Workspace Transforms Leroy House – Cutting Whole Life Carbon08 September 2022
Workspace Transforms Leroy House – Cutting Whole Life Carbon08 September 2022
At Leroy House in Islington, Workspace has demonstrated the carbon and commercial benefits of reviving existing spaces. Throughout the refurbishment, Workspace commissioned a series of carbon studies that identified additional savings opportunities and evidenced that the project outperforms best practice targets for embodied carbon. Upgrades to the building will also improve operational efficiency and promote wellbeing, delivering modern spaces for customers.
- Cutting embodied carbon – 34% lower upfront carbon than LETI 2030 target
- Improving operational energy efficiency – 24% better than Part L in the extension
- Preserving local heritage – reviving an existing building
Workspace is a leading commercial property company in London. As a founding signatory to the BBP Climate Commitment, Workspace aims to deliver a net zero carbon real estate portfolio by 2030. It has set science-based targets to reduce embodied carbon intensity (Scope 3) by 20% and absolute operational emissions (Scope 1) by 42% within 10 years.1
In refurbishing Leroy House, a 1960s-style brutalist building in Islington, Workspace engaged sustainability consultant Verte to carry out whole life carbon analysis at several stages of development, measuring emissions and identifying savings opportunities.
The project involved the refurbishment of 6,200m2 of existing space and a 1,900m2 extension, creating large light-filled offices, studios and workshops across four floors.
Drivers for Workspace’s net zero commitment include rising stakeholder interest. Customers are increasingly asking about energy efficiency and emissions, investors are seeking greater transparency on climate risks and mitigation, and employees want to work for a responsible business, aligned to their personal values.
Reflecting Workspace’s longstanding efforts to drive down emissions, many of the low carbon decisions at Leroy House were made several years before the launch of Workspace’s net zero commitment. The majority are now business as usual on all Workspace projects, as set out in its Net Zero Carbon Pathway. Leroy House has been designed in line with the UK Green Building Council’s Net Zero Carbon Buildings Framework, aiming to achieve ‘net zero carbon – construction’ status, once complete
Reducing embodied carbon
- Retaining as much of the existing building’s structure as possible.
- Not installing raised access flooring and installing perimeter trunking instead, still ensuring access to small power and data.
- Leaving ceilings exposed across a large area of the project, rather than covering them with plasterboard.
- Designing the building to use natural ventilation where possible, saving embodied carbon by reducing the amount of plant required, cutting energy demand for cooling and supporting wellbeing. Using materials with high recycled content, such as structural steel with 20% recycled content and concrete with 50% Ground Granulated Blast-furnace Slag (GGBS) content for the superstructure and 70% GGBS for the substructure.
Reducing operational emissions
- Replacing existing gas boilers with air source heat pumps, accelerating the transition away from fossil fuels.
- Installation of smart Building Energy Management System to allow for continuous energy monitoring and optimisation.
- Installing 25.125kW a solar panel system to generate clean power on site. All additional electricity is sourced from renewable supplies, backed by REGO certificates, as standard for Workspace since 2019.
- Installing high performance building fabric in the new extension and upgrading windows in the existing building to reduce energy demand for heating and improve thermal comfort levels.
- Installing high efficiency LED lighting. Workspace is also looking at trialling a system where customers choose whether to turn lights on by pressing a button when they enter spaces. Motion sensors then detect absence to turn lights off. This could improve efficiency versus systems that automatically activate lighting whenever someone enters. It would also increase people’s personal control over their environment.
Additional sustainability initiatives include:
- Encouraging sustainable travel and active lifestyles by adding 98 long-stay cycle spaces, six visitor cycle racks on the street and 10 showers, including a fully accessible wet room. There are no car parking spaces.
- Enhancing biodiversity and promoting wellbeing through greening, including 50m2 of biodiverse roof planted with wildflowers and featuring log piles, along with climbing plants by the main entrance and three street trees.
- Promoting wellbeing and productivity for customers by designing unit sizes around big windows, to provide good levels of natural daylight indoors.
- Contributing £25,000 to London charity XLP, which creates positive futures for young people growing up on inner-city London estates.
- Targeting BREEAM Excellent rating for sustainability and Considerate Constructor Scheme score of 38 out of 50.
Systematic consideration on the necessity of additional materials has brought environmental and cost benefits. By leaving ceilings exposed in most areas, the project achieves significant embodied carbon reduction and a £340,000 cost saving compared to a design with suspended ceilings throughout.
In line with Workspace’s ambition to enhance local biodiversity, it has invested £47,000 to create a 50m2 green roof, including plant species that are most compatible with local wildlife needs.
Accelerating progress towards net zero
- Embodied: 231kg CO2e upfront carbon per m2 GIA (A1-A5) – 34% lower than LETI 2030 target of 350kg and 77% lower than the LETI business as usual benchmark for new-build commercial offices of 1,000kg.
- Operational: 24% reduction in regulated energy consumption in the new extension versus Building Regulations Part L 2013. Upgrades to energy efficiency in existing spaces through improvements to glazing and equipment.
- Increasing market appeal for customers, keen to occupy low carbon, highly efficient spaces that promote wellbeing.
- Demonstrating management of climate risks for investors and driving long-term value.
- Reassuring employees that they are working for a responsible business, aligned to their personal values.
- Preserving heritage and character by reviving buildings that are already part of the local community.
- Supporting Workspace’s reputation for environmental and social governance, as part of a wider programme that includes high recycling rates and commitments to pay the London Living Wage.
Challenges and Achievements
How do you move away from gas boilers?
Early in the project, Workspace made the decision to create an all-electric building, replacing gas boilers with air source heat pumps. The customer experience needed to be the same, regardless of whether heating was supplied via gas boilers or air source heat pumps. This introduced a number of challenges, particularly around providing enough hot water for multiple showers on busy mornings. The design team developed a new control strategy and allocated additional space to store hot water to fulfil peak demand. In addition, the team fitted two compressors to build in resilience, so that, if one needed servicing, heating and hot water would still be operational.
How do you cut upfront carbon?
Informed by the initial embodied carbon study, Workspace challenged the design team to revisit various aspects of the design. They explored different foundation options to increase the percentage of GGBS content in the concrete. Uplifting the GGBS content affected floor to ceiling heights and was slightly more expensive. However, it significantly reduced embodied carbon, contributing to the low carbon space that customers want. The team also switched from triple glazing to high performance double glazing. Although the initial assumption was that triple glazing would be better from a carbon perspective, as it improves operational efficiency, it also significantly increased embodied carbon. The team identified a high performance double glazing solution with the same U values as the proposed triple glazing, saving carbon and reducing costs.
 Workspace targets: Reduce absolute Scope 1 GHG emissions by 42% and Scope 3 GHG emissions from capital goods per sq ft net lettable area by 20% by FY2030 from an FY2020 base year. Scope 2 market-based emissions are zero as Workspace procures 100% renewable electricity.
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