Structure Materiality and Carbon

Materiality

Existing

One of the challenges of re-use is making sure to use the existing materials (a) to their fullest potential.

Embodied Carbon

Mild Steel

Reinforced Concrete Milford Granite Buff Brick

(a) Diagram showing the existing materials on site

Proposed

As our environmental sustainability approach is at the core of our design strategy, we picked materials that perform well environmentally, structurally and aesthetically.

Our final embodied energy calculations (b) reflect how effective our choices in materials have been.

Polycarbonate

Material used for the roof of the timber huts.

Polycarbonate has a high strength and transparency. This means the hut rooves can be self supporting. It also has a low heat transmission, allowing the huts to be thermally insulated. Despite having high embodied energy costs to produce new material, polycarbonate is fully recyclable and therefore a very sustainable material. (b) Carbon Lifecycle Assessment for the materials in our building

Reinforced Ferrock Concrete

A carbon neutral structural alternative to cement which becomes stronger in salt water environments.

Used for the shear elevator cores in our building. These provide the structural benefit of acting as shear walls, helping to brace the structure along the planes in which they are built. They furthermore provide structural load bearing and fire resistance for the elevator shaft.

Cork Insulation

Cork insulation has been used in the central timber huts and interior walls. This material is sustainable because it can be harvested as bark from trees without cutting the tree down. As a result it has a very low embodied carbon. Cork also has high resistance to damp and rot and provides good sound insulation

Glass

Triple glazed windows with an argon filling, low-e coating and fibreglass frames for environmental performance.

Used to replace the existing windows in the structure as well as for a number of facades on the interior. Allows us to create defined spaces at each end of the building with some heat and noise insulation, whilst leaving

open a sight line running east to west.

Steel

ETFE Membrane will be used to replace the roof of the structure and for the roof of the new west end space frame.

Used over glass as a 3 layer ETFE roof has a lower embodied carbon, it self cleans with rainfall, 100% recyclable and has a high light and UV transmittance. Furthermore, the structure is incredibly lightweight making the installation process easier and reducing dead load on the structure. To conclude, the most expensive intervention made to our design in terms of embodied energy is replacing the existing roof structure with ETFE, which is around 300 tonnes CO2e, but this is roughly 65% of the figure for glass (460 tonnes CO2e) and it is heavily recyclable. We have used timber where possible to reduce the embodied energy of our interventions as much as possible. The embodied energy cost of steel in both the spaced frame and bridges is high, but only used for critical long span elements.

Steel

Large structural interventions have been made out of a steel frame, as it is more simple to connect to the existing mild steel.

Used for the long span bridge and the space frame roof, as it is lightweight enough to be raised and lowered by the existing frame. The high bending moment capacity in steel stair stringers allows us to cantilever stairs from the existing structure where necessary.

Hard Maple Timber

Used maple to create self supporting huts withing the central area of the building, as well as in treads, stairways and bleachers.

The hardwood can be locally sourced, as red maple is the mot commonly found tree in New York State. As maple is very hard timber, it is suitable for spaces at the heart of circulation as it can endure sustained use. Timbers also act as an effective carbon sink if handled sustainably.