Chapter 2: Cost Efficient Construction PDF

College of Engineering and Technology Department of Construction Technology and Management Chapter 2: Cost Efficient Construction and Embodied energy of building materials 1 Cost Efficient Construction It is the construction of :-...

College of Engineering and Technology Department of Construction Technology and Management Chapter 2: Cost Efficient Construction and Embodied energy of building materials 1 Cost Efficient Construction It is the construction of :- 1. Cost effective facilities using appropriate technologies; 2. Energy efficient and environmentally friendly structures; Energy efficient: Ø Using simple machines:- Save energy in production üRaw materials: Derived from agro-industrial and natural fibers, requires less energy in production. Environmentally friendly: Utilize of agro-industrial waste Improving waste management and environmental protection Utilize local resources WKU,Cost Efficient Construction, Lecture Note 2 s, 2022, BY:- Simachew B. 3. Facilitate that create employment and skill improvement opportunities (Employ ment generation); Simple machines:- with manual handling, increase employment for unskille d and semi-skilled workers. Small enterprises:- can be set up at decentralized locations Production of components:- involves people after short training 4. Structures that substitute expensive & scarce building materials and its componen ts by low cost locally available materials to suit local design typologies. WKU,Cost Efficient Construction, Lecture Note 3 s, 2022, BY:- Simachew B. 2.2.Concept/Problem Ba ckground WKU,Cost Efficient Construction, Lecture Note 4 s, 2022, BY:- Simachew B.  Conti.. v In 2008 The United Nations estimates that at least one hundred mil lion people in the world have no home. v If those with poor quality housing are included, the number is more than 1.6 billion. v Worldwide housing needs are expected to double over the next 50 years v In Africa alone, they are expected to grow more than threefold WKU,Cost Efficient Construction, Lecture Note 5 s, 2022, BY:- Simachew B.  Cont…  According to the United Nations Statistical Division (UNSD; 2008) groups homeless persons into two broad categories: (A) Primary homeless ( roofless).  This category includes persons living in streets or without a shelter or living quarters; (B) Secondary homeless  This category may include persons with no place of usual residence who mo ve frequently between various types of accommodation (including dwelling s, shelters or other living quarters)  This category also includes persons living in private dwellings but reporting ‘no usual address’ on their census form. WKU,Cost Efficient Construction, Lecture Note 6 s, 2022, BY:- Simachew B.  Root Cause Increase in cost of construction due to: üIncrease in cost of conventional construction materials pri marily steel, cement, bricks, timber and other inputs as well as cost of labour. üAs a result, the cost of construction using conventional building mat erials and construction is beyond the affordability of the low income groups of population as well as a large cross section of the middle - in come groups. WKU, Cost Efficient Construction, Lecture Not 7 es, 2022, BY:- Simachew B.  Conti… Affordable housing is a term used to describe dwelling units whose total housing cost are deemed “Affordable” to a group of people wi thin a specified income range. Low cost does not mean low standards, standards should be fulfilled or well compromised. Standards should be provided for newly founded materials or local materials which are not covered by the building code. WKU,Cost Efficient Construction, Lecture Note 8 s, 2022, BY:- Simachew B.  Conti…  Therefore, there is a need to adopt cost-effective construction met hods Ø By up grading of traditional technologies using locally available resources or applying modern construction materials and techniq ues with efficient inputs leading to economic solutions. Ø or inventing any new practical way that can solve the problem a nd provision of regulations for the new materials WKU,Cost Efficient Construction, Lecture Note 9 s, 2022, BY:- Simachew B.  2.3. Importance/objectives Ø To take advantage in a sustainable and ecologically acceptable way the local resources for the production of alternative construction materials; Ø To promote the production of local construction materials and alternative traditional an d modern constructive systems that are popularized and disseminated within Communit ies, Educational Institutions and in the Professional Training Centers; Ø To contribute to the creation of regulations of alternative constructive systems and unifor mity of the method and quality of the local production materials. WKU,Cost Efficient Construction, Lecture Note 10 s, 2022, BY:- Simachew B.  2.4. Embodied Energy q Embodied energy is the energy consumed by all of the processes associated with the production of a building, from the mining and processing of natural resources to manufacturing, transport and product delivery. q Embodied energy is the total energy required to produce any product or serv ice from the raw material extraction stage through the demolition of the infr astructure. q Embodied energy is the ‘upstream’ or ‘front-end’ component of the lifecycle impa ct of a home q Embodied energy of any construction material was calculated as: Embodied energy of material (MJ) = Weight of material in (kg) X value of embodied energy in (MJ/kg) WKU,Cost Efficient Construction, Lecture Note 11 s, 2022, BY:- Simachew B. WKU,Cost Efficient Construction, Lecture Note 12 s, 2022, BY:- Simachew B.  Low cost = Low energy The building material industries as a whole rely to a large extent on high temperature processes and are among the most energy-intensiv e industries. For example:- The cost of energy in the production of cement or clay bricks/tiles accounts for 50 to 70% of the direct cost of manufacturing. The use of energy in the production process has to be optimized so that overall cost of buil ding construction is reduced and the polluting impact of the excessive use of fossil fuel is arrested. According to Van Wyk, construction activities consume 50% of all resources globally, 70 % of all global timber products and 40% of energy. WKU,Cost Efficient Construction, Lecture Note 13 s, 2022, BY:- Simachew B.  Cont..  The consumption of these resources adversely affects the environment through ove r exploitation of both renewable and nonrenewable resources (materials and ener gy).  The creation of low-energy ecological habitats is a key component to sustainable de velopment.  Cost-effective construction technologies can bring down the embodied energy level associated with production of building materials by lowering use of energy-consu ming materials. WKU,Cost Efficient Construction, Lecture Note 14 s, 2022, BY:- Simachew B.  Cont.. Energy consumption stages r g y en e i e d b od E m WKU,Cost Efficient Construction, Lecture Note 15 s, 2022, BY:- Simachew B.  Cont.. Table 1 : energy consumption of some construction materials in MJ/Kg Source: Lawson Buildings, Materials, Energy and the Environnent (1996); * fibre cément16figur e update from earlier version and endorsed by Dr. Lawson  Cont.. Table 2: Cost of energy relative to production cost of selected materials WKU,Cost Efficient Construction, Lecture Note 17 s, 2022, BY:- Simachew B. WKU,Cost Efficient Construction, Lecture Note 18 s, 2022, BY:- Simachew B.