Social Housing -creating social and extended community living spaces for a more sociable housing strategy in Ampthill Square Estate, Somers Town
Claire Taggart Unit 22 BENVGA08 Design Realisation
Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 1
Contents: Project Introduction 2 3 6 8
Unit 22 Brief and Agenda Project Agenda and Aims Project Brief Building Programme
01 Building Form, Systems, Planning and Context 8 8 9 10
-Site Analysis Use and History Site Location Local Development Plans HS2 Demolition Plans
11 11 13
Site Issues to be addressed Design Pollution
14 14 15
-Planning Policies Unitary Development Plans Local Development Strategy
17 20 21 22 26 27 31 28 29 30
-Building Form Fifth Floor Plan Overall Section Floor Plans Tower Retrofit Scheme Interventions into Existing -Building Systems Access and Circulation Systems and Services Fire Strategies and Escape Routes
32 33 34 35 39 40 42 44 46 48 49 50 52 53 54
1
02 Building Construction- Area of Focus Overall Strategy Key Structural Systems Existing Structure Reinforcements Underpinning Balcony Extensions Tensegrity Systems Facade and Floor Systems Constructing a Landscape Hyperboloid Towers Connecting Existing to New Towers Tower Connections Suspended Deck System Deck Framework and Panels Balance and Anchoring
56 58 60 60 61 62
Skins Building Envelope Roof Structure Process of Construction Connections Processes of Manufacture
63
03 Building Performance
63 64 65 66 66 67 68 69
Material Sourcing User Comfort and Experience Air Pressure and Moisture Control Exhaust Ventilation and interstitial condensation External Insulation Wind Energy Micro-Turbines Wind- Driven and Stack Ventilation
70 71 72 73 74 76 77 78
Thermal Barriers Heating Strategy Sun Path and Shading Day lighting Solar Gain and Heating Solar Harvesting Rainwater Collection Air Quality
79
04 Building Delivery
80 81 82 83 84 85
Client, Funding and Users Procurement Route Role of Contractors and Suppliers Role of Consultants Role of Suppliers Construction Sequence
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Bibliography
Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 1
Unit 22 Agenda and Project Starting Point Vulnerability as Framework As a general condition affecting many parts of our world vulnerability could be viewed in many different ways. As part of a design program our perspective will focus on how the protection of vulnerable realities requires a change in design habits. International standards of design procedures are still having Modernity as a main conceptual and methodological framework. In this introduction, the definition of vulnerability will inevitably be linked to the evolution and influence of Modernity. We will first postulate Modernity has been an important source of vulnerability, extracting ideas from authors around “Risk Society” notions. But this production of vulnerability was not a part of Modernity’s set of goals. Therefore, while being a major cause, Modernity has not included vulnerability as a language, as a cultural principle or as a sensibility.
Somers Town Vulnerable Communities The project starting point was looking at Vulnerable Communities in Somers Town as communities ‘cut-out’ of previous environments and placed in a new one or having their environment cut-out from around them. The scheme aims to re-construct a new social living environment to connect these communities to benefit from one another.
Maybe only the technical rise of lighter materials and the use of previously considered weak techniques could suppose an attempt to face vulnerability as a main characteristic of the inhabitable world after Modernity. But this shy flirt with weakness did not mean Modernity could easily evolve to care for vulnerable realities. The first reason we will uphold for this is that in fact Modern traditions are still fighting for a first set of objectives that has never been fully achieved. The second reason is that Modernity is not only lacking anthropological and ecological clues on its route but includes logic and thought principles that are directly incompatible with those perspectives. Dare to Care, is a proposal to go beyond modern traditions on design and to face a new set of goals less “manifesto format” and more build up through others’ contributions and benefit achievements. ‘Dare to Care’ encourages design to empower identified ‘vulnerable communities’ ignored by the ‘modern world,’ through regognition of human vulnerablities and consideration of spaces of protection, intimacy and closeness. Condsideration of building merely as ‘construction’ is challenged and ‘good architecture’ is distinguished through use of different materials and methods of construction as well as careful consideration of the impact of the building on all involved and affected and the environmental and social implications of programme and construction. Connecting Vulnerable Communities
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Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 1
Project Introduction
Social Housing Agenda use and effects of communal spaces in housing
The project aims to create more “social� spaces in Ampthill Square Housing Estate, Somers Town, Camden, improving and extending existing private and public spaces and providing new community facilities on site, attempting to combat social isolation through encouragement of community interaction. The Social Housing scheme for Ampthill Square Estate aims to create model project for possible future housing strategies in other estates in the borough or nationwide, creating direct access onsite community facilities and services on a small scale. The project will focus primarily on community groups for which environmental and social isolation is a major problem, providing specialized spaces and services for their needs.
Redefining Public/Shared Spaces:
completely public shared space
openly observed interaction
unease and discomfort
open to anyone and overlooked
brings strangers close to home
forced interaction
withdrawal and avoidance
isolation
non-specific programme or use
no feeling of purpose or ownership of space
spaces left unused
crime in disused spaces
fear of using spaces
protected social spaces
more private interaction
designed for specific community needs
motive to use space, not forcing interaction
comfortable setting to meet neighbours
spaces used and inhabited regularly
good community relationships
more humanscale spaces for smaller groups
less intimidating, more attractive spaces
natural surveillance through use
feeling of security
In particular the scheme aims to empower new migrant women in Somers Town from Bangladeshi, Somali, Ethiopian and other minority communities and combat isolation, mental health problems and depression through social opportunities and networks, development of language and working skills and involvement in the local community. The project aims to give them time off from family care responsibilities through care exchange services, giving more time for social and other activities. These women make up one of the largest groups resident in the estate during the daytime and will play a key role in construction, management, running and maintenance of the facilities.
smaller enclosed shared spaces
social housing
Key Project Aims: -Empower the women and through increased social opportunities, community involvement and development of working skills -Improve and extend social living spaces on a gradient from private to public -Give opportunity for increased social interaction between neighbours whilst avoiding forced encounters -Set up a network of time, labour and services exchange
Key Social and Architectural Aims in Simultaneous Project Stages:
improve social living spaces on a gradient from private to public
give opportunity for increased social interaction between neighbours
set up a network of time and labour share and exchange through established connections
give access tospecialised social and community spaces for specific community needs
extend existing kitchen and living room spaces opened up to neighbours
create new garden spaces for social encounters and connect towers
provide spaces within existing towers for childcare and home care exchange
construct library, play and exercise centre, teaching rooms, gardens and communtiy hall
-Provide easy access to otherwise inaccessible or inconvenient community facilities and services, providing specialised spaces for specific community needs -Make the facilities as self-sufficient as possible through energy and water harvesting and sharing of spaces and services.
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Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 1
Social Actions Animating key social interactions of the project
Zoetrope Animation connect play
grow chat
share
meet
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exercise
Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 1
Members of Somers Town Community were asked about issues/difficulties in their home/community life and how they might solve them...
In conversations with members of Somers Town community it was clear that more social interaction between groups was needed. Although the new project will be for the whole of Ampthill Square Estate community it will have a particular focus on the needs of new migrant women as a community group with specific social needs and a particular difficulty in regard to access and use of existing community facilies and communal spaces.
hopscotch asian women’s centre:
Project Introduction
Community Members
ravenscroft primary school:
Comments on problems with access to public space and services and social isolation from local Bangladeshi women:
“i was very lonely when i got here, at home with just my baby. now i have some friends but i only see them at the [hopscotch asian women’s] centre” “My mum. She’s joined the gym recently. Every day she comes back and she’s just like so excited. Oh I did this at the gym today. She gets to socialise ”
“a lot of these ladies go to sewing classes to learn how to sew. With my mum – She suffers from depression so it’s a way to escape and socialise and just get away from everything like just moping around at home and just thinking”
“she would always be laughing with the other village ladies when they went to the pond [back in bangladesh] but there’s nowhere to do that here”
“back in bangladesh she could just pop round to all her friends’ house and they did washing and swimming and stuff together but here she stays at home. i think thats why she got depressed”
“i think that it’s true that men have taken that space so it really doesn’t leave very much room for women to be able to use the space”
“more and more these ladies are beginning to be allowed to take advantage of these things like the classes, the gyms, opportunities to socialise and get out there and that”
“there are children running around making so much noise. I am scared to let them play outside. Instead they play indoors and fight with each other; sometimes that can really stress you out – I can’t stand too much noise, my head just heats up”
ampthill square estate:
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Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 1
Brief:
-Extend and optimise existing living room spaces -Connect neighbours with shared balcony garden spaces -Replace demolished community hall with a large flexible use space -Flexible teaching rooms and function spaces for community courses, groups and societies -Spaces for homecare and childcare exchange services for resident migrant women, their families and the wider community -On site easily accessible play, leisure and sports facilities, catering for varying community requirements and needs, with single sex and private exercise spaces -Library with community curating of cultural and language collections with public and private reading rooms -Protected private and public gardens with small scale community crop cultivation projects -Minimise energy consumption and harvest solar, wind and vibrational energy from the site to cater for increased energy consumption of new facilities
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Programmes, Spaces and Requirements: Gardens Open public garden Private raised garden spaces Vertical spice and vegetable gardens Back Gardens Balcony garden spaces on all floors of the three towers Micro wind-farm facade Openable extensions to existing living rooms Solar privacy curtains
Library Main collection space Reception and Issue Desk Large public reading room Small private reading rooms Teaching spaces for between 5-30 student class sizes Computer room Teaching resources storage
Fitness Centre Access from within towers Single sex changing rooms Enclosed women-only gym space Mixed gym space Curtained games deck Children’s play area
Childcare and Drop-In Lounge Access from within towers Baby nursery Indoor soft play space for 1-6 year-olds with adjoining enclosed outdoor deck Climbing and adventure play for 7-11 year-olds Small kitchen with dining area Adult and children’s toilet Washing and baby changing room HomeCare Access from within towers Lounge and dining room Games room Enclosed outdoor garden/terrace Small kitchen with dining area Bathroom with bath/shower facilities Adjoining to teaching space for courses
Offices Site office for community-build Facilites management and maintenance offices Women’s soft-furnished lounge Connected to all facilities Kitchen facilities Private outdoor space
Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 1
Project Introduction
client, funding and users
The client for the project is Camden Council. Primary funding will come from Camden Council and the UK Department of Transport HS2 Compensation scheme for reconstruction of demolished community hall and play area. Energy harvesting and reduction in energy consumption through improved performance of existing homes in the design of the scheme would also entitle the scheme to extra government funding from the Energy Saving Trust. Construction, management and running costs will be reduced due to community participation and involvement through time and labour exchange
users:
funding:
Ampthill Square Tenants Association
compensation for loss of land and rebuilding of demolished community centre
funding adult education and employment
funding renewable enrgy installations
ampthill square estate management and residents
encouraging development and integration amongst local asian women in camden
all-female run organisation, aiding integration, sport and eductation amongst
long-term financing and management: Gender and Employment in Local Labour Markets (GELLM) Comittee
supporting selfsufficiency and city farming projects
eductaional courses and resources paid for by camden council
residents
staff and running of centre paid for by income from charges for use of the centre facilities by local community
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Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 1
Site: ampthill square estate, hampstead road, London
The project is sited in and around existing local authority and ex-local authority housing in three high-rise tower blocks (Gillfoot, Oxenholm and Dalehead) in Ampthill Square Estate, Hampstead Road, Somers Town. The estate also comprises adjacent 5-floor housing blocks and in total houses 366 dwellings and over 1000 people. Site History: The three existing concrete towers were built between 1965-1967 and reclad with white plastic panels and red, blue and yellow rims in 1988. The towers have 21 storeys, with 4 flats on each floor, arranged around a circulation core. A renewal project by Sprunt Architects re-landscaped the green space around the site and fenced it off from public access and was completed in 2008. The towers are supported on concrete columns at ground floor level and these entrance spaces remained open until they were walled up in the 2008 renovations.
gillfoot
oxenholm
dalehead
8
ampthill square estate
somers town
Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 1
Site Analysis
Site Context Plan 1:2500
The site is positioned on the junction between Hampstead Road (A600) and Harrington Square (a400) in Somers Town, Camden. The existing 21-storey 1960s residential tower blocks overlook the train lines leading into Euston Station. The project will be focused in and around the these blocks.
euston station
ham
pst
mornington crescent tube station
ead
roa
d
ampthill square estate
ampthill square community facility
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Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 1
HS2 high speed rail demolition
The proposed HS2 route from London Euston to Birmingham Moor Street is set demolish Ampthill Square Estate’s current community centre and children’s playground. The UK Department of Transport will be responsible for funding replacement of both facilities, as well as compensation to Camden Council for public land that is to be lost from the perimeter of the site. Construction is not set to commence until 2016. Consultation processes are currently underway however to determine when compensation can be given. Though the trains will be travelling at low speeds past the site, groundbourne vibrations as well as mechanical noise from motors, fans and ancillary equipment on the trains as well as will contribute to the current noise pollution on the site. This should also be a consideration for the structural scheme.
current
ampthill square estate ampthill square playground community centre
site estate land for removal buildings for demolition
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proposed hs2 route
ampthill square playground community centre
Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 1
Site Analysis
Design site issues to be addressed
There are a number of social and spatial issues with site access and use as well as design issues with existing towers that the new scheme aims to address. Existing communal spaces are under-used and public access is limited.
2 3 4 1 5
Key Private Access Public Access
1- towers overlooking railway lines
2- under-used cramped balconies
3- small windows
4- over-looked, under-used public space
5- site railings and locks
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Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 1
Site Analysis
Noise Pollution and Air Quality Noise Pollution: The towers overlook the train lines leading into Euston Station and as a result the site currently suffers from noise pollution from trains going in and out of Euston. The proposed new high-speed HS2 rail lines will increase this considerably. Busy Hampstead Road also contributes to noise pollution, as well as contributing to air pollution from car fumes.
site receiving up to 70 dB of rail sound pollution
site receiving between 60-75 dB of traffic sound pollution
Site sir containing more than 50 µg/m3 Nitrogen Oxide
Site air exceeds PM10 value (50 μg m−3 pollutants) for more than 50 days of the year
Air Quality: The site is positioned on a junction of main roads where the air pollution values excced the PM10 value for air-bourne pollutant particles for more than 50 days of the year Busy Hampstead Road also contributes to noise pollution, as well as contributing to air pollution from car fumes. The site receives more than rrr50 g/mcubed of nitrogen dioxide and
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Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 1
Camden Planning Policies -Unitary Development Plan: Specific Policies to be Adressed: Fulfilling UDP Overall Aims: -Making sure development meets our needs, now and in the future Introduced passive systems and energy-generating interventions will minimise energy useage from the grid for existing housing and new build structures will aim to be completely self-sustaining -Meeting the housing needs of Camden’s population Improvements and extensions to existing homes provide additional flexible use space for existing housing stock -Producing an environmentally sustainable pattern of land use and reducing the need to travel Community services provided with direct access to homes on Ampthill Square Estate and easy access from surrounding Somers Town, Regents Park Estate and Camden Town communities -Helping to improve and protect amenity and quality of life Safe, enclosed spaces are provided for back gardens, childcare and homecare services . Public spaces and services are made safer through natural surveillance with increased habitation of spaces -Protecting and enhancing our environment Any green space taken up in the construction of new buildings will be replaced in elevated and vertical gardens. New gardens and planting, along with new landscaped public gardens will provide vegetation zoning and specific habitats for endangered and threatened species -Providing facilities for all members of the community New community facilities will be designed to specific community needs and be made easily accessible to all residents and members of the neighbouring community. -Improving economic prosperity and diversity Spaces for child and adult education courses and training catering for specific access and design requirements creates an inclusive learning centre for all. This involves all members of the community and providing valuable knowledge capital and increasing employment opportunities. The migrant women will also be encouraged to develop management and employable skills through the running of the centre. -Balancing the needs of residents with the Borough’s London-wide role The project will provide for the Ampthill residents and neighbouring communities directly, as well as presenting a flagship model for sustainable and social urban living within the capital.
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-Euston Planning Framework: Specific area future planning framework, indicating how aspects of the Euston area may successfully and sustainably change in the future, highlights Ampthill Square Estate as a potential site for redevelopment and an important site affected by planned construction works.
Planning Policies
-Camden Local Development Strategies:
4. Townscape Character: To the north of the station is the Ampthill estate, a 1960’s Camden housing estate which is somewhat divorced from the area by the current station and the sunken railway tracks, as well as the urban motorway character of Hampstead Road and circulatory system. A9. Significant sites, places and spaces: Potential development sites and areas likely to experience change in the vicinity of proposed redevelopment of Euston station itself. Within this area there are number of large sites which may come forward for development in addition to any development on the station site itself.
Significant Sites 1) Railway carriage sheds at Granby Terrace 2) Former BHS depot site at 132142 Hampstead Road 3) National Temperance Hospital in Hampstead Road 4) Euston Police Garage in Drummond Crescent 5) Phoenix Road School 6) Ampthill Estate
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Building Form and Systems
Initial Design Concepts
The central concept of the project is creating specific use social spaces for the estate with direct access from homes on a gradient of private to public space. New living room and kitchen extensions opening onto shared balcony decks provide opportunity for interaction between neighbours. Decks extend into gardens and new spaces. Open public space is split into specific use enclosed spaces and gardens which connect to each other and towers via walking routes and decks.
Concept model showing creation of a social landscape in-between towers
connecting towers with new proposals
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balconies
protected gardens
connecting decks
dressing trees
play school run route
Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 1
Building Form
The project involves two main structural strategies, which will
raised decks connect towers and provide shared outdoor space
connect at different points in the scheme. Main structural frameworks will be constructed professionally and internal linings, skins and coverings will be constructed, altered and maintained by the women and resident community. The extended living spaces and new balconies will be hung from the existing tower structure. Light weight steel truss supports will fix to existing concrete columns with tensioned steel ca-
steel frame towers enclose private functions, circulation, fire escape and services
bles keeping structural rigidity and minimising shear forces at the beams’ extremities by taking part of the load down through interior concrete columns. The existing foundations will be reinforced with micro-piles and the existing structural concrete columns will be frp reinforced to accommodate new loads. New hyperbolic steel frame tower structures containing protected
Opening Living Room extensions into connecting Balconies
social spaces as well as services and circulation will support bridges and garden platforms connecting balcony spaces to programmes within the new towers. Bridges will be supported by a steel cable and bar tensegrity structural system, tensioned from the new and existing towers with aluminium floor trays, Skins of varying materials and properties will line the inside
Reinforcements to existing towers
of the tower structures and create protected spaces for community programmes. The structural reinforcements and new build primary steel framework structures will be constructed professionally but softer lining and skin materials and interior interventions in the existing are as lightweight and simple as possible to enable the resident community to construct their spaces themselves, giving opportunity to partake in design decisions as well as physical assembly. Training, supervision and tool and materials kits will be provided for this stage of construction. A tensegrity network of steel bars and cables will hold the outer ptfe skin of the façade in tension around the towers, which will act as a primary weather barrier. Under this first layer, a secondary layer of insulation.....
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Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 1
General Structural Strategy and Load Forces Existing buildings will be reinforced to take the load of balcony extensions. New hyperboloid and existing towers will share the load of connecting decks. Facade and linings will be adaptable by resident community
existing tower
transfer of load through structures
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new hyperboloid towers connect to existing structure
re-clad towers and extended facades
Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 1
Hyperboloid Tower Structures The tower will use steel frame lattice construction to gain maximum structural rigidity and load bearing capacity with minimum material useage. An outer bar and cable network system will act as a framework for adaptive skin systems to be applied on different areas of the facade by residents.
lattice structure gives rigidity
spiral circulation route braces tower structure
bar and cable network for skins or vegetation
thermal padding skin panels floors inserted into central spaces weatherproof external membrane
spaces dressed with screens and skins by residents to protect and adapt spaces
climbing plants- e.g honeysuckle, ivy, jasmine
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Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 1
Fifth Floor Plan 1:200
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Section 1:200
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Floor Plans 1:500 New towers rise out of landscaped garden, supporting shared communal decks connecting new and old towers at different levels, providing connections between existing and new programmes
Ground Floor Plan 1:200 1- Built up Landscape 2- Library 3- Outdoor Reading Garden 4- Cut-out Entrance 5- Community Hall 6- Enclosed Play Garden 7- Residential Tower Lobby 8- Pathways through scheme 9- School Run Play Route 10- Existing Multi-Purpose Sports Court 11- External Lifts 12- Play net
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Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 1
Building Form and Systems
First Floor Plan 1:200 1- Vertical Gardens and Farming 2- Library 3- Teaching Spaces 4- Reading Rooms 5- Community Hall 6- Play/Fitness Centre 7- Circulation tower 8- Public Seating/Climbing Frames 9- School Run Play Route 10- Back Gardens Balcony Extensions 11- Living Room extensions 12- Kitchen/Greenhouse Extensions 13- External Lifts 14- Cable Anchors
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Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 1
Seventh Floor Plan 1:200 1- Vertical Gardens and Farming 2- Library 4- Reading Rooms 5- Community Hall Tensegrity Roof 6- Play/Fitness Centre 7- Circulation tower 8- Communal Garden/REading Deck 9- School Run Play Route 10- Back Gardens Balcony Extensions 11- Living Room extensions 12- Kitchen/Greenhouse Extensions 13- External Lifts 14- Planting
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Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 1
Eleventh Floor Plan 1:200 1- Vertical Gardens and Farming 2- Library 3- Teaching Spaces 4- Reading Rooms 5- Community Hall Tensegrity Roof 6- Play/Fitness Centre 7- Circulation tower 8- Play/Exercise DEck 9- School Run Play Route 10- Back Gardens Balcony Extensions 11- Living Room extensions 12- Kitchen/Greenhouse Extensions 13- External Lifts 14- Planting
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Extensions to the Existing 1:100
Balcony spaces run around the perimeter of the existing towers, providing flexible extensions to existing living spaces, connecting neighbours together and linking existing homes up to the new towers.
green wall gardening trellis
greenhouse/ kitchen extension in winter and open garden (on nice days) in summer retractable sliding folding wall opens up to garden space
connecting balcony spaces
supports attach to existing carbon fibre-reinforced columns living room extension retractable living room sliding folding wall opens social space up to neighbours changeable floor system
deck connecting to towers
External insulation and new cladding system
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Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 1
Cantilvered steel supports fix to existing reinforced concrete columns to support extended living rooms and new balcony garden spaces. Glass facade slides back to open entire living space to balcony.
Building Form and Systems
Back Gardens
cantivevered steel floor supports garden trellis
cable net ballustrade
steel cable net bracing
micro wind turbines
extended private living rooms
shared balcony spaces retractable living room wall
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The main access to the scheme will be from within the towers with ground floor access from under the towers and new balcony platforms connecting homes to the new scheme. There will also be general public access through the library and circulation tower connecting all floors containing fire stairs and lift. Plan shows existing pedestrian access to towers, vehicle access, parking, proposed and current frequently-used pedestrian routes through the site (recorded from site visits at different times of day). Disabled access is through internal or external elevators and spiral ramps.
Key Key Key
PedestrianAccess Accessand andRoutes Routes Pedestrian Pedestrian Access and Routes VehicleAccess Access Vehicle Vehicle Access Parking Parking Parking SchoolRun Run School School Run Access from fromwithin withinexisting existing Access towers Access from within existing towers towers Lifts/Disabled access
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Fifth Floor Plan 1:500
Access and Circulation
Access and Routes through the site
Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 1
Building Systems
Public toilets will be housed in a central circulation core, providing one cubicle per floor with an exit to a platform. Existing services in own homes will be used by majority of users who will be residents. Electricity supply will be from circulation core and cables fixed and enclosed under main platforms. Cables will run along underside of circulation spirals in towers
Key Pedestrian Access and Routes Vehicle Access Parking School Run Access from within existing towers
Key
Water supply and drainage electricity supply
Fifth Floor Plan 1:500 29
Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 1
Fire Strategies and Escape Routes Ground Floor 1:500 Spiral ramps within new towers connecting externally to facades of the exisiting towers provide alternative escape routes from existing flats as well as from new programmes. A central protected fire escape stair provides escape routes from all raised platform spaces. The estate currently operates a floor-by floor evacuation strategy, which will be maintained with the new scheme
Fire- May 2011 First floor flat facade destroyed and smoke damage to floors above due to fire started by a discarded cigarette in Gillfoot tower. Disconnected fire alarms meant people were first made aware of the fire when smoke came into their homes. Existing fire alarm system will be improved and and a sprinkler system will be fitted into all flats. Flats are fitted with 30 mins fire-resistant front doors and fire doors between corridor and circulation spaces.New steel structures
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Fire Engine Access
Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 1
Fire Strategy
Fifth Floor Escape Routes
Exisiting fire escape
external escape from new towers
Central access tower with lift and fire escape stair
Fireproof fabrics and membarnes will be used in cladding and skins of the towers
Steel frame structures will be treated with intumescent paint to protect it for up to 2 hours.
Alternative Escape Routes
Balconies serve as external escape route
Escape up or down to deck levels Spiral ramps serve as secondary means of escape
spiral escape route up or down to connecting platform
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Building Construction -Overall Strategy The scheme consists of two key structural approaches- interventions within the existing towers and the new steel frame towers. Old and new towers and programmes are connected by bridges and decks, serving different functions at different levels within the scheme. These decks will be supported using cable-stayed bridge technology by new tower structures with a suspension network of steel cables. Tower skins and interior space linings will be fixed to steel pin and cable nets. These will be changeable and adaptable by residents. Flat facades will be fitted with additional exterior insulation and re-clad with removable and easily changeable rain screen panels, allowing residents’ personal choice and modification.
Construction:
reinforced existing
primary steel
curved bracing
structure
structure
beams
Detail model at 1:50
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steel lattice
bracing steel
floor plate and modular
floor frames
frame circulation
floor system frame
ramp
-Meeting point and interaction between existing and new interventions
Building Construction
Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 2
Key Structural Systems
2
1
1 reinforcements to
primary steel
existing tower
structure
2 6
3
4
4
landscaping and
connecting decks
gabion walls
5
7
8
5
6 personal facade
exterior skins
system
8
7
Interior linings
acoustic linings
3
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Resident Participation
New structures, though professionally designed and manufactured, should be easily adaptable and changeable and should involve the residents as much as possible in design and maintenance. Fabric linings, cladding and flooring systems will be maintained and partly constructed by resident women, so designs must be adaptable, interchangeable and lightweight.
making use of the women’s skills and heritage
bengali weaving patterns
tensioned structures, fabrics, frameworks and modular systems Structure should be as lightweight and adaptable as possible to be easily assembled and maintained by the Women
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Stage 2Proposed new Structures
Stage 1Analysis of existing structre
Structural reinforcements The existing structure must be analysed and appropriate reinforcements and repairs made as necessary. In design of new structures and reinforcements there are three key stages: Stage 1: Structural Assessment Stage 2: Design of intervention Stage 3: Consideration of impact of intervention, repair and strengthening of existing structure
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Building Construction
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Stage 1: The existing structure must be analysed before commencing reinforcement work to determine if there has been any structural degradation, deformation, corrosion or hardening over time and to what extent it will need to be repaired and reinforced for new interventions and increased load. Core samples taken from the existing structures can be used to determine: Compressive Strength- Overall in situ strength of the existing structure Tensile Strength- To determine strength of existing floor slabs and structure against tensile forces and wind loading Permeability- Determines durability and resistance to chemical and environmental attack using water absorption tests Fire Damage and Cracking- To assess degradation and stress fractures over time and damage from recent fires in the towers- using visual and microscopical examination Density
supports
floor slabs
structural system
concrete facade and external aluminium rainscreen
new facade structure hangs from main structure
Existing concrete columns will be reinforced with carbon fibre reinforced plastic wrap to prevent deformation in the structure due to added load. FRP strips will also be applied to the soffit of each floor slab at the junction with balcony supports and columns taking the load of new structures. Existing foundations will be reinforced using micro piles. A crown of new 150mm diameter micro piles will be drilled for each column’s pile foundation cap.
As the structures are over 40 years old, they will most likely have suffered at least 10% corrosion. It is also possible that the existing concrete structure if the towers will have hardened over time and may therefore have surplus capacity to be able to take additional load. As the structure is over 40 years old it will have a maximum of 110% extra capacity. This might mean that less reinforcements are needed. Stage 2: Consideration of where new balcony and deck structures will touch existing structure and points where load will be transferred. The new lightweight steel-frame balcony structures will fix to existing exterior concrete columns and floor slabs so these junctions will need to be reinforced. A tensegrity cable system will brace the structures and minimise shear forces. Anchor points for cables will need to be drilled into the existing supports. The concrete will therefore be under both tension and compression forces at junctions
Carbon Fibre Reinforced Plastic Wrap application
FRP Wrap on a structural column
lattice pattern of fibres wrapping concrete columns
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Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 2
Order of Interventions into the Existing Underpinning foundations, FRP reinforcement of structure, demolition and insertion into the existing flats
existing structure
36
underpin existing foundationsmicro-piling machine fits into ground floor to reinforce tower’s existing foundations
concrete supports to take additional load reinforced with frp wrapping
temporary pre-fab flats constructed on rooftops to house residents whilst modifications are done to their homes
Renovations floor-byfloor from top down: balcony extension cantilever supports fixed to newly reinforced concrete columns
floor structure and new living room and kitchen facades fitted
Building Construction
Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 2
Micro-Pile Foundations
Process of underpinning existing foundations150mm diameter micro-pile foundation crowns will be drilled for the existing concrete pile foundations. A a 2.8m high Micro piler will be used to drill the new foundations with access from the ground floor. The new crowns will spread the additional load from the new structures into the ground.
micropile machine- small enough to enter under towers on ground floor
existing column
existing concrete footing 150mm micropiles
micropile crown around existing concrete pile existing concrete pile foundation
micropiler drills down through
pile drilled through exitsing footing
drill left in and grout poured in to set to foundation
pile foundation reinforced
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Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 2
Flat InterventionsProcess of Construction The interventions in the existing flats will happen whilst the residents are still living there, so should be carried out as quickly as possible with minimum disruption to residents.
existing structure
strip plastic cladding
remove existing balcony walls
demolish living room wall (insert
fix strengthening tensile cable network from
lay steel-frame flooring
temporary blocking facade panels) and
beams (bracing and stiffening structure)
tray
Fix steel balcony cantilever supports to existing (reinforced) columns
38
reinforce columns with frp fabric wrapping
Install Sliding wall rail system and panels
Building Construction
Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 2
Balcony Extensions -Shared Kitchen extension/Greenhouse
Detail showing section through extended kitchen/greenhouse and new balcony structure with steel cantilever supports, lattice frame floor structure and tension cable network. A steel cable net trellis and bedding trays will provide space for growing produce in new kitchen/greenhouse spaces. Rainwater from gutter systems will collect in tanks with sprinkler taps for the beds.
plastic drainage pipe
double-glazed sliding folding doors
double-glazed window
steel trellis support pins tensioned steel trellis wires pierced plastic pipe sprinkles plants existing plaster and tiling existing concrete wall
gutter drainage pipe to sprinkler system
1:5
adhesive mineral wool insulation board fibre cement board
ballustrade clamp
waterproof membrane
glass ballustrade
plastic planter tray
silicone seal
pedestal and tile floor system
insulated profile sliding
rail
c-profile bolted beam plasterboard
cable anchor welded to steel plate cap steel beam bolts into existing column/floor plate
1:20
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Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 2
Balcony Tensegrity Cable network Bracing
Test Model Structural principles of tensegrity will be used for additional facade structures on the existing and for skin systems applied to the new towers.
cables in tension
bars in compression
testing different configurations
40
Tensile supports
Building Construction
Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 2
double-glazed window
Additional support for balcony floor beams will be provided by tensile cables holding the supports in compression against the existing concrete structure. These will occur externally, every 6m along the balconies.
steel plate cable anchor bolted into FRPreinforced concrete prestressed tefloncoated steel cable gutter
steel plate hinged cable anchor
welded steel lattice floor frame
1:5
prestressed teflon-coated steel cable
square steel profile bolted into concrete
1:20
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Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 2
existing concrete wall
Removable Faรงade Panels
bolts onto concrete top hat
fixings
aluminium profile clip rail The existing cladding of the towers will be stripped and recycled to create a new changeable cladding panel system. To encourage a feeling of ownership over the new spaces, changeable panels will slide easily on and off fixed horizontal bars. Residents will choose colours and prints of the panels for their flat and they can be easily changed or painted as desired. Alternative materials such as ceramic or timber may also be substituted at a later stage if desired.
aluminium panels slide onto profiles
long bolt into existing wall
waterproof membrane insulation board blocks gap allows air circulation and drying
recycled
existing aluminium cladding
new panel system
panels slide easily on and off wall rail
ptints and colours chosen by residents
42
panels overlap to prevent water ingress
base lip takes water away from wall
1:20
1:5
Building Construction
Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 2
Floor System
The floor slab structure will be a bolted and welded lightweight steel lattice structure, upon which a lightweight concrete slab is be laid. A removable floor panel system will be laid on top of steel pedestals to allow panels to be chosen and changed by residents whilst maintaining a relatively uniform aesthetic to the building exterior, creating a patchwork effect to the facade. balcony floor system panels clip over steel corner pedestals
floor tiles laid on top of clip corner pedestals
colours and prints chosen by residents
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Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 2
Constructing a Landscape A strip of land along the perimeter of the site is to be removed and the retaining wall to be demolished for HS2 lines. This removed land is to be used to construct the landscape for the scheme, as well as a sloped sound and sight barrier along the site perimeter to protect the estate from increased noise and disruption. Brick rubble from demolished walls is to be used in gabions for retaining walls around cut-in gardens in the new landscape.
earth-retaining gabion walls
constructing new landscapes with removed earth
retaining wall and land to be demolished for HS2
44
Building Construction
Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 2
Retaining Gabion Wall Detail The new landscape, built up from removed earth will be retained around cut-in gardens by recycled brick rubble gabions, 100x100x50cm Grass and plants will be allowed to grow over the gabions. Stabilizing timber posts will be driven into the ground before gabion baskets are placed over the top and bricks are filled in. The landscape will then be built up behind the gabion wall barriers.
recycled
soil layer over top of wall
timber reinforcing post brick rubble steel mesh
vegetation allowed to grow in-between bricks
posts
timber reinforcing post
section through cut-out garden wall 1:20
plan view 1:20
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Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 2
Tower Structural References The tower will use steel frame lattice construction to gain maximum structural rigidity and load bearing capacity with minimum material useage. Floor slabs will be supported by these tower structures at meeting points as well as by additional steel suspension cables
Tension Killesbergturm Observation Tower, Stuttgart, JĂśrg Schlaich 40m high steel mast and prestressed tensioned cable net structure. The cable net is tensioned from the top of the mast to grounded anchors, supporting the platforms and suspended staircases. As the cable net compresses the four platforms against the central mast, transferring the load, the cables take a reduced load, allowing their tiny diameter of 18mm.
Margaret Hunt Hill Bridge, Dallas, Santiago Calatrava The central steel arc structure is held in compression by fanning cables forming a hyperbolic net supporting the body of the bridge
Compression Sendai Meditheque, Sendai, Toyo Ito Structural steel frame cores support floor slabs whilst acting as building circulation cores, connecting floors
Shukov Tower, Moscow, Shukov Built 1920-1922, Vladimir Shukov’s tower reaches 148.5m in height and uses a lightweight hyperbolic paraboloid form lattice steel frame. Due to the structural integrity of its diagonal lattice form, it uses a third of the metal used per metre of height for the Eiffel Tower.
46
Building Construction
Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 2
Parametric Experiments for Towers and Cable Supports Decks will be supported by hyperboloid towers. Pre-tensioned steel cables fix to structure along the perimeter of circulation spiral structure.
load
This will distribute the load around the structure, minimizing issues with imbalance. Experimenting with constructing paraboloid cable net structures from spiral edge to platform edges
cables anchored at points of contact with reinforcing spiral structure tension cables transfer load to structure other tower structures share platfrom load
skin tensioned around structure
parabolic crossed cable net hangs from structure to support platform structure spreads load over wide area of ground through splayed structural members
basic load forces diagram
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Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 2
floor slab welded top rim bolts to ring beam
Connecting the existing to the new
steel lattice floor structure ring beam fits around primary steel tube structure
cable anchors on welded steel plate fit to spiral ramp edge
Detail taken across three key structures- deck connecting interventions within existing flats to new build towers
existing plasterboard ceiling curtain rail internal floor to ceiling curtain
double-glazed sliding folding doors
cable net balustrade
welded steel lattice structure
connecting deck steel lattice deck slab
1:20
48
2
Key Tower Frame Connections
15mm steel tubes in the main steel frame tower structures will be welded at cross-points. Sections of the frame can be made offsite and can be assembled by crane relatively quickly onsite with bolted joints, reducing the time of construction onsite.
frame member crossing point
Building Construction
Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 2
weld line
key junctions of primary frame welded plate
1 1
ramp structure
spiral ramps (see detail on p.59)
3
2
150mm steel tube
frame cross points
[Academic use only]
steel tubes welded at crossing point
tubes welded to steel base plate fixing bolts set into concrete main body of foundation buried concrete footing 150mm concrete piles
3
foundations
15mm concrete piles bolts set into concrete welded support edge plates bolts set into concrete
1:200
plan view 1 :20
foundation detail 1:20
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Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 2
Suspended Deck Structural References
Cable-stayed bridge technology will be used to support connecting decks between new and old towers. The floor of the decks will be made up of a steel lattice framework, and they will be supported by pretensioned cables fixed to main steel lattice structures along the perimeter of the bracing spiral ramps.
Blur Building, Diller & Scofidio Entire structure is supported on just 4 slender steel footings and the platform is held rigid by steel pin bars in compression by a network of steel cables
Kurilpa Bridge Brisbane, Cox Raynor Architects The bridge spans 130m and is supported at just two points. The bridge is held rigid by steel pillar and tensioned cables. This allowed for minimal deck thickness, minimal material useage and the integration of a canopy into the structural system.
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Building Construction
Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 2
Suspended Deck System
Cable-styed bridge technology will be used to support connecting decks between new and old towers. The floor of the decks is made up of a lightweight bolted steel lattice framework, supported by a tensegrity network of pre-tensioned cables and 10mm steel tube compression posts. The decks connect to main steel frame tower structures, anchored along the perimeter of the bracing spiral ramps.
steel lattice framework fixes to ring beams on connecting towers
steel post and cable structure holds platform rigid and level
The direction of the floor lattice grid is determined by direct radial connections between towers. A 2x2m grid is used and is supported from below by compression posts at intersection points. 2x2m composite floor panels fix onto the steel lattice framework to allow different floor types for differing programmes to be placed and replaced in individual modules.
tension and compression forces 1:500
tensegrity cable support network under platform
steel lattice frame
tension cables
compression pins
[Academic use only] floor frames fit into steel lattice grid ring beam cables anchor to main frame
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Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 2
Deck Framework and Floors
The deck’s structural lattice framework will hold modular floor trays which can be changed relatively easily by residents. A primary steel mesh tray will hold secondary trays containing function. Planting, play facilities, seating, different floor types or maybe even small-scale structures could fit into these trays and be changed, adapted and designed by residents.
floor panels
play
planting
open panel
balustrades fitted into secondary panel edge
steel lattice frame with tensegrity under supports
trays fitted into lattice frame secondary interior tray contains functions
patchwork deck panels housing different floorings, functions and structures
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Building Construction
Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 2
Balance and Anchoring
Where decks are hung from only one side of the tower structures, the opposite side must be anchored to the ground to balance forces acting on the tower. The anchor points will be fitted to the main hyperboloid frame along the edge of bracing spiral ramps and will be grounded in buried concrete anchor foundations. These will form elements of the site’s landscaping for play areas, seats and planting.
anchors balance deck load on opposite side of tower play landscape hills
library tower 1:200
Steel anchor cable foundation hidden in play landscape
concrete footing steel anchor welded to plate anchors buried in play landscape
steel plate welded reinforcement plates screw pile heads
screw micro-piles tie through steel plate, concrete base and ground 1:20
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Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 2
Skins Each of the towers will use a combination of three skin types at different locations and for different functions. These will be constructed and adapted by the women and other residents and will attach to a cable-stayed system as shown above. Central interior tower spaces will also be dressed and lined as required by the residents.
bars and tension cable net
Skin Elements:
Cable Net Structure: Exterior anchor bars with tensioned cable net provide a framework for tensioning skins from. Lightweight skin panels can be applied and taken away by the women
open tensile fabric panels
Semi-Open: Tensile ptfe or other fabric panels stretch between exterior pin bars, providing a visual barrier or shading whilst allowing light in and free air movement through the spaces Weather Coat: Complete tensile skin cover provides wind and rain-proofing Quilting: Inflatable and lightweight thermal membrane-lined pillows to line library space, to protect enclosed interior environment.
Spaces: Gardens: The interior façade of the structure will be dressed in a lightweight clip-on steel cable net acting as a giant trellis for climbing plants, seasonal flowers and hedgerows. Planting pots will line the edges of the walkways to plant climbing berry plants, seasonal flowers and vegetables. Climbing plants such as ivy and honeysuckle will be planted at the base of the framework structure and allowed to grow up the tower façade, creating habitats for local endangered wildlife such as hedgerow birds, bees and insects. Tensile …….fabric skins stretched across segments of facades and walkways provide shelter from wind and rain in winter and shade in summer. Library Spaces: Library, reading room and teaching spaces need to be well sound and thermally insulated. Exterior tensile cable nets will hold tensile skins Play/Fitness Centre: Individual tensile fabric panels provide visual privacy whilst allowing natural light in and free movement of air through exercise spaces.
54
trellis structures for
inflated pillow skin
lightweight high thermal
open tensile fabric
climbing plants
systems
performance fabrics
screening and shading
Building Construction
Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 2
Skin System Test Model A cable network attaches to the primary frame structure, from which steel pins hold a tensegrity cable network, and tensile skins and micro turbines.
primary framework structure
Different skin types and other add-ons are adjustable and changeable by the residents. The skin systems are accessible and adjustable from the circulation ramps
open tensile fabric panels
bracing circulation ramp closed rain screen
micro wind turbines
skins adjustable from inside ramps
cable network holds pins in compression
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Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 2
Building EnvelopeLibrary ramp and Skin Detail The vertical gardens, deck spaces and exercise towers will be semiopen spaces. The library spaces however must be enclosed, waterproof and thermally insulated. An external rain screen inflated pillow skin will cover the exterior of the structure. Cable-stayed bookshelves run along the centre of the ramps, with access from both sides. Lightweight, open bookshelves and translucent tensile skin will allow plenty of natural light into the space, whilst diffusing direct sunlight and avoiding glare.
stainless steel anchor cap fitting diagonal timber compression posts plasterboard ceiling electrical services and lights
aluminium profile edge clamp welded steel tube bars
central cable shelfdividers glass shelf
1:5
tops
timber shelf supports in compression hinged steel cable clamps tensioned plastic-coated steel cable supports diagonal timber compression posts
inflated etfe pillows 1:10
steel tension cables hold cable net ballustrade kick plate tile and pedestal flooring system concrete block weight bitumen dampening layer
spiral floor frame bolts over edge ring beam double-curved rolled steel ramp segments
56
Building Construction
Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 2
Reading Rooms
Open reading room spaces extend out from the main tower structure, connecting to balconies. Smaller, personal reading rooms will also be provided for individual study. As all spaces connect with a central atrium, thermal control across the whole space will be difficult. For this reason, these smaller reading spaces will be well thermally insulated for colder winter days, reducing the need to heat the entire space. As the spaces will be cantilevered from the main structure, tension cables will hold the catilevered beams in compression against the main frame to reduce shear forces.
communal reading room
tensile ptfe membrane A high thermal performance, lightweight silicone aerogel layer is sandwiched between layers of ptfe membrane, forming the outer skin of the communal reading room spaces. This will allow maximum day lighting, whilst filtering direct sunlight and avoiding glare in reading spaces.
glued, sandwiched lightweight aerogel insulation
individual study space quilted fabric cushion linings fix to supported by tensioned cables padded seat
pretensioned tefloncoated steel tension cables padded bench runs around space perimeter
floor to ceiling curtain draws around space
cantilevered beam bolts to spiral ramp structure cantilevered beam bolts to spiral ramp structure
edge fabric clamps (as previous page)
floor structure as previous page
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Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 2
Roof Structure -REferences The roof structure for the enclosed community hall and library spaces needs to allow maximum diffused natural light into the space, be quickly assembled, remaining as lightweight as possible and maintaining a delicate aesthetic. This will be achieved by once again employing principles of tensegrity, using compressed structural members held by a network of tensioned steel cables.
Tensegrity Dome, Buckminster Fuller Buckminster Fuller developed his “tensegrity� dome as a network of tensile cables and compressed bars. He sought to create and architecture with minimal need for compression forces. Its principles have been used extensively in subsequent wide span roof design
Gymnastics and Fencing Olympic Arenas, South Korea Both domes, constructed for the 1988 summer olympics used systems of tensioned cables from a central tension ring, through reinforcing compression posts to an external compression ring, covered in a fabric skin. Though different in size and span, both used identical materials and connection elements.
Georgia Dome, Atlanta The Georgia Dome is the worlds largest cable supported stadium and uses a network of tension cables and compressed bars to support a stretched fabric skin roof over a span of 185m x 234m
58
Library Tensegrity Roof Structure forces of tension and compression acting on the roof structure
The community hall and library spaces will be the only completely enclosed spaces of the new tower structures and will use a lightweight, quickly assembled roof system.
Building Construction
Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 2
The cable net roof structure is made up of tensioned cables and compressed bars. The cables, compression elements and fixings will all be made off site and the roof can be fixed and assembled very quickly on site The roof membrane needs to allow as much diffused daylight into the space as possible, whilst providing good thermal performance to minimise energy loss. For this reason, ptfe membranes, with a sandwiched high thermal performance, lightweight silicone aerogel layer will be used for the roof’s skin. compression ring beam compression ring beam steel tension ring steel compression bars
steel tension ring
tensioned cables
steel compression bars
tensioned cables
side elevation of structure
side elevation with tensile skin membrane
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Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 2
Process of Construction
The roof will be tensioned from a rolled steel ring beam, fixed to the main tower structure. The cable net will be attached first. Posts will be attached and tied into compression ring-by-ring.
PTFE and Aerogel welded sandwich fabric
Skins will then be fixed onto cable net in prefabricated panels and welded along seams.
tension ring beam
compression ring beam
top cables from ring beam to central ring
posts and cables tension from ring beam
60
first ring of compression bars tensioned and interior bars fitted to cables
ptfe and Silicone aerogel mebrane segments fix to tenioned cables
second ring of compression bars tensioned from first
edge panels attach to reinforcement cables around perimeter
third ring of compression bars tensioned from second
roof plan 1:50 central elevated membrane protects air vents and prevents water ingress
Lightweight Roof Construction
Building Construction
Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 2
ptfe sandwiched welded aerogel layer button fabric glip clamp holds top ptfe layer without piercing top layer bolts through aerogel and bottom ptfe layers
The structure will be made up of a set of standard elements that will be the same for both roof structures. Fixings are to be as minimal and lightweight as possible
hinged cable anchor
pre-tensioned teflon-coated steel cable gutter
button “grip clips,� devices for suspended tents grip the fabric firmly without piercing the membrane and increasing chances of water ingress
steel ring beam aluminium profile edge clamp expanded foam insulation
1:5 cable connection welded rubber sheet cover edge clamping profile aluminium shell form under covering panels
process of assembly
end cap and cable clamps steel compression posts
air vents for passive ventilation system
central tension ring
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Skins:
Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 2
Manufacture and Construction Processes
The majority of parts for the structure will be manufactured off site and can be assembled relatively quickly on site. THis helps to keep construction time to a minimum and avoid disruption to residents.
eden project, Cornwall
-efte panels clamped and fitted to frame structure
Concrete foundations will be set in situ and steel segments of the structure will be welded off site, craned up and bolted together.
Watercube, Beijing-
shaped membrane panels and frames manufactured offsite, assembled and inflated onsite
National Space Centre, Leicester- Steel frame con-
structed in rings from top-down. Etfe fitted and inflated ring-by ring
Platforms:
Diller and Scofidio, Blur building
Tensegrity roof systems for exercise, library and community hall spaces will use the same post, connection and cable elements, making design and construction more simple and less costly.
Steel beams, posts and anchor Elements lifted by crane, bolted,anchored and tensioned with cables
Composite tensile Fabric panels will be made, sealed and edge-welded off site and fitted over cable structures on site. Etfe pillow membranes will be cut off site and fitted to steel frame and inflated on site.
Frameworks: toyo Ito, Sendai Mediatheque-
decks
steel frame segments welded offsite and assembled by crane onsite
Skins frameworks
Tower Extensions
steel elements pre-fabricated in factory offsite
frame elements on site
elements lifted into position by crane
assembled, fixed and bolted
Tower Extensions: Lacaton & Vassal, Tour Bois le PrĂŞtre, ParisConstructed with occupants resident . Units pre-fabricated offsite. Scaffold set up on facade of tower and units lifted into position by crane
62
Transported to site
Material Sourcing, Treatment and Recycling
site materials to be recycled
Building Performance
Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 3
material treatment and element manufacture on direct rail routes from site
To reduce energy consumption, CO2 emissions and cost, recycled and local or onsite materials will be sourced wherever possible. This is most important for heavy weight materials, such as metals and brick. Lightweight materials such as high performance membranes fabrics will need to be sourced from futher afield. Steel: Steel is the most recycled material in the UK with 10.6 million tonnes recycled annually. An average UK household uses approximately 600 steel cans per year, meaning that Ampthill Estate alone will discard 219,600 cans per year Removed railway tracks from replacement and alterations to routes from euston station, along with collected household waste will be recycled and used in construction of the steel beams and tubing for new tower structures. Materials can be transported from and back to site by train and will be treated at metal recycling plants on train routes out of Euston. Elements can then be lifted from trains directly to site, minimising energy consumption, transport costs and disruption through road useage.
steelworks aluminium recycling and form maunufacturers
long-lasting, highly recyclebale material
brick rubble to be reused directly onsite
aluminium facade sheets to be recycled
Production of the steel beams and tubing from recycled materials will also use 75% less energy than production of new steel elements. As steel does not degrade with recycling, it can be recycled again at the end of the building’s life. Majority of plastic used in UK is in household products Of the 5 million tonnes of plastics used per year, 2.4 million tonnes is packaging Household appliances such as fridges are also recycleable Most recycled material in the UK
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Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 3
Energy Effcicency and User Comfort
AcousticsAs the project involves interventions within existing buildings with potentially noisy activities (e.g. play in childcare spaces) adjoining to residential spaces, sound insulation is important. Sound insulation from noise pollution from Hampstead Road and existing and proposed new high-speed rail lines will be essential in quiet spaces such as the library and teaching rooms Creating private spaces within a public landscape means that acoustic privacy will also be an issue ThermalOutdoor and semi-outdoor shared social spaces should be as comfortable and useable as possible both in summer and winter
Current Energy Ratings for dwellings in Oxenholme Tower
Extensions and alterations will be made to existing flats; creating changeable facades that can be opened in summer, but also provide good thermal insulation in winter
Bu il d in g E le m en t
Ma te r ia l
Th ic k ne ss
U- Va l ue ( W /m 2 .K )
Tower Cladding System
Existing cast concrete wall + new cladding system
315mm
0.19
Internal plaster
20mm
Existing cast concrete wall
100mm
External Plaster
20mm
Recycled paper and wool mix insulation
200mm
Aluminium cladding panels
10mm
LightingShading should be provided to south-facing tower facades during summer, whilst maximising solar gain in winter Maximum daylight should be allowed all year round on all north-facing facades Daylight needs to be brought in to under-landscape spaces through rooflights and cut-in gardens Day lighting in all spaces should be maximized, whilst views between some spaces will need to be controlled and limited Ventilation-
Extension
Passive cooling should be achieved during summer by maximizing airflow
Internal floor to ceiling curtains + opening glazed faรงade
1.1
through residential spaces in the towers Thermal Insulating curtains
Polluted air should be filtered and cleaned to achieve maximum air quality inside residential and shared work and leisure spaces
Library Wall
Translucent Skin
Double-glazed sliding folding doors
1.4
Inflated membrane cushion skin wall
0.25
Silicone Aerogel membrane
20mm
0.51
Inflated etfe membrane pillow
150mm
1.96 0.51
Ptfe Membrane with aerogel thermal fill Silicone aerogel layer
64
3mm (15mm pleated)
30mm
0.37
Building Performance
Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 3
Air Pressure and Moisture Control Vents fitted at the top of external walls, allowing rising warm, humid air to exit
As the existing towers are 60m tall, they will be subject to stack effects and pressure differences. Warmed humidified air from central heating, inhabitants, cooking etc. will rise gradually up the towers, causing high pressure at the top of the building. This leads to cool air being drawn in at the base of the building and warm air pushed out towards the top. This can cause problems with interstitial condensation and subsequent energy loss and structural decline where warm moist air hits cold exterior walls.
warm humid air rises and exits due to increased air pressure
Pressure can be reduced in the upper part of the building, moving the ‘neutral’ plane up as high as possible, through better ventilation and increased exhaust ventilation to reduce pressure and humidity. This will reduce problems with interstitial condensation throughout the building.
reduced stack effect through exhaust ventilation
stack effect
positive pressure
reduced positive pressure neutral plane exhaust ventilation reduces pressure
neutral plane
increased negative pressure
negative pressure
warming, rising air
warming, rising air
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Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 3
External InsulationAvoiding Interstitial Condensation
The stack effect in the towers also means that exterior insulation is an important issue in the re- cladding of the towers. Additional insulation will be fitted externally to avoid cold conduction through the concrete wall which causes condensation on the internal surface of the wall on meeting of warm internal air.
external insulation provides a thermal barrier between concrete and cold air preventing conduction of cold through wall and internal condensation
air gap allows drying behind rainscreen cladding panels
External insulation avoids this by providing a thermal barrier between conductive concrete and cold outside air. gaps between panel overlaps allow airflow
Although facades will be sheltered, the height of the towers mean that they may also experience problems with wind-driven rain. Windblown rainwater can travel sideways or even upwards on facades of tall buildings, penetrating joins in exterior cladding. This effect will be reduced by the new balconies, but substantial air gaps should also be provided within the wall assembly to allow drying of any condensation or moisture.
additional thermal barrier reduces heat loss
any moisture or condensation build up drains down the back of panels
expanded foam insulation fills ‘tophat’ profile
wind-driven rain
64
breaks in supporting rail profile allow air flow
Building Performance
Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 3
Wind Energy
height
Wind increases with height and although the average wind speed on site at a height of 6m is 4mph, at a height of 30m this is likely to be 20% higher, and 40% higher at a a height of 60m.
wind speed
Taking advantage of the height of the towers, wind energy could be utilized for ventilation and cooling systems as well as harnessing it for generating electricity.
Wind forces will also deflect across and around the facades of the towers, resulting in increased wind speeds and forces at different points across the facade.
energy increase
wind rose chart for yearly average wind on site(data -windfinder.com)
wind speed increase with height
deflection across tower facades
south-westerly prevailing wind on site
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Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 3
Micro Turbines Micro wind turbines could be used on site for generating electricity for existing homes and new scheme. Rather than large scale tower turbines, multiple small scale micro-turbines would to be light enough to collect any small wind forces and air movement across the facades, whilst not putting any strain upon the tower structure. The turbines scatter across new and existing tower facades and can harvest any small amount of air movement. Turbines of less than 25cm diameter can generate electricity with wind speeds from just 2m/sec. A total surface area of one square meter of turbines, with a light wind speed of 5 m/sec generates 131 kWh/yr. These would also be small 25cm diameter and other residents.
enough to be made and maintained by the women turbines on balconies and ballustrades turbines on new open-sided tower structures
homes
25cm diameter
current min 2m/sec
current
inverter and interconnectors
1m 2 surface area of turbines 1m
average 5m/sec
64
2
main utility breaker panel
surface area of turbines
micro wind turbine
average 5m/sec
131 kWh/yr
131 kWh/yr AC electrical circuits
DC voltage output
AC voltage input
exhaust vents reveloving doors prevent uncontrolled intake of air causing stack effect and condensation
VentilationWind and Stack Effect The height and wide clearance of other buildings around the towers means that wind power could be a valuable resource to be harnessed and utilized.
Building Performance
Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 3
Wind-driven ventilation systems could be used in new towers. Wind-driven fan vents on south westerly faces of the towers catch wind, bringing fresh air into the building. Air then heats up internally and rises through stack effect, exiting through exhaust vents under the roof canopy. Vents under the edge of the roof canopy allow air flow under the roof membrane, avoiding problems with condensation on the underside of the roof
air exits under central roof canopy cover
air enters under roof edge canopies
WSW prevailing wind
wind-driven vents
under-roof ventilation
exhaust vent allows warmed, moist air to exit drying of underside of membrane revolving doors air enters under roof edge of canopy
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Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 3
Thermal Barriers Insulation lines should be as continuous as possible, without break or cold bars to avoid heat loss through the external envelope of the buildings. Kitchen extensions are open to two flats so existing external walls will be kept. External insulation panels along with new green walls will provide additional thermal insulation and allow for double-glazed sliding folding facade to be left open permanently during summer months and overnight.
primary thermal barrier
primary external wintertime thermal barrier secondary internal summertime thermal barrier
secondary thermal barrier expaned foam insulation fills frame profiles
glazed facade opened up
secondary layer allows spaces to be left open over summer months
balcony becomes external space
summer winter
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expaned foam insulation fills frame profiles
insulated profile fitting
vacuum cavity double-glazing
Heating Strategy
roof area minimal to avoid heat loss
As the library space is a continuous spiral with an open atrium, it will be difficult to control the climate of the whole space well.
Building Performance
Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 3
The ramps house an underfloor heating system, extending around the spiral, concentrated most intensively under communal reading rooms and bookshelves, to directly heat the spaces where it is needed conical tower shape to minimise heat loss through stack effect
On very cold winter days, when it would use a large amount of energy to heat the entire space to a comfortable temperature for sedentary work, small personal reading rooms can be used. The enclosed quilted spaces provide a small, thermally and acoustically insulated space for private study.
inflated etfe pillows insulating silicone aerogel layer
In these small enclosed spaces, the heat of a person and a laptop could be emnough to keep the space warm enough for reading and sedentary work.
underfloor heating
quilted reading rooms
curtained group reading rooms
Quilted personal reading room Curtain Door allows daylight into space
Filled fabric cushions
occupant helps to heat space Heated seat
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Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 3
Stereographic Sunpath Diagram
Stereographic Shading Mask
Latitude of Site: 51.4 o N
N
Sun Path and Shading
Inclined Shading Plane
10
The new decks will provide shading from direct sunlight to the facades of the existing towers. Direct summer sun will be shaded from facades as much as possible and winter sun allowed to penetrate.
Balconies and extensions on facades receiving only morning and evening sun should be shallow to maximise diffuse daylighting
30 40 50 60
W
er mm su
The wider communal areas of the decks will be positioned to give shading to areas where direct sunlight hits in summer months whilst allowing maximum ambient day lighting to already shaded or northfacing areas of the faรงade.
20
su n
70 80
E
NOON
un winter s Vertical Shading Plane path of sun intensity around site
north-east facing facades receive low morning sun north-west facing facades receive low evening sun
Decks are deepest on south-facing areas of the facade receiving most intense sun for the longest period each day
south-facing facades receive greatest intensity for longest periods
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12.00pm -facades receiving direct midday sun
Building BuildingPerformance Form and Systems
Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 3
Day Lighting
New balcony gardens provide shading to south-facing facades and block views of railway with deeper balconies Tower skins allow diffused
daylight into
interior spaces whilst blocking direct sunlight and glare
solar energy gathered by day is used to light spaces at night
summer- balconies provide shading from direct sunlight
er
mm
su wint
er s un
diffuse light
diffuse light
n
su max- 61.5 winter- low winter sun reaches inside flats
min- 14.5
ht sig
balconies block view of rail tracks from inside flats
e
lin
tower skins allow filtered, diffused daylight to penetrate
library, reading rooms and teaching spaces shaded from direct sunlight
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Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 3
Greenhouse effect
mm su er mm su er n su n
New glazed extensions maximise daylighting and solar gain, creating a greenhouse effect for plant cultivation, and heating interior spaces in winter. High summer sun is shaded from facades by balconies, and sliding folding doors open balcony spaces up and allowing natural ventilation and passive cooling through living spaces.
su
urn sun s eirnte t n wi w trapped air heated by winter sun
sliding windows open to allow natural ventilation during summer sliding windows open interior space to heated extension on sunny days
fresh air allowed to flow in
closed double-glazed facade space opened to the outside
winter 64
summer
Building Performance
Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 3
Daylighting and Diffusion
Library spaces need to be well lit for reading and study, whilst avoiding direct sunlight and glare. As books are housed in suspended open bookshelves, they must be protected against direct sunlight to prevent sun damage and bleaching. Translucent membrane skins allow natural filtered natural light in all around the tower, creating a diffused, even light in the space.
dir
ect
sun
lig
ht
skins diffuse sunlight to create a reduced, even light
open bookcases allow sunlight to pass into main atrium
diffuse light
where no direct sunlight hits, tensile, skins allow more natural light into space
etfe pillows insulating translucent silicone aerogel layer
reading room
ptfe and aerogel membrane allows diffused sunlight into reading rooms
daylighting
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Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 3
Solar Harvesting and Artificial Lighting As the towers reach 60m high and are not shaded at all, there is good potential for harvesting solar energy. Existing towers already have a small number of solar panels on the rooftops. This has the potential to be increased dramatically. Solar panels could be fitted to south-facing facades, providing additional shading to the most intensely lit areas of the facade during summer. The energy gathered can be used to light the space at night.
light glows out of the translucent building skin at night time
artificial lighting above bookcases and reading rooms
solar harvesting on south-facing facade
photovoltaic fibres woven into interior curtains
lightweight solar ivy facade covering- harvests solar and wind energy through peizoelectric crystal generation
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conventional south-facing PV solar panels
artificial lighting
Building Performance
Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 3
Rainwater Collection
As the towers have a large surface area for rainwater run-off, this could be collected and used in the new scheme. Rainwater is collected from facade run-off via a gutter system and stored in tanks on each level, for watering plants.
rainwater flows down glazing and ballustrade
Tanks are tapped to prevent flooding with heavy rain. Overflow is taken down drainage pipes to grey water storage for new build toilets. It may not be feasible to change water supply and drainage systems in existing towers but small-scale sink-to-toilet systems could be fitted in each flat. behind-ballustrade gutter
New toilets in circulation towers will have a separated grey and blackwater drainage. Collected grey water from sinks, along with collected rainwater will
overflow to greywater tank external gutter
be used to flush toilets.
storage tank
tap
greywater
water used directly to flush toilet
perforated pipe sprinkles plants
installed filter/storage tank tensile wall trellis
bedding tray
simple to fit greywater recycling tanks can be fitted easily and cheaply into existing bathrooms
black water to sewage mains
1:20
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Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 3
Air Quality Planting on the facade of the garden tower filters surrounding polluted air to provide a “fresh air� garden haven in a heavily polluted area. Green walls on balcony spaces around, surrounding windows will also help to filter polluted air, providing cleaner air for inside spaces. Shading skins and curtains for the garden, play and exercise towers will also act as air and sound filters for the spaces
fabric skins and planting on semi-open exercise and garden towers filters polluted air to provide a cleaner interior environment
polluted outside air
pollutant particles caught by surrounding greenery
1:50
trellis and green walls in greenhouse extensions and on exterior of bathroom walls
filtered cleaned inside air
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Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 4
Lacaton & Vassal,
Building Delivery
Paris 1960s residential block- existing cladding was stripped and new extensions and balconies added to the facade. Residents were living onsite during the build.
The Ampthill Social Housing project, (as shown on pages 14-15, Camden Planning Policies) fulfills many of the key aims for Camden Council LDS and UDP planning policies. The site and existing buildings and housing are owned by Local Authority (Camden Council) so the project will be funded by the public sector and must therefore be tendered under the OJEU procedure. As the site is in a densely populated residential area and alterations will take place to existing inhabited homes, minimising the duration of the build on site and disruption to residents will be a very important consideration. There will also be considerable disruption on site from the demolition of land and construction of new HS2 lines, commencing in 2016. For this reason it would make sense for construction works for the Ampthill project to take place simultaneously to minimise duration of disruption. This means that an early start date of the project is not a priority, but duration certainty is. As the scheme is funded by a local authority, certainty of the cost of the project will also be an important consideration.
Click the first arrow of each procedure to link to a more detailed flowchart 52 (45) Days
OJEU NOTICE PIN (Electronic)
36 (29) Days
Open
30 Days
15 (10) Days
Receive tenders and negotiate (in successive stages if necessary) to identify best tender by applying the Award Criteria
OJEU NOTICE Urgent (Electronic)
37(30) Days
Issue ITT to shortlist
OJEU NOTICE Normal (Electronic)
Conclude dialogue and invite sufficient tenders to ensure competition
OJEU NOTICE Electronic
Conduct dialogue (in successive stages if necessary)
37 Days
Invite shortlist to participate in dialogue
OJEU NOTICE Normal
10 Days
Can be used when an Open or Restricted procedure has been discontinued because of irregular or unacceptable tenders. All original bidders (that were not excluded) must be invited to participate.
Submit OJEU Award Notice within 48 days
15 (10) Days
22 Days
Award contract allowing for 10 day Standstill Period
OJEU NOTICE Urgent (Electronic)
40 Days
Receipt of Tenders
37 (30) Days
Submitted Expressions of Interest Shortlist against qualification criteria (minimum of 3 bidders)
Negotiated Without OJEU advert
OJEU NOTICE PIN (Electronic)
Submitted Expressions of Interest Shortlist against qualification criteria (minimum of 5 bidders)
Negotiated with OJEU advert
37 (30) Days
Issue PQQs
Competitive Dialogue
Prepare Specification
Restricted
OJEU NOTICE Normal (Electronic)
Issue Invitation to Tender
OJEU NOTICE Normal (Electronic)
Evaluate Tenders against Award Criteria
As it is a publically funded project and will be owned by the local authority, under the European & UK Procurement Regulations, it must be approved under the Tender/OJEU Procurement Procedure and published in the Official Journal of the European Community (OJEC).
OJEU Process Chart
Scottish Public Procurement Toolkit
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Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 4
Project Introduction
funding:
client, funding and users
The client for the project is Camden Council. Primary funding will come from Camden Council and the UK Department of Transport HS2 Compensation scheme for reconstruction of demolished community hall and play area. Energy harvesting and reduction in energy consumption through improved performance of existing homes in the design of the scheme would also entitle the scheme to extra government funding from the Energy Saving Trust.
compensation for loss of land and rebuilding of demolished community centre
Construction, management and running costs will be reduced due to community participation and involvement through time and labour exchange networks. The building and services will be managed by the resident women on the estate who are currently not in employment. Training of the women and maintenance and running of services will be funded partly by Camden Council directly and partly by income for the use of services and hiring of spaces from the neighbouring community.
funding renewable enrgy installations
funding adult education and employment
users:
Ampthill Square Tenants Association
Planning Constraints
As shown on pages 14-15, the project falls under many of the UDP local planning policy aims and fulfills many of the Camden Local Development Strategies. It is also listed under the Euston Planning Frame work as a ‘significant potential development site’. The site is categorized as being of ‘low architectural merit’ and has been problematic socially as well as having problems with several fires in the past few years. Because of this, planning restrictions are fairly lenient in terms of building form and appearance and existing towers are not listed or protected. This means that design does not have to conform to existing or surrounding buildings.
ampthill square estate management and residents
encouraging development and integration amongst local asian women in camden
all-female run organisation, aiding integration, sport and eductation amongst somali women and children
long-term financing and management:
The proposed extensions will improve the ‘architectural merit’ of the towers aesthetically as well as through improvements to energy efficiency and new energy harvesting interventions.
Gender and Employment in Local Labour Markets (GELLM) Comittee
residents
Loss of green and public open space in the scheme may be an issue however- as the project builds on open green space between towers. Any green land taken up by structures at ground level, will, however, be replaced with planting on deck spaces and vertically on tower facades and vertical garden tower, in fact increasing public space, replacing destroyed habitats and creating new ones.
supporting selfsufficiency and city farming projects
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eductaional courses and resources paid for by camden council
staff and running of centre paid for by income from charges for use of the centre facilities by local community
Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 4
C2
COST
C1
C3
2
C2
COST
Q3
1
T1
C1 55
0
C3
2016
2014
2013
QU AL IT Y
2 1
4
Once the project is complete, Camden Council immediately own the building and are responsible for management and maintenance and so could directly employ residents as facilities magagement.
T3
Private Finanace InitiativeDesign and Build Operate
The Design and Build Operate contract combines fixed price design and build with an indexed service contract, involving a ‘special purpose vehicle’- a company formed between private service provider, contractor and a maintenance/management company.
Lowest possible capital expenditure Certainty over contract price, no fluctuation Best value for money overall
T1 T2 T3
Earliest possible start on site Certainty over contract duration Shortest possible contract period
Q1 Q2 Q3
Top quality, minimum maintenance Sensitive design, control by employer Detailed design not critical, leave to contractor
C1 C2 C3
Lowest possible capital expenditure Priority: 0 - lowest, 5 -fluctuation highest Certainty over contract price, no Best value for money overall
T1 T2 T3
Earliest possible start on site Certainty over contract duration Shortest possible contract period
Q1 Q2 Q3
Top quality, minimum maintenance Sensitive design, control by employer Detailed design not critical, leave to contractor Priority: 0 - lowest, 5 - highest
Q2
Q1
Camden Council
For this scale of public project a private finance inititative could be used. As cost and time will be the most important factors in the project,a fixed price Design and Build Operate could be used. HS2 compensation scheme is not to be paid until after works have started design will need to start immediately to get the project onsite simultaHS2. Involving private funding will mean that this will be possible and be made after completion.
AL
Q1
QU
T3
4
T2
ME
TI
Once hand-over has been made however, the client has very little say in choice of sub-contractors or flexibility for changes.
IT
Y
and so has increased control over design.
Funding from in 2016, yet neously with payments can
Q3
Q2
0
T2
T1
ME
Pre-fabrication of elements can commence Constriction works The client (Camden Council) has a direct contractual relationship with the architect offsite Consultation Initial Design commence on site
TI
This would be a relatively fast method and has a guaranteed completion date and cost. The construction time is also reduced due to design and build proceeding in parallel, There will be a guaranteed completion date, which it is the contractor’s responsibility to meet. Risk can also lie almost wholly with the contrator.
C1 C2 C3
4
Fixed Price Design and Build3
2012
As the project will be funded by the public sector, cost certainty is important. The construction works will take place whilst the residents are living on site. For this reason, the construction time also needs to be kept to a minimum. The majority of the building elements will be made offsite and can be assembled relatively quickly onsite.
3
4
55
Procurement Route
Collateral agreement / warranty
Bank Debt/ Bond
Contract for services
Special Purpose Vehicle Building contract
Contractor
Consultants
Equity
Client selected sub-contractors
Residents Facilities Management Co.
Design
As it is the resident women who will manage and maintain the facilities- an agreement could be made at the outset that they will be contracted as part of the facilites management co.
Contractual using a Typical ContractualRelationships Relationships in a TRADITIONAL Procurement Method PFI Scheme diagram represented from Which Contract? p.40-1
Contract for services
Collateral agreement/ warranty
This means that Camden Council have the advantage of cost and time certainty, which become the responsibility of the SPV contractor. They also have the contractor on board from early on in the project so this should allow communication between contractor, architect, client, residents and sub-contractors from early on in the project. As structural elements and fixings will generally be bespoke designs from specialist manufacturers, they will need to be involved in early stages in the design process.
Contractor
Consultants
Client
Client
Domestic sub-contractors suppliers
Contract for services Client selected suppliers
Design and build contract
Agent
Consultants
Sub-contractors suppliers
Contractor (consultant switch)
Contract for services
Consultants
Contractual Relationships in a FIXED PRICE DESIGN AND BUILD Procurement Method
Contractual Relationships in a FIXED PRICE DESIGN AND BUILD Procurement Method (which contract p.40)
The client (Camden Council) will pay upon successful completion of the project and for maintenance of the project for typically for 25 years+ after completion.
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Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 4
Role of Contractors and Suppliers Contractors
Suppliers
There may be several sub-contractors for different areas of work for the project. If a Design and Build contract is used, the client (Camden Council) will employ the main contractor directly. If a PFI scheme is used, the SPV will employ a main contractor.
The suppliers will be the responsibility of the specialist sub-contractors, agreed with architects and engineers.
Main Contractor: The main contractor will sub-contract out design and specialist services. These sub-contractors might be responsible for different areas of design and construction.
Concrete Reinforcement Contractor: A Specialist reinforcement contractor may be used to carry out underpinning and reinforcements of the existing structure, before works start on new interventions.
Groundwork Contractor: Demolition of retaining site wall and removal of earth will be the responsibility of HS2 construction works. The groundworks contractor may have to work in collaboration with the HS2 team in collecting and treating materials for re-construction and landscaping on site.
There are several main structural systems and materials used in the project that will be controlled by different contractors.
Concrete Reinforcement Contractor: Carbon fibre-reinforced wraps and adhesives Concrete mini piles
Groundwork Contractor: Reclaimed brick rubble Gabions and support posts Landscaping fillers Earth Paving Planting steel frame decks Steel works Contractor: Steel tubing for hyperboloid structures Steel lattice beams Bespoke cables, anchors and posts
Steel works Contractor: As the majority of new interventions are steel-frame structures, a specialist steel works contractor would be used to co-odinate maunfacture of elements offsite and assembly of structures onsite, working closely with the architect and engineers
steel towers
reinforcements
landscaping
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Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 4
Role of Consultants
A number of different consultants with different expertise will be employed for the scheme. They will be involved at all different stages of the project from design to completion. Structural Surveyors: Specialist concrete surveyors will be employed during the design phase to carry out concrete inspections, surveys and testing to determine the condition and strength of existing towers. This will determine the design of the interventions and necessary repairs and reinforcements Structural Engineer: Engineer will work with the architect on structural design. They will carry out necessary calculations of loading and forces acting upon the structure to ensure the new building and extensions will be structurally sound. Fire Engineer: As there have been two serious fires in existing buildings since 2008, fire prevention will be a very important issue in design of the new structures. A fire prevention engineer will be employed to assess risks and make sure building meets with fire regulations. Fire Consultant: Advises on fire strategies and means of emergency escape and complying with fire regulations Energy Engineer: Will be involved in design of energy-saving and harvesting elements, such as construction material energy efficiency, micro wind turbines and solar gain strategies. Environmental Engineer: Advises on energy-saving strategies and systems such as ventilation, day lighting, water use and recycling to maximise thermal and energy efficiency. Acoustic Engineer: Tests need to be carried out for design of interventions and acoustic linings within existing towers, as well as speculative calculations and advice on new structures and acoustic properties. Lift Engineer: Will be employed for design of new external lift shafts and mechanism connecting decks. M&E Engineer: Will be involved in grey water system design in new tower, new facade drainage, as well as installation of small-scale grey water systems in existing towers.
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Construction Risks, Health and Safety As the construction works will take place on an inhabited residential site, and within inhabited buildings, health and safety during construction is an important issue. Areas of the site will be closed off in stages to allow access to homes whilst work continues. As the project will be of a duration longer that 30 days, a CDM Officer will be employed to make sure that building works comply with the Construction Design and Management Regulations. They will oversee all arrangements to keep the site safe for workers and the general public from planning through to construction. Possible ricks will include: Fire riskAs the existing buildings have had issues with fire in the past and high rise residential is at high risk- this will be of particular concern. Flammable materials should be stored safely and fire emergency strategies should be put into place. Toxic MaterialsIn dealing with surface treatments of steel, paints, adhesives and plastic membrane welding, care must be taken to wear suitable protective clothing and to protect surrounding environment appropriately. Demolished wall and earth will also need to be tested for contamination before it can be used in the scheme. NoiseEar defenders should be worn by construction workers when working with noisy equipment and workers should rotate to prevent prolonged periods of . This will also need to be a consideration for residents and excessively noisy equipment can only be used during limited hours during the day. FallingWorking at height on existing and new tower structures mean that construction workers will be working at potentially dangerous heights. Suitable harnessing and scaffolding will be important. During demolition of existing tower facades, care must be taken to make sure appropriate scaffolding and fencing is used to prevent open drops with resident access.
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Claire Taggart Unit 22 Social Housing BENVGA08 Design Realisation -Part 4
2016
Initial Design
2014
Eight temporary pre-fabricated flats will be constructed on the rootops of the towers. Whilst building work is taking place on modifications to existing flats and building facades, residents of the affected flats can stay temporarily in the new flats until works are completed.
2013
2012
Construction Sequence -Site Closure
Consultation
Pre-fabrication of elements can commence offsite
Constriction works commence on site
Modifications will be made to the existing towers first, then new tower and deck structures will be constructed. To keep disturbance duration to a minimm, works will take place simultaneously with HS2 works.
stepped moving of residents floor-by floor
order of works and site closure
Bank Debt/ Bond
works on flats
Contra oxemholme tower closed off with pedestrian resident access
central area closed off from towers to lay foundations
dalehead tower closed off with pedestrian resident access
construction and landscaping
gillfoot tower closed off with pedestrian resident access
completion
as building work takes place on the floor above, residents on the floor below may also move up to temporary accommodation to minimise disruption. This also speeds up construction -as builders do not have to wait to move on to the next floor down
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