Costs and Financial Benefits of Undertaking Green Building Assessments
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Costs and Financial Benefits of Undertaking Green Building Assessments Final Report Contents 0 Research Highlights............................................................................................................ 1 0.1 Cost Premiums for Green Building Assessments in Hong Kong........................................ 1 0.2 Certified Green Buildings .................................................................................................... 2 0.3 Potential Financial Benefits................................................................................................. 2 0.4 Green Building Assessments in Hong Kong....................................................................... 3 1 Introduction ......................................................................................................................... 5 1.1 Background ......................................................................................................................... 5 1.2 HK-BEAM............................................................................................................................ 6 1.3 Timeline............................................................................................................................... 6 2 Green Building Assessments.............................................................................................. 7 2.1 Green Building Concepts .................................................................................................... 7 2.2 Certified Green Buildings .................................................................................................. 10 3 Cost and Benefits of Green Buildings............................................................................... 14 3.1 Perceived Cost Premiums for Green Buildings ................................................................ 14 3.2 Perceived Benefits of Certified Green Buildings............................................................... 15 3.3 Relative Costs for Office Buildings.................................................................................... 17 3.4 Relative Cost for Residential Buildings............................................................................. 18 4 Green Building Assessments in Hong Kong..................................................................... 20 4.1 Assessments under HK-BEAM 1/96R (New Offices) ....................................................... 20 4.2 Assessments Under HK-BEAM 3/99 (Residential) ........................................................... 21 4.3 Assessments Under HK-BEAM ‘New Buildings’ 4/04....................................................... 22 5 Energy Use Assessments................................................................................................. 27 5.1 Energy Use in Buildings in Hong Kong............................................................................. 27 5.2 Energy Use Assessments................................................................................................. 28 5.3 HK-BEAM Energy Use Assessments for Office Buildings ................................................ 30 5.4 Energy Use Assessments in Version 1/96R (New Offices) .............................................. 31 5.5 Energy Use Assessments in Version 4/04 for Office Buildings ........................................ 34 5.6 Differences Between Versions 1/96R and 4/04 ................................................................ 37 5.7 Residential Building Energy Assessments in HK-BEAM .................................................. 39 6 Study Methodology ........................................................................................................... 45 6.1 Cost Data .......................................................................................................................... 45 6.2 Cost Premium for Individual Credits ................................................................................. 46 6.3 Baseline Office Building .................................................................................................... 47 6.4 Baseline Residential Building............................................................................................ 48 6.5 Key Assumptions .............................................................................................................. 49 6.6 Premium for a Particular Performance Grade .................................................................. 50 6.7 Estimation of Overall Cost Premiums ............................................................................... 50 7 Cost Premiums for HK-BEAM Assessments .................................................................... 53 7.1 Cost Premiums for Certification to HK-BEAM 1/96R (New Offices) ................................. 53 7.2 Cost Premiums for Certification to HK-BEAM 3/99 (Residential) ..................................... 58 7.3 Cost Premiums for Certification to HK-BEAM 4/04 (New Buildings) ................................ 59 7.4 Cost Premiums for Energy Efficient Designs.................................................................... 61 8 Benefits from Green Building Assessments...................................................................... 64 8.1 Post-occupancy Evaluation of Existing Buildings ............................................................. 64 8.2 Indoor Environmental Quality............................................................................................ 67 8.3 Site Aspects ...................................................................................................................... 77 8.4 Materials Aspects.............................................................................................................. 78 8.5 Energy Use in Office Buildings ......................................................................................... 79 8.6 Energy Use in Residential Buildings ................................................................................. 81 8.7 Water Use ......................................................................................................................... 83 8.8 Production of Buildings ..................................................................................................... 85 8.9 Minimising Costs and Maximising Benefits....................................................................... 93 9 Observations and Recommendations............................................................................... 95 9.1 Increased Value of Green Buildings ................................................................................. 95 9.2 Incentives to Enhance Energy Performance .................................................................... 96 10 Cost Premiums for HK-BEAM 4/04 Credits ...................................................................... 98 ii 0 RESEARCH HIGHLIGHTS This study has examined the costs and financial benefits of green building assessments for new buildings in Hong Kong. The estimates are based on studies for two building types: a high-rise, air-conditioned office building of ‘generic’ design, and a low-cost (public sector) high-rise residential building. Most often investment decisions for building projects tend to be based on capital cost; consequently, any investment in green attributes for a building is likely to depend on the added cost, i.e. the cost premium over conventional design and construction practice. To understand the cost premiums for so-called green buildings, i.e. buildings assessed and certified under a building environmental assessment method, it is necessary to understand what assessment and certification entails, and what it achieves in terms of enhancements to building qualities and performance. Similarly, the financial benefits of a green building depend on the outcome of the assessment and the persistence over time of the performance enhancements. 0.1 COST PREMIUMS FOR GREEN BUILDING ASSESSMENTS IN HONG KONG The study has revealed that the minimum premium on total construction cost for buildings certified as ‘green’ under the Hong Kong Building Environmental Assessment Method (HK-BEAM) is likely to be of the order of 0-4%, depending on the certified performance grade achieved (e.g. HK- BEAM ‘Gold’). Costs for financing, additional design time/fees, and certification fees are excluded. The following table summarises the minimum premiums for the two types of buildings assessed under HK-BEAM versions 1/96R (1999) and 4/04 (2004) for office buildings, and HK-BEAM versions 3/99 (1999) and 4/04 for low-cost, high-rise residential buildings. The percentages for private sector residential buildings would be about half of the values given in the table. The estimates for HK-BEAM versions 1/96R and 3/99 are historical in that both assessment methods have been replaced by version 4/04. Projecting these estimates to particular development would not be appropriate given the variability of site conditions, building scale and design, as well as the correctness of the data used in this study. Rather, the cost premiums should be seen as indicative for the stock of new ‘green’ buildings in Hong Kong. Summary of minimum cost premiums for buildings assessed under HK-BEAM Office Building Certified Grade and required % of available credits HK-BEAM 1/96R - 59 credits* ‘Good’ 55%+ ‘Very Good’ 65%+ ‘Excellent’ 75%+ % Premium@ 0%+ < 1% 1%+ HK-BEAM 4/04 – 112+ credits* ‘Silver’ 55%+ ‘Gold’ 65%+ ‘Platinum’ 75%+ % Premium@ 0.8%+