GreenLight Alliance: Hope For The Future

20th December 2021

Created for the COP26 climate conference by Steuart Padwick with lighting designed by Buro Happold, Glasgow’s Hope Sculpture spotlights the global goals of the event with a 75% lower carbon build.

The Hope Sculpture started as a conversation with Ramboll and became a gift from 50 companies to Glasgow. It is a testament to the power of collaboration and dedication to deliver a better future” – Steuart Padwick. 

In terms of its lighting aspects, the Hope Sculpture project is one of the first to incorporate both CIBSE TM65 and TM66 assessments for the lighting equipment utilised.

Concepted, designed and led by artist Steuart Padwick, the Hope Sculpture is a new permanent public art installation situated in the natural landscape of Cuningar Loop, part of Clyde Gateway, Scotland’s biggest and most ambitious regeneration programme. Visible from long and short distance views, the 23-metre tall sculpture rises above the woodland, overlooking River Clyde. The sculpture is topped by an age/gender/race neutral child figure with their arms reaching out to a greener, hopeful future. 

Linked to the 2021 United Nations Climate Change Conference (COP26), the sculpture was constructed using low carbon, reclaimed, recycled or sustainable materials, of which, almost all have been locally sourced. It is a showcase for how leading industry partners are committed to build more sustainably, as we transition to a net zero future. The build demonstrates a 75% lower carbon impact.

The Hope Sculpture aims to raise awareness of the fragility of both our environment and our mental health and the importance of our natural environment and community in supporting our mental wellbeing. 

The Hope Sculpture, alongside the Beacon of Hope and Hope Triptych, is part of a trilogy of urban installations situated at key locations across Glasgow. Buro Happold Lighting was approached by artist Steuart Padwick to work as part of the team and to provide a sensitive and environmentally conscious lighting design scheme for the night-time illumination, respecting the natural context. The fundamental question on the need to apply lighting was among our initial conversations with the artist. Over time and as the hosting environment for each installation was defined, it was agreed that the Beacon of Hope and Hope Triptych will not receive dedicated illumination as the ambient light conditions were deemed bright enough to support viewing the installations and additional lighting would need to compete with surroundings. Therefore, the following information focuses on the illumination of the Hope Sculpture on Cuningar Loop.

Design Narrative

From the design to the construction techniques and implementation delivery, the primary design principle was to promote sustainability and environmental care with the aim of a reduced carbon build. The following key strategies were followed on a project wide basis:

• Collaboration with local consultants, suppliers

• Use of reclaimed materials (i.e recycled gas pipes for the piling)

• Use of existing upcycled equipment/ samples

• Use of materials with low embodied carbon content (e.g. 100% cement-free concrete)

• Use of construction processes with low carbon footprint

Working as a team and with sustainability embedded in every aspect of the project, we strived to promote the fulfilment of delivering something new through the creative reuse/repurpose/upcycling of existing materials and sustainable manufacturing/construction processes. 

Key Materials

The bespoke cement-free product has been developed by the Aggregate Industries’ technical experts in close partnership with the project team. This high strength product is part of their ECOPact Max green concrete range and reduces the carbon footprint by more than 70% compared to a standard concrete mix. Also incorporated in the concrete mix is recycled steel rebar. The cement-free concrete mix utilises a local Duntilland Dolerite aggregate and sand, and the cast child includes 20% recycled glass aggregate from Dryden Aqua, who recycle about a quarter of Scotland’s glass.

The Lighting Approach

At Buro Happold, we strive for our designs to be sustainable, sensitive towards nature and to contribute positively to climate resilience. As individuals, we are curious and conscious of our footprint paved by our design decisions. This leads to research and systematic actions supporting Buro Happold’s sustainability framework and commitments. 

Exterior lighting is a considerable contributor in the energy demands of the built environment. If not designed appropriately, lighting has adverse effects on climate resilience. Despite its undoubted benefits, uncontrolled lighting creates light pollution. In turn, light pollution results in a chain effect including energy wastage, disruption of ecosystems, season shifting and effects on human physical and mental health. In alignment with the project’s ethos and with sustainability at the forefront of our lighting principles, we designed the lighting for the Hope sculpture with respect to the natural environment and our planet. We utilised programmable light sources of low power and high efficacy, reducing the operating demands. We sought to use existing or re-purposed lighting equipment from local Scottish manufacturer Stoane Lighting, minimising embodied carbon emissions. The equipment’s small scale, premium built quality, interchangeability of components and the commitment for future service of components contribute further to reducing direct and collateral embodied carbon aspects of the lighting installation and the project in total whilst enhancing the equipment’s advanced circularity.

Reminiscent of the chimney stalks that once littered the East End of Glasgow, Steuart Padwick’s deconstructed chimney design is made of six elegant, angled columns, creating a dramatic 20-metre high pedestal for the child of hope. The base of the sculpture is paved using locally quarried Caithness stone slabs with engraved poems and words delivering messages of hope. Linking our built environment with improved mental wellbeing, the artist worked with Mental Health Foundation on all messaging. Words of Hope have been written by some of Scotland’s favourite voices, writers and poets. Four monolithic stone benches are placed around the sculpture, allowing people to sit, rest and reflect.

The need for environmentally considerate night-time illumination of the sculpture was part of our brief. As the hosting environment is a relatively dark context, we did not need to apply a high intensity of light to ensure sufficient illumination. Conscious of the light wastage and given the height of the structure (23-metres above ground level), we excluded the conventional way of uplighting from ground level via recessed luminaires. Instead, the child figure is illuminated using miniature adjustable luminaires integrated on outreach brackets and mounted on the capping plate carrying the child figure. The multiple small-sized luminaires with low output and tight optics provide flexibility in adjustment for uniform illumination of the organic form, while minimising light spillage towards the night sky. The pillars are illuminated via a single downlight housed on the joining surface at the top of the columns with downward light emission and narrow optics. As the light reaches the ground, it creates a soft shadow-play in a star shape generated by the casting shadows of the surrounding pillars. 

The lighting is warm white (3000K), dimmable, controlled separately and does not operate overnight. All control components are housed remotely in an overground feeder pillar for easy access and future maintenance visits. 

The Sustainability Calculation Methodologies

The Hope Project lends itself as an ideal opportunity for our scheme to be assessed using two sustainability metrics: CIBSE TM 65, Embodied carbon in the MEP equipment, 2021; and CIBSE TM 66, Circular economy in the lighting industry, 2021 (Beta version of CEAM-Make).

These technical memorandums describe two different calculation methodologies; one focusing on the embodied carbon on a product level and the other of the circularity aspects of the product.

TM65 has not been widely used for the assessment of luminaire products yet. TM66 was formally released in Q4 2021 but luckily, we had access to an early beta version of the calculation tool (CEAM-Make) that enabled Stoane Lighting to input product information and supporting evidence. 

The TM65 calculation took into account all luminaires and control components. The calculation method is based on total weight of the assessed system and material composition. The total estimated carbon emissions are 90kg CO2e. This figure reflects the worst case scenario as the drivers have been considered as an electronic component in their entirety and therefore bearing high embodied carbon content for their total weight (embodied carbon coefficient: 49kg CO2e/kg). Therefore, having the breakdown of the material composition of the driver component would have resulted in lower embodied carbon content of the total system. At the time of the calculation, the driver composition information was not available, highlighting the need to encourage lighting manufacturers and control component suppliers to take action now. Ultimately, having the base information publicly available will reduce the time required for the calculations to be performed and offer a more accurate impression of the performance of the system. 

TM65 and TM66 cannot be compared or characterised as more/ less complete as they are used for assessing different aspects. However, as TM66 is solely focusing on assessing lighting equipment, the calculation method is more detailed and specific to the manufacturing, materials and processes associated to lighting. The products are assessed under four main categories: Product Design, Manufacturing, Materials and Ecosystems. Through a series of questions for each category, the lighting manufacturer is asked to give a rating (from 0-4) based on the level of evidence at hand and action towards a circular economy. Points are collected for each category and summed up reflecting the overall performance of the product. Lastly, using a simple traffic light system, the score reflects the level of circularity of the product. The lighting equipment utilised for the Hope Sculpture ranks within the ‘Excellent circularity’ range (2.5 to 3.5) scoring 2.7.

The above findings were fed into the project-wide sustainability assessment led by Ramboll, one of the key supporting partners along with Glasgow City Council, South Lanarkshire Council and Clyde Gateway.

Next Steps

The project offered us a great opportunity to test the above sustainability metrics in a real project. Throughout the process, we engaged with our collaborators to source the information required. As the lighting industry is at the early stages of development on these aspects, there is plenty of room for improvement on all fronts. This project will remain as a reference point in our ongoing endeavours to design, specify and provide consultancy services towards sustainable and considerate projects. Our next steps include continued engagement with forums, manufacturers and clients and including carbon and circularity input in our project deliverables. 

Since the installation’s completion, all project collaborators have discussed the positive impact of the piece.

Steuart Padwick said: “We all need to address this new global agenda so our young can embrace a future of hope. It is very simple, why would anyone want to poison their future?”

Natalie Alexopoulos, Hope Project Director, added: “The most remarkable thing about this project has been collaborating with these companies and individuals. Their integrity, drive and commitment to make a difference has been inspiring.”

This series is curated by Roger Sexton of Stoane Lighting,