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

6 The Value Case for Better Commissioning

Using a 10,000 m² air-conditioned office as an example, and making the following assumptions, a value case for better commissioning can be made.

6.1 Assumptions

Capital cost assumptions

Commissioning agent’s cost	$35,000
Additional point-to-point BMS testing	$30,000
Additional design input into design intent and user guide	$15,000
Additional design input into post-occupancy stage	$15,000
Present value of re-commissioning at year 5	$9,313
Present value of re-commissioning at year 10	$5,783
Total	$110,096

Operating and maintenance cost reduction assumptions

Annual operating and maintenance cost	$270,000
Operating and maintenance cost saving (14% average)	$37,800

Economic assumptions

Discount rate 10%

O&M inflation rate 3%

6.2 Economic analysis

Simple payback	15-year lease period net present value (NPV)	Internal rate of return (IRR)
2.9 years	236,273	33%

The 15-year net present value (NPV) is 2.1 times the initial capital cost premium and represents one of the best sustainable building investments that can be made. The above analysis ignores any potential savings due to reduced reworking/variations as a result of the design review and commissioning management process improvements.

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