Environmental impact & modern methods of construction - Essay Example

Environmental Impact & Modern Methods of Construction Task Environmental Impact of Construction Works Employer Requirements The list of Employers Requirements (ER) is a critical step in which most construction projects are initiated. The purpose of the ER is to identify the planning mechanisms, resource mobilisation techniques and other aspects that will be used in the project. The ER intends to draw the statutory requirements and the desire of the management involved with the project to ensure that the construction will be implemented seamlessly. Most important, the ER will serve as guide that will be followed by all entities involved with the project. It will meet terms of all the DfES Constructional Standards 1997 and as amended (2001). The Constructional Standards override the current Building Regulations on Ramps Steps and Handrails (sections F, K & M). 1.1. Project Overview The project is focused on erecting a GBP 12.5 million school building. The building will constructed by demolishing the old structures. The new infrastructure is located in a residential area which is the main concern of the project proponent. Aside from successfully raising the building, the Project Manager needs to devise strategies that will eliminate environmental hazards and other related problems. 1.2. Project Participants The main proponent of the project is the government which serves as the main source of funds. The private contract shall be determined through public biddings. The private contractor is responsible for ensuring that necessary permits are obtained as well as systematic planning and execution are undertaken. The other players are the residents living adjacent to the proposed location which will likely be affected by the construction. 1.3. Contractor Determination The Authority requires all interested parties to submit their initial bids which have to include contract terms, tender and construction programmes, general work details and proposed design. The Authority will establish a committee that will decide which of the bidders will move to the next phase. The second part of the process involves actual costing, detailed work scope and the comprehensive construction plan. The winning bidder will be decided based on a majority vote and is required to provide a final tender for approval. The committee established by the Authority also serves as the oversight team which will ensure that the Contractor provides high quality and sustainable work. 1.4. Pre-acquisition and Post-acquisition Survey The Contractor will be provided with the information on the site upon acquisition by the Authority. The Authority stipulates no warranties regarding the information on the property. Other surveys that need to be implemented include for asbestos, trees, archaeological desktop assessment and geotechnical and environmental desktop assessment. The results from these surveys are not part of the contractual documentation. 1.5. Work Scope The scope involves the following aspects that needs to be considered to promote sustainable construction 1.5.1. Accessibility and Disability Discrimination The Department of Education has listed thirty eight statutory requirements for building schools in the UK. The Contractor has to include an Accessibility Plan which is an important necessity. The schools have to be designed to promote learning and facilitate the manner in which the students reach their classrooms. Another important statutory requirement is the disability equality policy. The Contractor must take into account the Disability Discrimination Act of 1995 as basis for designing the building. Classrooms and other amenities have to account for students that have physical impairments. 1.5.2. Workings Hours The hours involved in constructing the building have to be in accordance with governing rules and regulations. The Project Manager stipulates the allowable time for work from Monday to Friday which is 8:00 AM to 17:00 PM and on Saturdays which is from 8:00 AM to 13:00 PM. The Project Manager, through the oversight committee’s approval has the capacity to change work schedules. The approval must be secured 3 days prior to the scheduled adjustment in work time. Additional compensation is provided to workers that exceed the 9 hour daily requirement. 1.5.3. Maintaining the Greenery Sustainable construction involves the preservation of the greenery specifically trees in the location. Any tree that has to be cut requires approval from the committee and such action should only be done upon reviewing all possible alternatives. All trees and plants that are removed must be replaced by the Contractor. Aside from the trees, the Contractor is prohibited from excavating or putting additional soil in plants. 1.5.4. Noise Control The location of the new building is near houses and neighbourhoods. The construction has to be done in minimal noise to avoid complaints. The suggested working hours, as provided earlier, helps in ensuring that noise is controlled. Moreover, the use of effective construction equipment will lessen noise. One of the basic statutory requirements is for the construction not to disrupt learning and households. 1.5.5. Pollution Control The Contractor is mainly responsible for containing, disposing and storing chemicals and other pollutants during the construction phase. Aside from the hazards, debris, excess materials and other physical resources have to be removed from the site in the process of construction. 2. BREEAM Rating After receiving a BREEAM rating of “Good” during the first month, the goal of the Project Manager is to improve the rating to “Very Good”. The Project Manager first needs to identify the basic criteria that serve as basis for the grade. The assessment of the post-construction phase has to impress the individuals responsible for handing the BREEAM Certificate. The issues assessed include management, health, energy, transport, water, materials, waste, land use and pollution. The first step in creating the action plan is to focus on the areas where the building needs the most improvement. After zeroing in on the issues, the Project Manager has to provide specific actions that need to be undertaken. For the specific issues, the Project Manager has to highlight health and safety, resource use, waste management, and pollution control as priorities. Health and safety involves the students, faculty, staff and parents that consider the school as second home. Specific safety measures such as warning signs and alarms have to be installed. There has to be constant monitoring of areas that require maintenance and guards have to do inspections in all areas of the building. The resources for building are another major issue that should be highlighted. A BRE case study showed that the design and use of sustainable materials are keys in achieving a high BREEAM rating. In terms of waste management, a plan should be developed to ensure that proper waste disposal is done. Reduction of waste is also another strategy that can be used primarily promoting recycling of unused construction materials. The pollution emitted from the use of fuel can be reduced by balancing tasks among the manpower. There are certain areas of construction where manual labour is more efficient, hence machines could be rested. The most important aspect of the action plan is the execution which requires the right people, strategies and resources. 3. Site Waste Management Plan The Site Waste Management Plan (SWMP) details the plan of the Authority in properly handling waste. As per the UK law, constructions valued over GBP 300,000 are required to develop a SWMP. The Project Manager serves as the overall in-charge of implementing the SWMP. Other stakeholders that are important in the plan include the Authority, the Contractor, and other staff provided with specific roles. SWMP documents are produced to serve as guide. All members of the SWMP team have to be trained in accordance with the goals of the project. 3.1. SWMP Process The first stage in developing SWMP is the identification of people needed for the conception and implantation of the plan. As stated above, the Project Manager acts as the lead and other members will be provided with specific tasks. The second part involves identification of the different waste including quantity estimates. These include all forms from the start until the end of the construction project. The third step allows exploration of waste management options suitable for each form of waste. The process involves creating recycling and reusing strategies. The next process involves identification of waste management sites including the contractors for wastes. The Project Manager has to clearly show that the government knows that proper waste management plans were drafted. The Project Manager then proceeds with training the staff involved in the SWMP. Both internal and external employees will be oriented with the plan as well as provided with defined roles and responsibilities. The succeeding step requires drafting a plan focused on using efficient materials and proper waste handling. The plan has to clearly specify the nature of the project including the resources needed. The process will facilitate the assessment of waste prone materials and further improve the overall SWMP. Progress reports and milestone documentation are important to determine the success of the SWMP. The waste quantified and identified during the development phase of the SWMP has to be compared with current wastes observed. Figures retrieved have to be recorded in a database for analysis and projections. The project manager should require timely reports from the contractor regarding waste management. Flexible SWMP is also necessary to allow changes during the implementation phase. The plan provides margin for error but instant action is needed when flaws are observed. Finally, the Project Manager has to draw a list of experiences that will further improve the SWMP. The list should include best practices and lessons that need to be learned. 3.2. Waste Determination Excess or waste materials are derived from resources brought in to the site or materials generated during the course of the construction project. Most of the wastes are usually generated as a result of the demolition and excavation to be undertaken. Waste management should encompass reduction, segregation, and disposal. The Project Manager also needs to account the financial effect of the plan including recording, monitoring and reviewing of waste management practices. The plan should specifically underline the benefits of the plan and the successful actions that have to be sustained. Waste management usually consists of three different categories: reuse, recycle, and landfill. Materials that could still be used have to be tagged properly and stored in a different place. All materials that could not be reused goes to an evaluation process. Materials could still be recycled or could be sold to recycling industries. The project could save a significant amount of resources by exchanging scraps for new materials. Finally, the final process involves the disposal of materials that could neither be reused nor recycled. Coordination with the local garbage collection programme is important. 3.3. Site Waste Management Plan Based on the Waste Classification (Appendix), each of the waste matters shall be subject to the indicated methods: The categorizations are Waste Type, Waste Category, Waste Origin, and Waste Management where Concrete, an inert product will be demolished, reused or recycled, and so on. Other materials identified include Brick, Timber/Wood, Soil , Metals, Asbestos, Packaging, Mixed, Tarmac, and Water. Task 2 Modern Methods of Construction 4.1. Substructure The substructure, also known as under building is the hidden part of the building of which is built off the foundation of the building. The usual form of under building construction uses two skins of dense concrete block work for all external walls. This is built primarily off the foundation concrete to the ground floor or damp proof course level which is also known as DPC. There are several sustainable products that can be used to construct a substructure. The use of aerated concrete blocks, which is made from pulverised ash, will be promoted. Also, the damp proof membrane will consist of a blown film of extruded low-density polyethylene. The film is produced from 100% used waste, is black in colour and available in 250mu, 300mu and 500mu. Special foundation blocks are available which cancel out the need for a cavity to go up to ground level but in most instances the two skins of block work are constructed with a cavity that reflects the width of the designed superstructure walling. All suspended ground flooring systems requires ventilation. Beam and block concrete systems, allow the over site to remain as compacted subsoil, and cranked ventilators are used. 4.2. Superstructure The functional needs of the superstructure require it to have the strength to carry the loads imposed to support the roof and ensure stability. The structure should be durable, fire resistant and distant as reasonable considering its proximity to other buildings and if possible affordable and sustainably recyclable. The building of the superstructure is based on imposed British Standards for loading. The building has to maintain overall stability even during fire. A wall is created to resist the spread of fire among rooms. Frame structures and load bearing walls should be used to meet the functional requirements of the superstructure. The functional requirements of the external envelope are the following: thermal and sound insulation, adequate natural light, security and privacy, durability, reduce water absorption; built from sustainable materials, structurally stable, avoid vapour movement, ensure ventilation, and affordability. 4.3. Partition Walls A partition wall is an internal wall used for subdividing a storey of a building into sections and which supports no load other than wall fixtures. For this project, hollow concrete block, hollow glass block, autoclaved aerated concrete block or any related materials will be primarily used. Most of these materials are made of recycled wastes and are considered as stable and durable. In terms of structural performance, the walls have to provide fire protection, create thermal insulation, improve moisture resistance, and maintain sound insulation. The structural performance of the walls should include load burdened by partitions and adjacent structures, structural support, wind loads and air pressure, crowd pressure and fittings. The walls have to be finished with high quality materials and further improved by adding wall accessories. The building of the walls will also consider lighting, storage, accuracy of the finished partition, protection during construction and fixtures. 4.4. Use of Daylight Most modern buildings have been using the light coming from the sun to reduce the use of electricity. Buildings that have such features could save up to 50% of electricity consumption from the use of lighting. The use of daylight reduces greenhouse gases and slows fossil fuel depletion. Several studies have shown that daylight boost test scores in classrooms lit by daylight as compared with artificial lighting. The design should avoid glare and overheating when placing windows. Natural light has to be controlled and distributed properly throughout the rooms. 5. Low & Zero Carbon Low and zero carbon (LZC) energy sources are commonly installed in buildings. The goal to develop LZC energy sources is driving the rapid development of many technologies. 5.1. Absorption Cooling Absorption cooling is an innovation that uses heat instead of electricity to produce a cooling effect. The technology is applicable mainly to commercial and industrial buildings. Most units are produced small, gas-fired air-conditioning units. Absorption cooling is not likely to replace conventional refrigeration systems, but in economic and environmental benefits is clearly observed. Some favourable factors which reduce running costs and carbon emissions include the existence of a CHP plant that operates below maximum capacity, available waste heat, or a low-cost source of fuel. 5.2. Biomass Biomass is another source of solid fuel different to the conventional fossil fuels and provides a close to neutral effect to carbon emissions. The fuel is converted into a manageable form that can be directly fed to the heat or power generation plant, thus replacing fossil fuel. In effect, applications can range from large-scale heating boilers to individual house room heaters to combined heat and power generation (CHP). For building applications, the fuel usually takes the form of wood chips, logs and pellets. Wood pellets are essentially compacted high-density wood with low moisture content, thus having a higher calorific value per unit volume or weight. 5.3. CHP Combined heat and power (CHP) systems are now becoming accessible for individual houses, group residential units and school buildings. CHP at the large commercial size is now widespread in premises which have a concurrent demand for heating and electricity for long periods. Compared with using centrally produced electricity distributed through the grid, CHP can offer a more efficient and economic way of supplying energy demand, if installed and operated properly. This includes owing to the use of heat which is rejected to the atmosphere from central producing stations, and by reducing network distribution losses. 5.4. Ground Cooling Heat transfer from the ground results in cooler air in the summer. The technique is suitable for new mechanically ventilated buildings with appropriate ground conditions. The main benefits are reduced peak demand for cooling, which helps to reduce the size and cost of the HVAC system. Favourable factors include ground temperatures of less than 12?C and softer ground medium. Pipes are typically placed at 5m depth and sufficient land area should be available for the output requirements. The recommended distance between pipes is 1m. 5.5. Photovoltaic Photovoltaic modules convert sunlight directly into DC electricity and can be integrated into buildings. Photovoltaic (PV) is distinct from other renewable energy technologies since they have no moving parts to be maintained and are silent. Modules can be mounted using frames or they can be fully incorporated into the actual building fabric; for example, PV roof tiles are now available which can be fitted in place of standard tiles. PV system will cost between GBP 4.5 thousand and GBP 10 thousand per kWp, and frequently part of this cost can be offset owing to the displacement of a conventional cladding material. 5.6. Solar Hot Water Solar thermal and, especially, active Solar Domestic Hot Water (SDHW) heating is a well-established renewable energy system in many countries outside the UK. It can be one of the most cost-effective renewable energy systems available. It is appropriate for both residential and non-residential applications. For a single typical house, for instance, a suitable water heating system would occupy 2.5–4m2 of roof space. The cost would be GBP 1,500–GBP 5,000 for a flat plate system that will provide around 50% of the typical hot water demand and up to GBP ?5,000 for an evacuated tube system that will provide around 60%. Solar hot water can be applied cost-effectively in a number of non-domestic building types, such as hospitals, nursing homes and leisure facilities, which have high demands for domestic hot water. SDHW systems are not so cost-effective in commercial buildings, where the demand for hot water is lower. 6. Compliance Certificate To achieve an outstanding compliance certificate, the project has to achieve a high score in all the criteria set by the UK government. The certificate is critical to ensure that the project is carried through in a desirable process and statutory laws were followed. There are several strategies that could be deployed to obtain a commendable compliance certificate. The focus of the project is to ensure that sustainable construction is maintained. The first stage involves drawing a comprehensive plan that includes the manner in which the project will be built. The plan has to include the resources that will be used as well as the manner in which the project will handle waste from the construction. The plan also needs to detail the people who will be involved in managing the project and establishing an oversight to monitor the contractor. Conclusion The use of government recommended materials such as recycled construction products is a must. Aside from the use of such materials, the project has to prioritise technology that run on alternative energy. Solar, wind and geothermal are some of the emerging energy sources that could be tapped. Most important, the health and safety of the employees as well as the household within the project is paramount. The project has to prevent accidents and ultimately avoid any casualties during the implementation of the project. Appendices A: Sustainable Construction Diagram B: Action Plan Cycle C: Waste Classification Waste Type Waste Category Waste Origin Waste Management Concrete Inert Demolition Reuse/recycle Brick Inert Demolition Reuse Timber/Wood Bio Demolition/Import Reuse/recycle Soil Inert/Hazard Demolition/Excavation Disposal Metals Bio Demolition/Import Reuse/recycle Asbestos Hazard Demolition Disposal Packaging Processed Construction Recycle Mixed Processed Construction Recycle Tarmac Inert Demolition Reuse/recycle Water Bio Construction Disposal References Ander, G.D. (2011), Whole Building Design Guide, “Daylighting” Retrieved, 2 November 2011 from: www.wbdg.org/resources/daylighting.php Bleakman, J., Morgan Lovell. “How to achieve a high BREEAM rating for your office,” Retrieved, 2 November 2011 from: http://www.morganlovell.co.uk BRE, “First Design-Stage BREEAM Outstanding,” Retrieved, 2 November 2011 from: http://www.bre.co.uk The Building Regulations 2000, “Structure,” Office of the Deputy Prime Minister Retrieved, 2 November 2011 from: http://www.planningportal.gov.uk The Key, “Statutory policies and documents: complete list,” Retrieved, 2 November 2011 from: http://www.usethekey.org.uk The Landfill Site, “SWMP in 9 Easy Steps,” Retrieved, 2 November 2011 from: http://www.landfill-site.com “The Site Waste Management Plans Regulations 2008” Retrieved, 2 November 2011 from: http://www.legislation.gov.uk/uksi/2008/314/contents/made Wolseley, “Stage Five: Substructure” Retrieved, 2 November 2011 from: http://www.wolseleyselfbuild.co.uk/substructure Read More