Facilities Check List
Practical, step-by-step guides for the busy FM
November 1998
Specifications
Besides on-site supervision, what is your bestassurance of quality when it comes to a construction job?
A good set of specs.
Check out the general guidelines below for a few basicpointers about what makes a specification worth having.
Specs set forthdetailed and exact statements about the materials, components, andstandards of workmanship for everything to be manufactured, built, orinstalled. They include definitive detail on every component and materialto be used during the construction process.
In most smaller interiorprojects, specs are incorporated into drawing sheets as notes. In largerprojects, especially those which address base building work (constructingthe entire building, including footings, foundations, basic structuralsystem, and the exterior envelope to walls, windows, and roof), specs areissued in a book that is part of the construction document package. Thespecifications address quality control parameters regarding the applicationand installation of materials as well as hardware specs and catalog cutsheets (preprinted technical specs for individual products or items,prepared by their manufacturers).
Specifications give a detailed andexplicit description of the materials and construction procedures to beused on the project. Consider, for example, the spec for a slump test forconcrete: A sample of wet concrete is poured into a short tube; the tube isremoved, and the amount the concrete slumps down from the level of the topof the tube indicates how stiff (how much water it contains — the less thebetter) the concrete is . In addition, the spec describes in techinicaldetail how and when the test is taken, what the results must be, and soon.
Specs also describe building components in detail. For example, ifa drawing label identifies 2 x 10 wood joists, the specification shouldinclude the following:
- Species of wood
- Grade ofwood
- Permissible moisture content
- Tolerable limits of warping,bending, or twisting
- Shear and bending strength requirements in poundsper square inch (kilopascals)
- Acceptable types of connectors andfasteners
- How and where it can be delivered and stored on the jobsite
- How it must be protected on the job site
It is importantto make this detailed specification of building components to ensure thatyou get exactly what you want.
Differences Between Drawing Notesand Specifications: On smallerprojects, detailed notes are oftensubstituted for specs. However, theuse of notes does not mean you canafford to be sloppy or inattentive.If you care about the material used, besure to write out exactly whatyou want. If you do not, any product thatfits that description islegitimate. Unless you have worked with acontractor on many previoussimilar jobs or have a standing agreement orblanket specification, product specification must be clear. A notestating2 x 10 softwood joist 16 in. on center leaves the contractorresponsiblefor choosing exactly what type of wood is used. If it isexposed toview, and the contractor installs structurally soundbutroughly-finished structural grade with tight visible knots andwildgrain, you have no grounds to ask for a better grade of material. Ifyoucare about the particulars, you must spell themout.
Performance vs Proprietary Approaches: In addition to thelevel ofdetail to be provided, a spec writer must decide on one of twogeneralapproaches to writing:
1. Performance specifications, whichdescribe what the end result mustlook like, but not how it is to beachieved
2. Proprietary or prescriptive specifications, which describenot onlythe end result, but how it is to be achieved
Both methods maybe used in one specification, depending on the itemspecified. For example,if a specific plastic laminate is needed tomatch existing product, themanufacturer’s name, product color, andnumber would be spelled out — aprescriptive approach. However,specifying indoor air quality (IAQ) mightbe more appropriatelydescribed in terms of performance — acceptablecontamination levels inparts per million of various pollutants, volume ofair moved, velocityof the air, noise level of air entering the space, andso forth.
There are pros and cons to both approaches. A prescriptivespecificationis more explicit. You are more likely to get exactly what youwant. Thesimplest way to do this is to specify a manufacturer’s companyandproduct name and accept no substitutes. This approach will work aslongas your company’s procurement policies permit this (mostgovernmentagencies do not), until that product becomes unavailable foraprotracted period and the item must be installed soon to avoiddelayingother work. Then a substitution must be made.
Prescriptivespecs can be risky in another way. If, in the IAQ situationdescribedpreviously, you specify the exact duct sizes, bends, curveradii, ductsurface, fan capacity, etc., for a heating, ventilating,andair-conditioning (HVAC) system and the contractor discovers thatyoumade a mistake in your choice of equipment that impairsperformance,then you cannot hold the contractor responsible for meetingthe standardof performance you specified.
Performance specs work wellin the IAQ situation because the contractordecides on the details andassumes responsibility for meeting theperformance levels specified. Thecaveat is to be very careful tospecify exactly what you want. In the aboveexample, for instance, nomention was made of humidity levels. If thehumidity level of thecompleted HVAC system is unacceptably high and theperformance spec didnot specify an acceptable level, the job as deliveredmeets yourspecification. Once the spec is issued, your expectationsaremeaningless unless written down.
This check list is adapted fromBOMI Institute’s Building Design andMaintenancecourse, a requirement in itsSystemsMaintenance Administrator (SMA) designation program.
