BFT Notes PDF

The Natural Built Environment The natural environment is the surroundings which can be natural, man-made or a combination of both. The built environment is created by man with or without the aid of the natural environment. ◦The components of the built environment: -Environmental policies relatin...

The Natural Built Environment The natural environment is the surroundings which can be natural, man-made or a combination of both. The built environment is created by man with or without the aid of the natural environment. ◦The components of the built environment: -Environmental policies relating to land management 1. Planning requirements 2. Building regulations 3. Land restrictions by vendor or lessor 4. Availability of services 5. Local amenities including transport 6. Subsoil conditions 7. Levels and topography of land 8. Adjoining buildings or land 9. Use of building 10. Daylight and view aspects -Building and infrastructure to satisfy humans’ needs: 1. Natural contours of land 2. Naturals vegetation and trees 3. Size of land and/ or proposed building 4. Shape of land and/ or proposed building 5. Approach and access roads and footpaths 6. Services available 7. Natural waterways, lakes and ponds 8. Restrictions such as rights of way; tree preservation and ancient buildings 9. Climate conditions created by surrounding properties, land or activities 10. Proposed future developments Climate Change -Climate change is a change in the statistical distribution of weather patterns when that change lasts for an extended period of time. -Climate change is caused by factors such as biotic processes, variations in solar rotation received by Earth, plate tectonics and volcanic eruptions. -The 5 components of earth’s climate system include atmosphere, hydrosphere, cryosphere, lithosphere and biosphere. -Natural changes in the climate system result in internal “climate variability”. Example: distribution of species and changes in ocean currents. -Internal forcing mechanisms are natural processes within the climate system itself. Example: the thermohaline circulation. -External forcing mechanisms can be either natural (e.g. changes in solar output) or anthropogenic (e.g. increased emissions of greenhouse gases). The KYOTO Protocol -The KYOTO Protocol is an international treaty, which extends the 1992 United Nation Framework Convention on Climate Change (UNFCCC) that commits State Parties to reduce greenhouse gases emissions, based on the premise that: (a) global warming exists (b) man made C0₂ emissions have caused it -The KYOTO Protocol was adopted in Kyoto, Japan, on the 11th of December, 1997 and entered into force on the 16th of February 2005. There are currently 192 Parties (Canada withdrew effective December 2012) to the Protocol. -Some principle concepts of the KYOTO Protocol are: 1. The main feature of the Protocol is that it established legally binding commitments to reduce emissions of greenhouse gases for Annex I Parties (developed countries). 2. Implementations. In order to meet the objectives of the Protocol, Annex I Parties are required to prepare policies and measures for the reduction of greenhouse gases in their respective countries. 3. Minimizing impacts on developing countries by establishing an adaptation fund for climate change. 4. Accounting, reporting and reviewing in order to ensure the integrity of the Protocol. 5. Compliance. Establishing a Compliance Committee to enforce compliance with the commitments under the Protocol. Factors Affecting Choice of Site 1. Soil Load Bearing Capacity: the amount of force, pressure, weight, stress that a material, soil, foundation or structure can safely withstand without failure. 2. Cohesive and non-cohesive soils; Site Soil Tests: these tests are designed to elevate the density or shear strength of soils and are very valuable since they do not disturb the soil interacted. 3. Original Topography: whether the land was ever filled. 4. Other Problems: e.g. whether trees were recently removed to accommodate development of structures. 5. Underground lines: e.g. electric, gas or telephone lines. 6. Development: this is the measure of clearing and preparation activities associated with a site. It may also indicate the availability of services to the site. 7. Availability of Utilities: e.g. water, electricity, gas, telephones, internet access. 8. Zoning: zoning ordinances are enacted within a municipality or land — use district to manage growth, regulate land — use patterns, control — building density, direct development to areas with adequate services and amenities, protect environmentally sensitive areas, and conserve open space. 9. Prospect: existing holes from mining one test or soil explosion. 10. Aspect: the direction which a building faces with respect to the points of a compass. 11. Location: many influence the unit cost by providing certain advantages such as prevailing winds, scenic views and general neighbourhood. 12. Size: minimum sizes of building lots are usually specified in order that legal requirements of setbacks and offset distances are satisfied. The building should occupy the maximum percentage of the total land area as specified by authorities for the prescribed zone. 13. Climate: the conditions of the temperature, weather, wind, rainfall, sunshine, first, etc, for a particular region. Influences of Different Cultures on Caribbean Buildings -British 1. Bricks 2. Arches- a structure that spans a space and supports structure and weight above it 3. MDF- medium-density fiberboard 4. Steep Roof 5. Dormers- a structural element of a building that protrudes from the plane of sloping roofs surfaces. 6. Architraves- the lintel or beams that rests on the capitals of the columns -French 1. Louvered windows and doors 2. Veranda 3. Lattice work 4. Ornate mouldings 5. Double door 6. Plaster walls -Indian 1. Court yard 2. Circular roofs 3. Open floor plan 4. Cistern 5. Flat roof -American 1. High rise buildings 2. Dry wall 3. Steel frame building 4. Split- level building with separate roofs for each 5. Panel construction Advantages and Disadvantages of Framed and Solid Building Site Works: Backfill, Excavation, Demolition -A building or construction site can be considered a temporary factory employing necessary resources to successfully fulfil a contract. -Backfill is the replacement of earth and compaction unto an excavation to cover subsoil foundations and services once they have been laid. -Excavation is any work on a construction site involving digging, blasting and removing material from the ground. A pit, a hole or trench dug into the ground on a building site for the location of foundations, drainage services and other subterranean construction. -Demolition is the partial or complete destruction or the removal of unwanted structures such as buildings, hotels, etc. Stripping -Stripping is the removal of topsoil from the construction area. This area is usually stripped to a depth of 150mm, using a bulldozer, stripping helps to produce a sound level platform as well as the removal of vegetation and termites nests. Hoarding Hoarding is a temporary structure that encloses the construction site to provide safety and security to passers-by. This enclosure has other purposes and is developed accordingly. -Purposes of Hoarding 1. Protection of the public 2. General security 3. Protection of materials 4. Ground- to control the movement of workers and avoidance of unwanted situations and interruptions to increase productivity. 5. Reduction of interference and interruptions Responsibilities of a Building Contractor Temporary Services Cross Sectional Area of a Tree Hardwoods & Softwoods Hardwoods (angiosperms) -Most hardwoods are deciduous or broad-leaved trees -They have broad leaves -Hardwood trees grow in cool to tropical climates -They can be deciduous or evergreen -They have 2 distinct cells: 1. Fibrous 2. Vessel or pore cells -They shed their leaves seasonally -They are more expensive to use for timber Softwoods (gymnosperms) -Derived from a group of trees called conifers -Coniferous trees are mainly evergreen -Grow chiefly in the northern cold to temperature zone -Non-flowering and have needle shaped leaves -They have mainly one type of cell, the tracheid -They do not shed their leaves annually Conversion Concrete (CEMENT + WATER) + (SAND + STONES) = CONCRETE Cement/water paste + aggregates = concrete -Cement is a substance that binds aggregates together into a very dense material that possesses great compressive strength. -Mortar is a mixture of sand and cement that is most often used to build brick or block walls. Moisture Content -Moisture content is the measurement of how much water is present in the wood compared to the dry matter of the wood. Moisture content = Wet weight- Dry weight x 100 Dry weight A sample of timber is cut and weighed. This is the wet weight. It is placed in a kiln 100°C and taken out at intervals until no further weight is loss. This is the dry weight. A piece of timber weighs 132.5g Its dry weight is 108.7g Moisture content weighs 23.8g % of moisture 23.8/108.7 x 100= 21.9%