Modelling detail analysis (March 2013)

• Detailed geometry can improve a building energy model's reliability by 5% to 15%.
• Default HVAC values seem sufficient for annual energy consumption reliability for modelling.
• Modelling ventilation rates accurately is critical to creating an accurate model.

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Building design optimisation (March 2013)

• Savings from natural ventilation and daylight design (replacing electric light) can only be significant if the building form is kept narrow.
• An optimal combination of solar shading, insulation and free cooling can almost eliminate cooling energy consumption for Christchurch commercial buildings.
• Application of the optimisation software GenOpt in energy simulations was successful and will be used for future research.

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Christchurch urban form and energy (March 2013)

• Improved indoor environment is possible through natural (passive) measures provided buildings are no wider than 17 m.
• Courtyards  in conjunction with lanes (of 10 m width) could deliver a significant reduction in energy (up to 47.4% per m² less than the ‘deep-plan' baseline model) as they facilitate passive cooling and daylighting.
• Opening up the city centre with courtyards and lanes also creates useful outdoor spaces.
• Planned façade step-backs are not effective in saving energy or making sunnier streets during the winter period.

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Energy use outliers (November 2012) 

• Energy Use Intensity (EUI) normalises the energy use of the premise by floor area to allow comparisons between different sized premises.
• The premises operation was found to have the greatest influence on EUI.
• None of the high or low EUI premises in BEES were offices, they were retail.
• Low EUI premises tended to have poor space conditions, however many of the high EUI premises also had poor space conditions.

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• 791 premises from throughout New Zealand have participated in the BEES phone survey.
• The majority (85%) of premises surveyed are tenants, with only 13% being owner-occupiers.
• Most premises (70.5%) pay for their energy directly to their supplier.
• Not surprisingly, nearly all premises reported having reticulated electricity (99.4%)

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• High level surveys and a small number of in-depth interviews with building managers and owners have been used to examine barriers to uptake of resource efficiency solutions and technologies.
• Management of buildings is either done as a form of self employment or as an investment this affects how resource efficiency is looked at although they both have the same goal of having the best return on their investment.
• Resource efficiency or ‘green buildings' are seen as less of a priority now compared to a year ago.
• Low take up of resource efficiency solutions in non-residential buildings in NZ. There are two models that are used to explain this - ‘Vicious circle of blame' where all parties blame another for not providing, demanding or paying for resource efficiency and ‘split incentives model' where the group paying for the improvements are not the same as the group benefiting.
• New Zealand non-residential building types are very diverse, building owners and managers have large contrasts in the extent to which they are aware or driven by issues of building performance.
• Further in-depth work will be done in this area over the next year of BEES determining the representativeness of this work.

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Detailed monitoring (December 2011)

• Results are presented from detailed monitoring of buildings less than 9,000 m².
• The two biggest electricity uses in these buildings are power points and lighting.
• The most common type of heating/cooling in the buildings monitored is by heat pumps, although portable heaters are still used in roughly half of the buildings.
• The monitoring of buildings was more difficult than expected due to complex wiring and frequently out of date labelling.

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Delivered daylighting (December 2011)

• The BEES study has so far has found about 10% of spaces within non-residential buildings have sufficient access to daylighting to meet daytime lighting needs for that space. A further 25% have a level of daylighting that meets the daytime lighting needs at least half of the time.
• For these spaces, the use of lighting controls that turned lights on and off when needed according to the amount of daylight would be an effective energy efficiency measure.
• At this stage of the project the daylighting profiles analysed so far have been for buildings with a total floor area less than 9,000 m².

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Achieved conditions (December 2011)

• This report presents weekday daytime analysis of BEES spaces that have had temperature, lighting, relative humidity and carbon dioxide measurements recorded for a period of 2-3 weeks each.
• Temperature, lighting, relative humidity and carbon dioxide data has been separated by building type (Office, Retail and Other) and analysed against ‘ideal conditions' for different seasons (Summer, Winter and intermediate).
• The spaces presented in this report are all from buildings less than 9,000 m². These buildings are more likely to have smaller individually controlled heating and cooling devices compared to the larger buildings where most will have centrally controlled HVAC.
• During year 5 of BEES buildings over 9,000 m² will be monitored and analysed.

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Temperature control (December 2011)

• With monitored temperature data from about 240 spaces within BEES buildings analysis has been done to see how tightly controlled temperature are within these spaces.
• The outdoor temperature was found to have an influence on indoor temperature.
• About 10% of spaces can be considered to have well controlled temperatures and about 40% mostly controlled.
• Retail spaces are more likely to be less controlled than Office and Other spaces.
• The indoor temperature is more likely to be influenced by the outside temperature during Autumn and Spring.
• The spaces looked at are all in buildings that are less than 9,000 m², larger buildings will be looked at during Year 5 and 6 of BEES. Larger buildings are more likely to have centralised heating/cooling systems that allow greater control over temperatures.

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From warehouses to shops - changing uses in the non-residential buildings sector (December 2011)

• Quotable Value (QV) records include the use category of a building. These have been compared to their current use by information gathered from the BEES websearch, on the first 1000 buildings in the BEES sample.
• About 30% of buildings that have a QV use category of industrial service or industrial warehouses are being used differently to this recorded classification.
• There are no significant differences in changes of use between different size buildings or between Auckland and the rest of New Zealand.
• A change in use can mean the design of the building is possibly not appropriate for its new use. This can have affects on energy use and how the Building Code (in particular H1 Energy efficiency) is applied to the building.

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