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Literature review plan - Coggle Diagram

- - - - 39%
      - Increasing demand
  - - - Drive for embodied efficiency (i.e. optimisation)
    - - Balance required
- - - - First step is to define adaptability
      - Lack of consensus seen as blocker
        
        Further barriers discussed in later section
      - Not a new concept
    - - Discuss common words / themes in definitions from academic literature
    - - Discuss common words in industry guidance / literature
        
        Resilience
        
        Robustness
        
        Reliability
      - Compare to those of academia
    - - Find any definitions in legislation/regulations
        
        If can't find any, comment on why
    - - Define circular economy
      - Define design for deconstruction / disassembly
        
        [which word?]
      - Worth introducing and defining stategies that are complementary/symbiotic with DfA
    - - Conclude on definitions used in research
  - - - Materials
        
        Steel
        
        Little reuse
        
        certification too stringent
        
        no specialist stockist
        
        high cost
        
        low client / market demand
        
        time constraints
        
        Concrete
        
        Builds as monoliths
        
        Masonry
        
        Glass
        
        Short lifecycle
        
        Difficult to re-size
        
        Difficult to recycle
        
        Difficult to identify coatings used
        
        Timber
        
        Often poorly treated
        
        fungal decay, insect attack, knots, fixing holes
      - Design based on precedent
        
        Reluctance to change
        
        Link to economic risk avoidance / protectionism
        
        Trusted assembly methods, products and processes
        
        Typically do not consider deconstruction
      - Ignorance
        
        Designers unaware of DfA / CE
      - Buildings are unique
      - Fragmentation of supply chain
        
        Client, architect and engineers rarely truely work together
        
        Building owners and operators need to understand their role
        
        Strong integration promotes reuse
      - Lacking guidance
    - - Education
        
        Little focus on reuse / re-appraisal
      - Planning permission
        
        Focused on operational reductions
      - Element reuse certification
    - - Caused by changes in legislation, technology, economic conditions and architectural style
    - - of designers
        
        Unaware of DfA / CE
        
        Lacking guidance
        
        Difficulty of designing with reused components
        
        Uncertain properties/certification
        
        Insurance
        
        Lack of reuse markets
        
        Time constraints / no client buy in
        
        Therefore no ROI
        
        Perception of overspecification requirement
        
        Therefore increased cost
        
        Overspecification of services, loading, structure, etc.
      - of clients
        
        Increased cost
        
        Maybe without seeing ROI
        
        Unaware of benefits of DfA
        
        Designers can't explain/prove
      - of public
      - of architects
        
        Don't consider temporal dimension
    - - Cannot predict future
        
        Shouldn't try, should allow for future changes
      - Uncertainty disuades investment
    - - Loss/risk
        
        Cost and programme always primary concern
        
        More material and more design time with little guarantee of implementation
        
        Initial developer may not see ROI
        
        Quantification method needed to correctly value adaptability
      - Quantification
        
        Difficult to develop quantification strategy
        
        Buildings are unique
        
        Lacking data
        
        Insufficient knowledge in industry
    - - Designers unable to guarantee reused elements
    - - Difficult to persuade clients
      - Few existing adaptably-designed structures
    - - Difficult to develop quantification strategies
        
        Buildings are unique
      - Complex methodologies
      - Paradox: adaptability for uncertainty, uncertainty prevents quantification
      - Quantification methodologies themselves need to be adaptable, as sustainability priorities change in the future
  - - - Mentality
        
        Awareness of adaptability slowing increasing
      - Guidance
        
        Development of new DfA / CE guidance
        
        IStructE guide
        
        ISO 20887
        
        Sometimes recommended
      - Benefits
        
        Increase salvage / recycling rate
        
        Reduced consumption of new materials and energy in production
        
        Reduced waste and landfill
        
        Increase building lifespan
        
        Improved durability
        
        Allowing adaptation / avoiding obsolescence
        
        Simplifying maitenance
        
        Simplifying construction
        
        Standard connections
        
        Repeating geometries
        
        More economical initial construction and later modifications
        
        Adds value
    - - Necessity
        
        Climate change necessitating resilience
      - Adaptability needs to be linked to developer profitability
        
        Adaptability prioritised in building valuation
      - Cheaper construction
        
        Regular, orthogonal grid
        
        Steel reuse can save cost
        
        Easier procurement of standard sections
      - Increased ROI
        
        Adapt to tenants new requirements
        
        Reduced turnover of clients
        
        Reduced void periods
        
        Becoming more important with shift to shorter-term tenancies
        
        Quicker renovation
        
        Can maintain modern fit-out
        
        Keeping rent high
        
        Unrestricted building internal layout / configuration
        
        Reduced building depreciation
      - Cheaper renovation
        
        Savings within first maintenance cycle
  - - - Gross geometry
        
        Height
        
        Plan depth
        
        Lightwells / courtyards
        
        Not necessary in deep open plan office, but preferable in residential where more division of floor plate
        
        Retrofittable lightwells
        
        Area
        
        Keep under 10,000 m2 [still valid?]
        
        Too big will cause unacceptable stresses on nearby facilities in the event of use change
      - Internal layout
        
        Ensure non-structural
        
        Finishes
        
        Use finishes which can be easily removed
        
        Movable partitions
      - Floor-to-floor height
        
        Floor-to-ceiling height
        
        Perception based
        
        Little variance
        
        Helpful for daylighting and natural ventilation
        
        Service void provision
        
        Large variance
        
        Suggestion for overprovision
      - Grid shape
        
        Spans
        
        Larger spans require more material investment
        
        Balance required
        
        Larger spans allow for greater flexibility of space
        
        [What span is necessary for optimal flexibility?]
        
        Regular, rectangular
        
        Rationalisation increases likelihood of reuse
    - - Services
        
        Capacities
        
        Overspecification
        
        Service voids
        
        Dropped ceilings or raised floors
        
        Ease of access
        
        Varied types
        
        Fewer services makes adaptation easier and require less maintenance
      - Insulation
        
        Acoustic
        
        From outside to inside
        
        [Likely to be similar across uses?]
        
        From floor to floor
        
        [Can this be retrofit?]
        
        From unit to unit
        
        Higher in residential, although dependent on internal fit-out
        
        Thermal
        
        Higher in residential due to overnight sleeping risk
        
        [Can this be retrofit?]
      - Fire safety
        
        Means of escape
        
        Dependent on internal layout
        
        Higher in commercial / office, due to higher peak occupancy [check]
        
        [Overspecify in residentail first-use?]
        
        Fire detection and alarm system
        
        Likely to require upgrade in any retrofit, irrespective of change of use or not
        
        Due to developing technologies and regulations
      - Envelope
        
        Cladding
        
        Demountability
        
        Glazing
        
        Ratios
      - Overdesign
        
        Foundations
        
        Inaccessible / hard to strengthen
        
        Lateral stability
        
        Hard to retrofit
        
        Bracing foundations often extensive
      - Limit states
        
        ULS
        
        Floor loading
        
        Don't overspecify
        
        Allow for future strengthening
        
        Look at overlapping load requirements
        
        SLS
        
        Vibration
        
        Deflection
    - - Lateral stability
        
        Moment-resisting frame
        
        [Increased design complexity / cost?]
        
        Non-typical in UK
        
        Avoids interior obstacles of braced bays / shear walls
        
        [Allows for individual element removal?]
      - Separation of layers
        
        Layers
        
        Site
        
        Structure
        
        Skin
        
        Service
        
        Space
        
        Stuff
        
        Interdependence of systems
        
        Originally Duffy, furthered by Brand
        
        Upgradeability
        
        Lifetime compatability
      - Material
        
        Concrete
        
        Monolithic
        
        Steel
        
        Recycleable
        
        Deconstructable
        
        Attention to assembly / dissembly sequencing
        
        Mechanical fasteners
        
        Durability
        
        Higher durability, less maintenance, reduced operational costs
      - Floor system
        
        Flat slabs for ease of service retrofit
        
        Avoid composite systems
      - Start with end in mind
        
        Plan for change
        
        Design for long-life
        
        Design for loose-fit
        
        Design for deconstruction
    - - Record keeping
        
        Storage
        
        Physical black box
        
        BIM
        
        [Storage?]
        
        Online database
        
        'Patient' record
        
        [Responsiblity?]
        
        Material passport
        
        Design philosophy
        
        Adaptability strategies
        
        As-built plans
        
        Record of modifications
        
        Environmental impact / hazardous materials
        
        Remember, some materials considered safe now may later be discovered to be hazardous, therefore retention of details of all materials is key
        
        Inventory of building components
        
        Passing information from designer to owner, owner to owner, owner to refurbisher, etc.
      - Collaborative design
        
        Early onboarding of engineers
        
        Early design decisions can severly limit adaptability options
        
        Early onboarding of suppliers
        
        Early onboarding of contractors and demolition specialists
        
        Development of stockist industry
        
        Understanding of DfA from clients / architects
        
        Inclusion of building users
        
        Facilities managers
        
        Reduce expectations
        
        [Sufficiency?]
    - - Climate resilience
        
        Changing loads
        
        Snow
        
        Rain
        
        Wind
        
        Changing temperature
        
        Heating
        
        Daylighting
        
        Air temperature
        
        Cooling
        
        Ventilation
        
        Migration
        
        Changing demands of urban spaces
- - - - Carbon
        
        Operational carbon
        
        Embodied carbon
        
        Whole life carbon
        
        LCA stages included
        
        Cradle-to-gate
        
        Gradle-to-grave
        
        Cradle-to-cradle
      - Cost
        
        Material cost
        
        Volume
        
        Grade/durability
        
        Fabrication
        
        Availability
        
        Whole life cost
      - Material volume
    - - Academic
      - Industry
      - Legislation
  - - - Standardisation
        
        Reduces cost but reduces optimisation efficacy
        
        Custom sections very expensive
        
        Adds another layer of conservatism
        
        i.e. "discrete-continuous problem"
      - Prismatic sections
        
        In reality, requirements of an element vary along length
    - - Designer perceptions
        
        (Percieved risk of) errors
        
        Fragmentation of supply chain / construction industry
        
        Deliberate overdesign to allow for construction error
        
        No penalty for overdesign, but significant penalty for construction error / collapse
        
        Increased complexity of structure, through optimisation and non-rationalisation, could increase this risk of on-site mix-up
      - User perceptions
        
        Overdesign seen as positive attribute
        
        [By who?]
        
        Negative user perceptions of light-weighting
        
        Not specific to construction industry
        
        e.g. car panels, if they deflect when pressed, considered inferior, even if they perform function as well as heavy-weight and are technically sound
        
        e.g. computer mouse
        
        Light-weight products percieved as inferior by end-users
        
        Serviceability requirements often governing
      - Client perceptions
      - Contractor perceptions
      - Fabricator perceptions
    - - Simplicity
        
        Rationalisation
        
        Limited optioneering
        
        Risk of investing too much time at tender/concept stage - stage where greatest impact can be made
        
        Lack of push from clients
        
        Repitition
        
        Similar to adaptability barrier, construction sector highly dependent on precedent
        
        Retention / passing on of overdesign misconceptions
        
        Inefficiency cultural phenominon – automatically, unquestioningly repeat previous suboptimal designs
        
        Quicker detailing and fabrication
        
        Ease of construction
        
        Valued above material efficiency
        
        With labour costing more than material, and not paying carbon price
      - Lateral stability
        
        Pin frames easier to design and construct, but less optimised than continuous design
        
        Pin frames recommended and standard-practice in UK
        
        Hard to assess in simple UR checks
      - Codes
        
        Conservatism in design codes preventing optimisation
        
        Loading
        
        Safety factors
        
        Material strengths
        
        Serviceability recommendations
        
        Often governing but poorly understood
        
        Don't specify minimum UR
      - Utilisation
        
        Practitioners relucant to go above 0.8 UR
        
        To guard against changes during the project
        
        Concerns about 'optimising away' unconsidered margins of safety
        
        Reluctance to specify minimium URs
        
        "increased complexity"
        
        Typically about 50% in practice
      - Loading
        
        Office loading
        
        Typically 4 + 1 kN/m2
        
        Complacency / precedent
        
        From 1909 London County Council (General Power) Act
        
        Based on the idea of file storage / computer rooms (i.e. archaic idologies)
        
        Greater than requirements in codes
        
        Real office loading 0.3-0.5 kN/m2
        
        Specification often made by client / architect, rather than engineer
        
        [How to solve this?]
        
        Education
        
        Collaborative design process / early engineer engagement
        
        Construction loading
        
        Often governing
        
        Can often be reduced but increases constuction duration / sequencing
        
        Need change of priorities, from cost to carbon
        
        Uncertainty
        
        Loading not well understood, therefore over-specified
    - - Operational focus
      - Political uncertainty
        
        Property investment industry aware of vulnerability of property to sustainability agenda
        
        Putting off investors
        
        Caused by rapid political cycles
      - Financial incentives
        
        Few incentives for investing in energy efficient fit-out
        
        No cost associated with embodied carbon
    - - Designer profit
        
        Not prioritised by clients
        
        Designers not paid to optimise
        
        No penalties for overdesign
        
        Little incentive to optimise/cost save after tender
      - Risk mitigation
        
        Negligable cost of overdesign in comparison to cost of component failure
        
        Safety is overriding concern, material efficiency an afterthought
      - Lack of quantification
        
        No way to identify sustainability within existing building stock
        
        a "basic pre-requisite" for developing understanding of value, risk or return of sustainability
        
        Circle of blame
        
        Well recorded lack of interest from commercial property market
        
        Unquantifiable risks
        
        No benchmarks
      - Operational focus
        
        Operational efficiency over embodied
        
        Tenants more interested in operational, therefore so are developers
      - Speed
        
        Rationalisation / simplification (anti-optimisation) speeding design, fabrication and construction, therefore reducing cost
        
        Unknown how much more design time needed for incremental increases in average UR
        
        Also unknown increases in fabrication and construction
        
        Therefore reluctant client buy-in
      - Manufacturer profit
        
        Fabricators paid per tonne, therefore no incentive to optimise
        
        Could be offset by new market; leasing, servicing and retaining ownership of mateirals
        
        Need 'vertial integration' of supply chain
        
        Least weight solutions rarely most cost-effective
      - Lack of development
        
        Light-weighting measures are economically unattractive and may take years to develop
    - - Most development will be focused in developing countries
        
        Developing countries have least ability to optimise / prioritise sustainability
      - Operational and embodied emissions highly dependent on location
      - Varied locations prevents universal rules / optimisation strategies / benchmarks
        
        A lot of research focused on developed countries
    - - UK public sector buildings require operational efficiencies, but no embodied efficiency
      - Perception that eco-friendly = operational efficiency
        
        Unnecessary renewable tech - link back to increased maintance cost / limiting adaptability point
      - Embodied energy not a priority
      - Operational performance assessment mandatory for public buildings in UK and EU
        
        No equivalent for embodied
  - - - Engineers love to optimise
      - Most of the developments in operational and embodied efficiencies have been voluntary
        
        Indicating interest of designers/clients/public toward sustainability
    - - Some new guidance emerging pushing for optimisation
      - A lot of literature on optimisation
        
        Both academic and industry
    - - Optimisation starting to appear in legislation/design codes
      - Required change of construction industry to reach legally-binding carbon targets
      - Optimisation scoring starting to appear in building sustainability assessments
      - Planning permission could start to necessitate certain optimisation/embodied efficiencies
      - Suggestion for economic incentives added to optimisation
      - Engineers declare
    - - Over-design / over-specification could increase maintannce and refurbishment costs
      - Structural frame represents significant proportion of material cost - therefore good opportunity for cost saving
      - "On average, lower carbon solutions also have lower cost"
    - - Successful reductions in operational, increase focus on embodied
        
        Over whole life, emboded emissions starting to account for c.50-70% emissions
      - Grid decarbonisation further increasing EC contribution
    - - Construction industry significant contributor to annual global emissions
        
        Significant steel production contribution and usage proportion
      - Metal production accounts for significant proportion of energy generation
      - Considerable increase in raw material extraction from 1960s to now, expected to continue to 2050
      - Embodied emissions account for sigificant proportion of structural whole life carbon
  - - - 3.4.1.0 Importance of early design decisions
        
        Geometry, and frame and decking choice
        
        Biggest impact at same time as most uncertainty
      - 3.4.1.1 Questioning the brief
        
        Aim to produce a set of optimised solutions (optimised by different criteria) rather than providing just one (optioneering?)
        
        Specification of ULS and SLS criteria
        
        Therefore need to understand real loads / SLS
      - 3.4.1.4 Foundation design
        
        EC of foundations not often considered when optimising, there knock-on effects of design decisions not fully explored
        
        Location / soil characteristics should influence design / selection of site
        
        Although concept design has highest uncertainty (again)
        
        Often multiple different foundation options available - sustainability optioneering should be done
        
        Foundation EC contribution can be significant
        
        [Yet often omitted from LCA?]
      - 3.4.1.2 Structural muscularity
        
        Align members with loads, avoid bending
        
        Avoid transfer structures, large spans, cantilevers, complex load paths
      - 3.4.1.5 Material choice
        
        Substitute materials
        
        Timber
        
        Other bio-materials
        
        Not answerable
        
        Steel better than concrete
        
        Contentious
        
        [(Better CE potential)]
      - 3.4.1.3 Lateral stability mechanism
        
        Pinned frames easier to design
        
        [Easier to optimise?]
        
        "An ounce of bracing is worth a tonne of stiff joints", re: deflection
        
        Especially true in tall buildings
        
        Key factor in element sizing in tall buildings
        
        Governed by geometry rather than material
        
        Importance of concept stage
        
        No efficient optimisation technique, so design often based on precedent / trial-and-error
        
        Complex due to large number of possibilities
        
        [Any literature on which is more optimal?]
    - - 3.4.2.7 Material choice
        
        Higher strength / durability
        
        [Lower material volume but higher EC factor?]
        
        Serviceability criteria
        
        Characteristic values
        
        Why 95%
      - 3.4.2.3 Utilisation
        
        Benefited by CAD / tech developments
        
        Aim to design close to 1.0
        
        Secondary beams (and other neglected elements) could be more optimised
      - 3.4.2.6 Limit states
        
        Relaxing SLS criteria / allowing temporary breaches
      - 3.4.2.2 Partial factors
        
        Make carbon as important as safety
        
        Incrimental increase in safety factors over time, like "tiptoeing towards the edge of a cliff"
      - 3.4.2.1 Loading
        
        Avoid over-design / over-specification of loads
        
        5 kN/m2 not appropriate
        
        Based on historical tradition / precedent
        
        Proven to be inaccurate
        
        Build in flexibility, not overdesign
        [BALANCE SECTION?]
        
        Design for strengthening retrofit
        
        Single most influential variable
      - 3.4.2.5 Assessment criteria
        
        Primary
        
        Moment
        
        Shear
        
        Axial
        
        Buckling
        
        Combined axial and moment buckling
        
        Deflection
        
        Secondary
        
        Vibration
        
        Temporary / construction loads
        
        Section depth limits
      - 3.4.2.4 Geometric exploitation
        
        Structural form and overall geometry
        
        [Concept design?]
        
        Size and shaping of individual elements
        
        e.g. tapering columns
        
        Selecting lower carbon section shapes (e.g. open sections have lower EC than hollow sections)
        
        Optimise final product using most appropriate method
- - - - Lean yet resilient synergy
        
        Resilience protects value
        
        Lean design maximises value
      - Over- or under-provision of flexibility
    - - Carbon assessments to justify any decision (optimised or adaptable)
        
        Especially if strategy requires significant carbon investment
      - Minimising whole life carbon, not just of building but of system/city/society
        
        Adaptability providing future-proofing, but balanced with increased upfront emissions
        
        Some over-specifcation can actually lead to reduced adaptability
        
        Link back to carbon payback period
        
        Link between a building's adaptability and its level of sustainability
    - - Do not over-rationalise
        
        Rules for rationalisation extent
      - Not every building need to be adaptably designed
        
        Difficulty in determining required extent of deployment
  - - - Carbon payback period
        
        The time it takes operational efficiencies to pay back increased embodied emissions
        
        Compare against the estimated service life of the component
      - Benefits of delaying emissions
        
        Decreased cumulative impact of rising temperatures
        
        Delaying / avoiding climate tipping points
        
        Allowing time for technology development
        
        Grid decarbonisation
        
        Cleaner material production
        
        Carbon capture and storage
    - - Braced frame better than unbraced
  - - - Better for DfD
      - Reduces design, fabrication and construction durations - reduces cost
    - - Circular economy
        
        Facilitated by simplicity, standardisation and modularity
      - DfD
        
        Can optimise whilst still ensuring separation of layers?
      - Optimised structures more difficutl to re-use