the cost and quality of recovered products. The following important aspects have to be considered when designing the system structure:

• Location and layout of collecting centres and facilities.

• Transportation routes to distribute products and materials to facilities and centres.

• Personnel to be involved in the system structure: organisation’s own personnel or personnel from third party contractors.

65 6.8.5 Availability of information

An important aspect that has to be considered is the timely availability of accurate information. Information regarding available recovered products, location, quantity, and quality are required to reduce uncertainty [84].

For the successful implementation of RL in the construction industry, information management and design for RL are essential aspects. The harvesting of information is central to an effective RL system in the construction industry. The advantages of information availability are summarised as follows:

• It reduces risks and uncertainty, which results in the reduction of system cost [85].

• It increases the awareness of RL in the construction industry and increases the support from senior managers and company executives [86].

• It increases the overall efficiency of RL and cooperation between role players is improved. Cost of transportation, inventory levels and the loss of time is reduced through the availability of information [87].

6.8.6 Design for deconstruction

One of the main barriers that prevent the implementation of reverse logistics in the

construction industry relates to the fact that buildings were not designed for deconstruction.

This makes the recovery of quality material and components difficult or sometimes

impossible [88]. In the case of reusing bricks, as an example, it is important that the design and specification allow for effective recovery of bricks by not over specifying the mortar strength [89]. If RL is not accounted for in the design, the possibility to recover quality building materials and products cost-effectively is compromised [78], [88], and [90].

6.8.7 Principles for the design for deconstruction

In a paper presented by P. Crowther, Design For Disassembly – Themes and Principle [91], design guidelines were given for architects and building designers to design for the

disassembly of buildings. These design principles include:

• Use recycled and recyclable materials and products. Increased usage of these materials and products will encourage new recycling technologies and legislation.

• Use the same materials and products: this will simplify sorting during deconstruction and reduce logistical cost.

• Standardise building components.

• Do not use toxic and hazardous materials and products.

• Inseparable subassemblies should be fabricated from the same materials. This will reduce “contamination” by small quantities of different materials.

• Avoid the application of secondary finishes that may contaminate the base material.

• Recyclable material should be marked as such, for future sourcing. Material and fabrication properties should be indicated on elements.

• Use bolted (mechanical) connections and not welded connections where possible.

• Connections should be optimised to allow for easy disassembly and transportation.

• Connections have to be standardised throughout a building.

• Use modular design principles. This not only allows for better disassembly, but also for easier assembly.

• The design has to allow for the deconstruction (and assembly) of elements using “low-tech” tools and technology.

• Design the building with separate cladding panels, wall panels, and services. This ensures that some building components can be removed from the main building structure separately.

• All building components must be accessible to allow easy disassembly.

• Building components must be designed to allow for easy disassembly and transportation.

• Design components with special attachments to allow handling during disassembly.

Lifting/disassembly points have to be permanently marked for future identification.

• Connections must be designed for repeated use.

• Use, where possible, prefabricated units or elements.

• Use lightweight construction materials to allow for easier handling and transportation.

• The building frame has to be designed to allow partial disassembly. The building frame must be self-supportive during the process of disassembly.

• Building frame system information, construction information, and design-for-deconstruction information have to be well documented for future use.

6.9 Conclusion

A basic understanding of the major technical design aspects is regarded, by the author, as essential in the managing process of the design and development of high-performance buildings. Managers and leaders that are equipped with some basic technical knowledge of the design of sustainable buildings are better positioned to manage the process

successfully.

The integrated building design team has to integrate and consider aspects of sustainable land usage, material selection, and the sustainment of natural hydrologic systems. The protection of wetlands and agricultural land, prevention of erosion, protection of water sources, indoor environmental quality, and design for deconstruction are some of the important aspects in the design of high-performance buildings. By selecting building materials and products correctly, carbon dioxide emissions can be reduced. Through integrated design, building energy loading can be reduced and the provision of energy from sustainable natural resources can be increased. Building “envelope” details, building positioning, building volume optimisation, and the utilization of technology, are amongst some of the aspects that have to be considered during the sustainable building design process.

In the South African context, opportunity exists for the implementation of reverse logistics in the construction industry (also referred to as building deconstruction). For the successful recycling of building material and product, building designers and contractors have to design and construct buildings to allow for effective deconstruction and reverse logistics.

7 GREEN BUILDING RATING SYSTEMS

There is no universal rating system, but consensus exists with regards to the rating attributes and the weighting that these attributes should receive when a building is rated [9]. Although such a consensus exists, weighting of attributes is applied differently by different rating systems. For instance, Green Globes, a US online green building assessment system, attributes a 34% weight to energy, whilst the LEED system assigns an attribute of 29% to energy [9].

Listed below are a number of other rating systems [92]:

• Green Star Environmental Rating System (Australia)

• Building Research Establishment’s Environmental Assessment Method (BREEAM) (United Kingdom)

• Hong Kong Building Environmental assessment Method (HK-BEAM)

• Green Star (South Africa).

7.1 LEED Rating System

The US Green Building Council (USGBC) [93] (a non-profit organisation) was established in 1993 to promote green building practices. The Leadership in Energy and Environmental Design (LEED), a green building rating system was launched in 2000. In the USA the LEED

green building rating system has been adopted by USA government, various states, municipal agencies and private sector developers in the USA. The LEED rating system accounts for different type of buildings and building applications.

The LEED certification system consists of the following four different levels [92], [93];

• Certified (40-49 points)

• Silver (50-59 points)

• Gold (60-79)

• Platinum (80+ points)

The following aspects in the design and development of buildings are rated [92]:

1. Sustainable sites 2. Water efficiency

3. Energy and atmosphere 4. Indoor environmental quality 5. Materials and resources 6. Innovation and design

7.2 Green Star SA Rating System

The Green Star SA rating system is based on the Green Star rating system of the Green Building Council of Australia [94]. The Green Building Council of South Africa (GBCSA) regulates the certification of green buildings in South Africa. The GBCSA board consists of representatives from the property investment sector, property development sector, quantity surveying and construction economics sector, architectural design, construction and engineering companies, leading retail organisations, the energy sector, the South African Property Owners Association, property financiers, the Construction Industry Development Board, and the South African Local Government Association [94].

To achieve a Star rating, building owners have to submit the required documentation to the GBCSA. An independent panel of assessors is appointed by the GBCSA board to evaluate and score the submission. Three levels of certification exist within the GBCSA [94]:

• 4-Star, for recognising best practice; with a weighted score of 45 to 59.

• 5-Star, for recognising South African excellence; with a weighted score of 60 to 74.

• 6-Star, for recognising world leadership; with a weighted score of 75 to 100.

69 7.2.1 Green Star rating tools

The GBCSA developed Green Star rating tools to objectively measure green buildings. The rating tools are applicable to the following building sectors:

• Existing building performances

• The environmental attributes of interior fit-outs

• New office projects and major office refurbishments

• Public and Education Buildings (new and refurbished)

• New unit residential developments and major refurbishments of existing multi-unit residential developments

• New commercial retail centres and major commercial building refurbishments

• Socio-economic category, for recognising the socio-economic achievements and initiatives of green building projects.

According to the GBCSA the main objectives of the rating tools are to establish a standard for measuring green buildings, to promote integrated building design with a focus on whole-building design, to reduce the environmental impacts of property development, and to recognise environmental leadership [94].

The SA Green Star rating system considers the following categories. The weighting

indicated in brackets is applicable to new commercial retail centres as well as major building refurbishments.

• Management (10%): accredited professionals, building commissioning systems, and building management systems.

• Indoor environmental quality (IEQ) (10%): noise and thermal control, carbon dioxide monitoring and control, and the prevention of hazardous material during construction and operation.

• Energy (25%): reduction in energy demand and the provision of on-site sustainable energy sources.

• Transportation (12%): fuel efficient transportation systems, cyclist facilities, and the provision for mass transportation.

• Water (15%): effective landscape design, water recycling systems, and water consumption efficiency.

• Materials (13%): usage of recycle material, design for deconstruction, local sourcing, and sourcing from suppliers with sustainability policies.

• Land use (7%): reuse of topsoil, urban heat island management, and the development on reclaimed land.

• Emissions (8%): prevention of all forms of natural resource pollution.

The GBCSA considers both the “as-built” building systems as well as the design and construction phases of a project when evaluating the project.

7.3 Conclusion

A number of non-profit green building councils were established during the past two to three decades. These organisations were established to assist with regulating the development and certification of sustainable buildings. The performance of the integrated design team, as well as the building’s actual performance against a set of predetermined sustainability goals, must be measured as part of the certification process. The South African Green Star rating system developed a rating tool to ensure that the measuring of green building achievements is standardised. The Green Star rating system acknowledges 8 different categories. This includes building operational management systems, selection of materials, water

management systems, the provision of “clean” energy, transportation infrastructure, and indoor environmental quality.

8 SUSTAINABLE CONSTRUCTION

Sustainable development rest on three pillars [95]:

• Social sustainability that considers the needs and the well-being of individuals.

• Economic sustainability to ensure economic growth takes place within the capacity of the natural environment.

• Environmental sustainability that considers the effective application of natural resources and the elimination of waste and pollution.

The International Council for Buildings (CIB) developed 7 principles for sustainable construction: Reduce; Reuse; Recycle; Protect nature; Eliminate toxins; Apply life cycle costing and Focus on quality [96].

8.1 Sustainable Construction Aspects

Important aspects that have to be addressed during the construction of high-performance buildings include: (1) site protection, (2) managing indoor air quality during construction, (3) materials management and, (4) building commissioning. These aspects are briefly discussed below [96].

8.1.1 Site protection

Site protection ensures that disturbance of the site ecology is minimised. Several aspects have to be considered during construction to ensure adequate protection of the site. These

include: erosion and sedimentation control, pollution prevention, and reduced site disturbance.

8.1.2 Managing indoor air quality during construction

To ensure that the indoor air quality during construction is maintained, the contractor has to consider the following aspects: (a) HVAC ducting to be done in such a way that it limits dust and toxic contamination; (b) careful selection of construction materials like sealants, (c) occupied areas have to be isolated from the construction work site to prevent the

contamination of these areas, and (d) emissions and other forms of contamination due to poor construction practices have to be avoided.

8.1.3 Materials management

Effective management of materials reduces overall project cost and waste. The following have to be considered in the management of materials:

Procurement and delivery; different suppliers might be used to ensure that “green” products are supplied. Delivery routes have to be evaluated to ensure timeous delivery of products without using excessive amounts of fuel and without disrupting traffic.

Storage; special care has to be taken to ensure products are protected from moisture, temperature and UV damage. To minimise storage requirements and the risk of material being damaged, just-in-time delivery principles could be adopted.

Construction waste management: construction waste like bricks and concrete can be crushed and used as fill material.

8.1.4 Building commissioning

A building commissioning process is highly recommended as part of the development of high-performance building. It provides the developer with the assurance that the building will function, at optimal cost, and within the pre-defined limits. Commissioning can be done through installation inspections or performance testing, or a combination of the two methods.

The implementing of a commissioning process during the early stages of design and construction provides that design and construction mistakes are resolved effectively.

Building commissioning reduces equipment installation errors and provides for a fully functional building from the start of operations. The next section discusses the building commissioning plan in more detail.

8.2 Building Commissioning Strategy

An important aspect of sustainable construction is the process of building commissioning.

The US Green Building Council [12] gave the following benefits of having a well-planned building commissioning system in place:

• The performances of building systems are verified against the design through testing.

• Insurance is provided that the systems are constructed in accordance with the design.

This reduces problems at project completion and operation.

• Deficiencies are identified before project completion, making it more cost-effective to implement corrective actions.

• Post-occupancy commissioning tests evaluate the building systems under real world conditions.

• The design team is provided with an in-depth understanding of the building systems, which results in improved design work.

• Annual or biannual commissioning ensures that systems are functioning correctly during operation. It also ensures that that the systems are maintained properly and cost effectively.

A good commissioning system is essential to the process of developing high-performance buildings.

8.2.1 Building commissioning implementation

A commissioning process has to be planned and implemented correctly. The US Green Building Council [12] provided some practices for the implementation of a commissioning process. The commissioning process has to be planned during the design and

documentation phases of a building project. The following have to be considered during the planning stages: (1) building systems that are required to be commissioned have to be selected, (2) a commissioning implementation strategy has to be developed, (3) a

commissioning specification has to be prepared, (4) the facility “start-up” amount that has to be released to the contractor (after completion of the commissioning process) has to be specified, (5) the commissioning contractual matters have to be addressed, and (6) a commissioning team has to be elected.

8.2.2 Building commissioning process

The contractor plays a major role in the commissioning process. The commissioning process must be monitored by the design team and the owner’s field representatives. Some

important aspects that have to be considered during the commissioning process are listed below [12], [13], and [97]:

• Commissioning meetings have to be attended by the commissioning team and relevant design team members.

• The contractor has to perform system start-up tests.

• Building operation manuals and maintenance - and training manuals have to be provided by the contractor.

• Building systems operations have to be demonstrated by the contractor.

• System operations have to be reviewed by the design team to confirm conformance to the design.

• The contractor has to prepare and submit a commissioning report for acceptance by the owner.

During the post-occupancy phase, “fine-tuning” of the building systems are done by a predetermined support team. If system “fine-tuning” cannot be achieved, the contractor has to make system adjustments. This process should be done within the first 12 months of building occupation. Re-commissioning must be done on a regular basis, possibly yearly or every second year. Re-commissioning is required to ensure the building systems are operational as per the design intend, and that preventative maintenance actions are scheduled as required.

The US Green Building Council suggested that building staff be specifically trained to operate and maintain special equipment and systems [12].

8.2.3 Building commissioning report

A final commissioning report shall be issued to the owner by the contractor. The commissioning report needs to contain the following information and documents [12]:

• Details of the building

• Commissioning team members and their responsibilities

• Project “as-built” information (drawings, specifications and inspection sheets)

• Description (written or in diagram format) of different building systems.

• A summary of the system design intent and the actual performance of the constructed systems.

• Performance measurement documents

• Approval reports, non-conformance reports, and cost-tracking forms

• Testing reports

• Start-up verification documents

• Operations and maintenance manuals

• Emergency shutdown procedures

• Training manuals, training schedules, and programs

• System certification documents.

8.3 Conclusion

The building contractor and their sub-contractors play an important role in sustainable construction. The contractor has to align his construction practices with the predetermined goals. Provisions like minimising site disturbance, protection of open excavations to prevent soil erosion, the sourcing of materials and products locally, and from suppliers who adopted business practices to ensure long-term sustainability, pollution prevention, and indoor building quality are aspects that have to be planned and considered by the contractor. A well-planned building commissioning process is essential to ensure all building systems function in accordance with the design. Commissioning reports, maintenance manuals and building operating manuals need to be provided by the contractor. The building occupants have to be trained in system operation and maintenance.

9 HIGH PERFORMANCE BUILDING ECONOMICS

Profit-seeking organisations have to produce organisational profits to ensure long-term sustainability. Reducing the running cost of an organisation will contribute to its profit-making abilities. It is therefore important to consider the capital investment as well as the monthly operational costs of commercial buildings when developing the business case of a planned building project. Expressed over the complete life cycle, the operational costs of a building

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