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Greg KeeffeHead of Design, Manchester School of Architecture, UK [email protected]
Selective and Exclusive:Environmental Design of Larger Buildings
Environmental Design of Larger Buildings
From an environmental viewpoint -Architecture is about the following:
The production of shelter
The interpretation of place
Issues of perception
Issues of thermal comfort
Issues of resource depletion
Issues of shelter
Buildings create an inside
This is a disequilibrium and needs energy to maintain it.
Traditional architecture uses passive means to capture this.
But their means did not work for larger buildingssuch as offices.
Office Buildings
have a high density of occupation –
And this leads to several issues:People need oxygen and produce carbon dioxide and heat. The equipmentand lighting they use produce heat also
Thus key issues are
Provision of ventilationHeating and cooling in winterCooling in summer
Offices are complex environments
These give designers problems:
Environmental QualityIt was necessary to produce suitable conditions insidethe building whilst the external environment wasaltering hourly, diurnally, daily and seasonally.
Open Plan spaceThe development of office management techniques inthe 1960s had lead to the idea of “burolandschaft”:The large, open plan office.Large floor plates gave new problems for designers
Issues with large floor plates
They have areas in them very remote from the outside.
Thus they
can be difficult to ventilate
Tend to overheat
Create user stress
Modernist Solution
differed from traditional techniques which were passive.
Modernist architects and engineers proposed a technology leadsolution to suit the machine-age.
They would exclude the external environment from the building.
And recreate a stable environment using technology – airconditioning and electric lighting.
These have become known as EXCLUSIVE buildings
Exclusive buildings
Building seen as alien to itssurroundings.
Separate completely inside from out- a closed system
Use mechanical and electrical plantto provide internal environmentalconditions
Buildings are highly serviced – and plan is driven by air ducts andrisers.
GeneratedEnergy
Plant
LostEnergy
Building Envelope
Activities
Ambient
energy
Metabolic Energy
InternalEnvironment
Externalenvironment
Exclusive Building Model re Dean Hawkes ‘The Environmental Tradition’. 1998
“I do not like ducts, I do not like pipes, I hate themreally thoroughly, but because I hate them sothoroughly, I feel that they have to be given their place.If I just hated them and took no care, I think that theywould invade the building and completely destroy it. Iwant to correct any notion you may have that I am inlove with that kind of thing…”
Louis Khan
The Exclusive building
Building is a closed systemOutside is a nuisanceInternational styleSet points rule
Heating 21 deg CCooling 23 deg CVentilation 6 achLighting 400 Lux
Total Control of Artificial EnvironmentBuilding is ‘engineered’
Exclusive Building - Key Points
Static equilibriumDeep plan >15mLarge service coresImpermeable skinSuspended ceilings and raised floorsHighly servicedHigh energy useAutomatic control
Deep Plan BuildingsOver 14 metres depth – needs air con
Passive zone of occupation is approx 7m deepBeyond this electric lighting and mechanical ventilation needed
Central area
Remote fromoutside
Overheats even inwinter
Exclusive Buildings summing up
Key design issuesExclude incidental and ambient gains
Often open-plan form follow organisation
Service runs and cores
Key featuresLack of user control
Centralised control
Usually thermally lightweight
End result High energy use and Sick building syndrome
What is Gaia?
A holistic model of the outcome of Global Evolution andecology
Developed by J.E. Lovelock
The key theory:
That the Earth is a self -regulating entity – controlledcybernetically
Gaia theory
The Earth as a Cybernetic organism
Multiple processes of loose control give regulation
Variance to a degree is acceptable
Earth is part of a bio-econose
GeneratedEnergy
Plant
LostEnergy
Building Envelope
Activities
Ambientenergy
Metabolic Energy
InternalEnvironment
Externalenvironment
Selective Building Model re Dean Hawkes ‘The Environmental Tradition’. 1998
Bioclimatic Architecture
The inside of the building cannot be separated fromthe outside
Building and context are inseparable
Building must not damage context
Building seen as a landscape of site modifiers
The selective building
All areas are in the passive zone(sometime the passive zone is increased in size)
This allows for only natural heating, cooling, lighting andventilation
Building skin becomes selective and user-controlled
Over-riding idea:dynamic equilibrium
Selective Building: Key issues
Form derived from climate and siteOrientation derived by climateIncidental and climatic gains collectedSkinThermal weight of interiorInsulationPermeabilityUser controlCareful design of fenestration
Selective Building :Key generators
External ClimateSite forcesPassive solar designActive solar designVentilationDaylightingErgonomics and thermal comfort
Office Buildings – issues
Building and equipment is system to provideoccupant comfort
Key issuesForm OrientationMass (inside and out)Façade design – fenestration / shading in particularFabric LossesVentilation controlIncidental and ambient gainsBuilding and equipment a single system
Feilden Clegg Birmingham Uni Winchester College Rare HQ
Form
Minimise heatloss/gaincompact form
Maximise passive zoneminimise active zone
ING BANK AMSTERDAM Ton Alberts
Orientation
Longest Elevation South (of Course)
N
Heat gain June 100 115 130 UnitsSept 85 85 85 UnitsDec 40 30 15 Units
Mass
The thermal weight of the building is crucial
Particularly exposed internally
Wessex Water HQ Bennetts Assoc
The Hybrid Building
Selective building – dynamic equilibriumshifts may be too great
Eg in high towers, or places with extremeseasonal variations
Eg in mid winter natural ventilation can loselarge amounts of energy – or internalhumidity can be rather lowIn summer internal conditions can becomeuncomfortableHigh rise – high winds can be problematic
The Hybrid building
A compromise:
Runs selectively 80% of timeFlips to exclusive mode for a short timeWhen conditions are not favourable