Lighting. Introduction. Key lessons. Sustainability Victoria Fit-Out

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1 Level 28 Urban Workshop, 50 Lonsdale Street Melbourne v Lighting Key lessons Maximising daylight penetration is important for achieving good energy efficiency and indoor environment quality. Reducing overhead lighting levels can lead to substantial energy reductions. Lighting energy consumption can be significantly reduced by removing excess lamps. Lighting control systems can reduce energy consumption by 30% or more. Providing a flexible lighting control system can also improve occupant satisfaction with an office space. Introduction Lighting is an important issue to consider during a sustainable building fit-out. It has a significant impact on both energy consumption and indoor environment quality. Lighting typically consumes between 15-26% [1, 2] of the energy used in commercial buildings 1. A number of decisions can be made at the design and fit-out stage to reduce this consumption, including optimising the amount of natural light that can reach the space, specifying energy efficient light fittings, lowering the overall illumination level, providing task lighting and optimising the lighting control system. Indoor environment quality can also be greatly affected by lighting. Occupants are typically happier when working in daylight conditions [3]. Research also suggests that building occupants are happiest with their environment when they have some degree of control over it [4]. In terms of lighting, this means giving people control over their personal lighting needs and glare control. This type of control ideally needs to be built in at the design and fit-out stage. Both energy efficiency and indoor environment quality were considered in the lighting design of Sustainability Victoria s office at Level 28, 50 Lonsdale Street in Melbourne. Desk lamps provide additional localised lighting when required, reducing the need for strong overhead lighting 1 Note that these figures include a number of building types (such as retail buildings) which typically have higher lighting demands than office buildings.

2 Natural lighting Natural lighting offers a number of advantages, the biggest of which is that it is free and readily available during daylight hours. Natural light also has a positive psychological effect on occupants compared to artificial light [5]. Sustainability Victoria s fit-out at Level 28, 50 Lonsdale Street has been designed to maximise daylight penetration throughout the office space, which in turn allows for reduced energy consumption from artificial lighting. The base building orientation and elongated rectangular floor plate is such that it promotes maximum access to daylight for occupants. The majority of the base building services (lifts, communications, electrical) are located in the centre of the building and Sustainability Victoria s office design placed common areas such as reception, the kitchen, meeting room and rest rooms in the centre of the floor as well.these decisions mean the majority of perimeter areas can be used for workstations, giving them the greatest access to daylight. Most workstations are within eight metres of a window. Natural lighting can sometimes introduce glare issues. The 50 Lonsdale office features roller blinds, which are fitted to the inside of windows and can be lowered when glare becomes an issue. Artificial lighting High-efficiency T5 light fittings have been used throughout the 50 Lonsdale fit-out. T5 fluorescent lights are smaller and typically use less energy than a standard T8 fitting 2. consumption has been further reduced by dimming the overhead lamps so that they only emit a maximum illumination of 200 lux. By comparison, most office spaces are illuminated to 600 lux. Task lighting has been included at each desk to supplement the overhead lighting where required, as well as to give occupants better control over their lighting needs. These task lights have been used rarely, however, suggesting that the combination of natural lighting and dimmed overhead lighting has been sufficient for the majority of occupants. Once the space was occupied, lighting energy consumption was further decreased by removing overhead lamps that weren t required. These lamps were identified by measuring illumination levels in each area with a light meter, and comparing them to Australian Standard Most lamps in areas that were found to be over-lit were either dimmed or shut off using the lighting control system. In a few areas the lamps had to be manually removed. A total of 133 lamps were either shut off or removed from the office, with an expected energy usage reduction of 20.6 MJ/m²/year, a 36% reduction from the modelled annual lighting energy consumption and an 8% reduction in whole-office energy consumption (see Table 1 for full details). 2 T designates that the light is tubular, and the number indicates the diameter of the tube in eigths of an inch. Metric designations for T5/T8 lights are T16 and T26, respectively.

3 Table 1 expected energy saving from excess lamp removal Type of tube Method of delamping No of tubes No of ballasts Watts per tube Watts per ballast Hours not in operation per week (kwhr/week) (kwhr/year) (MJ/month) (MJ/sq m/year) large T5 remote small T5 remote compact fluro (social hub) compact fluro (meeting rooms) remote remote large T5 manual Total ,438 2, This process was carried out by the organisation s Green Leaders as part of its Environmental Management System. The Green Leaders aimed for Sustainability Victoria to achieve operational whole-office energy consumption of 290 MJ/m²/year. The office s NABERS energy rating found the target had been exceeded and only 246MJ/ m²/year was being used. The reduction in lighting energy consumption helped to meet this target. In addition to shutting off or removing lamps, a number of sensors have been adjusted since moving into the office, and diffusers have also been fitted to some lights. Artificial lighting specifications general office reception, social hub and meeting rooms Think Tank meeting room T5 fluorescent tubes (provided with base building) Versilux Vanna surface mounted compact fluorescent downlights (42W in social hub and reception, 18W in meeting rooms) Artemide Castore Sospensione Task lights Artemide Tolomeo 120, fitted with 11W compact fluorescent bulbs Control systems Even with the most efficient light fittings, much energy can be wasted if lights are left on unnecessarily. The average lighting control system, a manual switch on the wall, requires occupants to be diligent about turning lights off. Including a degree of automation in the lighting control system can take some of the onus away from occupants and reduce unnecessary energy consumption. A number of designers have reported that a managed lighting system (MLS) is one of the most cost effective means of achieving energy reduction targets. The Sustainability Victoria fit-out included an MLS, supplied by Conservation Systems (ECS). Overhead lights are fitted with daylight and movement sensors. These sensors automatically dim the lights when enough daylight is entering the space that the overhead lights aren t needed. The lights turn off when no movement is detected within a six metre radius of the relevant sensor. The sensors can detect very small movements, so normal movement while working at a desk will keep the lights on. The system also allows lights that aren t required to be turned off permanently. This feature was used in some of the areas staff identified as being over-lit that were discussed earlier. With a standard switching system, it was estimated that the lighting system would have consumed approximately 39,668 kwh of electricity per year. Using the ECS control system, however, energy consumption of about 25,802 kwh per year was modelled at the time of design a 34% reduction. The flexibility offered by this system has been cited as a major post-occupancy advantage for two reasons. Staff have reported that the system allows for a greater level of experimentation with lux levels, dimming controls and overall programming than could be expected from a standard system. It has also provided office occupants with a much greater degree of control over their space, an important part of occupant satisfaction with an office [4].

4 Challenges One of the biggest challenges encountered in the lighting design process for the Level 28 fit-out was addressing the Australian Standards for lighting levels, and preconceptions about the lighting levels required for office work. A problem was found with the lighting for the office s green wall. Plants on the wall initially weren t getting enough light. The problem was solved by fitting reflectors above the planter boxes, painting the soffit with a high-reflective paint and planting different species in some areas. AS/NZS 1680 Interior and workplace lighting prescribed a lighting level of 320 lux at 720mm height for task areas such as desks. That applied to task areas other areas didn t need to be lit to the same standard, and the entire tenancy didn t need to be lit to an average level of 320 lux 3. The figure also didn t take daylight into account the lighting system was designed on the basis that the full 320 lux shouldn t need to be supplied by overhead artificial lighting if daylight is sufficient. Sustainability Victoria commissioned a daylight modelling report, which was used during the final design of the artificial lighting system to achieve the right balance between natural and artificial lighting. An education process was also required to help occupants understand how the lighting system operated and its energy efficiency features. Glare control in particular was an issue. While occupants were lowering the roller blinds to decrease glare, they weren t always raising them again once the glare problem had ended. With the blinds left down, less daylight was able to enter the space and, in turn, more artificial lighting was being used to compensate. While this issue hasn t been completely resolved, staff are being encouraged to roll the blinds back up when they are not required for glare control. Some differences were also found in the energy savings predicted by the lighting controls supplier and the final modelled figures. ECS predicted an energy saving of 47.5% compared to a standard switching system, whereas the modelling found only a 34% reduction (discussed above). Modelling protocols were found to be the reason for this difference. Models for the Australian Building Greenhouse Rating (ABGR, now NABERS ) only allow for savings from enclosed spaces less than 50m² such as meeting rooms and quiet rooms to be included. Savings from occupancy sensors in the open office and entrance areas could not be included. 3 Sustainability Victoria s office was designed in 2006, using the standards applicable at the time. A revised edition of AS was issued in An abundance of natural light reduces the need for strong overhead lighting Conclusion Lighting can have a big influence on energy efficiency and indoor environment quality in an office. Sustainability Victoria has addressed these issues in its office by maximising access to daylight, installing advanced monitoring and control systems, using energy efficient artificial lighting and permanently turning off artificial lights that are not required. Compared to a standard system, Sustainability Victoria s approach to lighting has resulted in indoor environment quality improvements and more than 30% reduction in energy used for lighting. The Sustainability Victoria case study package Sustainability Victoria has developed a series of case studies to tell the story of our fit-out. The package provides an overview of our fitout plus four technical sheets: Information and Communication Technology, Lighting, Waste, and Materials. The package can be downloaded at

5 References 1 Centre for International Economics; Capitalising on the building sector s potential to lessen the costs of a broad based GHG emissions cut, report prepared for ASBEC Climate Change Task Group, published September 2007 and available from 2 Australian Greenhouse Office; Australian Commercial Building Sector Greenhouse Gas Emissions , available from 3 Brown, S; High quality indoor environments for office buildings, presented at the March 2006 Cooperative Research Centre for Construction Innovation Clients Driving Innovation: Moving Ideas into Practice conference and available from 4 Leaman, A and Bordass, B; Productivity in buildings: the killer variables, published in EcoLibrium April-June 2005, available from Building details Building name: Urban Workshop Address: 50 Lonsdale Street Fit-out cost: $2.02 million Total floor area (NLA): 1650m² Number of storeys: One (28th floor of building) Owner occupier / tenanted: Tenanted Project team Client: Sustainability Victoria Project manager: Gallagher Jeffs Architect: Hassell Environmentally sustainable design consultant: Sinclair Knight Merz New or refurbished: New Construction time: Two months Delivery method: Design, document, tender, construct Green Star Office Interiors rating: Rating TBC at time of writing NABERS rating 4 : Five stars Services engineers: Umow Lai Specialist solutions consultant: Conservation Systems Quantity surveyor: WT Partnership Builder: Waltons 5 Green Building Council of Australia; Green Star Diffusion manual mechanical engineering, downloadable from Further reading Green Star rating tools - Sustainability Victoria - Your Building - About Sustainability Victoria Sustainability Victoria is a statutory authority that helps communities, businesses and governments to reduce their environmental impact, turning policy into action. It s new office on Level 28 of the Urban Workshop, 50 Lonsdale Street, Melbourne demonstrates that excellence in sustainable office interiors can be achieved within a typical commercial fit-out budget. 4 Formerly Australian Building Greenhouse Rating (ABGR)