# By: Shirley HO Aedas Ltd.: Head of Specification CSI: Professional Member HKIS: Quantity Surveyor Date: 27 August 2009 What a QS sees in Technical Specification?

## Presentation on theme: "By: Shirley HO Aedas Ltd.: Head of Specification CSI: Professional Member HKIS: Quantity Surveyor Date: 27 August 2009 What a QS sees in Technical Specification?"— Presentation transcript:

By: Shirley HO Aedas Ltd.: Head of Specification CSI: Professional Member HKIS: Quantity Surveyor Date: 27 August 2009 What a QS sees in Technical Specification?

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

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.

Present written information that drawings cannot effectively convey Specifications – Function

DRAWING: (Graphical) Design Location Dimension Quantity Work Requirements – How to Describe? What is this tile made of? This drawing may look perfect, but does it tell the full story? If I cannot manufacture this tile in the exact dimension as it is shown, by how much I can deviate? Which color is this tile in?

Work Requirements – How to Describe? Concrete tile, XXXXX XXXXX XXX Perhaps I can add a lot of notes in this drawing to tell the full story? Tolerance: XXX XXXX XXXXX XXXX XXX XXX XXX XXX XXX XXX Color: XXXX

SPECIFICATION: (Written) Materials Equipment Systems Standards Workmanship Work Requirements – How to Describe?

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

It depends on how much the architect wants the contractor to design. Specifications – Prescriptive / Performance

100 kN Grade XXX 25mm thick Say what it is Performance Specification or Say what it does Prescriptive Specification

Prescriptive: E.g., proprietary product which has aesthetic requirement building structure Specification Types – Design Extent Variance

Performance: E.g., waterproofing other concealed elements Specification Types – Design Extent Variance

Similar to: Prescriptive Specification More appropriate to show with Drawings Performance Specification Specifications – Prescriptive / Performance 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.

Consider typical design process: e.g., drywall assembly Specifications – Prescriptive / Performance RestrictionsSpace available; Regulation compliance ObjectivesPerformance (fire resistant, moisture resistant, acoustic requirement, etc); Aesthetic requirement Design intentIndicative solutions (overall profile, proposed material, etc) Design check Suitability & availability of proposed material; Compatibility check Detailed design Fixing details; Interfacing treatment; etc Performance Specification

Consider typical design process: e.g., drywall assembly Specifications – Prescriptive / Performance RestrictionsSpace available; Regulation compliance ObjectivesPerformance (fire resistant, moisture resistant, acoustic requirement, etc); Aesthetic requirement Design intentIndicative solutions (overall profile, proposed material, etc) Design check Suitability & availability of proposed material; Compatibility check Detailed design Fixing details; Interfacing treatment; etc Prescriptive Specification

Specifications – Prescriptive / Performance 100 kN 25mm thick Prescriptive Specification: Say what it is Performance Specification: Say what it does Descriptive Specification Grade XXX

Consider typical design process: e.g., drywall assembly Specifications – Prescriptive / Performance RestrictionsSpace available; Regulation compliance ObjectivesPerformance (fire resistant, moisture resistant, acoustic requirement, etc); Aesthetic requirement Design intentIndicative solutions (overall profile, proposed material, etc) Design check Suitability & availability of proposed material; Compatibility check Detailed design Fixing details; Interfacing treatment; etc Descriptive Specification

Descriptive: E.g., Window Operable wall Specifications – Prescriptive / Performance

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

Who should prepare specification? Specifications

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.

Maybe you have confused these 2 kinds of specifications? Preliminaries Specification –It covers general requirement. E.g., size and facilities of site office scaffolding water & electricity supply as-built drawings Specifications – Who Technical Specification –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

Systematically categorize information Specifications – How

NBS MasterFormat and MasterSpec Specifications – Systematic categorization

Which type of specification? Specifications

Sometimes it is better to share commonly used information … Specifications – Which

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-specific 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

Office-wide specification contains more Material Codes than as called out by drawings of specific project Spec Coverage – Office-Wide or Not 11:EQ71 05:AL2 09:CR92 08:CW11 05:DM93 10:GR12 08:DH40 04:ST25 06:PL41 07:FG22 10:OP13 04:MS1 07:JT58 06:ML15 For Specific Project Project-wide part of 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

Sometimes it is better to share commonly used information … Specifications – Which

Specifications – Standalone or Particular 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 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

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 Particular Spec General Specification

Specification Types – Standalone or Particular 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

Critically analyze relevance of product information Specifications – How

Specifications – Example quality without specific standard reference standard reference for unknown quality Brand A

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

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

aluminium foil barrier Brand C XXX

Common Terminology Specifications

You have specified the size of tile, so this tile is required to be 200.00mm by 200.00mm. 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 200.00mm. Specifications – Tolerance 200mm

If you insist on the specified size, your specification becomes so unrealistic that nobody can possibly meet it. Specifications – Tolerance 200mm

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: Specifications – Tolerance Specified: 200mm Permitted deviation: +/- 0.03mm 200mm + 0.03mm = 200.03mm 200mm - 0.03mm = 199.97mm

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: Specifications – Tolerance Measurement StandardTolerance (example) Position on plan± 10 mm Length± 15 mm Height± 10 mm Level of bed joints (in any 5m)± 10 mm Straightness (in any 5m)± 5 mm Verticality (in any 3m)± 10 mm Verticality (in any 7m)± 14 mm Overall thickness± 10 mm

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 Specifications – Mockup, etc softwood post & frame plywood wall plywood box chalk mark plywood box

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 – Mockup, etc

Standards & Test Values Specifications

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 A36 –ASTM C509

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 “Breaking load (transverse direction): Minimum 300N when tested according to BS 1230-1.” Refer BS & say no further  minimum breaking load (260N) for 15mm thick board

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

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 – Common Problems

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

Could we name proprietary products in specification? Specifications

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 and 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 5,000,000 SDR (Special Drawing Rights) –Hong Kong @ 2006 and 2007: HKD57.636 million

Specification – Naming of Proprietary Products

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 !!! Besides WTO GPA, are there any other restrictions ?

Any Questions? 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

Download ppt "By: Shirley HO Aedas Ltd.: Head of Specification CSI: Professional Member HKIS: Quantity Surveyor Date: 27 August 2009 What a QS sees in Technical Specification?"

Similar presentations