Implementing the IWBDP

This section identifies the steps at each stage of the design process. It is worth remembering that this is an iterative process so there are very often feedback loops within, and possibly even between, the stages. For small projects (≤ 500m²) with only a few members in the design team some of the requirements of an IWBDP may be unnecessary and this is noted in the sections below. Table 2 at the end of this section compares the differences between the IWBDP for small, medium and large projects.

The first step in the process is developing the project brief by identifying the requirements of the building through consultation with stakeholders. This can be done through surveys or by holding a series of visioning workshops at which stakeholders can voice their opinions and have input into the design brief. The project goals at this stage do not need to be detailed, but do need to be clear enough for the project team to develop a relevant design concept and solutions.

Process

At this stage in a conventional design process the client would normally appoint an architect to prepare an initial architectural concept. With an IWBDP this stage is much more involved and all the principal design consultants should be introduced to the project. When selecting members of the design team, it is important to consider the qualities, motivation and knowledge they will bring to the project.

A kick-off workshop should be held to introduce the project goals to the project team. Stakeholders and key staff members should also attend this meeting. The purpose of this meeting is to develop the project goals and design requirements and to encourage a relationship among the team members. The meeting should be used to encourage discussion, recognise any design conflicts and help develop the main objectives for the project, which may include:

• objectives
• assumptions and givens
• opportunities and constraints
• risks
• timeline
• budget
• spatial requirements and interrelationships
• sustainability objectives and measures
• specialist consultants required and their time of introduction to the project.

The kick-off workshop will normally require at least one day to complete.

Following the kick-off workshop, a series of design workshops need to be held by the design team to develop an initial building concept or concepts for the project. At this initial stage workshop topics should include:

• site development, and urban design and landscaping approaches
• orientation, massing and building form
• initial services distribution strategies and plant space requirements
• initial structural systems.

The initial concept design(s) should be presented to the client stakeholders and refined as necessary by further workshops.

An initial costing should be carried out at this stage. This will be required as part of the review and approval of the concept design by the client. If the project is over budget, the design team need to reassess their ideas to provide more cost-effective solutions or justify the extra expenditure to the client.

Documentation

At the end of this stage the following documents should be produced:

• initial architectural and landscaping design
• initial engineering design
• initial infrastructure design
• initial sustainability report
• initial outline specification for the project
• initial concept design budget
• outline design and construction programme.

All the above should be combined in an integrated concept design report.

Refer also to NZCIC’s Design Documentation Guidelines for detailed deliverables [New Zealand Construction Industry Council website]

Process

Preliminary design workshops should continue to develop the detail of the initial concept design. An iterative process is required to develop the preliminary design so that it continues to meet all the project objectives. These workshops require team members to visualise and evaluate their design more clearly. More detailed workshop topics can include:

• internal space planning and circulation
• building envelope (daylighting, thermal and energy performance)
• structural systems
• lighting, acoustics and thermal comfort design
• HVAC options
• water and wastewater systems
• a fire safety strategy
• materials selection
• preliminary thermal, daylighting and energy modelling.

For small projects (≤500m²) these design workshops may not be required and conventional design meetings can be held. These meetings may not require the presence of all the design team members; however, it is important to keep all members informed of discussions and outcomes. Meeting minutes should be circulated to all members of the design team for them to review and provide feedback if required.

Documentation

At the end of this stage the following documents should be produced:

• preliminary design report and drawings
• initial Green Star pre-evaluation, if applicable, plus a checklist for Green Star documentation responsibilities. This can be a long and involved process unless the requirements for Green Star documentation are highlighted to the project team at an early stage so that they can structure their documentation accordingly. For small projects (≤500m²) the full Green Star process may be too extensive and can be used for design guidance only
• updated and more detailed outline specification
• detailed design and construction programme
• preliminary budget for the project.

Refer also to NZCIC’s Design Documentation Guidelines for detailed deliverables [New Zealand Construction Industry Council website]

Process

More detailed design workshops should be held during this stage of the design. Each one should focus on a particular part of the design. For example, the following workshops could be held:

• building envelope detailing
• final internal space planning and circulation
• air-conditioning and ventilation system integration
• structural design integration
• electrical systems integration
• hydraulic systems integration
• fire safety integration
• final materials selection
• final thermal, daylighting and energy modelling
• updated design and construction programme
• requirements and protocols for construction documentation.

It is imperative to the IWBDP that all team members are involved in the workshops so design conflicts can be identified and solved quickly. The workshops also allow pooling of knowledge and can help optimise the design.

As at the preliminary design stage, at the developed design stage small projects (≤500m²) can follow a conventional design approach with regular design meetings. Again, it is important to keep all design team members informed of the discussions and outcomes of each meeting so they can provide feedback.

It is important that the design team are informed of the Green Star initiatives being pursued on the project at the beginning of this stage. The preliminary Green Star assessment document should highlight which credits are being pursued, and also provide an indication of how the requirements can be met.

Documentation

At the end of this stage the following documents should be produced:

• developed design report and drawings, including the following specialist reports for projects >500m²:
  • energy modelling report
  • thermal comfort report
  • daylight modelling report
  • fire report
• provisional Green Star rating for buildings >500m²
• final outline specification
• updated design and construction programme
• updated budget for the project.

Refer also to NZCIC’s Design Documentation Guidelinesfor detailed deliverables [New Zealand Construction Industry Council website]

Process

Once the design concepts have been fully developed, drawings and specifications, in sufficient detail to allow construction, need to be prepared. To assist with building integration and coordination on projects >500m², a common CAD-based Building Information Model (BIM) should ideally be used by the design team to provide a set of coordinated 3D models or drawings. The BIM defines the spatial relationships between architecture, structure, services and infrastructure. The BIM can be used throughout the building cycle, including during the processes of construction and facility operation. An example of such a modelling package is Autodesk Revit.

On small projects (≤500m²) a BIM may be unnecessary and a more conventional method of producing detailed design drawings and specifications can be used.

It is important to maintain team collaboration even at this stage in the design process. Workshops may no longer be required, but regular meetings should be held to keep the team members up to date on the development of the design. Only team members directly involved with the detailed design elements being discussed are required at the meeting; it is no longer necessary for the whole team to be involved.

It may be useful to involve the independent commissioning agent and future facilities manager towards the end of this stage in the design. This allows them to review the design for its ability to be commissioned, operated and maintained and gives them a good understanding of the design intent of the system.

Documentation

This is possibly the most important stage for documentation as this is when consent and tender documents are produced. It is important that the documents are coordinated between disciplines as any differences may cause confusion during the tendering and construction process. The following documents should be produced at the end of this stage:

• consent and tender drawings for each discipline
• consent and tender specifications for each discipline
• fire report.

If applicable, Green Star accreditation documents should also be collated from each discipline on completion of this stage. The documentation can then be submitted to the NZGBC who will assess it and, if successful, award a design rating for the building.

Refer also to NZCIC’s Design Documentation Guidelines for detailed deliverables [New Zealand Construction Industry Council website]

Process

At this stage a contractor is engaged in the project and, if required, minor adjustments are made to the design so that it is suitable for construction. The contractor must be fully informed of the design objectives and specific project criteria that must be met. It may be useful to organise a kick-off meeting between the design team and contractor to discuss the project requirements and identify any potential issues. Contracts should include the necessary Green Star conditions, for example the inclusion of environmental management and/or waste minimisation plans, as appropriate.

A waste management company should be engaged at this stage in the process and informed of the recycling targets.

Documentation

At the end of this stage the following documentation should be produced:

• construction drawings
• construction specifications, and preliminaries and general (P&G) section
• site management plan (included in P&G)
• environmental management plan (included in P&G)
• waste minimisation plan (included in P&G)
• building consent
• project timeline, including commissioning programme for buildings >500m².

Refer also to NZCIC’s Design Documentation Guidelines for detailed deliverables [New Zealand Construction Industry Council website]

Process

The involvement of the design team must be maintained throughout the construction process. Meetings should be organised with the necessary team members whenever issues arise. Site, environmental management and waste minimisation plans should be put in place, and all contractors who work on the site should be made familiar with them through suitable induction and auditing processes.

During this phase the commissioning agent should provide a commissioning plan and programme, and should also visit the construction site periodically and note any conditions that might affect system performance or operation. For small projects (≤500m²) a commissioning agent is not required. Systems may be commissioned as part of the usual scope of the installers but an overall commissioning programme is not required for the building.

The testing and commissioning process should be carried out by the installing subcontractors to accepted codes (eg, codes and guides from Charted Institution of Building Services Engineers, Building Services Research and Information Association, and the American Society of Heating, Refrigeration and Air Conditioning Engineers). The process should also verify the proper operation of equipment and systems according to the design intent, design drawings and specifications. Point-to-point or end-to-end testing of the building management system (BMS) is highly recommended. If corrective measures are required, the commissioning agent should make sure they meet the design intent. Acceptable performance is reached when equipment or systems meet specified design parameters under full-load and part-load conditions during all modes of operation, as outlined in the commissioning plan.

A high standard of verification, completion, clearance of defects and documentation should be achieved before granting handover. After completing pre-handover commissioning, the commissioning agent should write a handover commissioning report, which includes all commissioning documentation, and submit it for review by the building owner and designers. Before handover, building operators should be trained in operating and maintaining equipment and systems. The commissioning agent should oversee the training sessions provided by the installing contractors’, designers’ and manufacturers’ representatives.

The commissioning agent also verifies that operation and maintenance manuals include a user guide and are complete and available for use during the training sessions.

Facilities management training should be carried out as part of the initial commissioning process.

Documentation

During this stage the following documents should be produced:

• technical submissions
• shop drawings
• documentation on any adjustments made to the specification
• detailed construction and commissioning programme
• site inspection reports and defects lists
• initial commissioning report for buildings >500m².

It is important that records of any changes made to the design are kept for future reference and the design team are fully involved with adjustments.

At the end of this stage the following documentation should be produced:

• draft as-built drawings
• draft operations and maintenance manuals
• building user guide for buildings >500m².

Process

A bake-out period of two weeks should be allowed for after the building has been completed. This period can overlap with the furnishing of the building. The bake-out period is used to allow off-gassing from the finishes in the building. The bake-out should be staged within the building and furnishing can commence in areas where bake-out has been completed.

Even though the project is considered complete, some fine-tuning commissioning tasks should continue throughout the typical one-year defects and warranty period. The commissioning agent should initially return on a monthly basis for the first three months, and then quarterly through the defects and warranty period to review systems’ operation and liaise with facility staff to address any performance problems. It is also helpful after six months to carry out a post-occupancy evaluation survey of the building’s occupants to identify any issues with the building, and this can inform the need for any further fine-tuning.

A monthly log of energy, water and waste consumption should be kept and reconciled with the agreed performance targets. Any non-performance problems should be addressed as part of the system’s fine-tuning and operational practices. Ideally, energy and water audits should be carried out six to twelve months after initial occupancy of the building. This will identify any unexpected energy or water use.

It is a good idea for the building owner to consider re-commissioning their facilities periodically to ensure that equipment performance levels continue to meet the design intent. In a sense, this means that, to maintain a high level of performance, commissioning never ends. Operation and management staff should be encouraged to audit and partially re-commission selected building systems on a regular basis, perhaps every three years, depending on building use, changes to layout equipment complexity and operating experience.

On small projects (≤500m²) a bake-out period and auditing may be applicable; however fine-tuning may not be necessary. Regular monitoring and maintenance of building systems should be carried out by the management staff.

Documentation

During this stage the following documentation should be produced:

• practical completion certificate
• code compliance certificate
• operational environmental management plan (produced at the beginning of this stage)
• commissioning report
• final operations and maintenance manuals
• final as-built drawings
• post-occupancy evaluation report
• energy audit report
• water audit report
• end of defects inspection reports
• completion certificate.

Table 2: Comparison of the IWBDP for different project size