SPECIFYING CONSTRUCTION MATERIALS AND EMERGING TRENDS OF NEW PRODUCTS by alicejenny

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									SPECIFYING CONSTRUCTION MATERIALS AND
  EMERGING TRENDS OF NEW PRODUCTS


                    Dr. S. M. Masu

 Department of Real Estate and Construction Management
                  University of Nairobi
         P.O. Box 30197-00100, Nairobi, Kenya
                    SPECIFICATIONS
• A written or printed description of the work to be done,
  forming part of the contract and describing qualities of
  material and mode of construction and also giving
  dimensions and other information not shown in the
  design drawings
• Specifications describe the details of the work to be
  executed under the contract, nature and quality of
  materials, processes, and workmanship
• Order and methods to be adopted in the execution of
  the work
• Specifications are a device for organizing the
  information depicted on the drawings
                 USES OF SPECIFICATIONS
• Specifications are written for use by:
   the Estimator who will procure materials and
    equipment
   the project representative who will supervise and
    direct the work
   the owner who should know what he is buying and is
    entitled to receive
   the contractors and sub-contractors who need to
    discern the scope of their contracts
   the manufacturers of building materials and
    equipment who need to know the grade and types
    that are defined
                DRAWINGS AND SPECIFICATIONS
• Drawings generally show the following information:
    Location of materials, equipment and fixtures
    Detail and over-all dimensions
    Inter relation of materials
    Schedules of finishes, windows and doors
    Sizes of equipment
    Quantity of materials to be used and their inter-relationship
• Specifications generally describe:
    Type and quality of materials, equipment and fixtures
    Quality of workmanship
    Methods of fabrication, installation and erection
    Test and code requirements
    Gauges of manufacturers’ equipment
    SOURCES OF BUILDING SPECIFICATIONS
              INFORMATION

•   Previous specifications
•   Drawings
•   Employer's Requirements
•   Site Conditions
•   Standards
•   Codes of Practice
•   Agreement Certificates
•   Trade Catalogues
•   Publications
              FORM OF THE SPECIFICATION


• It should amplify, not repeat, and never contradict
  information given in drawings
• It should explain the purpose and intent of the
  drawings more fully and clearly
• It should be concise, comprehensive, and avoid
  duplication of particulars and inclusion of vague or
  ambiguous details
• It should normally be subdivided into trades or works
  sections split into materials and workmanship
  subsections
           QUALITY OF FINISHED BUILDING
Will depend on:
• The client's budget
• Time frame
• Composition of the design team
• Choice of contractor
• Quality of materials
• Quality of workmanship on site
• Choice of procurement route
• Familiarity by site agents with and access to
  relevant standards and codes of practice in addition
  to drawings and written specifications
           DIFFERENT FORMS OF SPECIFICATIONS
• Prescriptive specification
    Describes a product by its brand name, a proprietary product as
     defined in the manufacturer's technical specification
    Uncompetitive and not providing value for money
    Subject to abuse without performance specifications and
     compulsory competitive tendering
    Widely used in supply-chain management techniques with
     working arrangement s with chosen suppliers
• Proprietary specification (no substitution)
    Products specifications made by designer and contractor given
     precise instructions as to what to use
    Warranties, guarantees, and insurances sought from
     manufacturer to transfer any implied liability from the designer
    Contractor cannot make changes without permission from
     designer
    DIFFERENT FORMS OF SPECIFICATIONS (CONT’D)
• 'or equal approved‘
   Clause common in majority prescriptive specifications
   By adding 'or equal approved', the contractor has some
    latitude in changing specified products as long as they
    are 'equal‘ and approval given by designer that the
    alternatives are fit for intended purpose
• 'or equal‘
   Clause often used in proprietary specification
   Contractors may substitute products without seeking
    approval from designer at his own risk
   Clients do not get what they are paying for: it is the
    contractor who profits
    DIFFERENT FORMS OF SPECIFICATIONS (CONT’D)
• Performance specifications
   A series of product performance characteristics are listed
    (technical brief), which must be met without identifying
    particular products by brand name
   Leaving choice of products to contractors may be open to
    abuse if the products are not certified by the specifiers
• Open and closed performance specifications
   Open (loose) performance specifications are written in a
    manner as to allow great deal of freedom of choice for the
    contractor
   Closed (tight) performance specifications are written in a
    manner as to severely limit the choice of the contractor
    DIFFERENT FORMS OF SPECIFICATIONS (CONT’D)
• Open (silence) specifications
  Particular items not specified because the specifier is
    negligent or has forgotten to specify them
  Most contracts allow for such for situations for very
    minor items with the contractor assuming
    responsibility to choose
  For major items then the specifier would be
    negligent
• Open (qualified silence)
   Use of vague terminology or lazy way of specifying
    amounting to not specifying e.g. 'use an approved
    undercoat'
                 WRITING SPECIFICATIONS
• Aim
   to convey explicitly information that cannot be easily and
    adequately indicated drawings and schedules such as
    quality of the materials and workmanship
• Essentials to specification writing
   Adopt a systematic approach - use industry-standard
    formats
   Use standard language formats as prescribed in various
    Standard Codes of Practice
   Use imperative or indicative mood to reducing repetitious
    and tedious sentence structures
   Use of proper style to ensure clarity, brevity, consistency,
    redundancy, accuracy while avoiding repetition
    TYPICAL BUILDING SPECIFICATION FORMATS

• That describe the general conditions under which
  the work should be carried out and various
  obligations of employer, contractor and designer

• That describe the materials and workmanship
  required in detail
SELECTION CRITERIA FOR BUILDING MATERIALS

•   Function
•   Aesthetics
•   Serviceability and environment
•   Compatibility
•   Construction demands
•   Code requirements
•   Economics
•   Maintenance
                   NEW PRODUCTS
Considerations
• Development of a product or a material to fit a
  particular situation created by specific requirements
• Evaluation of the properties of a newly de-veloped
  material or product to determine if the manufacturer's
  claims match his test results, thus warranting the use
  of his product
• Will there be adequate fully trained tradesmen who
  understand how to handle the new product?
• Are there any special precautions to be observed?
• What is the integrity of the manufacturer?
             COST AND NEW PRODUCTS

• Principal costs
   Initial cost - the acquisition or development cost
   Cost in use - the running or operating cost
   Recovery cost - cost of demolition and materials
     recovery
• Cost of individual products - cost of proprietary
  products is not always known to the specifier
• Availability - check directly with manufacturer
                         CHALLENGES
• Are professionals continuously up to date with:
    current regulations and codes?
    current building practices?
    changes to forms of contract?
    developments in materials and products, both new and
     obsolete?
• Establishment of bodies to develop standard building materials
  and components specifications including research, tests, and
  innovations in collaboration with local and international
  universities/research institutions
• Establishment of building materials and components directory
  indicating manufacturing sources, importers/stockists,
  availability, technical specifications, price indices
• Control the dumping of hazardous and inferior quality building
  materials and components, imported or locally manufactured
Thank you

								
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