BY: Arc. Ibrahim A. Haruna, FNIA, mni.


Communication has been the vital ingredient of interactions, between individuals, and even nations. Good communication bridges gaps, ensures understanding and yields positive results. Bad or lack of communications on the other hand widens gaps, causes misunderstanding, and may end up yielding negative results. Communication is the back bone of every profession, be it journalism (dissipating information as news), accountant (dissipating information in figures), Law, medicine and indeed architecture. One is either communicating news, or financial figures, or rights and privileges, or disease and cure, or how to construct. They are all ‘trading’ in information, ideas and acquired knowledge.

Without good techniques of communication, none of these professionals can achieve the desired results. Therefore, every professional must be able to instruct, inform or direct appropriately, and convey the exact information to the person being addressed in specific terms.  This often happens even in ones domestic affairs where one gives un-specific instructions, and end up getting unexpected results.

The fundamental symptom of incomplete specifications is excessive questions from the given to the giver of the specifications.   In construction, where the architect receives too many requests for more and more information from a contractor, it means the architects intention is not adequately specified.



In the simplest use of English language, specification means ‘a description of what is required.’   In construction, the meaning is not any different, except that the phrase ‘what is required’ in construction is a pregnant word, referring to what is required in terms of materials; in terms of procedure; in terms of quality; in terms of size and possibly time-frame. Unless the right description is given explaining which material, which quality and a times which procedure, the executor will not be able to carry out the works as expected.


Specifications in construction are prepared in both graphic representation, and in written form.   The graphic representation of specification is the set of drawings of the project produced, with all the information that can be shown on the drawings.   There is however a limit to how much information a drawing can contain, no matter how detailed it is.  Even the exigency of space to put the information is in itself limiting, no matter the scale of the drawing.   Coordinated Project Information (CPI) gave the minimum list of the information a working drawing should have.(see APPENDIX 1)   Unfortunately, many working drawings one sees from architects and engineers do not even cover 50% of the minimum stipulated in the CPI.   Even where more information is given than what the CPI stipulates as minimum, there will still be a lot more information that cannot be inserted in drawing.   These are presented in written form.   The objective of this paper is to focus on written specifications because it is most neglected in practice, not only in Nigeria, but the world over.   Architects and engineers tend to cling more to the graphics, to the detriment of written documentation.






Written specification is very technical in nature and legalistic in its terminology.   It is therefore more likely to become the basis for contractual dispute than drawings.   Unless complete information on materials, products and equipments selected by the designer is given, the quantity surveyor may not be able to prepare quantities to meet the designer’s intentions.   Consequently, the contract may not result in the works anticipated by the client. Yet, written specification usually receives less attention and time than its relative importance seems to dictate.   Perhaps this lack of attention to this important documentation could be responsible for the relatively low fees Nigerian professionals receive.   The clients see the drawings as too few to justify the amount paid, and the professionals accept such meager sums because they produce so little.   It is also a truism that all contract loopholes emanate from lack of attention to details, lack of technical coordination and absence of comprehensive written specifications.   Fortunately, one of the democratic dividends noticeable is the concern the Federal and some State Governments show on abandoned projects, and their resolve to finish them and put the gory memories they created in the closed volumes of history.   The best we can do as professionals is to cover all possible loopholes that can cause a repeat of that history, through preparation of detailed contract documentation, devoid of any ambiguity.




In the introduction, a sketchy mention was made of the purpose of writing specifications. Ideas of the designer are too complex to narrate accurately to the client, and to the contractor who is to execute. Until when telepathy becomes a real science, the designer has no option but to communicate his conceived ideas and intentions on paper, for other professionals to understand and make their input; for the client to understand how his requirements have been met; for the contractor to know what to do; and for facility managers to know how to approach routine maintenance.   The prospecting contractors require full information on what the project entails, to enable them understand its scope and offer prices by way of bidding.   In small projects, where the service of a quantity surveyor is not engaged, it is the drawings and written specifications that are given to the bidding contractors for tendering.   The contractor’s estimator or quantity surveyor prepares the estimates based on these documents.   The bidding contractors rely heavily on the specifications for the full descriptions materials and workmanship.   Hence, the drawings and specifications should clearly indicate all what is needed for inclusion in the tender.   Anything so omitted or whose description is not clear in the written specifications and drawings, is deemed not part of the contract.   The specifications in this case become part of the contract documents, and must therefore have the precision of an agreement.   This further emphasizes the need for specifications to be really specific, crystal-clear and complete in every detail.   It is common practice here, to ask a contractor to quote based on drawings only.   The drawings may not even have the CPI minimum.   The guess elements in such tender are often the sources of contractual disputes and consequent abandonment of projects.


In major contract, there is the need for more accurate basis for tender. Written specifications are therefore given to a quantity surveyor with the drawings to enable him to extract quantities. The quantity surveyor prepares the bill of quantities, which is to be given to each bidder to price and submit as a tender.   The specification here needs not have the precision of an agreement, because it is going to a fellow professional, who may revert to the designer for any issue that is not quite clear to him.   Unfortunately, this is where the designer’s laziness manifests by giving little or in most cases no written specifications to the quantity surveyors.   The quantity surveyors on their part, do not even ask for it, but rather take an existing written specification of another project and use it. Where incomplete specifications are given to the quantity surveyor, he is only being encouraged fills-in-the-blank the missing information. Which means, you as the designer, are relegating design decisions to the quantity surveyor. This is why when one reviews some of the specifications in a contract document; one finds the description of even those materials that are not relevant to the project in question.   The designer may not even review the quantity surveyors documentation before going out on tender.   The result is either an incomplete document is used for tender, or the intentions of the designer are not truly reflected in the documentations. This is the genesis of most of the changes that occur during construction, some of which course escalation of the final contract sum, and in some cases result in contract dispute. It is also partially responsible for high cost of maintenance, because some of the quantity surveyor’s choice may be born out of cost considerations rather than durability.


By all means one cannot blame the quantity surveyor for filling-in-the-blank, or adopting existing written specifications, but rather blame the designer for not giving the quantity surveyor the right in-put, and also giving blind approval to the quantity surveyor’s assumptions.   Decisions on quality of materials and workmanship are solely the responsibility of the designer.   It is the designer that has that vision of his intentions, and trained to make the right decisions on such.   The written specifications in this case do not form part of the contract document, but has to be appended in the contract bill to convey information that will fully describe and accurately represent the quality of the works. This is generally referred to as ‘trade preambles’ or ‘technical specifications’.


During construction, it is not always the case that the designer is the supervisor. In many cases, it is a different person, though of the same professional calling, that handles the supervision.   Without written specifications, the supervisor cannot be able to remember all what is expected on site. Neither can the contractor’s foreman know what to do. Written specifications therefore become necessary to remind both the contractor’s workmen and the supervising team of what is expected in the works. Unless specifications are provided, the designer has to be on the site permanently to tell the contractor what is to be done.


Having established the necessity of written specifications, let us now examine how to prepare this all important, yet neglected document.





The writing of specifications in building should start from the very moment the designer commences putting down his ideas on paper.   This the designer does by issuing specific instructions both in drawn and written forms.   Specification writing therefore commences right from the schematic design stage, where the designer starts by giving preliminary project description in written form.   At the design development stage of the project, the preliminary project description is further refined, to form outline specifications by the designer, so as to give a more clear expression of his intentions. Other specialists involved in the scheme should also prepare outline specification concerning their areas.   Outline specifications are written in sequential order.   The next stage of the project is the construction documentation stage. At this stage, outline specification is fine-tuned through revision and enhancement to form the full specifications. This is sometimes referred to as project manual, for it gives all what it takes to assemble the project physically on ground. This is what forms the basis for bidding.


The outline process of preparing specifications clearly indicates that it is a continuous process of review and updating from one stage to another.   The fact that specifications are arranged in sequential order makes revision of any part of it easy.   Once any section of the drawing is revised, the corresponding part of specification should at the same time be reviewed,   since all achieved stages of any project need to be presented to the client so as to assure him that his expectations are being met.   At such project review meeting, most clients concentrate on initial cost; maintenance cost; useful life trade-offs; areas of potential troubles during execution; favored suppliers and prior instructions given to designer. Clients that have technical staff in their employ, like FCDA, NUC, FMW may usually require a more detailed review of the specifications.   Inputs from such client/designer meeting are included as a revision to the specifications.


Design of complex building, is normally handled by a team of professionals (architect, structural, electrical & mechanical engineers and QS), so is the authorship of its specification.   Therefore when it comes to review, each professional reviews his areas.   For instance in a building project, the architect prepares his drawings and those aspects of written specifications that relates to method of contract delivery; finishes; choice of materials; general quality control; compliance with statutory regulations.   The architect in addition collates and coordinates the in-put of other building specialists with his own in a sequential order.   The structural engineer prepares structural drawings and written specifications on sizes of structural elements; concrete mixes; reinforcement rods types and sizes; material tests and grading. The services engineer on the other hand prepares drawings and written specifications on power loading; choice of fittings and their ratings; routing and sizing of conduits and pipes.


Mostly, specifications are written using an existing written specification as a spring- board. This is done by editing, through deletion of those items that are not relevant; insertion of those items that are new; and review of those items that recur.   The practice of writing specifications differs from one firm to another. Some firms assign specific officer whose duty it is to write specifications of all projects designed by anyone else in the firm. Such a staff could be an architect or engineer often referred to as specification writer.   Critics of such practice feel that the best person to write specifications of a project is the designer himself.   Whichever of the two options one chooses to adopt, it is the responsibility of the designing firm to produce specifications.





In the course of discussing the importance of specification writing, it has become clear that specification is a highly technical document to prepare. The author needs good knowledge of the materials, (thanks for the NIA ARCHI-BUILT program), and good technical vocabulary.   There are ten guidelines for writing specifications:


1. The style of writing is technical in approach. This means it should be devoid of long paragraphs in display of good literature. It should be short phrases with figures and good punctuations to make technical sense. One of the CSI’s (Construction Specifications Institute) tenets of writing specifications demands that “you say it once and clear, concise, complete, and correct.” Even though in general use of English as a language, use of comma before the conjunction ‘and’ is optional, in specification writing, it is not really optional. For instance, let us analyze the difference between these two sentences:

a) “provide water, and electrical installation equipments.” and,

b) “provide water and electrical installation equipments”


2.   Repetition is better than omission in specifications writing. In as much as it is desirable to ‘say it once’, it is better to repeat an item than to omit. Generally, it is accepted that repetition helps to impress.


3.   Only the information that cannot be shown on drawings is included in specification writing. Sketches should not be included in specification writing.


4. Each item in specifications writing, is arranged according to the type of building trade it belongs, for example earthwork, concreting, masonry, carpentry, etc. The introduction of Common Arrangements of Works Sections (CAWS), the sequence of arrangement becomes standardized from earthwork up to finishes in close sequence of execution of building works. Each section or division is further sub-divided into three Parts as thus:

1. Part 1, where general issues concerning the trade, materials

     and their handling are discussed.


  1. 2.Part 2, where type, colour, size and all other qualities of

materials are discussed.


  1. 3.Part 3, where fixing, mixing and all forms of installations

or execution of the job under that section/division are discussed.

This rule of CAWS sequence however applies only to fresh projects. In the case of renovation works, arranging specification in the CAWS sequence will not be most convenient. Rather, specification items are arranged in room-by-room sequence in either clockwise or anti-clockwise order.


5.   Making provisions for prime cost (PC) and provisional sums for specialist works. The amount so budgeted for each these items are then inserted against them in the written specifications.


6.   Making sure that all specified works do comply with building regulations in force in the vicinity of the site. For example, sizes and quality of connecting pipes for water and sewer connections must comply with what the local authority stipulates. It is the designer’s responsibility to find out the actual size, not just to say ‘contractor should provide and connect pipes as may be required by authority.’


7.   In specifications writing, use of standard specifications for material, like the British Standard Specification (BSS) and code of practice (CP) for workmanship is necessary. All materials used in buildings are codified and given a number as a mark of its established quality. Pending when we get what may be called ‘Nigerian Standard Specifications’ (NSS) for building materials, we have to rely on British Standard Specifications (BSS). Like-wise all workmanship must comply with the British Code of Practice (CP). With the awakening to what is now called ‘Green Architecture’, a catalogue of building products are codified into what is called ‘Green Product’. This is for the selection of those designers who wish to go for green products with the view to achieving energy saving sustainability. Recent issues of architectural journals like Architectural Records do dedicate a whole page or two to the descriptions and advertisement of coded green products. Similarly, a whole website has been established for green products.   Specifier should know the exact BSS or CP number of the material or workmanship he is specifying and should quote it, rather than just saying ‘so and so should comply with BSS’.


8.   Those materials to be supplied by the client for use in the contract have to be clearly described in types, quality and quantity in the specifications. Specification writing should also provide for delivery of such materials to site, and into contractor’s store by the client at no cost to the contractor. This is to eliminate complications of transport charges, loading, un-loading and insurance coverage in transit.


9.   Preliminary items of the contract have to be described in the specifications so that bidders or their estimators know the extent of their commitments in those associated areas and therefore append the right prices. Even where description of preliminary item tends to repeat some of the provisions under conditions of contract, it is better to repeat than to omit.


10.   Designers/Specification writers must have to keep up to date with developments of new materials and their methods of fixing. The architect must also keep track of those materials that are no longer in use. This can be done through subscription of Standard Specification Service, or rely on the products sections of architectural journals either on print or electronic.


Finally, specification writing, like any report writing, should have a cover page, which contains the title, name of the project, name of client, location, name of the author and date. It should also have a table of contents.






  1. 1.The Architect in Practice. By David Chappel & Christopher J. Willis – Black Science Ltd.
  2. 2.Architect’s Legal Handbook. By Anthony Speaight & Gregory Stone- Architectural Press.
  3. 3.Writing Specifications for Construction. By Peter Cox – Mc-Graw Hill.
  4. 4.Construction Specification. By William T. Lohmann – Butterworth Architecture
  5. 5.Specification Writing for Architects & Surveyors. By Christopher J. Willis & J. Andrew Willis – Blackwell Science.
  6. 6.Sheldon Wolfe, 1999.WWW.NorthStarCSI.Com


























  1. Overall dimension of piece of land on all sides.
  2. Provide all beacon numbers (if available).
  3. Provide all bearings.
  4. Indicate the direction of North.
  5. Name adjacent roads appropriately.
  6. Provide existing contours, service lines and structures on site.
  7. Indicate whether existing structures are to be demolished, retained or relocated.
  8. Indicate overall dimensions (on all sides) of all buildings located on site.
  9. Indicate set-back on all sides or to adjacent building.
  10. Indicate finished ground floor level of all buildings relative to an agreed datum.
  11. Indicate finished levels of all pavement, driveways etc.
  12. Indicate invert levels of all drains and discharge point of all drains.
  13. Provide finishes of all pavements and driveways etc.
  14. Provide lengths and widths of all pavements, driveways etc.
  15. Indicate size and swing of all gates including pedestrian.
  16. Locate type of landscaping, fountains, sculpture with type, dimensions and number.
  17. Indicate location of entrances on each block of building.
  18. Name blocks of buildings appropriately.


  1. Overall dimension o building on all sides.
  2. Internal dimension of all rooms, corridors, verandas etc.
  3. Internal dimensions of all recesses, wardrobes, cupboards, counters.
  4. Indicate width of all doors, windows and other openings.
  5. Thickness of all walls, partitions, facings etc.
  6. Indicate type of walls, i.e. block wall, brick wall, stone or timber etc.
  7. Indicate function of all rooms including semi-open spaces.
  8. Floor finishes of all spaces including veranda, wardrobe etc.
  9. Floor levels of all places relative to a fixed datum.
  10. Indicate all section lines.
  11. Indicate in broken lines extent of roof overhang, cantilevers etc.
  12. Width of all treads at staircases and all level changes.
  13. Number of all risers at staircases and all level changes.
  14. Indicate direction of flight at all staircases and all level changes.
  15. Indicate swings of all doors.
  16. Number all doors, windows and curtain walling etc.
  17. Locate all sanitary fittings and label them appropriately.
  18. Indicate position o all fixtures and label them appropriately.
  19. Indicate internal painting (finishing) schedule of al internal wall of all rooms.
  20. Indicate areas (if any) where further details are provided in subsequent drawings or by other consultants or manufacturers.
  21. Provide grid lines (both ways).



  1. State type of roof covering.
  2. State finishing to all concrete gutters.
  3. State roof trusses type and centres.
  4. Indicate fall of roofing sheets or screed.
  5. Indicate position of spouts or rain water pipes.
  6. Indicate grid lines.
  7. Indicate section lines.
  8. Indicate position of overhead tanks (if any).


  1. Indicate level of all rooms through which section passes.
  2. Indicate functions of all rooms through which section passes.
  3. Indicate floor finish of all rooms through which section passes.
  4. Indicate wall finish of all rooms through which section passes.
  5. State type of roofing sheets.
  6. State type of ceiling.
  7. State type of roof trusses (if further details are provided by other consultants, state so) and at what centres.
  8. State type of flashing to all walls.
  9. State finishing to concrete roof gutters.
  10. State type of skirting to all walls.
  11. Dimension floor to ceiling.
  12. Dimension floor to lintel of doors and windows.
  13. Dimension floor to cill of windows.
  14. Dimension cill to lintel of windows.
  15. Dimension height of parapets
  16. Dimension risers, steps, half landing etc.
  17. Dimension thickness of slabs, pavement etc.
  18. Dimension height of ground floor above natural ground level.
  19. Dimension of balustrades, shelves, counters, worktops above floor levels.





  1. Indicate levels of all floors, ceiling, parapet and assumed ground level.
  2. Indicate painting (finishing) to all surfaces.
  3. Indicate fixed and open-able parts of all doors and windows.




  1. Indicate size (width & height).
  2. Indicate fixed and open-able parts of doors and windows.
  3. Indicate hinge position.
  4. State type of door or window with type of glass.
  5. State number required.
  6. State location in building.


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