Information Related to Building Design - Essay Example

Running Head: BUILDING DESIGN Building Design and Energy Efficiency in Lights and Windows This is a research paper on various definitions and information related to building design. The first part of the paper talks about four concepts in financial analysis of projects or properties namely, payback period, rate of return, internal rate of return and life-cycle analysis. The next part of the paper talks about energy efficiency in buildings as contributed by various technologies in lighting. The last portion of the paper narrates the contribution of the latest technologies in window design that contribute to energy efficiency. Building Design Payback period is the amount of time it will take for a project to recover its initial capital investment through earnings generated from the project. Rondeau et al. suggests this formula for computing payback period as: Payback period = Cost of project/ Annual net cash flow (2006, p. 145). For example, an individual decides to purchase a condominium unit in Central London as an investment for £245,000. He further invests around £25,000 to furnish the unit and make it easily leasable. Thus his total investment is £270,000. He then is able to rent it out for £1,900 while spending about £100 in maintenance, thus is able to generate a net profit of £1,800 a month. Using the above formula, it will take a 12 ½ years for the owner to recover the condominium’s purchase price through the net profit of the lease. Rate of return is a financial measure of the profitability of an investment or a project. It is “what you get, minus what you started out with, expressed as a percentage of what you started with” (Getlner, et al., 2007, p. 176). Using the above example in the payback period concept, let us examine the rate of return of the condominium unit investment as several periods of time. At 12 ½ years, the owner would have made £270,000 of rental profits, equal to the initial investment on the unit. Therefore, the rate of return on the 12.5th year would have been 0%. However if he waited 2 ½ more years to assess his investment, he would realize a 20% rate of return or £54,000. There are two types of returns, one that is time-based, called periodic returns and one that is dollar-weighted (or in this case, pounds-weighted) called internal rate of return (Getlner, et al., 2007, p. 174). Internal rate of return, commonly referred to as IRR is applicable to real estate investments because it can compute investment performance over long periods of time which is the usual case in owning a property. One need not know the yearly value of the asset, the important information is the value of the capital investment at the beginning of the project and the cash flow generated periodically over the investment timeline. IRR being monetary-weighted means it will consider the value of interim investments, say additional capital in the middle of the investment timeline which adds on to the ability of the asset to generate income, and thus improve the rate of return of the asset over the balance of the period. Life cycle analysis is a means of determining the total cost of owning a property (Fuller, 2009). It takes into consideration the purchase cost of the building or property and all other costs involved in maintaining its life until and including its depreciation. In the above example, the cost of buying the condominium unit, the appliances used to furnish it as well as the maintenance costs of the unit will be taken into consideration until such time that the unit is deemed inoperable or not fit to be occupied. This type of analysis is usually used in evaluating a project or investment as well as assessing the value of an intervention, say a refurbishment of the unit, if it will deliver a prolonged use that will generate continued income. Energy Efficiency with Windows What makes windows energy efficient? The British Fenestration Ratings Council defines an energy efficient window “to contain and conserve heat within the home keeping out wind and rain, resisting condensation and yet allowing natural “free” energy - the warmth of the sun - to heat the home” (BFRC, 2008). The components of a window all contribute into the energy efficiency of it, namely the framing, glazing, coating, fill and gap. Window frames are the sturdy material forming the edges of the window. They are used to support the glazing as well as attach the window to the building. Framing materials range from wood to engineered materials such as fibreglass. To ensure energy efficiency, choose the material that has the least thermal loss (heat loss or gain). Presently, fibreglass presents the most energy efficient material for window frames and is also lightweight which positively affects window operability. However, it may be more expensive than wooden frames. Glazing is the middle part of the window, which allows for light to pass through and for the users to view the outside. The most basic installation is a single panel clear glazing; however energy efficient windows mandate a double glazing as a minimum. Tinting the glaze also contributes to the efficiency of the window. Depending on the coating used, it can block as much as 90% of the solar heat, while keeping the cold air inside the building. Low-E glass coatings, present breakthrough technology by selectively reflecting long-wave heat energy, while allowing visibility (US DOE, 2000) . Depending on the climate zone, low-E coatings will be applied to the part of the glazing where it will have the most impact. In between the double glaze, heat can still radiate and pass through the air in between. Energy efficient windows thus operate best in a vacuum filled double glazing. Modern technology uses gases such as argon which have better insulating properties than ordinary air. Lastly, condensation is a sign of energy loss on windows. These typically happen around the edges, where cold air escapes amidst warm humid air. Window spacers, a material to go in between the glazing and the frame can prevent condensation and therefore improve window efficiency. While aluminium spacers are most inefficient in preventing condensation, engineered fibreglass or vinyl reduce heat loss and prevent condensation. Energy Efficiency with Lights Laing et al. claims that 35% of energy costs in UK offices are spent on lighting (1998, p.119). Thus, it is worth the effort to look into ways of improving such consumption. Ten years past this study, a significant number of technological improvements have come about to improve the energy efficiency and thus consumption of lighting in offices. But before listing those new technologies, one of the major changes that have happened in the last decade or so is the change in the way offices are being used. Such change in work processes and dynamics are one of the major movers in changing and presenting opportunities for improving lighting efficiency. Laing et al., in cooperation with DEGW Consultants and BRE Ltd conducted a survey of leading companies to understand the dynamics of modern office work (1998, p.i ).The results showed the move from individual, routine work to a more creative and team-based interactive process. The use of space veered away from dedicated, exclusive areas to a more open, shared and flexible workspace that encourages collaboration and free thinking. From boxed, closed-office lighting, to open space illumination is the trend that resulted in the survey. In terms of space management, office spaces are owned, shared and temporarily owned. Owned spaces typically refer to one- to two-person enclosed offices which are exclusively dedicated to the occupant. Typically the head of the company, a significant financial officer or a worker involved in confidential activities will use such a space. The survey showed that these occupants need the ability to control the lights so the traditional on-off switch is a must for such type. However, with individual’s tendency to turn on lights and not necessarily turn them off, automatic controls such as a motion detector will work well without necessarily interrupting the occupant. The technology behind such motion sensor is the passive infrared technology or PIR. This is a sensor that detects the temperature of the human body, the absence of which signals the absence of the occupant and thus can command to switch off the lights (Keller, 2000). Open plan offices and collaboration rooms are usually shared spaces and not dedicated to individuals. In such areas, the traditional design would be to have a uniform array of luminaires emitting lux levels equal to task requirements. However, such design would be inefficient. Instead, open plan spaces must differentiate lighting needs for circulation, decoration and task (Laing et al., 1998, p.118). Circulation lighting will have lower luminance levels as that of task lighting. It should also carry emergency or back-up lighting, like battery-operated lights which turn on during the absence of direct electrical supply. This ensures the safety of the public during evacuations without the need for full power requirements. To meet the needs of task lighting, dedicated LED (light emitting diode) lamps can be scattered on to work surfaces or provided upon request. LED bulbs emit 50% more light and lasts 50 times longer than incandescent bulbs (Light emitting diode, 2010). For other office areas where individual control is less required, lighting timers can be used to control en-masse the opening and closing of lights. An example is a simple time-based controller which turns on or off the office lights at preset times of the day. More sophisticated timers are integrated into the building management system which synchronizes the over-all control of the building with that of the offices. Since high rise buildings will have access to a significant amount of daylight, photo-sensor timers are also available for automatically switching off lights when natural daylight is available. It uses photocell technology where a sensor senses light and controls an electrical circuit (Making Things, 2002). In the case of offices that operate 24 X 7, night shift lighting maybe automatically switched off as daylight comes in. References British Fenestrations Rating Council (2008). “What does BFRC ratings tell you?” Retrieved March 29, 2010, from http://www.bfrc.org/consumer/index.aspx. Fuller, S. (2009, December 7). Life-Cycle Cost Analysis. Retrieved on March 29, 2010 at http://www.wbdg.org/resources/lcca.php. Geltner, D.M., Miller, N.G., Clayton, J. & Eichholtz, P. (2007). Commercial Real Estate: Analysis & Investments. Mason, OH: Thomson South Western. Keller, H.J. (200, May 11). 30 Years of Passive Infrared Motion Detectors - a Technology Review. Retrieved on March 29, 2010 at http://www.kube.ch. Laing, A., Duffy, F., Jaunzens, D., &Willis, S. (1998) New Environments for Working: The Re-Design of Offices and Environmental Systems for New Ways of Working. London: Construction Research Communications. Light-emitting diode. (2010, March 25). In Wikipedia, The Free Encyclopedia. Retrieved March 29, 2010, from http://en.wikipedia.org/w/index.php?title=Light-emitting_diode&oldid=352052291 Making Things LLC (2002 – 2004). Photocell Sensor. Retrieved on March 29, 2010 at http://www.makingthings.com/teleo/teleo/cookbook/photocell.htm. Rondeau, E.P., Brown, R.K., & Lapides, P.D. (2006). Facility Management, Second Edition. Hobokien, NJ: John Wiley & Sons. Tregenza, P. & Loe, D. (1998). The Design of Lighting. London: E & FN Spon. United States Department of Energy. (2000, January). Energy Efficient Windows. Retrieved on March 29, 2010 at http://www.energycodes.gov/implement/pdfs/lib_ks_energy-efficient_windows.pdf. Read More