Sustainable Government Buildings: Beyond Design

Executive Summary

1 Introduction

2 The Current Commissioning Process in New Zealand

3 A Best Practice Approach to Commissioning

4 Commissioning Resources

5 The Benefits and Costs of Better Commissioning

6 The Value Case for Better Commissioning

Appendix A: Typical Procurement Documentation

Appendix B: Post-occupancy Environmental Management Plan

Appendix C: Green or Performance-based Leases

Executive Summary

This report has been prepared as part of the Govt³ programme. It provides advice to government ministries, departments and agencies on the better commissioning, completion and ongoing operation of the buildings they use. As the Government moves towards ensuring it is housed in more environmentally sustainable buildings, there will be a greater emphasis on achieving and maintaining environmental performance over their lease term or life. The gap needs to be closed between design expectations and real building performance. Better commissioning of new buildings and re-commissioning of existing buildings are excellent ways to achieve this.

Commissioning is a systematic process that ‘ensures through documented verification that all systems perform interactively according to the documented design intent and the owner’s operational needs’.¹ In short, it is a way to ensure buildings work as they are supposed to, and this becomes crucial when it comes to designing buildings that are environmentally sustainable. It is widely accepted that many buildings are not properly commissioned, and this is borne out by poorly performing buildings and complaints from their occupants. This report aims to identify a better approach to commissioning.

The basic idea is to extend the current process that is carried out immediately prior to handover by bringing it forward into the completion and review of the design, and extending into the first year of operation. Ideally, the building’s performance should also be regularly audited over its lease term or life, as its uses and demands change and equipment deteriorates. A process of “continuous commissioning” should therefore be adopted.

There are many potential benefits of proper commissioning of a building, including:

• improved quality assurance, documentation and co-ordination between design, construction and occupancy, leading to a better-quality product

• lower energy usage over the life of the building and a greater potential for meeting energy targets, particularly for sustainable buildings

• lower water usage over the life of the building and greater potential for meeting water targets, particularly for sustainable buildings

• improved indoor air quality, and reduced noise and draughts, with consequent increases in occupant comfort and satisfaction

• reduced operation and maintenance problems and costs over the life of the building (studies indicate an 8-15% saving in costs, ignoring soft benefits)

• fewer on-site changes and their associated costs

• fewer complaints or call-backs to the building owner, contractors and design consultants

• improved tenant satisfaction for a leased building

• a mechanism for proving compliance with the proposed changes to the New Zealand Building Code clause H1 amendments.

Of all the measures that can be taken to make a building more sustainable, better commissioning is perhaps the most influential. This is reflected in the value case for better commissioning, with simple paybacks in the order of three years and a 15-year net present value (NPV) equivalent to twice the initial investment.

Environmental ratings schemes such as the New Zealand Green Building Council’s Green Star rating system also recognise the importance of commissioning by allocating up to six points for commissioning-related features. These points represent nearly 10% of the overall weighted score for a four-star building and 7% for a five-star building, so they represent a cost-effective way of achieving a good Green Star rating.

This Main Report is complemented by three appendices. Appendix A provides documentation for inclusion in procurement documents for leased government premises. This can easily be adapted if the buildings are government owned rather than leased. It also deals with larger and/or more complex building types and should therefore be fine-tuned for smaller, less complex buildings, although the principles of the process remain the same.

A post-occupancy environmental management plan template is provided in Appendix B to assist with setting up processes to achieve and maintain sustainable building performance over the term of a lease.

Finally, the report also touches on so called “green leases” or performance-based leases, which set out to capture real building performance in relation to design predictions. Further information on this is given in Appendix C.

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