CARBON COPIES HOUSES TOWERS COMPLEX SHAPES MID-RISE AIRPORTS HOSPITALS/LABS BRIDGES
Andrew Reynolds Ching Yuet Ma Chloe Shang Daniah Basil Abdulazeez Al Mounajim Dario Biscaro Grant Donaldson Hayden Mills Janice Lo Lee Hei Yin Luca Luci Miles Elliott Mir Jetha Xinyi Shen Zhiting Jin Groupwork Royal College of Art
ACKNOWLEDGEMENTS
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CONTENTS 1.0 INTRODUCTION Purpose of research Construction methodology Reference: stone tower research project Case studies 2.1 EXISTING CONDITION A (OFFICE) Site and location Key information Tower overview Construction methodology Existing structural plans Existing elevations and sections Existing close up section Existing exploded axonometric Existing detail drawings Embodied carbon calculation Cost analysis
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8 10 12 14
18 19 20 22 24 26 28 29 30 32 33
2.2 CARBON COPY A (OFFICE) Stone exoskeleton + Timber in-between + Stone core Construction methodolgy Stone frame options Beam variations Structural plans Elevation and Section Close up section Exploded axonometric Detail drawings External view comparison Embodied carbon calculation Cost analysis
36 28 40 42 44 46 48 49 50 52 54 55
2.3 WHAT IF? Office additional internal columns Embodied carbon calculation Cost analysis
58 60 61
3.1 EXISTING CONDITION B (RESIDENTIAL)
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Site and location Key information Tower overview Construction methodology Existing structural plans Existing elevations and sections Existing close up section Existing exploded axonometric
64 65 66 68 70 72 74 75
76 78 79
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Existing detail drawings Embodied carbon calculation Cost analysis 3.2 CARBON COPY B (RESIDENTIAL)
82 84 86 88 90 92 94 96 98 100
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Variation 1 & 2 Construction methodolgy Structural plans Close up sections Exploded axonometric Detail drawings Piles foundation comparison Internal finishes comparison Embodied carbon calculation Cost analysis 4.0 DATA COMPARISONS
104 108
5.0 FINDINGS Overall savings Conslusion to the tower typology
114 120
6.0 MENU OF COMPONENTS
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Office tower 22 Bishopsgate Residential tower One Park Drive
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1 INTRODUCTION
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1.0 INTRODUCTION
PURPOSE OF RESEARCH
As the product of new technologies and response to spatial limitations, growing populations, zoning regulations, and business requirements, are towers logical extrusion of land values or irrational, anti-urban monster? In a world responding to the climate crisis, towering skyscrapers that use massive amounts of energy and materials to construct and operate may look increasingly out of place. This paper examines the current state of two tower types: office tower and residential tower. Focusing on the case studies of 22 Bishopsgate and One Park Drive, we selected these typical buildings in London that demonstrate the most up-to-date construction practices.
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In light of the current climate context, the report will focus on how timber and stone could be used in the tower typology. By replacing building materials and reconstructing details, we intend to provide a new strategy for the tower’s sustainable innovation while conserving the structure’s original features to the maximum extent.
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22 Bishopsgate, City of London, PLP Architecture. Image CC credit: Matt Brown – flickr
One Park Drive, Canary Wharf, Herzog de Meuron. Photographed by Lee Mawdsley
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TOWER
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1.0 INTRODUCTION
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Towers under construction, concrete / steel structures. Photographed by Lee Mawdsley
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22 Bishopsgate and One Park Drive, under construction, Two typical tower structures.
CONSTRUCTION METHODOLOGY Both belonging to the tower typology, 22 Bishopsgate and One Park Drive are stacked and combined by the same basic elements: core frame, slab, and facade. Both rely heavily on reinforced concrete; the office tower’s fundamental structure is made up of a huge number of steel columns and beams, while the residential tower’s construction logic is flat slabs supported by reinforced concrete blade walls and columns. Wind lateral force is dealt with differently in the two buildings: 22 Bishopsgate employs a specific steel outrigger system in the middle of the building levels, whilst One Park Drive uses a lot of concrete shear walls to keep the structure stable.
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TOWER
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1.0 INTRODUCTION
Stone Tower Research Project. Groupwork, in collaboration with Jackson Coles, Eight Associates and Webb Yates
REFERENCE: STONE TOWER RESEARCH PROJECT Researching how far one can go using stone, Groupwork has imagined a 30-story basalt structure with a total Gross Internal Floor Area of 37,800 m² / 406,875 ft², part of the Stone Tower Research project.
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The comparative study considering many structural solutions aims to “investigate whether large scale commercial buildings can be built with stone superstructures, stone and or timber floor plates to meet the same criteria of optimum office space and building height as steel and concrete structures and be the same or lower in construction cost and carbon footprint”.
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Stone Tower – Typical Plan (stone flooring cassettes shown)
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One Par Drive, Canary Wharf, Herzog de Meuron. Photographed by Lee Mawdsley
Stone Tower – Front Elevation
Stone Tower – Side Elevation
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1.0 INTRODUCTION
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Case study: 30 Finsbury Square, London, Eric Parry Architects , 2002. Source: https://www. ericparryarchitects.co.uk/ projects/30-finsbury-square/
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Case study: Sara Cultural Centre, Skellefteå, White Arkitekter, 2021. Source: https:// whitearkitekter.com/project/ sara-cultural-centre/
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CASE STUDIES
30 Finsbury Square, London, Eric Parry Architects , 2002
Sara Cultural Centre, Skellefteå, White Arkitekter, 2021
The project comprised a large office development of approximately 16,660 square meters of office floor space arranged over 7 stories.
The centre’s timber structure references the city’s historic wooden buildings, and is sheathed in a double layer of glass that reveals the crosslaminated and glue-laminated timber panels that form the spaces within.
This elevational study is nevertheless based upon the engineered distribution of weight bearing down through the piers. Parry had hoped to integrate an additional break in the tension of the visual grid by wrapping a small section of the stone frame composition in the sculpture of stainless steel balls by Richard Deacon RA, like an interweaving necklace.
The building, which makes use of locally and sustainably sourced and processed timber, has an aim to be carbon negative within 50 years.
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The use of stone under varying pressures, as if it were post-and-beam construction from the days of ancient Greece, working just like in a ‘hightech stone age’.
Structural engineers Florian Kosche developed two construction systems for the building that eliminate the use of concrete within the load-bearing structure. Prefabricated modules made from Cross Laminated Timber (CLT) were used to construct the high-rise hotel, while a combination of glue laminated timber with cores and walls in CLT was deployed for the cultural centre. In hand, an energy system created by Skellefteå Kraft and ABB was developed to reduce the building’s power consumption and includes roofmounted solar panels that produce renewable energy.
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2.1 EXISTING CONDITION A: OFFICE
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2.1 EXISTING CONDITION A
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22 BISHOPSGATE
22 Bishopsgate, also known as Twentytwo, is a commercial skyscraper in the City of London financial district.The project replaces an earlier plan a tower named The Pinnacle, on which construction was started in 2008 but suspended in 2012 following the Great Recession, with only the concrete core of the first seven storeys. The structure was later subjected to a re-design, out of which it became known by its postal address, 22 Bishopsgate.
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The Pinnacle is the second-tallest building in both the United Kingdom and the European Union after The Shard. Shaped to respect townscape views, its twentythree-sided, faceted glass form makes a strong and serene backdrop to the surrounding articulated towers and to the historic fabric of the Bank of England Conservation Area.
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22 Bishopsgate under construction, City of London, PLP Architecture. Image CC credit: It’s No Game – flickr.
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Existing site plan. Planning Application Documents.
KEY INFORMATION Completion: 2020 Height: 272.32m (AOD) Storeys: 62 Gross Internal Area (GIA): 196,982 m2 Net Internal Area (NIA): ~108,340 m2
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2.1 EXISTING CONDITION A
TOWER OVERVIEW Extensive amenity spaces form a “vertical village” in 22 Bishopsgate, these spaces encourage social interaction, collaboration, inclusion, shared experiences, services and events. At its base, pedestrian access is unlocked through the cluster in the heart of the City, converting it into landscaped public open space. Four main entrances access the Lobby, with an evolving programme of curated art and sculpture displays.
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The office building offers 1.275 million sq ft of high specification office space, arranged across four office zones. An innovative evacuation method is created by using passenger lifts rather than typical fire evacuation lifts. The four zones are separated by two-hour fire rating slabs, each has its own dedicated bank of lifts. The double-decker lifts, which run at a pace of 6-8 metres per second, provide a safe and quick escape route for the building’s occupants.
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The vertical village: varied amenity spaces where people and ideas thrive. 22 Bishopsgate Brochure
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Four office entrance and four banks of lifts, for swift and direct journeys to the destination floor – with no stops.
Four office zones. Not to scale, for identification purposes only.
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Outrigger system. Located at levels 25 and 41.
Transfer structure. Linking the new structures into the existing foundation.
CONSTRUCTION METHODOLOGY OUTRIGGER SYSTEM Responding to the pushing forces of the strong winds affecting the higher levels, the engineers designed a series of trusses that play the role of outriggers located at levels 25 and 41. These steel structures span from floor to ceiling and tie back to the concrete core. Restrain the building and help it to stand still when the wind tries to bend it down. The structure also compresses and shrinks due to the effect of the increased weight.
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TRANSFER STRUCTURE One of the biggest transfer structure in the design of 22 Bishopsgate, nicknamed by the design team as the “Rhino truss” for its geometry. It was required in order to transfer the loads from the south east corner columns of the building to the foundations that needed to be utilised from the old Pinnacle design.
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Top down construction. Temporary structural elements are built to support the core.
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Double skin system. Facade under construction.
TOP DOWN CONSTRUCTION It consists in starting to build the core from an elevated level, in this case from the ground floor. This way, construction can progress simultaneously above and below ground. Temporary structural elements are built to support the core. These usually occupy less space than the final configuration of the core walls would thus freeing space underneath and facilitating the execution of the works required below ground. DOUBLE SKIN SYSTEM Along the west side, the huge loads from the peripheral columns had to be brought into the piles located much nearer to the central core. Engineers do this by sloping the columns inwards from level six to level three, returning to vertical for the entrance lobby down to ground level, and then sloping again from ground to basement. To resist the horizontal forces, the truss at the top helps take the tension and another at the bottom to resist compression.
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Existing structural plan of typical floors
EXISTING STRUCTURAL PLANS The three main parts of the building: core, slabs and facade progress in a stepped sequence over time. The floor slabs are composite with cellular steel beams, providing a diaphragmaction restraint to the perimeter columns. The concrete core’s footprint at the ground floor is roughly 60 x 15 meters - is formed by walls that reduce their thickness as they rise to the top floors, accommodating the reduced structural demands of the upper levels in comparison to those of the lower ones, also reduces as a result of the lesser number of lifts and services that reach the top floors.
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RESIDENTIAL TOWER
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EXISTING SECTIONS AND ELEVATIONS
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Existing Section.
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Existing Elevation.
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CLOSE UP SECTION
Existing Close-up Section. Floor composition: 50mm Finish 150mm Concrete slab 130mm Metal deck 762mm Cellular beam Ceiling
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Wall composition: 25mm Outer glazing panel 125mm Air cavity 165mm Inner facade, with 100mm insulation and double glazing
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EXISTING EXPLODED AXONOMETRIC
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Steel Beam (b) Hot Rolled Structural Steel
Glass + Metal Outer Skin Aluminium (bar and rod) Flat Glass
Concrete Slab (b) Concrete 40 MPa
Galvanised Structural Steel
Glass + Metal Inner Skin Aluminium (bar and rod) Flat Glass
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Metal Deck (b)
Steel Column Hot Rolled Structural Steel
Steel Beam (a) Hot Rolled Structural Steel
Concrete Core Reinforced Concrete
Concrete Slab (a) Concrete 40 MPa
Metal Deck (a) Galvanised Structural Steel
Exploded axonometric, Level 8-25, Column 800x700 / UB 762x267x197
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EXISTING FACADE DETAIL
Existing facade detail. From planning application document.
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A triple glazing system, 25mm Outer glazing panels 125mm Air cavity 100mm Inner facade
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Existing Facade detail, with louver inside. From planning application document. The louver units will be installed on the East Facade, in order to minimise their visual impact from the more distant views, replacing the already installed glazed facade panels.
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OFFICE TOWER
EMBODIED CARBON CALCULATIONS
MATERIAL
ELEMENT
VOLUME M3
EMBODIED CARBON KGCO2E
Reinforced Concrete
Core
37,604
25,119,672
Light Concrete
Floor Slab
22,535
6,492,291
Zinc Coated Steel Sheet
Metal Deck
19,530
451,886,235
Beams and Hot Rolled Structural Steel Columns
14,447
155,765,857
Flat Glass
Glazing
29,658
70,445,455
Aluminium
Metal Frame
1,471
25,263,477
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TOTAL
734,972,987
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COST ANALYSIS
Total building area: 196,982 m2 Total building cost: £590,946,000 (£3,000/m2)
SUPERSTRUCTURE
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CONCRETE + STEEL SUPERSTRUCTURE (EXISTING): ENVELOPE
£590,946,000 / 3 = £196,982,000 (concrete = £1,000/m2) (steel = £2,500/t) FIT-OUT
* Assumptions: 1. Total building cost is calculated with the assumption of £3,000/m2 (data online) 2. Superstructure, envelope and fit out are each a third of the total cost
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2.2 CARBON COPY A: OFFICE
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2.2 CARBON COPY A
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22 BISHOPSGATE
Precedent: 15 Clerkenwell Close, London, GROUPWORK + Amin Taha Architects Stone - Timber - Stone structure Source: https://www.archdaily. com/891018/15-clerkenwellclose-groupwork-plus-amintaha-architects
CONSTRUCTION METHODOLOGY
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Taking 15 Clerkenwell Close as a reference, the alternative proposal will build a stone exoskeleton for 22 Bishopsgate. Simultaneously, the project will replace the original concrete core with stacked stone (using granite, basalt or marble). Timber structures such as CLT slabs and glulam beams will be placed in-between, connecting the stone elements and forming together a sustainable construction.
600,000,000 £
400,000,000 0
200,000,000
COST COMPARISON
750,000,000 500,000,000 250,000,000 0
kgCO2e
EMBODIED CARBON COMPARISON
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Alternative
Existing
Alternative
-95.8%
-18.8%
IN EMBODIED CARBON
IN PROJECT COST
CORE
Stacked stone; Pre-tensioned limestone.
COLUMNS
Pre-tensioned limestone, cross-sectional area decreases from bottom to top,
LINTELS
Pre-tensioned stone, 600mm thickness all the time Limestone
BEAMS
Glulam beams + Partial cellular beams Softwood glulam + Hot rolled structural steel
FLOOR SLAB INNER FACADE OUTRIGGER
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STONE EXOSKELETON + TIMBER IN-BETWEEN + STONE CORE
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Existing
CLT floor slabs Sustainably sourced CLT Refer to the louver strategy, doubling the thermal layer Aluminium (bar abd rod) + Flat glass Use bracing on the exoskeleton instead Limestone
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2.2 CARBON COPY A
Left: Limestones in the quarry. Right: A typical cast-in connection used for concrete. Image source: The design of cast-in plates report, ©J.R.Henderson, published in Berkshire, 2017
Stone Exoskeleton
Stone - Timber Connection
A stone exoskeleton is used for quicker erection on site and allowing a curtain wall to sit 150mm from it so that both weathering and thermal performance remains high without the need for window interfaces and thermal bridging points. In turn leaving the envelope as high performance and lower in cost.
There are two main connections between stone and wood involved in the alternative project: the glulam beams and the core, and its connection with the exoskeleton. Therefore, internal steel plates can be used as the mediator for load transmission. By pre-designing the connection nodes, the metal pieces are firmly embedded in the stone with the help of mortar, the glulam beam is stabilized by metal anchors which tie it back to the stone structure.
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Right: Exposed timber structures in the 53-m-high (18-storey) Brock Commons Tallwood House.
Large Span Glulam Beam
CLT Slabs
Glulam members are built with individual laminations of structural timber and give an effective material usage.
CLT is a highly engineered wood product that is excellent for all sorts of different structures. CLT’s composition and method of manufacture offer huge opportunities, since the panel can be glued and worked into almost any shape and size.
The laminations are finger jointed to produce great lengths and are industrially bonded with adhesive so as to create the required size. Thanks to the lay-up of glulam, very large structural elements can be produced out of timber from smaller trees.
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Left: Long-span glued laminated timber beams, image source: https://www. structuremag.org/?p=16406
CLT has excellent strength and stiffness properties, which mean that CLT panels can compete with other more traditional structural materials in high-rise buildings.
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2.2 CARBON COPY A
STONE FRAME OPTIONS The size of the stone skeleton is closely related to the amount of material, which affects the final calculation of embodied carbon. Taking the maximum span of the CLT floor (6m) as a reference, three options were discussed at the beginning of the project: 3m column spacing + single-layer frame, 3m column spacing without lintel, and 6m column spacing + double-layer frame. When comparing the calculation results for the typical floor, the 6m + doublelayer frame option offers the highest performance in terms of sustainability.
3M SPACING COLUMNS WIT
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3M SPACING COLUMNS + SINGLE-STORY FRAME
LINTEL COLUMN
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TOTAL
Volume m3
Embodied Carbon kgCO2e
158.4
188,592
COLUMN
368
438,140
TOTAL
626,732
Volume m3
408.6
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Frame diagrams in elevation
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TH NO LINTEL
6M SPACING COLUMNS + DOUBLE-STORY FRAME
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Exploded axonometric, Typical floor of level 8 - 25. Not to scale, for identification purposes only. Structural and sustainability comparison.
Embodied Carbon kgCO2e
Volume m3
Embodied Carbon kgCO2e
486,479
LINTEL
79.1
94,176
486,479
COLUMN
181.8
216,452
TOTAL
310,628
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BEAM VARIATIONS
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VARIATION 1:STEEL CELLULAR BEAMS
Exploded axonometric, Typical fllor of Level 8 - 25. Not to scale, for identification purposes only. 200mm CLT slabs 762x267x197mm Universal beam
Volume m3
Embodied Carbon kgCO2e
CELLULAR BEAM
0.11
1,186
CLT SLABS
5.15
- 4,333
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TOTAL
- 3,147
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VARIATION 2:GLULAM BEAMS WITH SERVICE AREA
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Beam to core diagram, Typical floor of Level 8 - 25. Not to scale, for identification purposes only. 200mm CLT slabs embedded in the beam; 300x800mm Glulam beam; 533x165x66mm Universal beam.
Volume m3
Embodied Carbon kgCO2e
GLULAM BEAM
0.96
- 982
CLT SLABS
5.08
- 4,274
CELLULAR BEAM
0.02
216
TOTAL
- 5,040
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Existing structural plan of typical floors
STRUCTURAL PLANS The three main parts of the building: core, slabs and facade progress in a stepped sequence over time. The floor slabs are composite with cellular steel beams, providing a diaphragmaction restraint to the perimeter columns. The concrete core’s footprint at the ground floor is roughly 60 x 15 meters - is formed by walls that reduce their thickness as they rise to the top floors, accommodating the reduced structural demands of the upper levels in comparison to those of the lower ones, also reduces as a result of the lesser number of lifts and services that reach the top floors.
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SECTIONS AND ELEVATIONS
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Alternative Section.
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Alternative Elevation.
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CLOSE UP SECTION
Alternative Close-up Section. Floor composition: 200mm Raised floor 200mm CLT slab, embedded on the glulam beam 800mm Glulam beam Ceiling
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Wall composition: 500mm Stone exoskeleton 150mm Air cavity 410mm Inner facade, with 210mm insulation and double glazing
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EXPLODED AXONOMETRIC
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Glulam Beam (b) Softwood Glulam
Cellular Beam in Service Area (b) Hot Rolled Structural Steel
Pretensioned Stone Lintel Limestone
Stone Column (b) Limestone
Sustainably Sourced CLT
Glass + Metal Inner Skin Aluminium (bar and rod) Flat Glass
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CLT Slab (b)
Glulam Beam (a) Softwood Glulam
Cellular Beam in Service Area (a) Hot Rolled Structural Steel
Stone Bracing Limestone
Stone Core (a) Limestone
Stone Column (a) Limestone
CLT Slab (a) Sustainably Sourced CLT
Alternative axonometric, Level 8-25, Column 800x500 / Glulam beam 800x300 / UB 533x165x66 mm
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FACADE DETAIL
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Alternative facade detail.
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3D diagram of the facade detail. Knife plate connector helps to link the stone frame and glulam beam.
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EXTERNAL VIEW COMPARISON
Existing architectural appearance.
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source: https://www. buildington.co.uk/londonec2/22-24-bishopsgate/22bishopsgate/id/2171.
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Alternative architectural appearance. Conceptual Collage.
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2.2 CARBON COPY A
EMBODIED CARBON CALCULATIONS
VOLUME M3
EMBODIED CARBON KGCO2E
44,605
8,430,307
Cross Laminated Floor Slab Timber
30,046
- 25,278,392
Glulam
Beams
9,478
- 9,698,284
Flat Glass
Glazing
14,382
34,160,266
Aluminium
Metal Frame
1,141
19,601,477
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3,322,930
MATERIAL
ELEMENT Core
Limestone
External Column
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Stone Lintel
Hot Rolled Service Beams Structural Steel
TOTAL
30,538,305
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95.8% SAVING
Total building area: 196,982 m2 Total building cost: £590,946,000 (£3,000/m2) SUPERSTRUCTURE
ENVELOPE
COST
108,793
32,637,900
Cross Laminated Floor Slab Timber
150,230
37,557,500
Glulam
31,593
7,898,250
2,461(t)
6,152,500
ELEMENT Core
Limestone
External Column Stone Lintel
Beams
Hot Rolled Service Beams Structural Steel
TOTAL
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VOLUME M2/T
MATERIAL
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FIT-OUT
CONCRETE + STEEL SUPERSTRUCTURE (EXISTING): £590,946,000 / 3 = £196,982,000 (concrete = £1,000/m2) (steel = £2,500/t)
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COST ANALYSIS
84,246,150 + 196,982,000x2 = 478,210,150 18.8% SAVING
* Assumptions: 1. Total building cost is calculated with the assumption of £3,000/m2 2. Superstructure, envelope and fit out are each a third of the total cost 3. Building envelope and internal fit out stays the same 4. Stone = £300/m2, CLT = £250/m2, Glulam = £250/m2, Steel = £2,500/t
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2.3 WHAT IF?
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22 BISHOPSGATE
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ADDTIONAL INTERNAL COLUMNS
Additional columns diagram.
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The What If section provides another possibility for the office tower. If the client does not mind breaking the concept of no column working space and chooses to have additional internal glulam columns, the use of additional columns can help reduce the thickness of glulam beams, and there is no need to attach cellular beams to the side of the core to place the service area on the ceiling. The tower thus will have better sustainability performance.
200,000,000
£
400,000,000
600,000,000 Alternative
0
COST COMPARISON
750,000,000 500,000,000 0
250,000,000
kgCO2e
EMBODIED CARBON COMPARISON
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Existing
Existing
Alternative
-20.3%
IN EMBODIED CARBON
IN PROJECT COST
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-95.7%
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Glulam column - CLT slab connection By using an additional flat connection between the column and slabs, the strategy can lead to better fire performance, and can also reduce the length of the span required by CLT slabs, therefore reducing costs and embodied carbon.
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2.3 WHAT IF?
EMBODIED CARBON CALCULATIONS
MATERIAL
ELEMENT
VOLUME M3
EMBODIED CARBON KGCO2E
44,605
8,430,307
30,046
- 25,278,392
Core
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Limestone
External Column Stone Lintel
Cross Laminated Floor Slab Timber
Glulam
Beams and Columns
5,436
- 5,562,635
Flat Glass
Glazing
14,382
34,160,266
Aluminium
Metal Frame
1,141
19,601,477
TOTAL
31,351,023
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95.7% SAVING
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COST ANALYSIS
SUPERSTRUCTURE
ENVELOPE
FIT-OUT
ELEMENT
VOLUME M2
COST
108,793
32,637,900
150,230
37,557,500
27,180
6,795,000
Core Limestone
External Column
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MATERIAL
CONCRETE + STEEL SUPERSTRUCTURE (EXISTING): £590,946,000 / 3 = £196,982,000 (concrete = £1,000/m2) (steel = £2,500/t)
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Total building area: 196,982 m2 Total building cost: £590,946,000 (£3,000/m2)
Stone Lintel Cross Laminated Floor Slab Timber
Glulam
TOTAL
Beams and columns
76,990,400 + 196,982,000x2 = 470,954,400 20.3% SAVING
* Assumptions: 1. Total building cost is calculated with the assumption of £3,000/m2 2. Superstructure, envelope and fit out are each a third of the total cost 3. Building envelope and internal fit out stays the same 4. Stone = £300/m2, CLT = £250/m2, Glulam = £250/m2, Steel = £2,500/t
61
ADS 5 ROYAL COLLEGE OF ART TOWER 62
3.1
EXISTING CONDITION B: RESIDENTIAL
ROYAL COLLEGE OF ART
ADS 5 TOWER
63
ADS 5
3.1 EXISTING CONDITION B
ROYAL COLLEGE OF ART
ONE PARK DRIVE
One Park Drive is a residential skyscraper situated in the south west corner of Wood Wharf, within the Canary Wharf development on the Isle of Dogs, London. The building was designed by Herzog & de Meuron, is cylindrical in shape, and with 58-storeys comprising 468 private residential apartments.
RESIDENTIAL TOWER
The skyscraper was designed to have the appearance of a cylindrical tower, but the majority of the apartments have regular straight edges. This creates an aesthetic appearance that differentiates the building from the oblong-shaped office towers, but does not impact the quality of the apartments.
64
Canary Wharf, London Herzog de Meuron Photo from CBRE Residential
ROYAL COLLEGE OF ART
SITE AND LOCATION ADS 5 RESIDENTIAL TOWER
Wood Wharf Masterplan Scheme Development Plot A1
KEY INFORMATION Completion: Q1 2021 Height: 204.93m Storeys: 58 Residential Units: 468 Gross Internal Area (GIA): 54,656m2 Net Internal Area (NIA): 40,992m2 (75% of GIA)
65
ROYAL COLLEGE OF ART
ADS 5
3.1 EXISTING CONDITION B
TOWER OVERVIEW One Park Drive is a single building made up of three distinct typologies. Each typology evolved from a re-examination of city living, has its own distinct characteristics while also working together as a harmonious whole.
RESIDENTIAL TOWER
One Park Drive celebrates its communal spaces, with the residents’ amenities being on the first two floors, where they are fully integrated into the life of the building. The library and residents’ lounge are on the ground floor level, with the pool and gym on the first floor above. These interior spaces, radiating out from the central core of the building, are enhanced by their seamless interaction with the surrounding gardens and water.
66
Three apartment typologies
ROYAL COLLEGE OF ART RESIDENTIAL TOWER
The Cluster apartments form the heart of the building. Here the floorplates are mirrored and rotated to create a rhythmic visual complexity, while still maintaining the clarity of the internal spaces. The lower levels are connected with the parks and the water; the higher floors are connected with the sky.
ADS 5
The spiralling top of the building contains the Bay apartments. The orthogonal geometry of the apartments intersects the implicit curve of the building, creating the opportunity for double-height terraces which are recessed into the building. The design of the Bay apartments is focused on maximising light and the views across London.
The lower floors feature the Loft apartments – some of the largest apartments with high ceilings and wrap-around terraces. This location exploits their immediate connection to the surrounding green spaces and the waterfront.
Tower Overview
67
ROYAL COLLEGE OF ART
ADS 5
3.1 EXISTING CONDITION B
CONSTRUCTION METHODOLOGY The structural concept adopted for the tower superstructure typically consists of reinforced concrete flat slabs supported by reinforced concrete blade walls and columns. The core of the tower is located centrally within the internal layout and is partially enhanced by frame action of the surrounding tower.
RESIDENTIAL TOWER
Levels 10 through to 32 uses post-tension slabs. Praeter and AKT II developed the design and the use of post-tensioning to limit the deflections in the cantilevered areas due to the span of the cantilevered areas making it impossible to design as traditional RC without increasing slab depths or adding downstand beams.
68
Tower under construction Photo from Praeter Engineering Ltd
ROYAL COLLEGE OF ART ADS 5 RESIDENTIAL TOWER
Tower under construction Photo from Praeter Engineering Ltd
69
ROYAL COLLEGE OF ART
ADS 5
3.1 EXISTING CONDITION B
EXISTING STRUCTURAL PLANS
RESIDENTIAL TOWER
Bay
Cluster
Loft
70
0
5
10
20m
ROYAL COLLEGE OF ART ADS 5
0
5
10
20m Key plan showing how 1/4 of each floorplate is repeated to form one floor
RESIDENTIAL TOWER
The geometry of One Park Drive is expressed in the profile of the external facade for each typology Additional complexity is created by the stacking, rotation and mirroring of individual floor plates. This gives varying aspects to each apartment type establishing individuality within a unified whole. The terraces are naturally formed between the apartments’ enclosing walls and the outer edges of each floor plate, making them an intrinsic element of the apartment planning.
0
5
10
20m
71
ROYAL COLLEGE OF ART
ADS 5
3.1 EXISTING CONDITION B
EXISTING ELEVATIONS AND SECTIONS AOD 211.43
Level 56 Level 55
RESIDENTIAL TOWER
Level 54
Level 32 Level 31
Level 10
Level 02 Level 01 Ground Level 6.50
North Elevation 1:1000 1 North Elevation
72
1 : 500
ROYAL COLLEGE OF ART
AOD 211.43
Level 56 Level 55
AOD 211.43
Level 56 Level 55 Level 54
Level 54
ADS 5 RESIDENTIAL TOWER
Level 32 Level 31
Level 32 Level 31
Level 10
Level 10
Level 09
Level 09
Level 02
Level 02
Level 01
Level 01
Ground Level 6.50
Ground L 6.50
Section NE-SW 1:1000 1 Section AA' 1 : 500
2 Section BB' 1 : 500
73
ROYAL COLLEGE OF ART
ADS 5
3.1 EXISTING CONDITION B
CLOSE UP SECTION
EXTERIOR
INTERIOR
INTERIOR
INTERIOR
EXTERIOR
INTERIOR
RESIDENTIAL TOWER
Separating Wall composition: 25mm Finish 75mm Insulation 300mm Reinforced Concrete 75mm Insulation 25mm Finish
External Wall composition: 100mm Reconstituted Stone Cladding 200~500mm Reinforced Concrete 50mm Air Cavity 100mm Rigid Insulation 150mm Insulation 25mm Finish
Floor composition: 25mm Finish 150mm Insulation 230mm Reinforced Concrete 100 Shallow Decking 12.5mm Proprietary Metal Frame 12.5 mm Ceiling
0
74
Existing Close-up Section
1
2
4m
ROYAL COLLEGE OF ART
EXISTING EXPLODED AXONOMETRIC Glazing +Frame Aluminium (bar and rod) Flat Glass
Cladding Reconstituted Stone (Light Concrete)
Separating Wall Plasterboard
ADS 5
Bay
Concrete Shear Wall Reinforced Concrete
Concrete Core Reinforced Concrete
Concrete Slab 250mm Reinforced Concrete
Aluminium (bar and rod) Flat Glass
Cladding Reconstituted Stone (Light Concrete)
Separating Wall Plasterboard
Cluster
Concrete Shear Wall Reinforced Concrete
RESIDENTIAL TOWER
Glazing +Frame
Concrete Core Reinforced Concrete
Concrete Slab 250mm Reinforced Concrete
Glazing +Frame Aluminium (bar and rod) Flat Glass
Cladding Reconstituted Stone (Light Concrete)
Separating Wall Plasterboard
Loft
Concrete Shear Wall Reinforced Concrete
Concrete Core Reinforced Concrete
Concrete Slab 250mm Reinforced Concrete
Exploded axonometric: Loft, Cluster, Bay
75
ROYAL COLLEGE OF ART
ADS 5
3.1 EXISTING CONDITION B
RESIDENTIAL TOWER
EXISTING BALCONY DETAIL
76
Close-up detail of existing balcony
ROYAL COLLEGE OF ART ADS 5
EXTERIOR
INTERIOR
RESIDENTIAL TOWER
Close-up detail of existing balcony
Schock thermal breaks are used in the existing balcony system in order for the reinforced concrete floor slab to be continue onto the terraces.
4m
Structural thermal breaks for concrete balcony construction contain components that are cast into the concrete floor slab on the interior side, and into the concrete balcony on the exterior side. The assembly is engineered to carry the same design load as a conventional reinforced concrete balcony.
77
ADS 5 ROYAL COLLEGE OF ART
3.1 EXISTING CONDITION B
EMBODIED CARBON CALCULATIONS
MATERIAL
ELEMENT
VOLUME M3
EMBODIED CARBON KGCO2E
22,131.3
14,783,708
Core Reinforced Concrete
Structural Wall
RESIDENTIAL TOWER
Floor Slab Light Concrete
Cladding
3284.1
945,821
Flat Glass
Glazing
677.8
1,609,775
Aluminium
Metal Frame
299.4
5,141,596
Plasterboard
Separating Wall
3349.8
877,648
78
TOTAL
23,358,548
ROYAL COLLEGE OF ART
COST ANALYSIS
Total building area: 54,656m2
SUPERSTRUCTURE
ENVELOPE
£163,968,000 / 3 = £54,656,000 (concrete = £1,000/m2)
FIT-OUT
RESIDENTIAL TOWER
CONCRETE SUPERSTRUCTURE (EXISTING):
ADS 5
Total building cost: £163,968,000 (£3,000/m2)
* Assumptions: 1. Total building cost is calculated with the assumption of £3,000/m2 2. Superstructure, envelope and fit out are each a third of the total cost
79
80 TOWER
3.2 CARBON COPY B: RESIDENTIAL
ROYAL COLLEGE OF ART
ADS 5
ROYAL COLLEGE OF ART
ADS 5 TOWER
81
82
-20,000,000
Existing
Stone
Stone + Timber
0
0
10,000,000
50,000,000
20,000,000
100,000,000 150,000,000 200,000,000
£
COST COMPARISON
-10,000,000
kgCO2e
EMBODIED CARBON COMPARISON
RESIDENTIAL TOWER
ROYAL COLLEGE OF ART
ADS 5
3.2 CARBON COPY B
ONE PARK DRIVE
VARIATION 1: STONE
VARIATION 2: TIMBER + STONE STRUCTURAL WALLS AND CORE
Existing
Stone
Stone + Timber
Two carbon copies have been proposed in order to test the best alternative for the tower in terms of embodied carbon, costs and aesthetics.
ROYAL COLLEGE OF ART
CONSTRUCTION METHODOLOGY
The first variation is to replace all reinforced concrete with post-tensioned stone. Stone is stronger than concrete, hence less amount of it is needed for the same structure.
VARIATION 1: STONE
ADS 5
The second variation also uses post-tensioned stone for the core and structural walls but floor slabs and separating walls are CLT, which lowers the overall weight, embodied carbon and costs of the tower.
VARIATION 2: TIMBER + STONE
-111%
IN EMBODIED CARBON
IN EMBODIED CARBON
-23.3%
-24.5%
IN PROJECT COST
IN PROJECT COST
CORE
Post-tensioned stone
Post-tensioned stone
STRUCTURAL WALLS
Post-tensioned stone
Post-tensioned stone
SEPARATING WALLS
Plasterboard
CLT
FLOOR SLAB
Post-tensioned stone
CLT
BEAMS AND COLUMNS
-
Glulam
RESIDENTIAL TOWER
-50%
83
RESIDENTIAL TOWER
ROYAL COLLEGE OF ART
ADS 5
3.2 CARBON COPY B
Post-tensioned stone Photo from R. Pedreschi
Post-tensioned Stone In contemporary applications stone is attached to buildings in a variety of ways, connecting to the supporting structure using steel angles and brackets or by incorporating the stone in a pre-cast concrete panel. By post-tensioning the stone, prefabricated panels can be made which eliminate either the secondary steelwork and subsequent site operations or avoid the need for pre-cast concrete panels.
84
Replacing reinforced concrete with stone also means that less amount of the material is needed for the same weight and building structure. This further reduces emobided carbon and costs of construction.
ROYAL COLLEGE OF ART ADS 5 RESIDENTIAL TOWER
CLT residential interior Photo from PATH Architecture
Timber interior + exposed beams and columns Mass timber such as CLT and Glulam is only used in the internal walls, floor slabs, beams and columns of the proposed carbon copies. This is due to the UK policy which prohibits the use of timber materials in the external walls of buildings over 18m tall. No extra wall or floor finishes are necessary as the timber can be left exposed for aesthetic pruposes. Using timber for the internal components has the benefit of reducing the overall weight of the building, hence less foundation piles are needed.
85
ROYAL COLLEGE OF ART
ADS 5
3.2 CARBON COPY B
STRUCTURAL PLANS
Bay
RESIDENTIAL TOWER
0
5
10
20m
5
10 10
20m 20m
Cluster
Loft
VARIATION 1:
86
STONE
0
0
5
ROYAL COLLEGE OF ART ADS 5
0
5
10
20m
RESIDENTIAL TOWER
VARIATION 2:
00
55
10 10
20m 20m
TIMBER + STONE STRUCTURAL WALLS AND CORE
87
ROYAL COLLEGE OF ART
ADS 5
3.2 CARBON COPY B
CLOSE UP SECTIONS
EXTERIOR
INTERIOR
INTERIOR
INTERIOR
EXTERIOR
INTERIOR
Balcony composition: 200mm Post-tensioned Stone Thermal break
RESIDENTIAL TOWER
Separating Wall composition: 25mm Finish 75mm Insulation 250mm Post-tensioned Stone 75mm Insulation 25mm Finish
External Wall composition: 250mm Post-tensioned Stone 50mm Air Cavity 150mm Insulation 25mm Finish
Floor composition: 25mm Finish 150mm Insulation 200mm Post-tensioned Stone 12.5 mm Ceiling
VARIATION 1:
88
STONE
0
1
2
4m
140x225mm Glulam Beams 100mm CLT wall
EXTERIOR
ROYAL COLLEGE OF ART
Internal wall composition:
INTERIOR
200mm Post-tensioned Stone Thermal break
ADS 5
Balcony composition:
Separating Wall composition: INTERIOR
25mm Finish 75mm Insulation 250mm Post-tensioned Stone 75mm Insulation 25mm Finish
RESIDENTIAL TOWER
INTERIOR
External Wall composition: 250mm Post-tensioned Stone 50mm Air Cavity 150mm Insulation 25mm Finish
EXTERIOR
INTERIOR
Floor composition: 25mm Finish 150mm Insulation 250mm CLT Floor Slab
VARIATION 2:
0
1
2
4m
TIMBER + STONE STRUCTURAL WALLS AND CORE
89
ROYAL COLLEGE OF ART
ADS 5
3.2 CARBON COPY B
EXPLODED AXONOMETRIC
Glazing +Frame Aluminium (bar and rod) Flat Glass
Separating Wall Plasterboard
Stone Structural Wall Post-tensioned stone
Bay
Stone Core Post-tensioned stone
Stone Slab
RESIDENTIAL TOWER
200mm Post-tensioned stone slab
Glazing +Frame Aluminium (bar and rod) Flat Glass
Separating Wall Plasterboard
Stone Structural Wall Post-tensioned stone
Cluster
Stone Core Post-tensioned stone
Stone Slab 200mm Post-tensioned stone slab
Glazing +Frame Aluminium (bar and rod) Flat Glass
Separating Wall Plasterboard
Stone Structural Wall Post-tensioned stone
Stone Core Post-tensioned stone
Stone Slab 200mm Post-tensioned stone slab
VARIATION 1:
90
STONE
Loft
ROYAL COLLEGE OF ART
Glazing +Frame Aluminium (bar and rod) Flat Glass
Beams and Columns Glulam
Separating Wall CLT
ADS 5
Bay
Timber Floor Slab CLT
Stone Structural Wall Post-tensioned stone
Stone Core Post-tensioned stone
Stone Balcony Slab 200mm Post-tensioned stone slab
RESIDENTIAL TOWER
Glazing +Frame Aluminium (bar and rod) Flat Glass
Beams and Columns Glulam
Separating Wall CLT
Timber Floor Slab
Cluster
CLT
Stone Structural Wall Post-tensioned stone
Stone Core Post-tensioned stone
Stone Balcony Slab 200mm Post-tensioned stone slab
Glazing +Frame Aluminium (bar and rod) Flat Glass
Beams and Columns Glulam
Separating Wall CLT
Timber Floor Slab CLT
Loft Stone Structural Wall Post-tensioned stone
Stone Core Post-tensioned stone
Stone Balcony Slab 200mm Post-tensioned stone slab
VARIATION 2: TIMBER + STONE STRUCTURAL WALLS AND CORE
91
ROYAL COLLEGE OF ART
ADS 5
3.2 CARBON COPY B
RESIDENTIAL TOWER
BALCONY DETAIL
92
Close-up detail of proposed balcony
ROYAL COLLEGE OF ART ADS 5
EXTERIOR
INTERIOR
RESIDENTIAL TOWER
Close-up detail of proposed balcony
1m x 1m post-tensioned stone slabs are used for the proposed balcony system. They are connected to the stone structural walls with a 50mm gap for thermal insulation. This system can be used for both the stone and stone + timber carbon copies.
4m
93
ROYAL COLLEGE OF ART
ADS 5
3.2_CARBON COPY BB 3.2 CARBON COPY
FOUNDATION PILES COMPARISON
EXISTING
ST
RESIDENTIAL TOWER
635,385 KN
X127
Royal College of Art
24 m
1.8 m
* 5000 kN / pile assumption 94
94
CFA PILES
ADS 5 COLLEGE OF ART ROYAL
TONE
STONE + TIMBER
ADS 5
417,186 KN
X108
X83
CFA PILES
CFA PILES
15% Emodied Carbon Savings
35% Emodied Carbon Savings
RESIDENTIALTOWER TOWER RESIDENTIAL
539,740 KN
Royal College of Art
95 95
ROYAL COLLEGE OF ART
ADS 5
3.2 CARBON COPY B
RESIDENTIAL TOWER
INTERNAL FINISHES COMPARISON
96
Existing bedroom interior
ROYAL COLLEGE OF ART ADS 5 RESIDENTIAL TOWER
Stone finishes bedroom interior
Timber finishes bedroom interior
97
ADS 5 ROYAL COLLEGE OF ART
3.2 CARBON COPY B
EMBODIED CARBON CALCULATIONS
VARIATION 1: STONE
MATERIAL
ELEMENT
VOLUME M3
EMBODIED CARBON KGCO2E
21,589.6
3,756,590
Core Sandstone
Structural Wall
RESIDENTIAL TOWER
Floor Slab
Flat Glass
Glazing
677.8
1,609,775
Aluminium
Metal Frame
299.4
5,141,596
Plasterboard
Separating Wall
4080
1,068,960
TOTAL
11,576,922
98
50% SAVING
ROYAL COLLEGE OF ART
VARIATION 2: TIMBER + STONE STRUCTURAL WALLS AND CORE
ELEMENT
VOLUME M3
EMBODIED CARBON KGCO2E
13,925.7
2,423,072
13,808.6
-11,613,033
ADS 5
MATERIAL
Core Sandstone
Structural Wall Balcony Slab
Separating Wall Hardwood
Beams and Columns 144.4
-147,721
Flat Glass
Glazing
677.8
1,609,775
Aluminium
Metal Frame
299.4
5,141,596
TOTAL
RESIDENTIAL TOWER
Floor Slab Cross Laminated Timber
-2,586,311 111% SAVING
99
ADS 5 ROYAL COLLEGE OF ART
3.2 CARBON COPY B
COST ANALYSIS
Total building area: 54,656m2 Total building cost: £163,968,000 (£3,000/m2)
CONCRETE SUPERSTRUCTURE (EXISTING):
RESIDENTIAL TOWER
SUPERSTRUCTURE
FIT-OUT
ENVELOPE
£163,968,000 / 3 = £54,656,000 (concrete = £1,000/m2)
STONE SUPERSTRUCTURE (VARIATION 1): £300/m2 x 54,656m2 = £16,396,800 (stone = £300/m2)
STONE + TIMBER SUPERSTRUCTURE (VARIATION 2): (£300/m2 x 16,396.8m2) + (£250/m2 x 38,259.2m2)= £14,483,840 (stone = £300/m2) (CLT = £250/m2)
100
* Assumptions: 1. Total building cost is calculated with the assumption of £3,000/m2 2. Superstructure, envelope and fit out are each a third of the total cost 3. Building envelope and internal fit out stays the same 4. Stone = £300/m2, CLT = £250/m2 5. Variation 2 uses 70% CLT and 30% stone
ROYAL COLLEGE OF ART
VARIATION 1: STONE
MATERIAL
ELEMENT
COST
54,656
£16,396,800
Core Sandstone
Structural Wall
ADS 5
VOLUME M2
Balcony Slab £125,708,800 + 54,656,000x2 = £125,708,800
TOTAL
VARIATION 2: TIMBER + STONE STRUCTURAL WALLS AND CORE
MATERIAL
ELEMENT
VOLUME M2
COST
16,397
£4,919,040
38,259
£9,564,800
RESIDENTIAL TOWER
23.3% SAVING
Core Sandstone
Structural Wall Balcony Slab
Cross Laminated Timber
TOTAL
Floor Slab Separating Wall £14,483,840 + 54,656,000x2 = £123,795,840 24.5% SAVING
101
102 TOWER
4 DATA COMPARISONS
ROYAL COLLEGE OF ART
ADS 5
ROYAL COLLEGE OF ART
ADS 5 TOWER
103
ADS 5 ROYAL COLLEGE OF ART
4.0 DATA COMPARISONS
22 BISHOPSGATE EMBODIED CARBON COMPARISON
VARIATI STONE
EXISTING
VOLUME M3
EMBODIED CARBON KGCO2E
VOLUM M3
0
0
44,605
Cross Laminated Floor Slab Timber
0
0
30,046
Glulam
Beams and Columns
0
0
9,478
Flat Glass
Glazing
29,658
70,445,455
14,382
Aluminium
Metal Frame
1,471
25,263,477
1,141
Hot Rolled Structural Steel
Beams and Columns
14,447
155,765,857
308
Zinc Coated Steel Sheet
Metal Deck
19,530
451,886,235
0
Reinforced Concrete
Core
37,604
25,119,672
0
Light Concrete
Floor Slab
22,535
6,492,291
0
MATERIAL
ELEMENT Core
Limestone
External Column
OFFICE TOWER
Stone Lintel
104
TOTAL
734,972,987
VOLUME M3
EMBODIED CARBON KGCO2E
8,430,307
44,605
8,430,307
- 25,278,392
30,046
- 25,278,392
- 9,698,284
5,436
- 5,562,635
34,160,266
14,382
34,160,266
19,601,477
1,141
19,601,477
3,322,930
0
0
0
0
0
0
0
0
0
0
0
30,538,305
31,351,023
95.8% SAVING
95.7% SAVING
OFFICE TOWER
EMBODIED CARBON KGCO2E
ADS 5
ME
VARIATION 2: STONE - TIMBER - STONE WITH ADDITIONAL COLUMNS
ROYAL COLLEGE OF ART
ION 1: - TIMBER - STONE
105
ADS 5 ROYAL COLLEGE OF ART
4.0 DATA COMPARISONS
22 BISHOPSGATE COST COMPARISON
EXISTING
COST £
MATERIAL
ELEMENT Core
Limestone
External Column
OFFICE TOWER
Stone Lintel
Superstructure
196,982,000
Cross Laminated Timber
Floor Slab
Glulam
Beams and Columns
Hot Rolled Structural Steel
Beams and Columns
Envelope
196,982,000
-
Fitout
196,982,000
-
TOTAL
590,946,000
106
* Assumptions: 1. Total building cost is calculated with the assumption of £3,000/m2 2. Superstructure, envelope and fit out are each a third of the total cost 3. Building envelope and internal fit out stays the same 4. Stone = £300/m2, CLT = £250/m2, Glulam = £250/m2, Steel = £2,500/t
ROYAL COLLEGE OF ART
QUANTITY M2/T
COST £
QUANTITY M2/T
COST £
108,793
32,637,900
108,793
32,637,900
150,230
37,557,500
150,230
37,557,500
31,593
7,898,250
27,876
6,795,000
2,461(t)
6,152,500
0
0
196,982,000
196,982,000
196,982,000
196,982,000
478,210,150
470,954,400
18.8% SAVING
20.3% SAVING
OFFICE TOWER
VARIATION 2: STONE - TIMBER - STONE WITH ADDITIONAL COLUMNS ADS 5
VARIATION 1: STONE - TIMBER - STONE
107
ADS 5 ROYAL COLLEGE OF ART
4.0 DATA COMPARISONS
ONE PARK DRIVE EMBODIED CARBON COMPARISON EXISTING
MATERIAL
ELEMENT
VOLUME M3
EMBODIED CARBON KGCO2E
VOLUM M3
22,131.3
14,783,708
0
3284.1
945,821
0
0
0
21,589.6
0
0
0
Core Reinforced Concrete
Structural Wall
RESIDENTIAL TOWER
Floor Slab Light Concrete
Cladding Core Structural Wall
Sandstone Floor Slab Balcony Slab Floor Slab Cross Laminated Timber Separating Wall Hardwood
Beams and Columns
0
0
0
Flat Glass
Glazing
677.8
1,609,775
677.8
Aluminium
Metal Frame
299.4
5,141,596
299.4
Plasterboard
Separating Wall
3349.8
877,648
4080
108
TOTAL
23,358,548
VOLUME M3
EMBODIED CARBON KGCO2E
0
0
0
0
0
0
3,756,590
13,925.7
2,423,072
0
13,808.6
-11,613,033
0
144.4
-147,721
1,609,775
677.8
1,609,775
5,141,596
299.4
5,141,596
1,068,960
0
0
11,576,922
-2,586,311
-50% SAVING
-111% SAVING
RESIDENTIAL TOWER
EMBODIED CARBON KGCO2E
ADS 5
6
VARIATION 2: TIMBER + STONE STRUCTURAL WALLS AND CORE
ROYAL COLLEGE OF ART
ME
VARIATION 1: STONE
109
ADS 5 ROYAL COLLEGE OF ART
4.0 DATA COMPARISONS
ONE PARK DRIVE COST COMPARISON
EXISTING
COST £
MATERIAL
ELEMENT Core
Sandstone
RESIDENTIAL TOWER
Superstructure
Structural Wall
54,656,000
Balcony Slab Floor Slab
Cross Laminated Timber
Separating Wall
Envelope
54,656,000
-
Fitout
54,656,000
-
TOTAL
590,946,000
110
* Assumptions: 1. Total building cost is calculated with the assumption of £3,000/m2 2. Superstructure, envelope and fit out are each a third of the total cost 3. Building envelope and internal fit out stays the same 4. Stone = £300/m2, CLT = £250/m2 5. Variation 2 uses 70% CLT and 30% stone
ROYAL COLLEGE OF ART
VARIATION 1: STONE
VARIATION 2: TIMBER + STONE STRUCTURAL WALLS AND CORE
QUANTITY M2/T
COST £
54,656
£16,396,800
16,397
£4,919,040
38,259
£9,564,800
-
54,656,000
54,656,000
54,656,000
54,656,000
£125,708,800
£123,795,840
23.3% SAVING
24.5% SAVING
RESIDENTIAL TOWER
COST £
ADS 5
QUANTITY M2/T
111
112 TOWER
5 FINDINGS
ROYAL COLLEGE OF ART
ADS 5
ROYAL COLLEGE OF ART
ADS 5 TOWER
113
114
0
200,000,000
400,000,000
£
COST COMPARISON
600,000,000
0
ROYAL COLLEGE OF ART
250,000,000
500,000,000
kgCO2e 750,000,000
EMBODIED CARBON COMPARISON
TOWER
ADS 5
5.0 FINDINGS
OVERALL SAVINGS
22 BISHOPSGATE (OFFICE TOWER)
Existing Alternative What If
Existing
Alternative
What If
0
50,000,000
100,000,000 150,000,000 200,000,000
£ -20,000,000
-10,000,000
0
kgCO2e 10,000,000
EMBODIED CARBON COMPARISON
ADS 5
COST COMPARISON
20,000,000
ROYAL COLLEGE OF ART
ONE PARK DRIVE (RESIDENTIAL TOWER)
Stone Stone + Timber
Existing
Stone
Stone + Timber TOWER
Existing
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ADS 5 ROYAL COLLEGE OF ART
5.0 FINDINGS
22 BISHOPSGATE
-96%
-18.8%
IN EMBODIED CARBON
IN PROJECT COST
PROS
TOWER
Less amount of stone is needed for the same structural properties (around half the dimensions of concrete walls); CLT / glulam are carbon sequestering materials; Overall lighter weight of building so less foundation piles needed; Timber can be left exposed without extra finishes for aesthetic purposes.
CONS Requires more mature, clear, industrialized construction processes; Requires more skilled labour; Construction time may be longer; As an alternative to the original double skin system, the performance of the new stone-thermal envelope should be studied in more detail;
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Requires stronger response to lateral force.
ONE PARK DRIVE
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5.0 FINDINGS
STONE
IN EMBODIED CARBON
-23.3% IN PROJECT COST
Less amount of stone is needed for the same structural properties (around half the dimensions of concrete walls); Thickness of stone floor slabs can also be less than concrete slabs; Overall reduction in embodied carbon and costs.
ADS 5
-50%
PROS
CONS Requires more skilled labour; Construction time may be longer.
TOWER
TIMBER + STRUCTURAL WALLS AND CORE
PROS
-111% IN EMBODIED CARBON
-24.5% IN PROJECT COST
Less amount of stone is needed for the same structural properties (around half the dimensions of concrete walls); Timber is a carbon sequestering material; Overall lighter weight of building so less foundation piles needed; Timber can be left exposed without extra finishes for aesthetic purposes; Carbon negative.
CONS Requires more skilled labour; Construction time may be longer; Slight increase in cost.
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TOWER
ROYAL COLLEGE OF ART
ADS 5
5.0 FINDINGS
22 Bishopsgate, City of London, PLP Architecture. Image CC credit: Matt Brown – flickr
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One Par Drive, Canary Wharf, Herzog de Meuron. Photographed by Lee Mawdsley
ROYAL COLLEGE OF ART ADS 5
CONCLUSION TO THE TOWER TYPOLOGY
TOWER
Following the Stone Tower Research Project where Groupwork and other consultants have proposed a notional 30-storey commercial office tower in central London, we have taken their optimal scenario (stone exoskeleton + CLT floors) and tested it on the latest and second tallest office tower in the City of London 22 Bishopsgate. The combination of replacing traditional concrete and steel frame with stone exoskeleton and timber slabs and beams lead to an overall reduction in embodied carbon and cost, without comprising on office internal space or appearance. The facade of the tower differs slightly from the original as a result of the stone exoskeleton and bracing system, but overall shape and layout of building are kept the same. We also chose to look at One Park Drive in order to see if there are any limitations to our carbon copy proposals for a residential tower. Both the stone and stone + timber proposals led to a reduction in embodied carbon and cost, while keeping the dinstinctive circular shape of the floorplates and internal unit sizes.
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120 TOWER
6 MENU OF COMPONENTS
ROYAL COLLEGE OF ART
ADS 5
ROYAL COLLEGE OF ART
ADS 5 TOWER
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ADS 5
22 BISHOPSGATE
TOWER
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6.0 MENU OF COMPONENTS
Exploded axonometric, Typical fllor of Level 8 - 25. Not to scale, for identification purposes only.
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200mm CLT slabs 762x267x197mm Universal beam
ROYAL COLLEGE OF ART ADS 5 TOWER
Beam to core diagram, Typical floor of Level 8 - 25. Not to scale, for identification purposes only. 200mm CLT slabs embedded in the beam; 300x800mm Glulam beam; 533x165x66mm Universal beam.
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TOWER
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ADS 5
6.0 MENU OF COMPONENTS
Alternative Close-up Section. Floor composition: 200mm Raised floor 200mm CLT slab, embedded on the glulam beam 800mm Glulam beam Ceiling
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Wall composition: 500mm Stone exoskeleton 150mm Air cavity 410mm Inner facade, with 210mm insulation and double glazing
ROYAL COLLEGE OF ART ADS 5
Glulam Beam (b) Softwood Glulam
Cellular Beam in Service Area (b) Hot Rolled Structural Steel
Pretensioned Stone Lintel Limestone
Stone Column (b) Limestone
CLT Slab (b) Sustainably Sourced CLT
Aluminium (bar and rod) Flat Glass
TOWER
Glass + Metal Inner Skin
Glulam Beam (a) Softwood Glulam
Cellular Beam in Service Area (a) Hot Rolled Structural Steel
Stone Bracing Limestone
Stone Core (a) Limestone
Stone Column (a) Limestone
CLT Slab (a) Sustainably Sourced CLT
Alternative axonometric, Level 8-25, Column 800x500 / Glulam beam 800x300 / UB 533x165x66 mm
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ADS 5 TOWER
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6.0 MENU OF COMPONENTS
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Alternative facade detail.
ROYAL COLLEGE OF ART ADS 5 TOWER
3D diagram of the facade detail. Knife plate connector helps to link the stone frame and glulam beam.
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ADS 5
6.0 MENU OF COMPONENTS
TOWER
ROYAL COLLEGE OF ART
ONE PARK DRIVE
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Close-up detail of proposed balcony
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EXTERIOR
INTERIOR
TOWER
Close-up detail of proposed balcony
4m
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ROYAL COLLEGE OF ART
ADS 5
6.0 MENU OF COMPONENTS
EXTERIOR
INTERIOR
INTERIOR
INTERIOR
EXTERIOR
INTERIOR
Balcony composition: 200mm Post-tensioned Stone Thermal break
TOWER
Separating Wall composition: 25mm Finish 75mm Insulation 250mm Post-tensioned Stone 75mm Insulation 25mm Finish
External Wall composition: 250mm Post-tensioned Stone 50mm Air Cavity 150mm Insulation 25mm Finish
Floor composition: 25mm Finish 150mm Insulation 200mm Post-tensioned Stone 12.5 mm Ceiling
VARIATION 1:
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STONE
0
1
2
4m
140x225mm Glulam Beams 100mm CLT wall
EXTERIOR
ROYAL COLLEGE OF ART
Internal wall composition:
INTERIOR
200mm Post-tensioned Stone Thermal break
ADS 5
Balcony composition:
Separating Wall composition: INTERIOR
INTERIOR
TOWER
25mm Finish 75mm Insulation 250mm Post-tensioned Stone 75mm Insulation 25mm Finish
External Wall composition: 250mm Post-tensioned Stone 50mm Air Cavity 150mm Insulation 25mm Finish
EXTERIOR
INTERIOR
Floor composition: 25mm Finish 150mm Insulation 250mm CLT Floor Slab
VARIATION 2:
0
1
2
4m
TIMBER + STONE STRUCTURAL WALLS AND CORE
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ROYAL COLLEGE OF ART
ADS 5
6.0 MENU OF COMPONENTS
Glazing +Frame Aluminium (bar and rod) Flat Glass
Separating Wall Plasterboard
Stone Structural Wall Post-tensioned stone
Bay
Stone Core Post-tensioned stone
Stone Slab 200mm Post-tensioned stone slab
Glazing +Frame
TOWER
Aluminium (bar and rod) Flat Glass
Separating Wall Plasterboard
Stone Structural Wall Post-tensioned stone
Cluster
Stone Core Post-tensioned stone
Stone Slab 200mm Post-tensioned stone slab
Glazing +Frame Aluminium (bar and rod) Flat Glass
Separating Wall Plasterboard
Stone Structural Wall Post-tensioned stone
Stone Core Post-tensioned stone
Stone Slab 200mm Post-tensioned stone slab
VARIATION 1:
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STONE
Loft
ROYAL COLLEGE OF ART
Glazing +Frame Aluminium (bar and rod) Flat Glass
Beams and Columns Glulam
Separating Wall CLT
ADS 5
Bay
Timber Floor Slab CLT
Stone Structural Wall Post-tensioned stone
Stone Core Post-tensioned stone
Stone Balcony Slab 200mm Post-tensioned stone slab
Glazing +Frame Aluminium (bar and rod) Flat Glass
Beams and Columns
TOWER
Glulam
Separating Wall CLT
Timber Floor Slab
Cluster
CLT
Stone Structural Wall Post-tensioned stone
Stone Core Post-tensioned stone
Stone Balcony Slab 200mm Post-tensioned stone slab
Glazing +Frame Aluminium (bar and rod) Flat Glass
Beams and Columns Glulam
Separating Wall CLT
Timber Floor Slab CLT
Loft Stone Structural Wall Post-tensioned stone
Stone Core Post-tensioned stone
Stone Balcony Slab 200mm Post-tensioned stone slab
VARIATION 2: TIMBER + STONE STRUCTURAL WALLS AND CORE
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