Construction Technology: Provisions of the Basic Environmental Envelope and the Effects of Weather on Buildings - Term Paper Example

Feb. 3, 2009 Construction Technology Provisions of the basic environmental envelope The building envelope is a of everything that separates the interior of a building from the external environment of the building. These include the walls, windows, roof and the ground floor. The prime function of the building envelope is to provide shelter from the cold or hot temperature outside of a building, the rain, the wind or excess sun. The envelope also allows beneficial interaction with the external environment in the form of natural daylight, direct solar heating gains and the natural ventilation. The envelope of a building is no doubt has the greatest potential impact on heating or cooling energy consumption and it can also influence lighting and ventilation loads. The building envelope is a key aspect in the design, in terms of the external climatic factor that is driven upon the internal environment. Besavilla(1997) in his book stated that the composition and physical properties of the envelope are determined by external climatic drivers at given locations. Having a temperate maritime location, UK has better opportunity to significantly reduce the energy requirements of any given building. Elements of a passive solar design can be done in the south side of any given building or structure that is super insulated, while the super insulated approach would be a feature of the north side of a passive solar building. Energy efficiency that is improved can be used to help make a case for refurbishment of a building envelope. A very common building envelope element to be upgraded is glazing. Glazing is utmost generally accepted in energy terms because it replaces perfectly serviceable even in thermally inefficient steel frames. However, double glazing normally provides additional non-energy related benefits such as reduced risk of condensation. Moreover, if the glazing of frames needs replacement, you need to consider the over-cost of high performance system in comparison to the base-case option courtesy of the Building Regulations. Considerations must be given to higher performance glazing such as the low emissivity (low -E), inert gas- filled and triple glazing systems. Windows are sources of ventilations or they could also cause heat loss in the interior part of any given building. Thus, certain measures can be done to illuminate these factors. For the purpose of ventilation, windows can be located on the east side or west side of any given building, The manner of location would contribute to the ventilation or it could add to the needed heat inside the building. This is in terms of the solar heat that the building needs to contain or reduce. The roofing of any building needs proper insulation from the solar heat that enters the building thru the roof. Materials for insulations are readily available in the market as per construction material. The cost of the insulation panels would vary, but the function remains the same. The ground floor of any structure of building normally absorbs moist from the soil or earth material underneath. It would be a very practical move if we plan or decide on what materials for the floor would best suit the location of the building. A programme for an effective planned maintenance is very essential to ensure the preservation of the building envelope and the weather proofing of the building. In the establishment of a planned maintenance regime, the first step is to draw a schedule of envelope types, materials and manufacturers/suppliers. Estimated area, installation date, warranty information, contractor's information, records of repair and inspections are a few of the useful additional information in the programme to be followed. Gillesana(1997)Accordingly, regular inspection of the planned maintenance program is very vital. Gutters must be regularly cleared (more often in autumn to prevent blocking of rainwater, hoppers and downspouts which can lead to water spillage onto the envelope fabric. Expansion joints, mastic seals, flashings, conditions of pointing, pest infestation, plant overgrown are a few of the key items to look out for during inspection of the building envelope. Any defect should be noted, and taken action immediately. Exterior walls, whether it be timber or concrete, needs repainting every 5 years or so, possibly more frequent in the areas where there is more exposure to the wind the sun and rain. The speed of construction of any structure, or reduced overall contract costs of any building affects the durability of the building. Serious consideration should be given to off-site construction. There are additional benefits if we consider factory-level quality control and reduced construction waste. Structural insulated construction panel systems, which are becoming popular and widely used these days, incorporate an insulated core within concrete or sustainable timber panels that forms structural walls or roof elements. It is very prudent to say that with timber construction, it provides some thermal mass by blocking the internal walls, to reduce risk of overheating during summer. Shading is another method carried out at the building envelope. Several ways are considered in the accommodation of the envelope. A very typical example is the overhangs and depths of reveals, brise-soleil(either fixed or movable) and solar control glazing films. The most effective form of shading is the external since the solar gains can be screened out before they penetrate the glazing, and movable in order to respond to the different variation in the solar intensity and incidence angles. External movable shading is more prone to mechanical failure requiring greater maintenance. External shading is also more costly since it involves a more considerable impact architechturally on the building. On the other hand, internal shading is less effective as solar gains have already penetrated the glazing, and unless reflected back out directly, it will result in the buildup of heat behind the glazing. Fixed shading can be positioned and sized to cope with extremes but will not be able to adapt to all situations. Be very careful in considering the shading strategies in denying the useful daylight. A combination of external and internal shading , by brise-soleil extended internally into a light shelf, will reduce unwanted glare, and heat gains while helping to transmit useful daylight in the building or structure. In the consideration of solar control glazing or films, be very careful to select the type with the required properties of thermal and daylight transmittance. New construction techniques and products are soon to be in the market all the time. The intention is not to provide a comprehensive account of all available innovative technologies, but rather to focus on a few which may be of interest in the building envelope and the construction business. The effects of weather on buildings Smith(1999)Stated the fact that buildings have been subjected to attacks by weathering. The frost, wind, su and the rain, had greatly affected buildings and other structures. Acid rain adds up the rate of this damage. It is the emission of sulphur dioxide nitrogen dioxide that contributes to the problem of acidification internationally. Acid deposition affects building and structural materials to some degree. Building materials that are easily damaged by acid rain are: limestone, marble, and sandstones, carbon-steel, nickel, zink, copper, paint, some plastics paper, leather and textiles, while granitic-based rocks are resistant to acidity. Stainless steel and aluminum are more resistant metals. Structural damage also occurs in underground pipes, cables and foundations which are submerged in acid water. Bridges and vehicles above ground are also prone to acid rain. Building materials and other pollutants are very complicated in many aspects. The deposition of these pollutants onto surfaces depends largely on atmospheric concentration of pollutants, the climate and microclimate around the surface. The moment the pollutants reach the surface, interaction will occur depending on the amount of exposure, the reaction of the different materials and the amount of moisture that is present. This factor is very important due to the sulphur dioxide that falls as dry deposition is oxidized to sulphuric acid with the moisture on the surface. Internal Building Elements From the center for window and Cladding Technology[4], The wall or panel is an essential building element. Concrete wall or wood or timber wall panels are used for lining for walls usually with no structural performance required. Decorative board panels are used internally are not structural in most cases. An internal grade is appropriate, and should not be exposed to water in normal service. As with the floor system, there is importance to have enough or adequate ventilation in the floor paneling and there must be equilibrium in the moisture content with the installed environment before the fixing in to limit damages caused by shrinkage or swelling in service. Regular maintenance and appropriate protection is essential for the preservation of the desired appearance. The stairs is that structural member of internal building element wherein it carries the load of people ascending , descending, leaning on rails and sometimes, even sitting on the rails. Often times, timber is selected for the use of stairs and balconies as well. Timber stairs for some stairways may be required by some building code to be high density timber for resistance to abrasion, strength and resistance to fire. Basic Structural Principles and Behavior of Common Structural Forms The basic structural principles and behavior of common structural forms such as frames and wall structures utilizes a framework to provide structural support. Typical applications range from private dwellings to hotels and community buildings. These frameworks are strengthened with concrete or other sheet materials which will provide the stiffness in order to withstand lateral loads. The control of vapor and moisture are incorporated, and the outer portion is constructed to add aesthetic value, appeal and durability. The behavior of the structural materials that are used depends extensively to form the internal elements comprising external wall linings, partitions, that separates the different compartment walls and floors, ceiling linings, and ceiling membranes below the roof spaces. The foundation of any building to be built are absolutely critical. Whether you are building a low dwelling place or a high rise building, the foundation is always the most critical part of the construction. All the load details of the building are taken into account. A variety of different methods of foundation buildings are in common use today and the one which you are likely to use depends on time, cost and the ground conditions, was indicated by Waterfield(2006). Nature and Behavior of Different Ground Conditions and their Fundamental effect on Building form Smith(1999) Accordingly, there are different types of ground conditions that affect the construction of buildings. Backfilled land is one type. This is when the surface ground is much softer than the deeper ground. In building constructions, it is very necessary to reach the hard ground soil in the excavation of the land. The foundation of any building must rest within the hard core soil for maximum load strength. Proximity of surrounding trees must also be accounted. Soil types, existing drains and future drains in the area and wind speed all dictates to the ground conditions and effects to the building to be constructed on the area. There is no "made" ground(imported soil) or wide soil strength variation in the proposed area, or weak soil patches because this will likely cause foundation failure. Before any excavation of soil in construction sites take place, soil testing must be performed and subjected or submitted to the local soil testing department of the area. This is very important because this will determine the depth of the foundation of any building to be constructed in that certain location. Inclusion of seismic analysis of the ground is also to be of equal importance. Because concrete reacts to the chemical composition present in the soil, there must be an appropriate approval from the British Standards that the concrete should meet under these conditions. Material Science, the Characteristic and behavior of Common building materials Singer(1988) In his statement said that reinforced concrete in building construction forms corrosion on surfaces of steel frames. This contributes to the reduction of residual bond capacity. Steel, as we know, is also a good building material. One characteristic of steel frame is that it is light. It is also durable and it is best used for large window frames. Although steel forms corrosion when it is installed on concrete, it would still take a long time before corrosion sets in if properly cleaned and maintained. Clay is another construction material that is commonly used. Not only does it add beauty to the structure, it is also a durable and good building material. It is used as roofing tiles, floor tiles and decorative element on building entrances. Bricks is another construction material that are used in foyers entrances and gardens, It beautifies the area and adds color to walls and gardens. Proper maintenance of bricks would last for a lifetime. Gypsum boards are used for partitions and exterior walls. It is almost fireproof, and is considered a light material. It can withstand seismic reaction, and it does not break easily. It is also used for acoustic purposes. It is used for sound proofing and mainly present in music rooms. It absorbs sound easily and that makes music more pleasing to the ear. It also lasts for a lifetime. Timber is another building material that is a favorite among the other building materials. Wood frames for dwelling places are in most use. Timber is used in almost every part of the building. It is used as posts, staircases, rises, balusters ceilings and joists. Floors that are of timber material become eye catchers. Exterior walls and interior walls that are of timber materials are considered of aesthetic value. Timber is also used for window cladding, It makes the windows more pleasing to look at and the price of timber is very reasonable. Decks that are constructed with timber material are also beautiful. It is considered a light material but durable in nature. Proper maintenance of wood frames and structures would make timber last for a long period of time. This is a house made of brick material Concrete structure Steel Frame Clay, as building material Gypsum board used as building material in large warehouses Wood/Timber frame Basic Principles of Building Science in term of heat, light, sound, and moisture In the construction of buildings, basic principles of building science in terms of heat plays an important factor in the structure. The design of the structure would sometimes demand that heat or temperature inside the building is to be considered. This system goes hand in hand with the building envelope. The building envelope would determine the amount of heat retention or the amount of heat that is released out of the building due to temperature changes or climatic conditions outside of the building. Window cladding is one design to be considered. The cold air in prevented from entering the building during winter and thus prevents the heat of the sun during the hot months or summer. The design of lighting system of any structure will be of great help to the occupants. Natural source of light is implemented in the design of the building. The sizes and design of windows are in nature does an important role in the building. It adds light inside the building, and has its aesthetic value. It adds beauty to the building itself. Sound that is produced by people or occupants in a building structure is considered in the design of a building. Materials to be used must be sound absorbers. Acoustical materials such as gypsum board can be used as ceiling material in order to reduce the sound that is produced by the occupants inside the building. As we all know, construction materials absorbs moisture that are either coming from the ground or from the moisture that the air conditioning inside the building emits. Moisture absorbed by the concrete in buildings are usually emitted when the environment becomes warmer. The warm air and the moisture that has accumulated meets and thus the process of heat transfer occurs. Basic Building Environmental Services Provisions The basic building environmental services provision is a focused tool that is aimed for the encouragement of significant improvements in the performance of buildings in the UK. It is to provide recognition in the form of environmental label. Management overall policy and procedural issues and health and well being indoor and external environmental issues are among the categories that are taken into account. Operational energy and CO2 issues, together with the issue of transport related CO2 and location. The water consumption and leakage related matters and environmental implication and material selections. Land use, site ecology, air and water pollution are the basic environmental services provisions. Principles of Sustainability and the Impact of buildings and their users on natural and urban environment The design principle of sustainability is the implementation of new developments based on established principles of sustainable construction. The reduction of energy consumption must have particular attention. The shape of the building can have an effect on energy use. There is a very slim chance of heat escape for compact buildings than with those that have larger external envelope. As far as the energy cost is concerned, the layout in the accommodation within a building is just as important as the ways the buildings are established within the urban environment. The design of buildings must allow on the outset the possible changing needs. This will be of help to avoid the costly alteration and prolong the life of a building. The selection of sustainable materials can be a very complex matter. There are a number of environmental issues to be taken into account. The Building Research establishment has developed a system for environmental profiles that measures the performance of products throughout their life span. Water is an important natural resource. The design of a building can help avoid water wastage. The run-off from the roofs of buildings can be used for flushing toilets or watering the plants or it can even be treated for the use of drinking water. Fundamental Health safety and Welfare Provisions of building in Use The provisions of safe building is an integral part of the responsibility of employers. The employer must provide safe working environment. New building services are to be installed and subsequent modification and maintenance of the services is to be covered by the act on Health and Safety at Work, and a number of statutory regulations. Legislation Applied to the Provisions of buildings The compliance of the legal requirements is to ensure that the work must be controlled effectively, planned, managed and is undertaken by competent personnel. These factors will effective cooperation, coordination and communication between the parties involved. This include the residents/tenants, contractors and site estates management teams. The primary tasks for the provision of safe work environment and safe buildings resides with estate groups who manages the building works. The other staff will carry out such works on the authorization of the respective heads. Appraisal and illustration on appropriate ranges of construction form for the provisions of internal division of spaces within building(and their Access) In the design of any building, specially buildings which are to be multifunctional. The interior design is to be considered. Open space design are mostly considered. There are several reasons given to open space design. An open space design could be converted to any functional space depending on the needs of the occupants. The construction forms for the internal division of spaces are also taking a great role in the open space design. The following image is an example of an open space area. Coventry,(1999) openly discussed that designs solutions for partitions exists in offices and other internal building open spaces. In fact, there are numerous buildings that opt for open office space for the purposes of reusing and rearranging the internal look of a building of structure. Comparing the two images, this is an example of an open office space. The floor plan on the right was the original plan of the open office space. But soon after the office space had been occupied, and the office equipments started to come in, the office staff decided to make the shelves as partitions and thus, the partitions added privacy to each of the staff and each table space became a cubicle. Another image shows that open spaces around structural columns can be converted into computer clusters. As a result, the building space is efficient from the design layout for stacks, study spaces and computer points. The efficient use of open office space is achieved with the use of ergonomically designed chairs and tables and stacks. The provision of internal division of spaces within buildings (and their access) also applies to those occupants of the buildings with disabilities. The open office spaces can be redesigned in such a way that the space would cater to all the people who wants to enter the building premise regardless of whether you are handicapped or not. The construction, would conform to the provisions of building premise with the use of ergonomically designed facilities that would provide comfort and beneficial to all concerned. Analysis of the physical characteristic of materials used to provide the structure and fabric of the building There are several kinds of structural materials used for building fabric. From the different analysis that was done, one common physical characteristics that they are flame resistant. Asbestos is one example of fire resistant material. Another one is high quality coated polyester fabric material. This is a viable construction material which offer excellent long term durability. This is often used for cladding structures. The high quality coated polyester fabric had also been tested for both physical tear and tensile strength and for flame resistance. The results were remarkable. Resistance to weathering is amazing. Another physical characteristic and behavior fabrics used in buildings is that it take a long time before the physical appearance change. Critical Review on the performance of building structures Since we are to give a critical review on the performance of building structures, we must consider the type of construction materials that we had put all together to build the structure. Basically the performance of any building depends on the design factor, buildings designed for residential dwelling must be equipped with facilities that are in a residential dwellings. The materials that are used in the building must conform with the needs of the occupants of that certain building. Building structures that are built for certain purposes are to be designed for that particular purpose. In the design of a structure, there are basic rules to be followed. This is because, when we plan to design a building structure, we consider "facts". We consider the use of the structure. Proper planning increases the performance of a building structure. We consider the location, the amount of light that enters the building, the number of people to occupy the building, the temperature of the location and the kind of people that would go in and out of the building. A building that is well planned and designed performs well. The maintenance of the building to maximize its performance is taken into account. The materials used and the facilities installed also plays a great factor. Building performance ensures the safety and health of the people in and around the building. To obtain maximum efficiency and performance of a building, the design and construction must be fully functional. IN addition, the energy efficiency, and the meeting of the needs of the disabled occupants one commitment of the building. Such increased building performances will also help to work towards compliance of the requirements of the Directive on Energy Performance of Buildings. A structure that is pleasing to the human eye is a building with great efficiency. Therefore, the plan, the design, and the aim to have a high performance building is in the system of the construction learned. As a result of the study, building format could be a possible way to provide a durable structure that would allow some changes in the finishes, and in the secondary building elements and services. Changes in the building design would allow changes in the building us, which at times, causes the over-design in terms of its structural loading and sizing (floor to ceiling dimension). External and internal secondary elements should be designed for reuse. Finishes are also included in the design for reuse and recycling, following possibly the examples of other structures, which leases floor coverings and the recycling of used carpets. The proposed format is limitless in terms of building type, References Besavilla, 1997, Building Plan Technology, ASM Publishing House, Philippines. Gillesania, Diego Inocencio, 2006, Civil Engineering Technology Handbook, DIT Gillesania, Philippines. Coventry, Woolveridge, hiller, 1999, The Reclaimed and Recycled Construction Materials Handbook, CIRIA C 513 Center for Windows and Cladding Technology, Available at http://www.cach.co.UK, [accessed 1, February, 2009] Patrick Waterfield, 2006, Series 3 Module of Fundamental Series, The Continuity Development Program, Available at http://www.opm/articles.co. [accessed 1, February,2009] Robert Angus Smith, 1999, Buildings, Available at http://www.enviropedia.or.UK [accessed on 5, February, 2009] Octopus Interiors, Space Planning, Available at http://www.octopusinteriors.com/ Singer, Ferdinand, 1988, Materials for Construction, A Harper International Edition, Harper & Row, Publishers, Incorporated Read More