Chapter 3: Planning and Low cost Design PDF

College of Engineering and Technology Department of Construction Technology and Management Cost Efficient Construction Chapter 3: Planning and Low cost Design 1  Stages of building construction  Four stages of building...

College of Engineering and Technology Department of Construction Technology and Management Cost Efficient Construction Chapter 3: Planning and Low cost Design 1  Stages of building construction  Four stages of building construction:  Conceptual stages: Normally, the conception of the project starts with the client. This is where the dream begins as well as the research for the right location and the specifications/standards that should be followed.  Preliminary design stages( design, pre-construction, procurement..)  Final design and  Execution/construction stages.  Cost minimization could be achieved through close and serious consideration at all stages. WKU,Cost Efficient Construction, Lecture 2 Notes, 2022, BY:- Simachew B. Stages for Cost Minimization Integrated Planning Planning Stage Detailed Planning Documentation Material Labor Construction Stage Wastage Minimization Building Systems Low electricity Building Use Stage Low water Maintenance WKU,Cost Efficient Construction, Lecture 3 Notes, 2022, BY:- Simachew B.  Cont...  At all stages, coordination among professionals is very crucial. Example:  Architects  Structural Engineers  Sanitary Engineers  Electrical Engineers  Electro-mechanical engineers  Sociologists and Others WKU,Cost Efficient Construction, Lecture 4 Notes, 2022, BY:- Simachew B.  Integrated planning  Cost effectiveness through material quantity modulation could be achieved during preliminary and final design stages. For example: A. Substructure 1. Mat foundation: Upper part of mat foundation can be used as a ground floor element. This could save the cost of ground floor slab construction. 2. Isolated Footing: Volume concrete could be reduced by adopting an optimum shape of a footing. (b and c types need lesser volume of concrete in Fig of next slide) WKU,Cost Efficient Construction, Lecture 5 Notes, 2022, BY:- Simachew B. WKU,Cost Efficient Construction, Lecture 6 Notes, 2022, BY:- Simachew B.  Cont.... 3. Combined Footing:  This kind of footing is adopted when there is a limited space. Due to lack of space we cannot cast individual footing, Therefore footings are combined in one footing.  They are classified into two types based on their shape:  Rectangular combined footing.  Trapezoidal combined footing  Trapezoidal type needs lesser volume of concrete and reinforcement steel if the geometrical conditions and loads allow. WKU,Cost Efficient Construction, Lecture 7 Notes, 2022, BY:- Simachew B.  Cont.... WKU,Cost Efficient Construction, Lecture 8 Notes, 2022, BY:- Simachew B.  Cont.... B. Super structure  Simplicity and Repetition  The use of simple structural elements repeated throughout a project can reduce the overall cost as design and set-out need only be done once.  Number of amenity areas  Kitchens, laundries and bathrooms are more expensive to fit-out than other rooms because of the intensive use of fixtures, fittings, wet area treatment, tilling and joinery items.  Therefore, a good way to reduce cost is to minimize the number of amenity areas. WKU,Cost Efficient Construction, Lecture 9 Notes, 2022, BY:- Simachew B.  Cont....  Amalgamating services  Locating bathrooms, kitchens and laundry’s adjacent or above each other, can reduce the cost of providing services (particularly plumbing)  Accuracy of Documents  The completeness and proper coordination of contract documents, including consultant’s documents, can be an important factor in the cost of construction because it can affect the accuracy of tendering and the likelihood of changes to the design or variations to the building contract. WKU,Cost Efficient Construction, Lecture 10 Notes, 2022, BY:- Simachew B.  Cont.... Geometry and planning Simple geometry with minimal re-entrant angles minimizes external wall length while maximizing area. Similarly simple roof geometry minimizes junctions and materials. Planning to reduce circulation space can maximize the usable area of a home and minimize wasted space.  Economies of Scale  The larger the order, the lower becomes the cost. Generally medium to large construction projects are more economical, per sqm, than smaller ones. WKU,Cost Efficient Construction, Lecture 11 Notes, 2022, BY:- Simachew B.  Detailed planning Adequate time and information should be available to perform detail planning and design Examples:–  Increasing the quality of concrete / steel needs benefit/cost analysis  Reinforcement cuts: in beams and slabs (proper reinforcement cutting schedule) to minimize waste.  In high rise buildings lower story columns have higher load carrying capacity they might not need much increased section (concrete, steel)  Steel truss systems: all members need not be of the same cross section, proper orientation of members. WKU,Cost Efficient Construction, Lecture 12 Notes, 2022, BY:- Simachew B.  Documentation  Therefore, documents prepared during design should be clear enough so that ambiguities are avoided during the actual construction phase.  List of some of the documents produced by the designers:  Drawings including details  Technical Specifications  Bill of quantities  Work schedules  (Contract Documents)  (Guide Lines and manuals)  Models etc. WKU,Cost Efficient Construction, Lecture 13 Notes, 2022, BY:- Simachew B. WKU,Cost Efficient Construction, Lecture 14 Notes, 2022, BY:- Simachew B.