Glass Specification Challenges in London

Russell Cole Arup London Glass Processing Days – 28th – 29th June 2017 Glass Specification Challenges in London

Or why can’t my building get high visual quality glazing Contents London’s Building Boom High End Goals and Challenges The Players and Procurement The Supply Chain and their Worries The Way Ahead London Property

Very mature market Highly valuable London properties have been booming

City A.M. November 2014 High value of property Every Square Metre is valuable

City A.M. November 2014 Extremely high prices in the central West e.g. Mayfair, Belgravia, Chelsea, Kensington

City A.M. November 2014

https://data.london.gov.uk/dataset/average-house-prices-borough Mark Lane River Plate House 207 Old Street London Commercial Projects

The Post Building Monument Street Aldgate Tower

W5 Eland House White Collar Factory One Blackfriars 52 Lime Street Guys Hospital High rise Projects Road

Skipton House 100 Bishopsgate London Spire

6-8 Bishopsgate 40 Leadenhall .. With high property prices comes high quality expectations

Your new property should look good, work well and not need much maintenance Desirable Aesthetics

• Clear, • Undistorted views, • Good colour rendition • Crisp and undistorted reflections Physical Implications

Consistent thickness Flatness Controlled and consistent coating Controlled and consistent body tint of glass Physical Issues

Full range of potential issues that create visual effects that are undesirable, that are physical phenomena that arise from glass production and processing Intentions v Real World

How do teams try to achieve these aims in the real world?

The Players and how they are related Specification and Design Intent Behavioural Drivers Design and Planning

The Client Owner / Developer

Project Manager

Design / Consultant Team The Client Design / Consultant Team

The Client Owner / Developer

Engaged on a serves of consultancy Project Manager agreements

Structural Engineer Other Consultants

Building Services Architect Façade Consultant Engineer

Acoustic Consultant Fire Consultant Construction Stage - Traditional

The Client Owner / Developer Construction Contract Comprising of: • Contractual Terms Project Manager • Preliminaries • Bill of Quantity • Contract Drawings Design / • Prescriptive Design • Design Intent Consultant Contractor(s) • Specifications Team A few definitions

Prescriptive v Performance Specification Under prescriptive everything the contractor needs to do is fully described in the contract Performance Specification lets the contractor take over design responsibility but what the façade needs to do is described by the specification

Design Intent – sets the geometry and appearance of that the contractor needs to achieve as they meet the performance requirements

Contractor’s Design Proposals – under either prescriptive or performance the contractor proposes their own design or alternative. Construction Stage - Traditional

The Client Owner / Developer

Project Manager

Contractor(s)

Design / Consultant Team PCSA Pre-Construction Services Agreement

Before the contract is finialised in many London projects contractors are engaged to advise on design and procurement in parallel to the final design stages

Gives flexibility to contractors and clients to refine the eventual design and specification The Contractors

The Client Owner / Developer

Main Contractor

Glazing / Curtain Wall Other Sub- Sub-Contractor Contractors

Glass Processor Other Suppliers

Float Glass Supplier Other Suppliers The Supply Chain

The Client Owner / Developer

Architect

Façade Consultant

Main Contractor

Glazing / Curtain Wall Sub-Contractor

Glass Processor

Float Glass Supplier Specifications Specification

Facades normally procured under a performance specification.

Performance Specification should have three main parts

Performance Criteria – various design and performance parameters, e.g. g-value, light transmission, wind loads, climate etc

Minimum Criteria – materials (and exclusion of others) standards, sizes, grades etc.

Verification Methods – how the contractor has to describe and demonstrate that their design meets the requirements The Specifiers

The Client Owner / Developer

Client Design Team Façade Consultant Architect Services Engineer Safety Appearance g-value / Strength Colour Shading Coef. Weather resistance Light Levels U-value Build-up Reflectivity

Acoustics Consultant Security Consultant Noise Insulation Security Rating Making an Effort

Most every project will develop the appearance of their façade • Visualisations • Selection of materials and geometric forms • Chose glass based on performance and samples • Describe in a specification

Some teams will go further

Need to be positioned externally, and have a room at the rear to assess glass visual quality First Panel Checks and Quality Benchmarks

Panels taken from production and scrutinised

Best when architects and clients are involved, as last chance to make any changes Production Checks Specifications aim to set criteria and methods of reviewing the visual criteria

• Codes have limited coverage, • Criteria in codes do not lead to high visual quality • In response broad criteria are set • Sometimes technical criteria outside of codes are set • Visual quality assessed through samples and mock-ups • Desire by client and architectural teams to have the option of rejecting that which does not meet the visual requirements Specifications aim to set criteria and methods of reviewing the visual criteria

In response to tenders contractors make their proposals

These proposals often seek to modify the specification The Supply Chain

The Client Owner / Developer

Architect

Façade Consultant

Each link in the Main Contractor supply chain have their own drivers, Glazing / Curtain Wall impacting the Sub-Contractor finalised Glass Processor

specification Float Glass Supplier Architect Drivers

Achieving the aesthetic intent, concerned with appearance, views through the glass, colours, textures and reflections

Resolving details to find beauty

Consistency of appearance

Weathering and durability Client Drivers

• They want the building delivered as designed • They are paying – so cost is an issue • Need competition to be maintained • Budget certainty as soon as possible – PCSA useful • Transfer risks to contractors – Design and Build • Compliant with regulations and planning requirements • Demonstrable compliance with standards and property market specification • Low maintenance in service

• Risk reduction • Clear responsibilities • Agreed programme, on time • Eliminate uncertainty • Avoid subjective criteria – no “to acceptance of the Client / Architect” • Maximising the pool of potential suppliers • Push for simple specification • Avoid custom requirements, stick to the codes • Avoid tricky requirements, e.g. warranties against NiS breaks Beware!

Unobtainium Sub Contractor Drivers

Similar to Main Contractor, but with specialist insight

• Essential need to have multiple potential suppliers – maintaining competition • Looking for reliable suppliers • Delivery dates • Production sequence • Problem free performance • Avoid installing something that will be rejected Glass Processor Drivers

• Avoidance of customization • Improve efficiency of production and minimize wastage and potential for rejection of product. • Speed and simplicity of production • Limited responsibility and limit the extent of warranties. • Reliance on standards and industry norms that they are confident that their production can meet. Specifications are therefore challenged

Main Contractors and Sub-contractors collect comments from their supply chain, or Request amendments based on experience The result: • Few criteria beyond standards • Common Denominators • Limited role of visual mock-ups • Cleaning out of subjective criteria • Avoidance of control samples • Limited recourse for unattractive outcome In practise not that bad

Good contractors try to identify best selection of glass

Quality usually maintained

But Reliant on relationship Outcome not guaranteed No recourse Ways Ahead

Two ideas:

Improved Techniques

New Standards Ways Ahead - Improved Techniques

Use technology for measuring physical parameters – e.g. laser measurement of surface flatness

Fine tuning of equipment to get better more consistent results

New techniques will allow new standards based on measurements

Progress with anisotropy is evidence of this approach in application Ways Ahead – New Standards

What motivation is there for the supply chain to lock themselves into more demanding specifications?

How can the glass processors avoid working to an array of ad-hoc criteria developed on each project Ways Ahead – New Standards

Industry needs to agree a standard for high quality visual glass

The standard will need to be based on measureable optical outcomes

Other physical parameters could be specified or set Ways Ahead – New Standards

I have a Dream…

A new standard will make it clear for everyone and avoid the risks and subjectivity that cause trouble in the supply chain.

It would allow processors that can do a better job to have a market for their abilities

A premium could be charged for this

Where do we start? Thank you Russell Cole [email protected]