Specifications for a building project are written descriptions, and the drawings are a diagrammatic presentation of the construction work required for that project. The drawings and specifications are complementary.
Specifications are addressed to the prime contractor. Presenting a written description of the project in an orderly and logical manner, they are organized into divisions and sections representing, in the opinion of the specification writer, the trades that will be involved in construction. Proper organization of the specifications facilitates cost estimating and aids in preparation of bids. The architect should coordinate the specification terminology with that shown on the drawings.
Content of Specifications
It is not practical for an architect or engineer to include sufficient notes on the drawings to describe in complete detail all of the products and methods required of a construction project. Detailed descriptions should be incorporated in specifications.
For example, workmanship required should be stated in the specifications.
Contractors study specifications to determine details or materials required, sequence of work, quality of workmanship, and appearance of the end product. From this information, contractors can estimate costs of the various skills and labor required. If workmanship is not determined properly, unrealistic costs will result and quality will suffer. Good specifications expand or clarify drawing notes, define quality of materials and workmanship, establish the scope of the work, and describe the responsibilities of the contractor.
The terms of the contract documents should obligate each contractor to guarantee to the client and the architect or engineer that all labor and materials furnished and the work performed are in accordance with the requirements of the contract documents.
In addition, a guarantee should also provide that if any defects develop from use of inferior materials, equipment, or workmanship during the guarantee period (1 year or more from the date of final completion of the contract or final occupancy of the building by the client, whichever is earlier), the contractor must, as required by the contract, restore all unsatisfactory work to a satisfactory condition or replace it with acceptable materials. Also, the contractor should repair or replace any damage resulting from the inferior work and should restore any work or equipment or contents disturbed in fulfilling the guarantee.
Difficult and time-consuming to prepare, technical specifications supply a written description of the project, lacking only a portrayal of its physical shape and its dimensions. The specifications describe in detail the material, whether concealed or exposed, in the project and fixed equipment needed for the normal functioning of the project. If they are properly prepared, well-organized, comprehensive, and indexed, the applicable requirements for any type of work, kind of material, or piece of equipment in a project can be easily located.
The technical specifications cover the major types of work architectural, civil, structural, mechanical, and electrical. Each of these types is further divided and subdivided in the technical specifications and given a general title that describes work performed by specific building trades or technicians, such as plasterers, tile setters, plumbers, carpenters, masons, and sheet-metal workers, to name a few.
The prime contractor has the responsibility to perform all work, to furnish all materials, and to complete the project within a schedule. The contractor, therefore, has the right to select subcontractors or perform the work with the contractors own forces. In recognition of this, each specification should contain a statement either in the General Conditions or in the Special Conditions, that, regardless of the subdivision of the technical specifications, the contractor shall be responsible for allocation of the work to avoid delays due to conflict with local customs, rules, and union jurisdictional regulations and decisions.
Standard forms for technical specifications can be obtained from the Construction Specifications Institute (CSI). The CSI publishes a Master List of Section Titles and Numbers, which is the generally accepted industry standard. In it, technical specifications are organized into 16 divisions, each with titles that identify a major class of work. Each division contains basic units of work, called sections, related to the work described by the division title. Following is the division format developed by CSI:
1. General Requirements
2. Site Work
6. Woods and Plastics
7. Thermal and Moisture Protection
8. Doors and Windows
13. Special Construction
14. Conveying Systems
Language should be clear and concise. Good specifications contain as few words as necessary to describe the materials and the work. The architect or engineer should use the term shall when specifying the contractors duties and responsibilities under the contract and use the term will to specify the clients or architects responsibilities.
Phrases such as as directed by the architect, . . . to the satisfaction of the architect, or . . . approved by the architect should be avoided. The specification
should be comprehensive and adequate in scope to eliminate the necessity of using these phrases. Approved by the architect may be used, however, if it is accompanied by a specification that indicates what the architect would consider in a professional evaluation. The term by others is not clear or definite and, when used, can result in extra costs to the client. The word any should not be used when all is meant.
Types of Specifications
Technical requirements may be specified in different ways, depending on what best meets the clients requirements. One or more of the following types of technical specifications may be used for a building project.
Descriptive Specifications. These describe the components of a product and how they are assembled. The specification writer specifies the physical and chemical properties of the materials, size of each member, size and spacing of fastening devices, exact relationship of moving parts, sequence of assembly, and many other requirements. The contractor has the responsibility of constructing the work in accordance with this description. The architect or engineer assumes total responsibility for the function and performance of the end product. Usually, architects and engineers do not have the resources, laboratory, or technical staff capable of conducting research on the specified materials or products. Therefore, unless the specification writer is very sure the assembled product will function properly, descriptive specifications should not be used.
Reference Specifications. These employ standards of recognized authorities to specify quality. Among these authorities are ASTM, American National Standards Institute, National Institute of Standards and Technology, Underwriters Laboratories, Inc., American Institute of Steel Construction, American Concrete Institute, and American Institute of Timber Construction.
Reputable companies state in their literature that their products conform to specific recognized standards and furnish independent laboratory reports supporting their claims. The buyer is assured that the products conform to minimum requirements and that the buyer will be able to use them consistently and expect the same end result. Reference specifications generally are used in conjunction with one or more of the other types of specifications.
Proprietary Specifications. These specify materials, equipment, and other products by trade name, model number, and manufacturer. This type of specification simplifies the specification writers task, because commercially available products set the standard of quality acceptable to the architect or engineer.
Sometimes proprietary specifications can cause complications because manufacturers reserve the right to change their products without notice, and the product incorporated in the project may not be what the specifier believed would be installed.
Another disadvantage of proprietary specifications is that they may permit use of alternative products that are not equal in every respect. Therefore, the specifier should be familiar with the products and their past performance under similar use and should know whether they have had a history of satisfactory service. The specifier should also take into consideration the reputation of the manufacturers or subcontractors for giving service and their attitude toward repair or replacement of defective or inferior work.
Under a proprietary specification, the architect or engineer is responsible to the client for the performance of the material or product specified and for checking the installation to see that it conforms with the specification. The manufacturer of the product specified by the model number has the responsibility of providing the performance promised in its literature.
In general, the specification writer has the responsibility of maintaining competition between manufacturers and subcontractors to help keep costs in line. Naming only one supplier may result in a high price. Two or more names are normally supplied for each product to enhance competition.
Use of or equal should be avoided. It is not fully satisfactory in controlling quality of materials and equipment, though it saves time in preparing the specification.
Only one or two products need to be investigated and research time needed to review other products is postponed.
Base-Bid Specifications. These establish acceptable materials and equipment by naming one or more (often three) manufacturers and fabricators. The bidder is required to prepare a proposal with prices submitted from these suppliers. Usually, base-bid specifications permit the bidder to submit substitutions or alternatives for the specified products. When this is done, the bidder should state in the proposal the price to be added to, or deducted from, the base bid and include the name, type, manufacturer, and descriptive data for the substitutions. Final selection rests with the client. Base-bid specifications often provide the greatest control of quality of materials and equipment, but there are many pros and cons for the various types of specifications, and there are many variations of them.
For building projects, specification writers normally maintain a library of master documents that are used as a basis for creating project specifications with a computer.
Typically, they employ the industry-standard Construction Specifications In stitute format (Art. 2.17.1). Computers are used to facilitate and speed production of specifications and other technical documents.
Although computer systems can be complex, requiring an experienced person for setup and maintenance, they are cost-effective, saving time and effort. For example, one program used for preparing specifications has a point-and-click graphics user interface with directories and files represented by icons and manipulated by a mouse. Multiple files are viewed and edited on the screen simultaneously, and each file is seen as a full-page display exactly as it will be printed. The graphics and document layout capabilities of the program are suitable for producing technical manuals and for publishing periodicals. Documents displayed on the computer permit the architect to eliminate the editing of drafts on paper or markups. Instead, editing is performed directly on the computer screen, thus reducing the amount of paper filing and printing that would otherwise be required.
am currently doing cert.4 in building & construction . one assessment task is to find out the difference between PC & PS items in a specification. cannot find any info or am just not looking in right place. any help would be much appreciated. cheers