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 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

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 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 !!!) Let’s build an ark to save the selected ones ! God OK, Boss. Noah Even God has to say what He wants, surely you have to say it too.

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 !!!) Architect OK, Boss. Contractor

Specifications –Function Present written information that drawings cannot effectively convey

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

Work Requirements –How to Describe? 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 Concrete tile, XXXXX XXXXX XXX Color: XXXX Of course, if you really want this drawing to look so complicated!

Work Requirements –How to Describe? SPECIFICATION: (Written) • Materials • Equipment • Systems • Standards • Workmanship Wouldn't it be easier to keep these notes in one place?

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

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

Prescriptive: E.g., proprietary product which has aesthetic requirement building structure Specification Types –Design Extent Variance As you must articulate how it looks. As it has been designed with full details.

Performance: E.g., waterproofing other concealed elements Specification Types –Design Extent Variance As you don't care how it looks, so far as it performs.

Similar to: Prescriptive Specification 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 Performance Specification

Consider typical design process: e.g., drywall assembly Specifications – Prescriptive / Performance Prescriptive Specification

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

Consider typical design process: e.g., drywall assembly Specifications – Prescriptive / Performance Descriptive Specification

Descriptive: E.g., Cladding wall system Specifications – Prescriptive / Performance restriction performance: loading, thermal insulation, etc aesthetic requirement As its performance is critical, & you care about how it looks, but you don't want to do the details. design intent

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

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.

Preliminaries Specification It covers general requirement. E.g., size and facilities of site office scaffolding water & electricity supply as-built drawings Specifications –Who Maybe you have confused these 2 kinds of specifications? • Technical Specification • It covers technical requirement. E.g., • material and product • workmanship • compliance with international standards • Sample & mockup Architect's job Quantity Surveyor's job ≠

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.

Specifications –How Systematically categorize information

Specifications –Systematic categorization • NBS • MasterFormat and MasterSpec

Which type of specification? Specifications

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

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 For Specific Project Spec Coverage –Office-Wide or Not Project-wide part of project 10:OP13 06:ML15 08:DH40 09:P24 05:AL2 07:JT58 07:FG22 11:EQ71 09:CR92 06:PL41 08:CW11 04:ST25 04:MS1 05:DM93 10:GR12

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 External Sharing

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 Specifications –Standalone or Particular • 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 7 5 + 2 = 7

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 Specificationcan 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 Brand A quality without specific standard reference 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 product’s restriction advertisement

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 XXX XXX Brand C aluminium foil barrier XXX XXX

Common Terminology Specifications

What a QS sees in Technical Specification?