NZ Faade Design Current NZ Paradigm (Synopsis and Critique) Building - PowerPoint PPT Presentation

NZ Façade Design Current NZ Paradigm (Synopsis and Critique) Building Enclosure Council Forum – June 2017

Introduction

Karl Jones BAS, BE(hons), CPEng, MIPENZ 05/07/2017 Mott MacDonald | Presentation 3

Project Examples 6

Agenda 1. Current Paradigm (Design/Compliance) 2. Façade Consultant Role 3. Assessing/Minimising Risk 4. Conclusion Mott MacDonald | Presentation Claddings Intitute 7

Current Paradigm

Building Act Lawct Building Code Alternative Compliance Solutions Documents Other Standards Acceptable Solutions Other Testing Verification Methods Opinion Codemark Certification?? 05/07/2017 Mott MacDonald | NZIA Technical Series 9

Functional Requirements Objectives Performance 05/07/2017 Mott MacDonald | NZIA Technical Series 10

E2- AS1 Misappropriation 05/07/2017 Mott MacDonald | NZIA Technical Series 11

E2/ AS1 is not “the Building Code” 05/07/2017 Mott MacDonald | Presentation title 12

Master Builder 05/07/2017 Mott MacDonald | NZIA Technical Series 14

Architect Mason 05/07/2017 Mott MacDonald | NZIA Technical Series 15

Architect Builder Engineer 05/07/2017 Mott MacDonald | NZIA Technical Series 16

Main Architect Contractor Engineer Sub Contractors 05/07/2017 Mott MacDonald | NZIA Technical Series 17

Main Architect Contractor Mechanical Structural Engineer Engineer Sub Contractors 05/07/2017 Mott MacDonald | NZIA Technical Series 18

Project Main Manager Contractor Quantity Surveyor Structural Mechanical Engineer Engineer Acoustic Engineer Façade Architect Engineer Sub Contractors Fire Engineer Landscape Architect 05/07/2017 Mott MacDonald | NZIA Technical Series 19

Façade Consultant Role

WHAT IS A FAÇADE ENGINEER? Mott MacDonald | Presentation Claddings Intitute 27

CONSULT LATIN: CONSULTARE – to deliberate, to question Mott MacDonald | Presentation Claddings Intitute 34

Design Process Sequential – Naïve – Simplistic Design Compliance Procurement Mott MacDonald | Presentation Claddings Intitute 44

Design Process Holistic – Integrated – Pragmatic Compliance Design Procurement Mott MacDonald | Presentation Claddings Intitute 45

Minimising Risk

NZ Building Code Compliance 48

A Risk Awareness Tool for Multi-Storey Buildings?? Limitations? Simple Informative Critical 10/ 15 /20/25 Parameters? Non Technical Not Compliance 49 Storeys

Wind Pressures Ultimate Limit State (Corner Pressures) 3s Gust 1/500 return • >2.5kPa • 1.5-2.5kPa • <1.5kPa

Geometric Complexity Complexity in the base design Non vertical • • Many recesses Varying floor plans • • Complex Plan – most similar Some recesses • Balcony over habitable spaces • Simple Rectangular • <2 recesses •

Types of systems Key Words: Track record, engineered, redundancy, rational, responsibilities • e.g. Site installed rain-screen over fibre cement • e.g. Stick curtainwall • e.g. Fully unitised curtainwall

Types of systems Types of systems – Low Risk Prefabricated Systems • Engineering Responsibilities easily defined and design completed to local standards • • Building movements accommodated by mechanisms that are comprehended by simple rational analysis • No exposed sealants, no flashing tapes or foam tapes, limited use of site applied sealant Overall responsibility for design, fabrication and installation by a • contractor/subcontractor experienced with system More than 10 years in service history •

Types of systems Types of systems – Medium Risk • Some on site, some off site fibrication Engineering requires coordination by multiple parties • • Design or certification to less familiar standards not cited in AS/NZS Building movements accommodated by mechanisms that are comprehended by • more complicated rational analysis • Some exposed sealants in protected locations, no flashing tapes or foam tapes, site applied sealant to very stable substrates • Overall responsibility for design, fabrication and installation by no more than 2 contractor/subcontractors experienced with system 5-10 years in service history •

Types of systems Types of systems – High Risk Systems with mainly site fabrication • • Design and/or testing to less unfamiliar standards (not codified methods) Building movements accommodated by mechanisms that are comprehended by • complicated rational analysis, or unable to be rationally assessed • Exposed sealants in protected locations, flashing tapes or foam tapes Overall responsibility for design, fabrication and installation by more than 2 • contractor/subcontractors experienced with system Less than 5 years in service history •

Number of Systems More systems = more interfaces Multiple Subcontractors (Coordination) • >5 • 3-4 • 1-2

9 Six Risk Parameters 7 systems subcontractors

2 Six Risk Parameters 3 subcontractors 6 systems

Subcontractor Experience Time & Relevance • No experience on similar building Limited company experience • • Some staff have personal relevant experience >10 years • Successfully delivered many similar •

Building Movements Seismic/Earthquake & Vertical Serviceability • Seismic Drift 15-40mm • Vertical Differential 15-35mm • Seismic Drift 6-14mm • Vertical Differential 10-14mm • Seismic Drift <6mm • Vertical Differential <10mm

Performance Testing AS/NZS4284 (Sirowet) Often non project specific (Historical) Include Seismic • No testing • Systems tested but not together Project specific interfaces untested • All systems tested 1 Specimen •

Six Risk Parameters Performance Façade Wind Pressure Testing Complexity Building Number of Movements Systems Facade System Experience Type

Conclusion

05/07/2017 Mott MacDonald | Presentation 68

Thank you