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GBS A90 Performance Specification (RSP) G#511 N#529

By 6 April 2014December 25th, 2016Specifications

GBE > Encyclopaedia > Files > Specification > G#511 N#529,

GBS A90 Performance Specification (RP)

GBS A90 Performance Specification

GBS GreenBuildingSpecification

GBS A90 P SC Performance Specification

About A90

  • This section was developed initially on the British Library Euston project and subsequently developed on most projects carried out by ASWS, NGS, GreenSpec and BrianSpecMan
  • GBS A90 has been created, tested, developed and refined on £2412m worth of projects from £50k to £500m and packages worth between £10k and £12m in General Contracting (GC), Construction Management (CM), Management Contracting (MC), Design & Build (D&B), Design Manage & Construct (DMC), Build Own Operate and Transfer (BOOT), Guaranteed Maximum Price (GMP) procurement methods.
  • It has a role in ERs (Employer’s Requirements) in D&B projects, supporrting any Brief, Outline Specification, or Full Specification to provide some control to the CA (Contract Administrator) over the final outcome.

What is in this specification?

  • GBS A90 describes whole building or individual element performance requirements, and facilitates contractor and specialist subcontractor design responsibilities in contracts with Contractor Design Portion
  • In contracts with no contractor design responsibility the presence of selected GBS A90 clauses can help manage Specification Substitution and ensure Equivalency.

What is ‘green’ about it?

  • GBS A90 address all normal performance issues:
    • design life
    • repairability
    • Lightning protection
    • wind resistance
    • strength
    • fire
    • acoustic
    • thermal insulation
    • Moisture vapour
    • building competency
    • durability
    • buildability
  • many that can be associated with ‘sustainable’ including:
    • equivalency
    • decrement delay
    • Vapour open/closed
    • resource efficiency
    • local procurement,
    • transport impacts
    • Environmental Assessment Methods,
  • and can address any other ‘green’ issue and already includes clauses related to:
    • material choices,
    • demountability,
    • reusability
    • healthy materials
    • Carbon sequestration
    • Moisture mass
    • Low embodied Water Carbon and Energy
  • etc.

How does it differ from the NBS work section?

  • NBS A90 does not exist.
  • NBS Domestic or NBS SpecWriter used to create an A90, a Workmanship only specification section.
  • NBS includes occasional performance clauses throughout NBS work sections
  • NBS A70 prelims for package documents (now withdrawn) brought together a collection of Quality clauses from the NBS Preliminaries A30-A37.

How or where can the specification be used?

  • It can be adapted and used in any procurement method
  • GBS A90 can be used as a front to a package specification or whole building specification and even in Employer’s Requirements in D&B.
  • GBS A90 is often used when the Preliminaries are another party’s responsibility, are often not NBS based and often fail to address quality and cost issues, it attempts to fill some of these gaps within a package specification.

Why should I pay to download this specification?

  • If you want more control than NBS specifications provides consider adding this.
  • Performance Specification writing can be as difficult to create as prescriptive (materials and workmanship) specifications especially since NBS does not address the issue head on.
  • A ready made framework of clauses and procedures to adopt quickly.
  • In conjunction with 4 appendix it provides the CA with the tools to manage and control any performance related work.

Appendix to be used with GBS A90

  • Declaration of Conformity
  • Declaration of Excluded Materials
  • Statement of Manufacturers Review
  • Enquiries about Contract Documents

Additional Appendix to be used with GBS A90

© GBE NGS ASWS BrianSpecMan aka Brian Murphy
2nd January 2013 – 23rd February 2016

GBS A90 Performance Specification

 A90 P SC PerformanceSpec A15BRM160316A90PrinciplesOfElementDesign_Page_1 A90PrinciplesOfElementDesign_Page_3


© GBE NGS ASWS BrianSpecMan aka Brian Murphy
21st April 2013 – 23rd February 2016

GBS A90 Performance Specification
See Also:

GBE Shop

Green Building Specification GBS A90

GBS Appendix Pages

GBE Jargon Buster

GBE Checklist


GBE Jargon Buster

Initials Abbreviations and Acronyms

  • ASWS
  • BOOT
  • CA
  • CM
  • D&B
  • DMC
  • ER
  • GBE
  • GBS
  • GC
  • GMP
  • MC
  • NBS
  • NGS


  • Uniclass
  • J A90
  • CAWS
  • A90
  • (A3u)

Words and Phrases

  • Architectural Specification Writing Services (ASWS)
  • BrianSpecMan
  • Brief
  • Building element
  • Build Own Operate and Transfer (BOOT)
  • Common Arrangement of Work Sections (CAWS)
  • Construction Management (CM)
  • Contract Administrator (CA)
  • Contractor Design Portion
  • Design & Build (D&B)
  • Design Manage & Construct (DMC)
  • Design responsibilities
  • Employer’s Requirements (ER)
  • Equivalency
  • Full Specification
  • General Contracting (GC)
  • Green Building Encyclopaedia (GBE)
  • Green Building Specification (GBS)
  • Guaranteed Maximum Price (GMP)
  • Management Contracting (MC)
  • National Green Specification (NGS)
  • Outline Specification
  • Performance requirements
  • Performance Specification (A90)
  • Procurement method
  • Specialist subcontractor
  • Specification (A3u)
  • Specification Substitution
  • Uniclass

© GBE NGS ASWS BrianSpecMan aka Brian Murphy
21st April 2013 – 25th December 2016

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