Buro Happold Sustainable refurbishment Dept. Materials and Zoology, Cambridge
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Sustainable refurbishmentDept. Materials and Zoology,
Cambridge
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Background to the Project
Approach to Sustainability
Design Challenges
Introduction
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Existing west Elevation
•1960s/1970s
•Post modern Architecture
•Dept Metallurgy and Mat Science•Museum of Zoology
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Artists Impression of Existing
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old• Floor area ~ 15,000m2
•Current Uses: Lecture Theatre, University Computing Service, Materials Science Labs and teaching space, Zoology Department labs, Museum of Zoology, storage •Key materials are concrete, glass and lead •Complex form which steps out as you move up, with overhanging details •The main building connects to the two towers, the Zoology building, and there is a walkway to Chemistry. Also in close proximity to the Corn Exchange building •20th Century Society describe the engineering as “elegantly ostentatious”•Original master plan concept was to link the podium to the grand arcade•Pre-dates lots of our current building regulations relating to thermal performance and structural stability
Background
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old• Museum of Zoology and Archive, Department of Zoology, Lecture
Theatre
•, CCI (Cambridge Conservation Initiative ) Urban Ecologists eg RSPB
• Offices & shared facilities
•Underpin transformation in work practices
•Sustainability Key to influencing users and planners
Key aspects of Brief
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Sustainability
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oldBenefits of refurbishment
Refurbish vs. demolition
� Reduce running and maintenance costs
� Increases thermal comfort, productivity and happiness
� Avoids the cost, noise, disruption and environmental impact of demolition
� Retains the embodied carbon in the existing structure
� Avoids new land take
Bu
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old� It is important to consider the whole life cycle
CO2 when renovating existing buildings
� We have estimated the embodied carbon in new build to be at least 3.5 times higher than the operational energy consumption in the existing Arup Building.
� The difference in operational CO2 savings between refurbishment & new-build does not justify this decision.
Embodied carbon
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Average CO2 emissions of non-domestic buildings in UK
Baseline performance data
� Gas consumption = 2,780 MWh/yr
� Electricity use = 2,012 MWh/yr
� Excluding servers
� Energy audit at Stage D
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Gas consumption
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100,000
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500,000
600,000
700,000
Aug
-08
Sep
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Oct
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Nov
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Dec
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Jan-
09F
eb-0
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n-10
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Jun-
10Ju
l-10
Aug
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Nov
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Jan-
11F
eb-1
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To
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Total gas consumption area weighted for the Arup Building & DoZ building
Departmentof ZoologyBuilding
ArupBuilding
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Electricity consumption
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-08
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08
Jul-0
8
Aug
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Dec
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Jan-
09
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Jul-0
9
Aug
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Jan-
10
Feb
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Mar
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Apr
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May
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Jun-
10
Jul-1
0
Aug
-10
Sep
-10
Oct
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Nov
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Dec
-10
Jan-
11
Feb
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Mar
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Apr
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Jul-1
1
Aug
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Oct
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12
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To
tal e
lect
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(kW
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Total electricity consumption for the Arup Building
UCS serverroom
HPC serverroom
Rest of ArupBuilding
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oldChallengesAspirations
What sustainability means for the Arup Building
• A pioneering refurbishment which expresses the sustainability credentials of the users
• A shared vision from the client, design team & building users
• Get the maximum efficiency out of the existing building
• Obtain full buy-in from the building users to ensure that long term savings are achieved
• Working within a typical university budget
• Being ‘green’, but not necessarily the ‘greenest’ in every aspect
• Finding the right balance between capital cost and operational savings
• Retaining stakeholder engagement and aspirations over the long-term
• Resolving potential conflicts in aspiration from a mixture mix of building users
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How to engage users – ask them?
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Stakeholder engagement workshop
• Stakeholder workshop with representatives from 15 organisations
• Aim was to engage with building users and establish what really matters to them in terms of sustainability for the Arup Building
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Themes arising from the workshop
� A rich mixture of responses were obtained from the stakeholder workshop
� These responses were categorised into various themes
Energy & Carbon
Materials
Water
Waste
Health & Wellbeing
Heritage & culture
Collaboration & Inclusion
Transport & Mobility
Education & Outreach
Pollution
Biodiversity & Ecology
Key
All Groups
40
24
11
12
21
9
30
12
22
2
14
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Relationships with BREEAM
� Pre-assessment was carried out, achieved a “very good” score
� Stakeholder workshops identified that users wanted to set targets for many social & collaborative factors, not captured in BREEAM
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Description Base target Stretch target Measurement process
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Development of target Project timing ResponsibilityStretch target constraint
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Energy
• ICT – computer types, diversity factors, server space requirements
• Ventilation strategy vs. layout
Biodiversity
• Green roofs / living walls – identifying CCI experts
Transport
• Cycle facilities• Remote working –
teleconferencing / offsite ICT requirements
Next steps – topics requiring input
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Health & Wellbeing
• Sustainable food choices• User control
Collaboration & inclusion
• Collaboration plans within CCI
• Collaboration plans within all users
Education & outreach
• Need to confirm baseline museum visitor numbers
• Concepts for visitor education
• Post occupancy evaluation – plans for monitoring & dissemination
Focus groups – some topics requiring input
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Value of Museum Architectural Heritage
Right to Light WayfindingFood choices
Collaborative workingTechnology & tools Accessibility Extending user group
Construction WasteOperational Waste
TargetsCompostingReduce generationRecyclingClosed-loop
Efficient useAlternative sources
Embodied CarbonResponsible procurementEnvironmental impact of production Loose fit – long life
In-use energy targetsMonitoring and management - controls and bills Building FabricBuilding Services IT
Local / GlobalRoofscape, Atrium Green/ Brown RoofButterfly house CCI Impact on Global Ecology
Flooding Run-offAir quality Low emission boilers
MitigationCarbon emissions Embodied carbonEnergy impactsRenewable Energy
Adaptation Green roof FloodingIncreased temperaturesResilience
Museum engagementCCI engagement University Public
Reduce travel Working practices
Mode shift Walking / cycling / car club
Bespoke plan
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Key design issues
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Enabling Natural ventilation
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Cellular Vs. Open plan
Open plan
Open plan
Cellular
Cellular
Cellular
Cellular
Cellular
Cellular
Cellular
Cellular
Openplan
Open plan
Open plan
Cellular
Cellular
Cellular
Cellular
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Thermal comfort in naturally ventilated perimeter bays
Bays with cellular office core Bays with cellular & open plan core
Heat gains from 16 people Heat gains from 12 people(25% less risk of overheating)
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Ventilation
Stagnation
Draughty
Length of office is approximately 25m – too long for effective cross ventilationMechanically assisted solution is required
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old• Risk of draughts in window bays, causing control difficulties
• Additional infrastructure would be required for the extract
• Higher demand for fresh air in winter
• No heat recovery in winter
Option 1: Natural intake with mechanical extract
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old• System utilises already existent supply & extract infrastructure
• Allows for improved control in both perimeter & core areas
• Heat recovery system will be present
• Can utilise chilled water system during peak cooling conditions
Option 2: Single sided natural ventilation with mechanical supply & extract
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old• Feasibility is unclear due to additional riser space requirements
• Additional infrastructure would be required
• Fresh air intake will require additional heating component in winter
• No heat recovery in winter
Option 3: Single sided natural ventilation with mechanical assisted chimney
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Summary
• Energy is not the main driver for being open plan
•Instead it will provide improved thermal comfort, better collaboration and less cramped working environment in the window bays
•Assisted ventilation solution can be achieved with no added infrastructure
•Baseline framework target can be achieved with mech. assisted ventilation solution
•Will be important to invest in modern ICT equipment over the next 3 years leading towards the move – standard equipment increases overheating risks
•Lighting & ventilation to be linked to occupancy sensors in cellular areas
•Spatial allowance for chilled water infrastructure & electrical resilience is also being designed to deal with future climate change.
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Constraints of Existing FacadeCondition, performance & planning
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oldImprovement of thermal performance of building envelope as compared
to current performance:
� % reduction in heat loss through building envelope
Thermal performance of the building envelope
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oldChallenge in understanding current performance
� Envelope inspection – build ups
� Performance estimation – U-value calc
Establish achievable improvement
� Benchmark against part L
� Consideration of feasible improvements
Thermal performance of the building envelope
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Envelope performance estimation tool
Outcome is a middle ground based on improvement where reasonable
� Limited by space, structure & access
� Limited by planning constraint
� Improvement beyond Part L where possible to compensate
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Target development example
Tool to calculateheat loss throughthe building fabric
70% reduction feasible based on building regulations
80% reduction possible if more insulation isspecified and hard-to-treat areas are addressed.
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Constraints of Existing Frame
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ICT Strategy
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ICT loads
Generic desktop computer
(with LCD monitor)
Thin client computer
(with LCD monitor)
Laptop
(with docking station + LCD monitor)
99 Watts 33 Watts38 Watts
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Thin client computers
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Laptop computers
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Generic desktop computers
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Lessons learned so far...
- Developed Bespoke Sustainability Framework
- Good level of User Engagement - Helps define the Problem
- Possible to Deliver Natural Ventilation to >60% of Building
- Targetting 70% reduction in Conduction Heat Losses (thermal bridges still an issue)
- LAM (Laser Assisted Modelling) survey of Existing Frame successful but watch the briefing !
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Laser Survey Model
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Central Model Development
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Existing Vertical Services Distribution – 1st Floor Plan
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Existing Horizontal Services Distribution
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Access & Maintenance
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www.burohappold.com