What a QS sees in Technical Specification? By: Shirley HO Aedas Ltd. : Head of Specification CSI: Professional Member HKIS: Quantity Surveyor Date: 27 August 2009
Contents • Function of technical specification • Difference between prescriptive specification and performance specification • Knowledge and skills required to prepare technical specification • How to prepare technical specification • Common problems & potential disputes
• Function of technical specification • Difference between prescriptive specification and performance specification • Knowledge and skills required to prepare technical specification • How to prepare technical specification • Common problems & potential disputes
Specifications – Function Tell the contractor what you want
Specifications – Function Bible Genesis 6: 14 -16: Spec for Noah’s Ark • The vessel was to be made with planks of gopher wood sealed with chemar. • The ark was to be 300 cubits long, 50 wide and 30 deep. • The ark was to have one door, built into its side, and a window. The inside of the ark was to be divided into three floors. • It would house the 8 people, and the animals.
Specifications – Function Let’s build an ark to save the selected ones ! Noah, please build an ark like this: 1. gopher wood sealed with chemar 2. 300 x 50 x 30 cubits deep 3. XXX (i. e. , SPECIFICATIONS !!!) OK, Boss.
Specifications – Function My Client wants to build a house ! Contractor, please build a house like this: 1. Wood enclosure sealed with waterproofing 2. 300 x 50 x 30 m high 3. XXX (i. e. , SPECIFICATIONS !!!) OK, Boss.
Specifications – Function Present written information that drawings cannot effectively convey
Work Requirements – How to Describe? ay s g m doe win ut ra t , b d c ry? is fe sto Th er full k p the loo tell it DRAWING: (Graphical) • Design • Location • Dimension • Quantity What is this tile made of? Which color is this tile in? If I cannot manufacture this tile in the exact dimension as it is shown, by how much I can deviate?
Work Requirements – How to Describe? da ad s an thi ll I c in fu ps tes ha no the er f ell P o ot ? lot ing t ry sto aw dr Concrete tile, XXXXX XXX Tolerance: XXXX XXX XXX XXX Color: XXXX
Work Requirements – How to Describe? SPECIFICATION: (Written) • • • Materials Equipment Systems Standards Workmanship
• Function of technical specification • Difference between prescriptive specification and performance specification • Knowledge and skills required to prepare technical specification • How to prepare technical specification • Common problems & potential disputes
Specifications – Prescriptive / Performance It depends on how much the architect wants the contractor to design.
Specifications – Prescriptive / Performance Say what it does Say what it is Grade XXX 100 k. N or Performance Specification 25 mm thick Prescriptive Specification
Specification Types – Design Extent Variance • Prescriptive: E. g. , • proprietary product which has aesthetic requirement • building structure
Specification Types – Design Extent Variance • Performance: E. g. , • waterproofing • other concealed elements
Specifications – Prescriptive / Performance Bible Genesis 6: 14 -16: Spec for Noah’s Ark Similar to: • The vessel was to be made with planks of gopher wood sealed with chemar. • Prescriptive Specification • The ark was to be 300 cubits long, 50 wide and 30 deep. • The ark was to have one door, built into its side, and a window. The inside of the ark was to be divided into three floors. • It would house the 8 people and the animals. • Prescriptive Specification • More appropriate to show with Drawings • Performance Specification
Specifications – Prescriptive / Performance Consider typical design process: e. g. , drywall assembly Performance Specification Restrictions Space available; Regulation compliance Objectives Performance (fire resistant, moisture resistant, acoustic requirement, etc); Aesthetic requirement Design intent Indicative solutions (overall profile, proposed material, etc) Design check Suitability & availability of proposed material; Compatibility check Detailed design Fixing details; Interfacing treatment; etc
Specifications – Prescriptive / Performance Consider typical design process: e. g. , drywall assembly Restrictions Space available; Regulation compliance Objectives Performance (fire resistant, moisture resistant, acoustic requirement, etc); Aesthetic requirement Design intent Indicative solutions (overall profile, proposed material, etc) Design check Prescriptive Specification Suitability & availability of proposed material; Compatibility check Detailed design Fixing details; Interfacing treatment; etc
Specifications – Prescriptive / Performance n n atio cific Spe tive crip Des 100 k. N Performance Specification: Say what it does Prescriptive Specification: Say what it is 25 mm thick Grade XXX
Specifications – Prescriptive / Performance Consider typical design process: e. g. , drywall assembly Restrictions Space available; Regulation compliance Objectives Performance (fire resistant, moisture resistant, acoustic requirement, etc); Aesthetic requirement Descriptive Specification Design intent Indicative solutions (overall profile, proposed material, etc) Design check Suitability & availability of proposed material; Compatibility check Detailed design Fixing details; Interfacing treatment; etc
Specifications – Prescriptive / Performance • Descriptive: E. g. , Cladding wall system restriction aesthetic requirement design intent performance: loading, thermal insulation, etc
Specifications – Prescriptive / Performance • Descriptive: E. g. , • Window • Operable wall
• Function of technical specification • Difference between prescriptive specification and performance specification • Knowledge and skills required to prepare technical specification • How to prepare technical specification • Common problems & potential disputes
Specifications Who should prepare specification?
Specifications – Who Architect should prepare it because: • It is technical, it requires someone with technical knowledge to write. • It closely links with various parts of drawings which are prepared by architect. It also has to change in the same pace with changing drawings. • It tests the practical feasibility of design done by architect. • It provides an opportunity for architect to put in requirements which cannot be effectively illustrated by drawings.
Specifications – Who Maybe you have confused these 2 kinds of specifications? • Preliminaries • Technical Specification – It covers general requirement. E. g. , • size and facilities of site office • scaffolding • water & electricity supply • as-built drawings – It covers technical requirement. E. g. , • material and product • workmanship • compliance with international standards • Sample & mockup ≠
Specifications – Knowledge & Skills Required QS can prepare it because: • Technical knowledge can be acquired through working experience. • Coordination with drawings is similar to the preparation of BQ / SR. • Practical feasibility test is similar to the process of understanding drawings in preparing BQ / SR. • Writing skill, esp. precision, is a skill possessed by QS who prepares contract conditions, preliminaries specification, etc. • Patience is a skill possessed by QS who prepares BQ / SR.
• Function of technical specification • Difference between prescriptive specification and performance specification • Knowledge and skills required to prepare technical specification • How to prepare technical specification • Common problems & potential disputes
Specifications – How Systematically categorize information
Specifications – Systematic categorization • NBS • Master. Format and Master. Spec
Specifications Which type of specification?
Specifications – Which Sometimes it is better to share commonly used information …
Specification Types – Office-Wide or Not Office-wide Specification • Company-wide standard specification • Each project specification is developed from this base • Specific for each architectural firm
Specification Types – Office-Wide or Not Office-wide Specification Advantages: • Maintain a minimum quality for all project specifications • Shorter time and less effort required for drafting project-specification • Easier for inexperienced specification writer • Allow updating of current code/standard reference • If all project specification writers feed back to the office-wide keeper, previous error can be discovered & improved for whole company.
Specification Types – Office-Wide or Not Office-wide Specification Disadvantages: • Additional resource for maintaining a company standard • On long term, specification writer becomes reliant on company standard, and loses ability to create specification on his own
Spec Coverage – Office-Wide or Not • Project-wide Office-wide specification contains more Material Codes than as called out by drawings of specific project part of project 06: ML 15 08: DH 40 10: OP 13 09: P 24 05: AL 2 07: JT 58 07: FG 22 11: EQ 71 06: PL 41 04: ST 25 09: CR 92 08: CW 11 04: MS 1 05: DM 93 10: GR 12 For Specific Project
Specification Types – Office-Wide or Not Tailor-made Specification for Each Project Advantages: • Meet project specific needs • Flexible in format • Save effort in maintaining a company standard • Learn from mistakes of previous projects
Specification Types – Office-Wide or Not Tailor-made Specification for Each Project Disadvantages: • Take more time & effort to prepare for each project • To save time & effort, one may attempt to copy & modify from previous projects’ specification, but this may inappropriately copy the project-specific requirement in previous projects’ specification
Specifications – Which Sometimes it is better to share commonly used information …
Specifications – Standalone or Particular Specification • Supplement to a General Specification • Modify, amplify and update the contents of the General Specification as necessary to address the project-specific needs • Complicated interpretation: To interpret the technical requirement of a project, one has to refer to multiple documents – Particular and General Specification Standalone Specification • Suffices on its own • Tailor-made for an individual project • Simple interpretation: To interpret the technical requirement of a project, one simply has to refer to one standalone document
Specification Types – Standalone or Particular Spec • General Specification • For a particular jurisdiction, e. g. , in Hong Kong: – Architectural Services Department • For a particular owner , e. g. , in Hong Kong – Hong Kong Airport Authority – Mass Transit Railway Corporation – Hong Kong Housing Authority
Specification Types – Standalone or Particular Specification Advantages: • Expected user is familiar with the General Specification, it saves time & effort to learn the full specification for each project • Difference between 2 projects referring to the same General Specification can be easily spotted • Maintain a minimum quality • Serve as a safety net of supplementing necessary requirement missed in project specification
Specifications – How Critically analyze relevance of product information
Specifications – Example Brand A quality without specific standard reference for unknown quality
Specifications – Example • But we still need the following information about this Sports Floor: – What are the various components does it comprise? – What material is it made of? • If it is flammable, does it have any fire resistance quality? Has such quality been tested to any acceptable standards? – Which kind of finish does it have? – Regarding the mentioned shock absorption, deformation, friction, balls bounce, rolling load; exactly which DIN standard has been used to achieve the test result shown? – About the mentioned BS 7044, what is the test result? – Is there any special installation requirement? – Does it come with a warranty? For how many years?
Specifications – Example Brand B selection factor quality without standard reference advertisement product’s restriction
Specifications – Example • But we still need the following information about this Mortar: – What material is it made of? What is the proportion of various material in it? – Regarding its rapid drying, low tension, high strength; has it been tested to any acceptable standards? What are the test results? – Is there any special application requirement? – Does it come with a warranty? For how many years?
Specifications – Example XXX XXX XXX Brand C m iu r in rie m lu bar a il fo XXX
Specifications Common Terminology
Specifications – Tolerance You have specified the size of tile, 200 mm so this tile is required to be 200. 00 mm by 200. 00 mm. But in real world, it is impossible to fabricate 5000 pieces of this type of tile and each of them measuring exactly 200. 00 x 200. 00 mm.
Specifications – Tolerance If you insist on the specified size, 200 mm your specification becomes so unrealistic that nobody can possibly meet it.
Specifications – Tolerance Hence, you have to relax the size requirement. Yet you cannot allow the contractor to give you whatever size he likes. That’s why you permit some degree of deviation to control the actual size within an acceptable range: Specified: 200 mm Permitted deviation: +/- 0. 03 mm 200 mm 0. 03 mm = 199. 97 mm 200 mm + 0. 03 mm = 200. 03 mm
Specifications – Tolerance Obviously, site erection is inevitably imperfect, e. g. , masonry wall: Typically, its faces will not be perfectly flat & vertical, its position on plan will not be exactly as set out on drawings, its opening will not form a perfect rectangle, …
Specifications – Tolerance To address such imperfection, you may specify the tolerance from various angles: Measurement Standard Tolerance (example) Position on plan ± 10 mm Length ± 15 mm Height ± 10 mm Level of bed joints (in any 5 m) ± 10 mm Straightness (in any 5 m) ± 5 mm Verticality (in any 3 m) ± 10 mm Verticality (in any 7 m) ± 14 mm Overall thickness ± 10 mm
Specifications – Mockup, etc Sample • Verify visual appearance • Reference for controlling consistent standard • Natural work range sample • Painting, etc applied on a simulated substrate • Indicate required size & quantity on specification
Specifications – Mockup, etc Dimensional Mockup • Full-scale three-dimensional model • Not actual materials • On-site or off-site • Confirm dimensional co-ordination • Indicate requirement on drawings softwood post & frame chalk mark plywood box plywood wall
Specifications – Mockup, etc Mockup / Prototype • Full-scale three-dimensional model • Utilise specified materials • On-site or off-site • Destructive test, not re-used as final work • Approval commence similar works at final location • Indicate requirement on drawings
Specifications – Mockup, etc Benchmark • Complete part of similar works on site • Standard for checking quality of remainder of the similar works • Approval commence remainder • Protection • Indicate requirement on drawings
Specifications Standards & Test Values
Specifications – Standards & Test Values Common international standards • British Standards or European Standards – BS (e. g. , BS 952 or BS 476: Part 23) – BS EN (e. g. , BS EN 179) – BS EN ISO (e. g. , BS EN ISO 105) • ASTM – ASTM A 36 – ASTM C 509
Specifications – Standards & Test Values Principle of reference standards • Not stand alone as specification • Testing methods with established: – test procedures – measurement standard – acceptable test values specified
Specifications – Standards & Test Values Principles of reference standards • E. g. , BS 1230 -1 - gypsum plasterboard
Specifications – Standards & Test Values Principles of reference standards Refer BS & say no further minimum breaking load (260 N) for 15 mm thick board • “Breaking load (transverse direction): Minimum 300 N when tested according to BS 1230 -1. ”
• Function of technical specification • Difference between prescriptive specification and performance specification • Knowledge and skills required to prepare technical specification • How to prepare technical specification • Common problems & potential disputes
Specifications – Common Problems • Inconsistency between technical specification and : – Another part of technical specification • Between general & particular specification – Drawings – BQ / SR • Unsaid requirement • Impossible requirement • Bad writing style
Specifications Bad Writing Style
Specifications – Writing Style Unclear • ambiguity – “in a workmanlike manner” unenforceable term; it must always be necessary! – “to the satisfaction of the architect” subjective, subject to abuse – “shall function as intended” contractor has to hire a psychic to read the mind of the architect! – “etc. ” • difficult for normal reader • do not define all abbreviations • inconsistent format font style & size, alignment, spacing, heading style, numbering system, etc.
Specifications – Writing Style Incorrect • • inaccurate technically and grammatically incorrect improper terminology meaningless capitalization
Specifications – Writing Style Incomplete • leave out anything that is important • achieve brevity at the expense of completeness • missing objects – “as allowed” by whom? – “as appropriate” according to what? – “as approved” by whom? – “as directed” by whom? – “as indicated” where? – “as required” according to what or whom? – “as necessary” according to what or whom? maybe appropriate if a definition is specified that establishes the criteria for determining the necessity
Specifications – Writing Style Inconcise • contain unnecessary words • not specific enough – Example 1 - “… metal plate …” – Example 2 - “… steel plate …” – Example 3 - “… galvanized mild steel plate …” – Example 4 - “… Grade 316 galvanized mild steel plate …” • conflicting terminology – “supply and install” • Redundant -> always true unless otherwise stipulated!
Specifications – Writing Style Concise • No verbiage – well-crafted specification = the fewest words that can be used to complete the description and make sense
Specifications Could we name proprietary products in specification?
Specification – Naming of Proprietary Products WTO’s restriction • WTO: World Trade Organization • Agreement on Government Procurement (1994) (GPA) • Principle: non-discrimination amongst products, services and suppliers of a greater or lesser degree of foreign affiliation or ownership • GPA “parties” are required to accord to the products, services and suppliers of any other “party” to WTO GPA treatment “no less favorable” than they give to their domestic products, services and suppliers
Specification – Naming of Proprietary Products WTO’s restriction • GPA “parties”: Canada, European Communities, Hong Kong, Iceland, Israel, Japan, Korea, Liechtenstein, Netherlands (Aruba), Norway, Singapore, Switzerland United States – Hong Kong has committed to adhere to the WTO GPA since 20 May 1997 • procuring entities: relating to central government entities, sub-central government entities and other entities such as utilities • construction services • estimated value not less than 5, 000 SDR (Special Drawing Rights) – Hong Kong @ 2006 and 2007: HKD 57. 636 million
Specification – Naming of Proprietary Products
Specification – Naming of Proprietary Products
Specification – Naming of Proprietary Products Besides WTO GPA, are there any other restrictions ? • Some project clients may have their own established restrictions : – Some may promote non-discrimination in similar way as WTO GPA – Some may promote protection for domestic products, services and suppliers • Always check with your own project client !!!
Specification for QS Future Questions Shirley Ho Aedas Ltd. : Head of Specification CSI: Professional Member HKIS: Quantity Surveyor (852) 2821 -6487 shirley. ho@aedas. com Any Questions?
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