Birnbeck Island

Basil Spence Project: Birnbeck Island

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AR30021 Group 20 Paul Sidebottom, Olly Hessian, Anastasia Christakopoulou

page contents site 3 site context 4 site climate site constraints 5 site photographs 6 geology concept 7 materiality 8 axis promenade 9 multi-purpose space precedents 10 material 11 programme

‘What slice of sun does your building have? What light enters your room? as if to say the sun never knew how great it was until it struck the side of a building’ Louis Kahn

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12 13 14 15 16 17 18 19 20 21

scheme design site plan basement floor plan ground floor plan first floor plan second floor plan roof plan long section cross section section details south elevation

22 23 24 25 26 27 28 30 31

sceme specifics night visual visual from Sand Bay visual of main space visual of restaurant visual of east courtyard 1:500 site model 1:100 main model 1:10 detail model section diagrams

page structural & constructional development 32 wall development 33 stacked glass 34 wall construction 35 roof construction 36 main structure 37 construction process 38 materials 39 calculations

41 42 43 44 45 46

environmental control & conditioning thermal Labyrinth main hall main space lighting & acoustics calculations sustainability

critique 47 final crit post crit 48 ambitions

AR30021 Group 20 Paul Sidebottom, Olly Hessian, Anastasia Christakopoulou

Site Site Context Weston-Super-Mare is an English seaside town in North Somerset and located on the Bristol Channel. It grew at Victorian era boom in seaside holidays. In 1867 Birnbeck Pier was built to cater for this growing market, containing amusements and funfair rides.

In the post war period Weston suffered a decline in popularity as did most seaside resorts. However recently Westons’ tourist trade seems to be increasing. It attracts people with its shopping centre, helicopter museum, sea life centre, miniture railway and in a few years potentially a new Tropicana and Grand Pier, which recently suffered a catastrophic fire.

Sand Bay - bunglows, leisure resorts, beach villas, campsites

Birnbeck pier sits on Birnbeck Island just off a headland splitting Sand Bay and Weston Bay. The shortest width of the channel at its point is approx. 13km. Therefore it is an ideal position for investment in the form of a multi-purpose venue and passenger ferry facilities.

Birnbeck Island

Cardiff

Knightstone Island - new housing development

sand bay Grand Pier - competition winning design by Angus Meek

flat holm

Weston-Super-Mare Sealife Centre

steep holm

Tropicana centre scheme by MountfordPigott

Basil Spence Project: Birnbeck Island

brean down

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AR30021 Group 20 Paul Sidebottom, Olly Hessian, Anastasia Christakopoulou

Site Climate The climate of Birnbeck Island is very important to consider when designing a suitable response to the brief.

NE wind

The prevailing wind is from the South West meets the island without interruption leaving it very exposed. Historically, buildings that had previously been built on the South West side of the island have been destroyed. This creates the need for protection and also for consideration of materials that can be allowed to withstand the elements.

North Jetty

displaced waves to protect ferry

ferry

Site Constraints Entrance to the site is from the East across the existing pier.

potential wind energy concrete breakwater device

pier high tide

The reason for the current lack of ferry traffic is the enormous tidal range of up to 13m in the estuary. The only realistic position for docking a ferry is on the West side of the island. Furthermore with high tide level, storm surge level and rising sea levels it informs the decision to raise the building up on a plinth.

The island is steeper on the North, which creates the opportunity for pushing the building up to the cliffs to make available the most desirable space to the South and allowing access to the rocks.

low tide prevailing SW wind

Preferable views in the evening are towards where the sun sets. Therefore by locating the main hall towards the East it provides the opportunity to locate the restaurant towards the West and maximise these views.

North Jetty was historically used for paddle steamers. If repaired it could provide an opportunity for recreational use such as fishing or birdwatching.

The existing concrete slab denies the South and East of island. It could be removed to reveal natural rock

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AR30021 Group 20 Paul Sidebottom, Olly Hessian, Anastasia Christakopoulou

View of Birnbeck past weathered headland

View of Birnbeck from headland

Sunset over Birnbeck Island

View of Birnbeck from headlond

Knightstone Island and Weston Bay from Birnbeck

View from North coastline

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Birnbeck at high tide and bad weather (NE wind direction)

AR30021 Group 20 Paul Sidebottom, Olly Hessian, Anastasia Christakopoulou

Geology Birnbeck Island is situated in an anticline.

An anticline is a fold in the rock layers that face convex up. The peak is then eroded to reveal progressively older rock layers towards the centre of the fold.

Birnbeck Island and Worlebury Woods lie in the fold of the anticline and therefore consist of older rock. This older sedimentary rock has gained strength from the pressure of being packed down beneath other rock layers. This explains why Birnbeck Island still survives due to its strength.

There is a fault line that cuts directly through the island. Gobline Combe Oolite forms the south of the island and to the north is Birnbeck Limestone.

Both are types of Carboniferous Limestone and occur frequently around the local area.

Looking at the headland reveals the angular sheared bedding planes that occur due to the anticline and this is what make the place so unique.

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AR30021 Group 20 Paul Sidebottom, Olly Hessian, Anastasia Christakopoulou

Concept We wanted to make a building that has a strong connection to the nature of its site. We began by trying to understand the site through its history, geology, through photographs, sketches and site visits. Our initial observations were that the island is very exposed to the elements. Weathering is evident from the wind, the moist air and the waves as they crash up against the rocks as the tide comes in.

crashing waves, seaspray monolithic, geology, sheared planes staining, weathering, exposure

Birnbeck is most commonly seen from the coastline at a distance and sits on the furthest stretch into the expansive estuary. This suggested a bold simple building form that will be prominent at a distance. We wanted the building to be monumental and timeless in its very nature.

Materiality We wanted to explore the idea of abstracting this relationship between rock and water into the architecture of the building. In our scheme.

Landscape and built form will share similar qualities that root the building into its site.

Our investigation of this led to us limiting our palette of materials in the exterior of the building to stone and glass. We propose that the building facade be made from thick cladding panels of locally sourced Birnbeck Limestone cast into concrete. To reflect its surroundings we decided the stone should have a rough and rustic feel to it similar to the weathered and fissured rocks of the coastline. Over time this effect will be dramatised by the weathering of the stone.

The glass sits in the stone as small pools of light that will not be obvious from a distance but from inside will glow as they catch the light. The homogenous effect of the horizontal faรงade makes reference to the sheared bedding planes of rock that occur along the local coastline.

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AR30021 Group 20 Paul Sidebottom, Olly Hessian, Anastasia Christakopoulou

Axis Birnbeck Island has a degree of duality suggested by its neighbouring bays; Sand Bay to the North a calm, tranquil, untouched place that dictates a restrained, simple intervention. The other, Weston Bay, to the South is busy, dazzling and colourful. This has informed a linear footprint from East to West which maximises preferable views.

We propose that the main promenade route from the pier to the ferry be external along the southern edge of the building. This East – West axis continues beyond the island boundary to a landing platform for the ferry and into a floating concrete breakwater which allows ferries to dock safely at the platform. Where this is tied down in the estuary, foundations will be put in place for an 850 kW wind turbine which doubles up as a small stream turbine to gain energy from the tide as it rises and falls.

Promenade We were aware that the distance across the pier and consequently to the ferry landing station is substantial we therefore wanted to animate this journey as much as possible to engage the visitors with the landscape and architecture.

The external promenade space is protected from the elements by a stacked glass wall which runs the entire distance along the route. Perforations and punctuated points occur along the wall to allow views of Weston Bay and access down to rock pools.

The facade of the building is pulled in to create an entrance sequence that pulls you into the heart of the building, while the shop volume is pushed out into the promenade space to engage visitors with the building. Our intention is for this area to be more flexible in summer to allow the shop to become a part of the promenade experience without having to enter the building.

Where masonry construction gains stability through turning corners, our cladding panels will transfer the load onto a structural frame and therefore retain the linearity we are intending. It also allows us to lift up the facade to allow entry and light into the ground floor spaces.

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AR30021 Group 20 Paul Sidebottom, Olly Hessian, Anastasia Christakopoulou

Multi purpose space bar

Hall

outdoor performance

restaurant

foyer

Traditionally venues consist of supporting spaces that cater for events that occur in a main hall.

We imagined our interpretation of a multipurpose venue and ferry terminal to be embodied in an individual flexible space.

Our realisation of this was to allow our ground floor to flow across the footprint of the building.

We felt this would be attractive to a client as less of the buildings area would be occupied by the hall, where the occupancy would be very peaked, but also have the potential to cater for large scale events increasing the costeffectiveness of the total space.

Allowing the building to be occupied in this way also enriches the experience of a large scale event as there are more spaces to cater for the varying desires of the people attending. For example in a concert opening up the hall to the bar area allows for free movement between the seated area or dance floor and the bar while maintaining and elevating the views of the stage.

In the case of a large conference the restaurant is able to serve the catering needs and informal meetings away from any presentations taking place in the hall, and there are private meeting spaces on the 2nd floor for more formal business meetings.

By lifting the back of house above the hall floor level it allows the hall to open up to the East and provide outdoor performance in summer months.

This also allows stage equipment to be driven straight into the hall from pier level.

outdoor performance space

Basil Spence Project: Birnbeck Island

flexible foyer space

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AR30021 Group 20 Paul Sidebottom, Olly Hessian, Anastasia Christakopoulou

Precedents Material Our aim was to explore and abstract the relationship of stone, glass and light into a workable wall section.

Mortensrud church by Jensen & Skodvin Architects appears to emerge out the rocky ground. The interior is characterised by a steel frame with dry stacked stonework, protected by a glazed screen.

Initially we liked the effect of the stone having a transluscent quality but we wanted something more monumental and were interested in using the thermal properties gained from wall thickness.

We decided on prefabricated panels of stone and concrete, similiar to the Kursaal in San Sebastian by Raphael Moneo. He creates a powerful horizon of panels of slate and concrete that reflect the granite boulders strewn along the sea walls of San Sebastian

a.

We explored the use of transparent stone in an attempt to find a material that could bring light and warmth into the foyer and bar spaces.

Madridejos & Sancho’s Town Hall & Civic Centre in San Fernando, Spain uses polished onyx panels to create a luminous void at the heart of the building.

b.

We were interested how Clavel Rojo’s Mausoleum in Murcia, Spain, speaks through dignity and simplicity in the use of stacked glass in the entrance panel. The rough texture of the glass relates to the surrounding rock.

The massive solidity of Danny Lane’s work seems to move away from the traditional use of glass.

He uses it as a load-bearing, flexible material as opposed to the fragility and instability to which it is usually associated.

c.

e.

d.

Basil Spence Project: Birnbeck Island

f. a. Mortensrud Church, Oslo, Norway, Jensen & Skodvin Architects b. The Kursaal, San Sebastian, Spain, Raphael Moneo c. Town Hall & Civic Centre, San Fernando, Spain, Madridejos & Sancho d. Mausoleum, Murcia, Spain, Clavel Rojo e. Empress, Queen’s College, Cambridge, Danny Lane f. Dairy House, Somerset, England, Charlotte Skene Catling

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One of our intentions was to achieve protection and thermal mass alongside desirable views and openness. Architect Charlotte Skene Catling achieves this in her design for Dairy House. She uses matching alternating layers of oak and laminated glass blocks. The wall allows light to flood through and give it a lightweight feel on the interior while the exterior feels much heavier and rustic in its aesthetic.

AR30021 Group 20 Paul Sidebottom, Olly Hessian, Anastasia Christakopoulou

Programme The Sainsbury Centre integrates spaces for viewing art, and facilities for recreation, teaching and research, within a single, light-filled space that opens up to views of the surrounding landscape. Elements within the space are used to create divisible spaces.

Conceptually this is what we were aiming to achieve. We wanted to respect the monilithic shell which we created by seperating it from the internal elements. This achieves simplicity of expression and flexibility in the variety of uses in one space.

a.

The University Library in Utrecht by Wiel Arets has been designed in the form of a dense structure which is dissected by narrow lanes and broader open spaces. Volumes seem to hover within the vast 6 storey open space. Floating platforms contain bookshelves and reading spaces.

c.

Our scheme attempts to embody the idea of flexibility by a single open space with volumes that relate to one another. We wanted to enliven circulation spaces and mezzanine areas by animating them with seating areas and viewing areas. This aims to strengthen our concept of providing a flexible venue for exhibitions and events.

d.

a + b. Sainsbury Centre for Visual Arts, Norwich, Foster & Partners c + d. Utrecht University Library, Wiel Arets b.

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AR30021 Group 20 Paul Sidebottom, Olly Hessian, Anastasia Christakopoulou

Scheme Design

Site Plan scale 1:2000

(post crit)

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AR30021 Group 20 Paul Sidebottom, Olly Hessian, Anastasia Christakopoulou

Basement floor plan scale 1:100 (reduced)

labyrinth utility room

air handling unit

storage & waste

Hall (below stage)

external courtyard

labyrinth

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AR30021 Group 20 Paul Sidebottom, Olly Hessian, Anastasia Christakopoulou

Ground floor plan scale 1:100 (reduced)

flexible space reception

terrace

lounge

foyer bar

hall

backstage

shop

colonnade view

external promenade

ferry deck

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AR30021 Group 20 Paul Sidebottom, Olly Hessian, Anastasia Christakopoulou

First floor plan scale 1:100 (reduced)

kitchen office male changing

green room

bar/view

restaurant

female changing

gallery

events

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producer

hall supervisor

fire

AR30021 Group 20 Paul Sidebottom, Olly Hessian, Anastasia Christakopoulou

Second floor plan scale 1:100 (reduced)

meetings

flexible space

meetings

exhibitions

sound tech.

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sound contr.

lighting -cont.

stage lighting

AR30021 Group 20 Paul Sidebottom, Olly Hessian, Anastasia Christakopoulou

Roof Plan scale 1:100 (reduced)

(post crit)

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AR30021 Group 20 Paul Sidebottom, Olly Hessian, Anastasia Christakopoulou

Cross-section scale 1:50 (reduced)

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AR30021 Group 20 Paul Sidebottom, Olly Hessian, Anastasia Christakopoulou

Section Details We used the sectional perspective construction section as our main presentation image for the crit.

We felt the image accurately demonstated the integration of structure, materials, environmental strategy and architecture as clearly as possible.

b.

a. c.

a.construction section b.skylight/parapet detail c.office detail d.labyrinth detail e.external wall detail

e.

Basil Spence Project: Birnbeck Island

d.

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AR30021 Group 20 Paul Sidebottom, Olly Hessian, Anastasia Christakopoulou

South Elevation Scale 1:500

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AR30021 Group 20 Paul Sidebottom, Olly Hessian, Anastasia Christakopoulou

Night Visual We felt from an early stage that the bold axis of the stacked glass wall had the potential to be an amazing feature especially when lit at night, our decision to continue this beyond the boundary of the island with the breakwater allowed us to highlight the linearity of the design and allow the venue to become a beacon on the headland.

Our desires for the building to be a comforting shelter from the elements on the exposed headland are reinforced when the light glows from within the building through the openings and translucent stone, making it appear inviting despite its remote location.

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AR30021 Group 20 Paul Sidebottom, Olly Hessian, Anastasia Christakopoulou

Visual from Sand Bay From the tranquil and calm Sand Bay the site is only visible from a great distance, this combined with the nature of this bay encouraged us to treat the north elevation as something that could be discerned at a distance. We achieved this by keeping the elevation as simple as possible, the only break in the stone wall is at ground level where there is a glazing layer of clear and stacked glass. We wanted to continue this layer, however the presence of the hall meant that glass was not an option. We decided then to express the volume of the hall at ground floor level in timber to continue the datum line.

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AR30021 Group 20 Paul Sidebottom, Olly Hessian, Anastasia Christakopoulou

Main Space To maximise the flexibility of the ground floor we wanted the space to flow through the building with a minimum amount of interruptions. This is flanked by the shop, which is able to open out to the external promenade as well as the internal main space. It could even display stands and stalls within the space if required.

We also imagine the bar area to be flexible, having a possibility of turning 90 degrees or even demounting and relocating to the restaurant to cater the needs of formal dining events and champagne receptions.

The spaces created between the permanent accommodation, we imagine would be available for flexible occupancy from exhibition panels to informal seating. (post crit)

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AR30021 Group 20 Paul Sidebottom, Olly Hessian, Anastasia Christakopoulou

Restaurant By deciding to place the hall on the East of the building we were able to take advantage of the views over the estuary and especially the sunsets over the water. We decided to use this opportunity by placing the lounge and restaurant against this faรงade as well as providing access to a terrace at ground floor level. We wanted this faรงade to not only allow for these views but also allow a continuity of space along the east west axis.

We felt the best treatment of this faรงade was a lightweight frame glazed faรงade that matched the scale of the building.

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AR30021 Group 20 Paul Sidebottom, Olly Hessian, Anastasia Christakopoulou

East Courtyard The east side of the island is the culmination of the pier journey and the first stage of the entrance sequence of the building. This also provides access to the north pier which we wanted to preserve.

To cater to the access to this pier we moved our building west creating a outdoor space to the east of the building. This space we felt could be manipulated to become an enjoyable outdoor space.

By raising the back of house facilities up we allowed direct access into the hall but also the potential for the hall to open out to the external space.

We wanted to landscape this area to cater for outdoor performances. By continuing the line of the countours we banked up an amphitheatre style seating that faces the south and protects the open space from the wind.

From research we found that public spaces are often enhanced by steps and seating as it alows people to gather and enjoy the surounding environment which is something we felt was paticularly relevant to the site.

We imagine the performance space being used in summer for small courtyard performing or local school performances. (post crit)

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AR30021 Group 20 Paul Sidebottom, Olly Hessian, Anastasia Christakopoulou

1:500 Site Model

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AR30021 Group 20 Paul Sidebottom, Olly Hessian, Anastasia Christakopoulou

1:100 Main Model

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AR30021 Group 20 Paul Sidebottom, Olly Hessian, Anastasia Christakopoulou

1:100 main model Our decision to treat the internal spaces as individual volumes sitting inside the sheltering structure meant we had to be careful with the floor plate design. We intended to limit the floor area on the 1st and 2nd floors and link the islands with walkways. We also made the decision to clarify the concept of volumes within a space by pulling the floor plates away from the structural walls.

We wanted to achieve a uniform space that had a strong relationship vertically as well as flowing horizontally. The mezzanine levels act to enhance the vertical relationship between floors while being orientated by the horizon at all times.

We wanted the main stair to pick people up out of the main circulation space and lead them up into the more private areas. We decided to kink the main stair route to reinforce the public route towards the restaurant as opposed to the more private meeting and office spaces. There is then a conscious rather than instinctive decision to continue to the 2nd floor.

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AR30021 Group 20 Paul Sidebottom, Olly Hessian, Anastasia Christakopoulou

1:10 Detail Model The detail model was very useful in showing how the cladding panels were constructed. Each panel is made from rough cut Birnbeck limestone blocks cast into a concrete panel. These panels are seperated by a 50mm air gap and 50mm of rigid insulation.

Secondary beams support the interior panel and are hidden within the wall construction.

The exterior panel hangs off the interior by steel brackets at their base and steel ties throughout.

Stacked glass elements are held in aluminium channels to protect them from the stone. steel ties

stacked glass

rigid insulation

secondary beam

exterior

interior

stacked glass wall

We cut up slate sheets with a mortar and hammer to represent the limestone. We then cast these into exterior polyfilla to act as the concrete. Lasercut perspex sheets were used for the stacked glass.

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AR30021 Group 20 Paul Sidebottom, Olly Hessian, Anastasia Christakopoulou

Section Diagrams We wanted to demonstrate the various sections throughout the building to show the variety of spaces that are located within the single space.

Section A shows the flexible double height space at the West entrance.

Section B shows the restaurant, kitchen and meeting areas, looking over the estuary (post crit)

A

B

A

B

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AR30021 Group 20 Paul Sidebottom, Olly Hessian, Anastasia Christakopoulou

Structural & constructional development Wall Development From an early stage we felt that developing the buildings skin would be integral to the success of the design. We knew the effect we wanted to achieve and we looked at a number of precedents to establish what was possible and how to achieve the massive and transparent wall section.

We looked at examples of creating a perforated building skin and its effect at night. This was important as we felt from an early stage the site had the potential for lighting at night and to stand as a beacon on the headland.

The earliest precedent that we looked at was the Mortensrud Church by Jensen and Skodvin.

The raised dry stone walling achieved an internal effect that was similar to what we desired. They had also raised this mass above ground floor.

The difficulty with using dry stone walling was to seal the internal space. In this case they have an external glazing layer with steel fins to provide support to the stone wall as well as protect the space inside.

We experimented with various combinations of shading systems, glazing layers and the dry stone wall. The decisions we made following this study was to try and integrate this sealing/glazing layer into a single building skin. This seemed to be the best way to resolve excessive solar gain or limited light travelling through gaps in the wall.

a.

b.

b. a. The Dolder Grand, Foster+Partners, Zurich b. Mortensrud Church, Jensen+Skodvin, Oslo c. Shanghai Expo, Foster+Partners d. Polish Pavillion, Wojciech Kakowski, Shanghai Expo d.

Basil Spence Project: Birnbeck Island

d.

d.

c.

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AR30021 Group 20 Paul Sidebottom, Olly Hessian, Anastasia Christakopoulou

Stacked Glass By enlarging the wall section we were able to house the structure within the main wall as well as reinforcing a feeling of security and shelter from the elements. By punctuating this faรงade with stacked glass and double glazing we were able to maintain the views out to the beautiful surroundings and allow light to refract into the building. The stacked glass will appear to glow brightly even on overcast days as the light catches the edge of the glass.

There were concerns about the stacked glass being a cold bridge. However after researching the subject and looking at precedent we deduced that glass, when stacked or laminated together, has a strength in thermal mass, rather than a weakness in conductivity.

a.

b. a + b. Laminata Glass House, Netherlands, Kruunenburg Van der Erve Architecten

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AR30021 Group 20 Paul Sidebottom, Olly Hessian, Anastasia Christakopoulou

Wall Construction

Primary Structure Insulation Cavity Pre-fab stone/concrete panel

Glazing Module

We established at an early stage that we wanted to create a building material that achieved a number of objectives: • Appears rooted in the islands rock • Achieves clarity from the coastline • Reinforces a sense of shelter • Performs well thermally • Allows natural light through • Frames views to the coastline • Encourages entry to the venue We made some early decisions to use local limestone as the primary material and to raise this above a ground floor level of glass, to encourage entry and allow more light into the building.

We wanted to establish a relationship with the site by abstracting the sea crashing onto rocks into the architecture using stone and stacked glass as our primary materials.

Due to the nature of the site conditions we felt that pre-fabrication of the building skin would be beneficial to the construction process. This then allowed us to integrate glass into the stone panels.

Secondary Structure Stacked Glass Wall Match Cast Joint

By allowing for a deep wall section to reinforce the feeling of shelter we were able to layer the wall construction as a cavity wall including insulation and an air gap. This gave our building a low u-value.

By choosing to have a modular system for the glazing we are able to choose where glazing openings are double glazed for views out and where they are stacked glass for the refracted light. We have organised the openings randomly across the facades to allow a dappled light to fill the internal volume.

By using the stacked glass for light openings not only will this produce a spectacular effect internally but from a distance the glass merges into the wall when the light hits the outside. This reinforced the clarity of the design from the coastline.

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AR30021 Group 20 Paul Sidebottom, Olly Hessian, Anastasia Christakopoulou

Roof Construction To integrate the technical servicing and the structure in the hall roof without bringing the ceiling height down too far we needed sidewalks with head clearance underneath the deep roof beams with the catwalks running between beams at a higher level. The walkways and acoustic panels would be hung from the roof beams and supported at the walls.

Structural Beams Access Walkway Support Cable

We have attempted to integrate servicing, acoustics, lighting and external aesthetics into our roof section. Internally the acoustic panels and exposed beams reduce reverberated sound across the venue. There is then a generous servicing zone between ceiling finish and structure.

Handrail Catwalk Timber Panels Cavity External Wall Section

Stone Ballast

In looking at the local pebbled beaches we felt that a ballasted roof would make reference to the washed up stone against the weathered cliffs.

The stone ballast would need to be large enough to not be blown away in high winds, however the advantage of using this technique is that the EPDM membrane would not need to be glued down and therefore is more easily recycled at the end of the building life. This also allows for any heat movement.

EPDM membrane 100 - 300mm Insulation 50mm below gutter 80mm Screed

Structural Beams Steel Catwalk Access Walkway Acoustic Panels

The roof will be visible from the headland and therefore needed to be considered aesthetically.

The difficulty we had was finding a way of continuing our material concept on a horizontal plane. We wanted to achieve something that was in keeping with stone and glass and the coast.

150mm pre-cast conc. slab Pre-stressed conc. beams 1.5m (Detail A) w/ acoustic insulation.

The skylights would then sit as minimal glass boxed in a plane of washed up stone.

Steel connectors

EXPLODED HALL ROOF CONSTRUCTION

In-situ conc. columns 400 x 320mm @ 4500mm c/c 500mm Pre-fabricated stone/concrete/glass panels w/ hidden secondary beams 500mm Stacked glass Concrete pad footings

Basil Spence Project: Birnbeck Island

EXPLODED CONSTRUCTION

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AR30021 Group 20 Paul Sidebottom, Olly Hessian, Anastasia Christakopoulou

Main Structure

reinforced concrete roof acts monlithically as a flat, deep beam to transfer lateral loads to shear walls and cores

loading from the longitudinal direction is spread between columns and shear walls by secondary beams (not shown) and roof slab

The concept of elements within a large single space created a challenge for the structural strategy. The large portal type frame had to appear to be self supported with little help from the internal elements.

After sizing the main columns it was decided that in the main space the columns would have to be propped along their length using the mezzanine slab. The props make the columns short rather than slender and help transfer the wind loading through the slabs to the shear walls. This allowed smaller profile columns to be used, which enabled the faces of the columns to be flush with the inside of the wall. If they were not propped then the deeper columns would either protrude from the wall, thereby interfering with the linearity of the wall, or the thickness of the wall would have to be increased to hide the large columns.

In the latter case, this would increase the width of the stacked glass and therefore reducing the amount of light entering the space.

In the hall there is nothing to prop the columns from so they are larger in order to take the full loading. This is not a problem because the columns in the hall are hidden behind timber cladding.

The main structural grid consists of 25m pre-cast T-beams, 1.5m deep, at 4.5m centres. The make up of the roof slab is shown on the previous page. These sit on 600x400 columns in the hall and 400x400mm columns in the mezzanine area.

Between the columns are 300x150mm secondary beams to support the dead load of the facade panels. These are spaced every 1.75m up the columns.

The foundations are concrete pads, with reinforcement bars drilled and anchored into the rock to provide moment resistance.

rigid elevator cores and shear walls provide lateral and torsional stability, transferring loads to foundations

Basil Spence Project: Birnbeck Island

pad foundations transfer vertical and horizontal loads to rock

wind loading on the facade panels (not shown) is transferred by the columns to the foundations and roof slab

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AR30021 Group 20 Paul Sidebottom, Olly Hessian, Anastasia Christakopoulou

Construction Process

Removal of slab and existing buildings, concrete slab is retained underneath building and promenade.

Construction of reinforced in situ concrete frame (Columns, secondary beams and shear walls). Precast roof T-beams are brought to site and connected to columns using small crane.

Prefabricated stone/concrete cladding panels are specially produced in factory, shipped to Avonmouth, transported down M5 and attached on site.

Internal columns and mezzanine floor slabs can now be cast in situ over a steel former within the protection of the outer shell.

Variety of tradesmen can work, protected from the elements, to provide bar, meeting and office spaces, surface finishes, electrics, plumbing etc.

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Build labyrinth walls and plinth up to a height of 3m above pier levell. Foundations for main hall are improved.

Precast roof panels are brought to site and roof is constructed rendering the building watertight.

AR30021 Group 20 Paul Sidebottom, Olly Hessian, Anastasia Christakopoulou

Materials We chose to use timber, specifically oak, for the finish of the internal volumes. This evolved from wanting to use timber for the hall interior due to the acoustic performance of timber as well as the warmth it can provide a space. This warmth is something we felt was necessary to provide a soft touch to the colder materials used in the enveloping structure.

We decided to rely on locally sourced reclaimed timber for the panelling of the internal volumes, however for the hall this would not be sufficient to provide the required finish. The forest of Avon provides a good source of sustainable wood and there are a number of reclaimed wood suppliers in the local area.

To achieve the glass effect we desired we realised that float glass would not be adequate as when viewed from the side it has a strong shade of green due to the iron content in the glass. There is another process of creating glass sheets which reduces the iron content however it is significantly more expensive.

e.

a.

We felt this form of glass could be justified for the building openings however for the protective external wall we needed to find a more sustainable resource. We looked into using recycled glass which is easily available however the embodied energy is high in re-melting the glass as well as rarely being clear glass.

f.

An alternative to this we found was recycled polythene or specifically PET bottles as this can be cheaply returned to clear panels. Our only concern with this was that it was not of the same grain as the natural based materials the rest of the building is made up of.

b.

c.

d.

g. a.white oak b.reclaimed oak c.stacked glass d.low iron glass e. transluscent onyx f. cut limestone g.birnbeck limestone

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We investigated transluscent stone facades for the two foyer entrances. This comprises a thin veneer of stone (igneous) bonded on to a hard polymer resin panel, making it thin, light and creates a luminous void in the bar space. The exchange between light and transluscent onyx is played against internal surfaces of oak and polished concrete.

The limestone would be sourced locally and cleft cut from the quarry. The finished blockwork would need a minimum of treatment before being used for the pre-fabricated panels, to increase the natural feel of the building skin.

AR30021 Group 20 Paul Sidebottom, Olly Hessian, Anastasia Christakopoulou

Structural Calculations

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AR30021 Group 20 Paul Sidebottom, Olly Hessian, Anastasia Christakopoulou

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AR30021 Group 20 Paul Sidebottom, Olly Hessian, Anastasia Christakopoulou

Environmental control & conditioning Thermal Labyrinth The labyrinth works on the principle that the rock of the island will not vary in temperature very much throughout the year. By drawing air through a system of concrete tunnels using a mechanical fan, heat exchange takes place between the air and the concrete, which passively pre-cools or pre-heats the air before it reaches the building. The walls are saw-toothed to increase the surface area and maximise heat transfer. The system is extremely low energy, only requiring a fan in the air handling unit to draw the air through at approximately 2m/s.

Cooling is provided by two 250m thermal labyrinths situated under the main space. The labyrinth will therefore be at a temperature close to the mean ground temperature. In summer the labyrinth can be flushed with cold air at night, cooling down the concrete structure, which will retain its coolth for the following day and increase its capacity to take heat from the daytime supply air. Air rises through displacement ventilation and is expelled through the sky lanterns. In peak summer conditions the labyrinth will be capable of delivering air to the hall that is 10째C below that of the air outside.

In winter the labyrinth will also offer a certain amount of pre-heating to the air, reducing the heating loads on the air handling unit.

In this marine environment the labyrinth has another advantage of removing contaminants in the air. As the air meets the cool surface of the labyrinth it will condense and deposit salt which would otherwise be a burden on the filters in the ventilation system.

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AR30021 Group 20 Paul Sidebottom, Olly Hessian, Anastasia Christakopoulou

Main Hall When the main hall is full, during a performance for example, there will be no need to provide heating due to heat given off from people and electrical equipment; only cooling is required.

Cool air is provided by the labyrinth and will enter the hall in two systems; for when the demountable tiered seating is up, and for when the raised floor is flat. We intend to distribute the treated air through pressure diffusers in the side walls. To cater for the central areas flexible ducting is required for the demountable seating.

Due to air moving by natural convection the ducts will distribute air at a low velocity as it is not necessary to force air movement in the room.

The warm stale air is then extracted through ducts in the ceiling and in winter, when heating is required in the main space, can be passed through a heat exchanger in the air handling unit. It can then either be stored in the second labyrinth or released into the main space. pressure diffusers

central ducting

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AR30021 Group 20 Paul Sidebottom, Olly Hessian, Anastasia Christakopoulou

Main Space Raised flooring above the mezzanine concrete slabs allows services to be distributed out of sight. The rooms are heated, ventilated and cooled by air ducts that run from the air handling unit, through wall cavities, to low level vents around the side of the rooms. Heating and cooling requirements will change seasonally and with occupancy levels, which will vary between rooms. Therefore individual ducting runs in wall cavities and raised floors, so that the temperature of each room can be individually controlled. The stale air flows through high vents into the main space and then extracted out of the sky lanterns.

The concrete floor slabs would be cast in situ with servicing integrated into the structure so that lighting and electrics are easily installed in the underside of the slab.

The stone and concrete cladding panels are 500mm thick; meaning the envelope of the building contains a large amount of thermal mass. This contributes directly to the climate control of the main space. As heat is introduced into the venue through people, lighting or solar gain, the temperature of the exposed thermal mass of the floor plates will rise far slower than the air in the space would by itself. This alleviates the heat build up and lowers the apparent heat gain sensed by the occupants. The stacked glass at ground level also contributes to this. Glass has a similar thermal conductivity to concrete (k-value) and in this case when it is very thick (500mm) can actually add to the thermal mass of the building.

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AR30021 Group 20 Paul Sidebottom, Olly Hessian, Anastasia Christakopoulou

Lighting and Acoustics

Stone Balllast EPDM Membrane 100mm thermal insulation Waterproof membrane 80mm scree 150mm precast concrete slab Electrical services zone 100mm rockwool acoustic insulation Acoustic membrane Precast pre-stressed roof beam: SE specifications

ROOF DETAIL 1:20

Lighting fixture

The glazed west facade, entrances on the South side and sky lanterns in the roof allow plenty of natural light into the building, reducing the amount of artificial lighting needed throughout the day.

Using pre-cast concrete columns and beams gives us the benefit of being able to integrate servicing and especially lighting directly into the structure.

This led to us designing the profile of the beams to have enough space above the lower flange to house hidden lighting to wash the beams in light as well as providing reflected light from the ceiling panels.

We explored the effects of expressing the columns visibly and physically. We decided not to allow the column to protrude from the rough stone wall as we felt it would detract from the horizontal nature of the walls. This limited our options for integrated lighting however we still wanted to highlight the columns rising into the large beams. This is when we decided to have up-lighters placed flush with the floor in front of each column.

Acoustically exposing the beams has its advantages as well. By exposing the roof beams and placing acoustic panels in the span between we should be able to reduce the reverberation of sound in the main space dramatically.

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AR30021 Group 20 Paul Sidebottom, Olly Hessian, Anastasia Christakopoulou

Environmental Calculations

(Hall)

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AR30021 Group 20 Paul Sidebottom, Olly Hessian, Anastasia Christakopoulou

Sustainability Our vision of a truly sustainable building is one that is well constructed and contains durable, low emobodied energy materials. Therefore the building has an incredibly long lifetime and its parts will not need to be replaced.

The construction uses local materials such as Birnbeck limestone. They can be repaired and maintained using local expertise.

The birnbeck limestone will have a very low embodied energy because it requires a small amount of work before it is ready for casting into the concrete and also transportation is minimal as it is sourced in the local area.

We aim to use reclaimed timber for the exterior of the hall volume and terrace area. Also timber for the interior finishing can be sustainably sourced locally from The Forest of Avon.

After the crit we decided this energy will be produced by a 950 kw wind turbine which doubles up as a stream turbine. This is located at the end of the concrete breakwater device, approx 100m into the estuary. Our buildings energy usage will peak at inconsistent times.

On a typical day the wind turbine will provide excess energy that can be sold to the national grid. However at times some additional energy may be required from the grid. On average the building will produce more energy than the building needs and so after a few years the wind turbine should pay for itself.

Rainwater recycling will be considered for grey water. Hidden gutters behind the parapet (see cross section) carry rainwater through downpipes in the hall wall to a tank in the basement, this can then be filtered and distributed to the appropriate areas.

Constructing a building only contributes a small amount of the overall energy use, most of the embodied energy comes from running the building after its completed. We have tried to reduce this energy use as much as possible by providing a well shaded envelope

thermal mass time lag decrement factor

The large thermal mass in our building (red line) will contribute to its climate control by acting as a heat sink to reduce the range in temperatures throughout the day, compared to a building with a low thermal mass (green line).

Furthermore our interior wall contains rusticated stone which increases the surface area and improves its thermal performance. The building will have a time lag decrement factor so that peak heat gain occurs later in the day when it is required, for people entering the foyer before a performance.

Our two Labyrinths will cover the cooling requirements of the hall, during seated events.

Mechanical heating and electricity for lighting and sound will require some energy input.

Wind turbine technology

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AR30021 Group 20 Paul Sidebottom, Olly Hessian, Anastasia Christakopoulou

Final Crit

East

Our scheme was received well in the Final Crit by our panel of critics. We also received some interesting observations about the design.

The public space at the east of the building we felt could be developed as a landscaped courtyard providing seating and space for performances from the hall as well as in the space itself. We felt to create a realistic space it would need an element of shelter from the wind from the north, we integrated this into the landscape by artificially extending the contours of the island to 2m above the pier level to create large, south facing amphitheatre seating. This space also serves as the only route to the north jetty so needed to allow for this. The seating also allows access over the top down to the rocks and specifically the spit of land at low tide.

Key Criticisms and Suggestions • • • •

Due to the uncompromised concept, the scheme inherently limits its relationship with the island.

Grand scale of the building and its monolithic nature supports that the integration of the initial wind turbine strategy.

East end of the island as an arrival point is under developed as a potential space.

Potential for the labyrinth to store heat produced by building as well.

Post Crit We used the time after the crit to take into account some of the points made at the crit. We also developed further some other areas of our scheme.

Concept We have not made any revisions to the overriding concept as we felt that by trying to change the schemes relationship with the island would be to dilute the clarity of the concept and reduce its effect. Our response to the site has been the development of the materiality of the building and the major concepts evolved directly from the site and its conditions.

Energy Early in the design process we felt that extending the architectural concept beyond the boundaries of the island with the breakwater was a strong statement, and inherently had the strength to sustain as bold a statement such as a wind turbine.

After a series of tutorials before the crit we decided this was not an accepted architectural decision and decided to remove it from our design. After discussing this at the crit we believe that not taking advantage of the sites natural resources would be a chance missed. Therefore we believe the next step would be to propose a 950 Kw turbine which we have discussed in the sustainability section of this document.

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Environmental Our labyrinth design evolved to consist of two separate labyrinth systems that feed into the air handling unit, thereby doubling its capacity and allowing one to be used to store heat while the other can provide cooled air.

Plan We made some small alterations to the plans to develop the nature of the main atrium space.

To encourage this space becoming an area of interest we wanted the floor plates above to allow a gallery depth to provide views down into the atrium.

Roof We felt the Skylight detail needed some attention as the effect the initial design had was not what we wanted. We made a decision to extend the external boundary of the projected box so that from the inside you would only see the horizontal surface of the skylight giving the appearance of an opening in the roof as opposed to a skylight.

AR30021 Group 20 Paul Sidebottom, Olly Hessian, Anastasia Christakopoulou

Ambitions We believe that given more time on the project there are specific areas we would spend more time on to develop there full potential.

The East courtyard has the potential to be a really animated space and also an area that could develop the schemes relationship with the island. I believe we would look into the work of some landscape artists in sculpting the natural landscape of the island into an architectural feature.

c.

a.

b.

d.

The Ferry landing station is a complex challenge that we have not resolved. The transition from the stacked glass wall to the breakwater and in turn the public access to the changing tides is something that would take a lot more development but we believe could be an interesting feature of the journey.

We felt from an early stage that the buildings beauty would come through in its detail, there is great potential for a wonderful lighting scheme internally and externally. We only had time to touch on this area, however we did research the use of wind powered led’s that could be embedded in the openings of the stacked glass wall and allow the wall to glow in response to the changing wind.

The interplay of scale is something that has the potential to be exploited in this scheme as well.

Due to the large scale simplicity of the overriding space there is the chance to introduce smaller more intimate spaces into the architecture that gives the building real character and embed an impression upon the people who visit it. The best spaces within the building are still yet to be really developed.

e.

Basil Spence Project: Birnbeck Island

a.wind powered led, jason bruges. b.scattered wind powered led’s mounted on reeds, southbank exhibition, jason bruges. c.led close up d.mulitple leds e.boulder, andy goldsworthy f.untitled, andy goldsworthy

f.

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AR30021 Group 20 Paul Sidebottom, Olly Hessian, Anastasia Christakopoulou