green conversion
In a new development it is easier for the parties involved to provide a value proposition of a green building. The main parties involved are the developer, the landlord and the tenant, all of whom may be the same person which would make the decision process a lot easier. The parties would have to negotiate and implement tenancy arrangements. This should not be to difficult provided that the building is fit for its purpose, and is capable of achieving the environmental performance targets and benchmarks that were set out, and the parties agree and understand their mutual obligations to achieve those targets and benchmarks.
However if the building has not been designed to achieve environmental performance targets, or implement ESD (Ecologically Sustainable Development) principals, the situation becomes a lot more difficult. If a landlord or tenant is proposing to retrofit an existing building but incorporation environmentally friendly practices and reduce the energy consumption, the parties involved will first have to look at the lease agreement to see how it can accommodate all of the green measures suggested. A substantial retrofit of a building that involves substantial construction works and imposing additional obligations on a tenant will require a variation to a lease, or a substitute of a new lease (Power, 2004).
The retrofitting process of ESD principals into an existing building is on the most part driven by the owner. The owner of the building will therefore have two possibilities available to him. The first of these is if the owner intends to undertake substantial retrofit work, which would require an empty building. If the lease has not expired the owner would have to reach a commercial accommodation with the tenant to bring their lease to an end, which could result in a potentially significant cost. The second possibility is for the landlord to undertake work while the tenant remains in occupation of the building. Depending on the magnitude of the of the refurbishment to make the building more ‘green’, the tenant may also need to consent to the reasonable interruption or interference to its use of the leased premises arising due to the refurbishment. The refurbishment to a greener environment can be either landlord-driven or tenant-driven, although tenants usually have a very limited power as to undertake any physical works in respect of the leased premises (Power, 2004).
Low-energy building design techniques are application specific. There are seemingly infinite possibilities with regards to the implementation of energy efficient design techniques subsequent to determining their potential use given the applicable needs and preferences of any specified development. There is an inherent need to comprehend the various energy efficient design alternatives and apparent technologies available so as to integrate the paramount mix of these constituents to the specified project and financial feasibility. For a particular project, the explicit energy-saving techniques, strategies, and mechanisms to be deployed will contrast greatly, depending on building and space type (Federal Energy Management Programme, 2001).
The main objectives of sustainable design are to avoid resource depletion of energy, water, and raw materials; prevent environmental degradation caused by facilities and infrastructure throughout their life cycle; and create built environments that are livable, comfortable, safe, and productive (Green Building.com, 2005).
Green building brings together a vast array of practices and techniques to reduce and ultimately eliminate the impacts of buildings on the environment and human health. But effective green buildings are more than just a random collection of environmental friendly technologies. They require careful, systemic attention to the full life cycle impacts of the resources embodied in the building and to the resource consumption and pollution emissions over the building's complete life cycle (Green Building.com, 2005).
On the aesthetic side of green architecture or sustainable design is the philosophy of designing a building that is in harmony with the natural features and resources surrounding the site. There are several key steps in designing sustainable buildings: specify 'green' building materials from local sources, reduce loads, optimize systems, and generate on-site renewable energy.
Building materials typically considered to be 'green' include rapidly renewable plant materials like bamboo and straw, lumber from forests certified to be sustainably managed, dimension stone, recycled stone, recycled metal, and other green products that are non-toxic, reusable, renewable, and/or recyclable. Building materials should be extracted and manufactured locally to the building site to minimize the energy embedded in their transportation.
Low-impact building materials are used wherever feasible: for example, insulation may be made from low VOC (Volatile organic compound)-emitting materials such as recycled denim or cellulose insulation, rather than the building insulation materials that may contain carcinogenic or toxic materials such as formaldehyde. To discourage insect damage, these alternate insulation materials may be treated with boric acid. Organic or milk-based paints may be used. However, a common fallacy is that "green" materials are always better for the health of occupants or the environment.
Many harmful substances (including formaldehyde, arsenic, and asbestos) are naturally occurring and are not without their histories of use with the best of intentions. A study of emissions from materials by the State of California has shown that there are some green materials that have substantial emissions whereas some more "traditional" materials actually were lower emitters. Thus, the subject of emissions must be carefully investigated before concluding that natural materials are always the healthiest alternatives for occupants and for the Earth (The Greenhouse Project, 2006).
Architectural salvage and reclaimed materials are used when appropriate as well. When older buildings are demolished, frequently any good wood is reclaimed, renewed, and sold as flooring. Any good dimension stone is similarly reclaimed. Many other parts are reused as well, such as doors, windows, mantels, and hardware, thus reducing the consumption of new goods. When new materials are employed, green designers look for materials that are rapidly replenished, such as bamboo, which can be harvested for commercial use after only 6 years of growth, or cork oak, in which only the outer bark is removed for use, thus preserving the tree. When possible, building materials may be gleaned from the site itself; for example, if a new structure is being constructed in a wooded area, wood from the trees which were cut to make room for the building would be re-used as part of the building itself.
To minimize the energy loads within and on the structure, it is critical to orient the building to take advantage of cooling breezes and sunlight. Day lighting with ample windows will eliminate the need to turn on electric lights during the day (and provide great views outside too). Passive solar can warm a building in the winter, but care needs to be taken to provide shade in the summer time to prevent overheating. Prevailing breezes and convection currents can passively cool the building in the summer. Thermal mass stores heat gained during the day and releases it at night minimizing the swings in temperature. Thermal mass can both heat the building in winter and cool it during the summer. Insulation is the final step to optimizing the structure. Well-insulated windows, doors, ceilings and walls help reduce energy loss, thereby reducing energy usage. These design features don't cost much money to construct and significantly reduce the energy needed to make the building comfortable.
Optimizing the heating and cooling systems through installing energy efficient machinery, commissioning, and heat recovery is the next step. Compared to optimizing the passive heating and cooling features through design, the gains made by engineering are relatively expensive and can add significantly to the projects cost. However, thoughtful integrated design can reduce costs, for example, once a building has been designed to be more energy-efficient, it may be possible to downsize heating, ventilation and air-conditioning (HVAC) equipment, leading to substantial savings. To further address energy loss hot water heat recycling is used to reduce energy usage for domestic water heating. Ground source heat pumps are more energy efficient than other forms of heating and cooling.
Finally, onsite generation of renewable energy through solar power, wind power, hydro power, or biomass can significantly reduce the environmental impact of the building. Power generation is the most expensive feature to add to a building. Good green architecture also reduces waste of energy, water and materials. During the construction phase, one goal should be to reduce the amount of material going to landfills. Well-designed buildings also help reduce the amount of waste generated by the occupants as well, by providing onsite solutions such as compost bins to reduce matter going to landfills. To reduce the impact on wells or water treatment plants, several options exist. "Greywater", wastewater from sources such as dishwashing or washing machines, can be used for subsurface irrigation, or if treated, for non-potable purposes, e.g., to flush toilets and wash cars. Rainwater collectors are used for similar purposes.
Green building often emphasizes taking advantage of renewable resources, e.g., using sunlight through passive solar, active solar, and photovoltaic techniques and using plants and trees through green roofs, rain gardens, and for reduction of rainwater run-off. Many other techniques, such as using packed gravel for parking lots instead of concrete or asphalt to enhance replenishment of ground water, are used as well (Wigginton & Harris, 2002). While the definition of what constitutes sustainable building design in a property management context is constantly changing, there are six fundamental principles that nearly everyone agrees on.
Optimise Site Potential
Creating sustainable buildings starts with proper site selection, including consideration of the reuse or rehabilitation of existing buildings. The location, orientation, and landscaping of a building affect the local ecosystems, transportation methods, and energy use. Sifting for physical security has become a critical issue in optimizing site design. The location of access roads, parking, vehicle barriers, and perimeter lighting must be integrated into the design along with sustainable site considerations. Site design for security cannot be an afterthought. Along with site design for sustainability, it must be addressed in the preliminary design phase to achieve a successful project.
Optimise Energy Use
With America's supply of fossil fuel dwindling, concerns for energy security increasing, and the impact of greenhouse gases on world climate rising, it is essential to find ways to reduce load, increase efficiency, and utilize renewable energy resources in federal facilities.
Protect and Conserve Water
In many parts of the country, fresh water is an increasingly scarce resource. A sustainable building should reduce control, or treat site-runoff, use water efficiently, and reuse or recycle water for on-site use when feasible.
Use Environmentally Preferable Products
A sustainable building should be constructed of materials that minimize life-cycle environmental impacts such as global warming, resource depletion, and human toxicity. These environmentally preferable materials are defined by Executive Order 1310 1 to be "products or services that have a lesser or reduced effect on human health and the environment when compared with competing products or services that serve the same purpose." As such, they contribute to improved worker safety and health, reduced liabilities, reduced disposal costs, and achievement of environmental goals.
Enhance Indoor Environmental Quality (IEQ)
The indoor environmental quality (IEQ) of a building has a significant impact on occupant health, comfort, and productivity. Among other attributes, a sustainable building should maximize day lighting; have appropriate ventilation and moisture control; and avoid the use of materials with high-VOC emissions. Additional consideration must now be given to ventilation and filtration to mitigate chemical, biological, and radiological attack.
Optimise Operational and Maintenance Practices
Incorporating operating and maintenance considerations into the design of a facility will greatly contribute to improved working environments, higher productivity, and reduced energy and resource costs. Designers are encouraged to specify materials and systems that simplify and reduce maintenance requirements; require less water, energy, and toxic chemicals and cleaners to maintain; and are cost-effective and reduce life-cycle costs.