WSP @ The Mailbox, Birmingham A Case Study Presentation by James - PowerPoint PPT Presentation

WSP @ The Mailbox, Birmingham – A Case Study Presentation by James Healey and Adam Walker December 2019

The Office  Layout  Neighbourhoods  Activity Based Working  Meeting Rooms  Open Bistro  The Street  The Town Hall

The Office  Activity Based Working  5.6mH Ceiling  Exposed soffit / services  Low absorption  Desks 2.3m apart, 1.1mH screens between  20 no. meeting rooms

The Office  Activity Based Working  Collaborative booths

The Office  Activity Based Working  Project Desks  The Street  The Bistro

The Office  Activity Based Working  Phone booths

The Office  Activity Based Working  The Street and The Town Hall

The Office  Activity Based Working  The Town Hall

The Office  Activity Based Working  Privacy chairs  High backed sofas  Breakout & Dining area

Guidance BS 8233 & BCO  Historical Standards & Guidance Document Parameter ‘Good’ conditions  Some useful information BS 8233 Unoccupied L Aeq,T (dB) 45 – 50  Outdated BCO External noise NR40 (L eq,T )  Doesn’t reflect ABW principles Building services noise NR40 (L eq,T ) BS 8233: 2014 – room absorption • BCO 2019 – fit-out considerations • BS 8233: 1999 – Privacy Rating • D w + L A > 75 = reasonable • D w + L A > 85 = good •

Guidance BS EN ISO 3382-3: 2012  ISO 3392-3: 2012 Parameter ‘Poor’ conditions ‘Good’ conditions  Some relevant paramters D 2,S (dB) <5 ≥7  Not reflective of ABW  No account for occupancy L pA,S,4 m (dB) >50 ≤48 noise level r D (metres) >10 ≤5 Speech Transmission Index • Unoccupied background noise, L A90,T •

Guidance French Norm NF S 31-199 Activity Ambient Speech level Reverberation Spatial decay  Collaborative Activity noise difference time of speech  45 to 50 L Aeq,T between stations  Low speech level difference Collaborative 45 to 50 L Aeq,T D n < 4 dB 0.6s D 2,s > 9 dB  Low T60 (250Hz to 4kHz)  High spatial decay rate of <0.8s at 250Hz speech Low 40 to 45 L Aeq,T D n ≥ 6 dB 0.6s D 2,s > 7 dB  List of active areas not collaborative (250Hz to comprehensive 4kHz) <0.8s at 250Hz Call centre 48 to 52 L Aeq,T D n ≥ 6 dB 0.6s D 2,s > 7 dB (250Hz to 4kHz) <0.8s at 250Hz

Guidance Liveliness  Vallenga et al  Promotes principles of significance of signal to noise ratio and low STI  Proposes liveliness rating Proposed Method for Measuring 'Liveliness' in Open Plan Offices’. Vellenga*, Bouwhuis and Höngens. M+P | Muller-BBM group  Apex study Use Type Liveliness Rating  More comprehensive list of Breakout 8 ABW uses Meetings 7  Background based on L A90,T Phone (call centre) 6  Some uses in WSP office not Collaborative 6 covered Non-collaborative 5 Focused phone 6 (as a source) / 4 (as a receiver) Focused individual work 3 ISO 3382-3: Necessary but not sufficient. A new approach to acoustic design for activity-based-working offices. J Harvie-Clark & F Larrieu. Apex Acoustics Ltd.

Testing  Activity-Based-Work  Non-collaborative  Collaborative  Focused Collaborative  Focused Pair  Breakout & Dining

Testing  Quantities  STI  D n  Noise ( L eq,5min , L 90,5min , L 05,5min )  D w  T 60  Subject impressions

Testing  Speech Transmission  Non-collaborative to non- collaborative  Collaborative to non- collaborative  Focused collaborative to non-collaborative  Focused Pair to non- collaborative  Breakout & Dining to non- collaborative  Cellular Privacy  Sound Insulation & T 60

Sound Environment 58 / 54 / 51 55 / 52 / 35 48  Open Plan Working  Acoustic conditions at the 57 / 54 / workstation 51 A: 61 / 57 / 53  Relationship between B: 70 / 66 / 58 workstations 54 / 50 / 47 44 Area L Aeq,5m  Reduction in speech between workstations Non-collaborative 55 52 / 48 / 42 61 / 57 / 53 61 / 58 / 55  Cellular Working Collaborative 56  Sound Insulation 57 / 54 / 51 Focused 48 59 / 56 / 53  Privacy Collaborative Focused Pair 50  Comfort 58 / 55 / 51 Breakout & Dining 57 - 66

Sound Insulation / Privacy Rating  Moveable Wall R w 47 dB D w 35 dB PR = 79

Sound Insulation / Privacy Rating  Fixed Wall R w 50 dB D w 42 dB PR = 77

Proposed Method for Measuring 'Liveliness' in Open Plan Offices’. Vellenga*, Bouwhuis and Höngens. Liveliness M+P | Muller-BBM group  Key Points  Start at 40 dB L Aeq,T  Δ L up to 4 dB  Rating scale in 0.5… 5 5.5 6 6.5 7 8 9 10 4 3.5 4 4.5 5 5.5 6.5 7.5 8 3 2 2.5 3 3.5 4 5 6 7 2 1.5 2 2.5 3 3.5 4.5 5.5 6.5 1 1 1.5 2 2.5 3 4 5 6 0 ≥61 40 43 46 49 52 55 58

Liveliness Area PI MI Apex Non- 6 6.5 5 collaborative  Key Points Collaborative 6 6.5 6  PI and MI close, except for focused collaborative  Focused collaborative MI Focused 3 6.0 to 6.5 - higher due to matrix collaborative banding and high Δ L  Apex similar to WSP PI and Focused pair 4 5.0 - MI Breakout & 8 9.0 8 Dining (low occupancy) Proposed Method for Measuring Breakout & 9 10.0 8 'Liveliness' in Open Plan Offices’. Vellenga*, Bouwhuis and Höngens. Dining (high M+P | Muller-BBM group occupancy)

Speech Adjacency STI SNR Sound Speaker to c 0.20 @ 3m +2 dB Levels & Distraction Speaker to d 0.32 @ 5m +3 dB Speaker to e 0.10 @ 7m -1 dB  Non-collaborative to non- collaborative  NF S 31-199 D n ≥ 6dB   3382-3 D 2,s ≥ 7dB x Adjacency D n  Low STI – not distracting Speaker to c 6 dB  SNR low, no correlation to Speaker to d 10 dB STI Speaker to e 10 dB D 2,s ≈ 3 dB

Adjacency STI SNR D n Bothered by Speech Speech Non-collaborative to 0.20 @ 3m +2 dB 6 dB Low Sound non-collaborative 0.32 @ 5m +3 dB 10 dB Levels & 0.10 @ 7m -1 dB 10 dB Distraction Collaborative (raised 0.29 @ 4.5m +5 dB 15 dB Low to medium voice) to non-  Other Adjacencies collaborative  Privacy chairs: very Low STI Focused collaborative to 0.15 @ 4.5m -2 dB 13 dB Low non-collaborative  All SNR low, except collaborative, and Breakout Focused pair to non- 0.03 @ 6m -7 dB 15 dB Very Low & Dining areas collaborative  Breakout & Dining during Breakout & Dining (1 0.41 @ 2m +6 dB 11 dB Medium high occupancy (lunch) person raised voice) to noticeable at desks non-collaborative Breakout & Dining (3 0.52 @ 2m +11 dB High people raised voice) to non-collaborative

35 Speech Level 13 dB 30 Difference 25 15 dB  Key Points 10 dB 20  Performance at high D n , dB frequencies from focused 15 dB collaborative 15  Collaborative to non- collaborative 3dB lower 11 dB than Apex 10 6 dB 5 0 125 Hz 250 Hz 500 Hz 1.0 kHz 2.0 kHz 4.0 kHz 8.0 kHz Octave Band Centre Frequency, Hz Dn,Focused_Pair,4m Dn,Breakout_Dining,2m Dn,Collaborative,4.5m Dn,Focused_Collaborative,4.5m Dn,Non-collaborative,3m Dn,Non-collaborative,5m Dn,Non-collaborative,7m

Source / Receiver LR Collaborative Non- Focused Focused collaborative pair collaborative Liveliness Fun! L R 6 6 4 3 Breakout & Dining 9 -9 -9 -15 -18 (high occupancy)  Key Points  High occupancy breakout impact higher Breakout & Dining 8 -6 -6 -12 -15 (low occupancy)  Breakout to non- collaborative lower (ambient noise)  Good agreement elsewhere Collaborative 6 -6 -9  Not achieving this SNR but still works -6 -9 Non-collaborative 6

Tweaks  Key Points  Dining to existing Collaborative area ( D n 15 dB)  Focused pair adjacent to non-collaborative (low source, screening)  Collaborative to existing focused pair area

• No absorption works in a high ceiling large volume Take-home space Points • Higher activity ambient noise level beneficial • Liveliness compares well • Privacy chairs = 15dB D n @ 6m • Privacy booths = 13dB D n @ 4.5m • SNR doesn’t always align with subjective benefits • Account for activity ambient noise in D n requirements

Contact James Healey Adam Walker Associate Director, WSP Graduate Consultant, WSP Email: james.healey@wsp.com Email: adam.walker2@wsp.com Thank you. Questions?