Helping Stride Treglown measure, reduce and report its carbon emissions across a multi-site architecture practice

Overview

Stride Treglown has measured its carbon emissions since 2018. As a B Corp and architecture practice, it wanted a robust, credible footprint that could support both its own reduction targets and growing client demand for emissions data.

About Stride Treglown

Stride Treglown is an employee-owned architecture and design practice with studios across the UK. Sustainability is embedded in its operations and the work it delivers for clients, from low-carbon housing and Passivhaus projects to biodiversity and sustainable design. The practice has also set SBTi-verified targets to reduce its operational emissions.

The Objective

Stride Treglown wanted to reduce its carbon footprint year after year while improving data accuracy and making the process easier to manage.

Having previously measured emissions in-house and used a consultancy to check the results, the team wanted more hands-on expert support with the measurement process itself. They also wanted to move away from managing carbon data across different spreadsheets and sources and instead centralise data collection, calculations and reporting in one platform.

With clients requesting more emissions information from their suppliers, having reliable data that could also be used for client reporting was becoming more important.

The Challenge

For a multi-site architecture practice, calculating an accurate carbon footprint involves bringing together data from across the business. Stride Treglown operates around 10 sites across the UK, with emissions coming from areas including energy, business travel, commuting and homeworking.

The practice also has some more unusual operational emissions sources, including a biomass energy generator, meaning its footprint needed to account for the quantity of wood pellets used to generate energy.

Rather than relying heavily on spend-based estimates, Stride Treglown also wanted to use more granular activity data wherever possible. For example, its travel portal provided actual mileage data, giving a more accurate representation of the journeys employees were making.

Why Stride Treglown Chose Seedling

Stride Treglown wanted a combination of carbon accounting software and expert support. This would centralise its data and make annual footprinting more efficient, while providing assurance on methodological and reporting questions.

Seedling also provided a way to bring historical data into the platform. When Stride Treglown started working with Seedling, its 2018 emissions data was uploaded as its baseline, preserving its existing carbon history and allowing progress to be tracked over time.

How Seedling Helped

1) Created a central place to manage carbon data

Seedling brought Stride Treglown's carbon data into one platform, giving the team a consistent place to collect, manage and report emissions.

Its existing 2018 baseline was retained, meaning the practice could continue tracking its progress rather than starting again with a new reporting system.

The platform also allows members of the sustainability, accounts and facilities teams to collaborate on carbon data collection, making the process less dependent on one individual.

Crucially, the same underlying carbon data can be used across multiple reporting and disclosure requirements. Seedling supports Stride Treglown to produce its GHG inventory for clients, as well as outputs such as Carbon Reduction Plans for public sector requirements and Climate Transition Plans for B Corp reporting.

2) Improved the accuracy of emissions data

Where more detailed activity data was available, Seedling helped Stride Treglown use it to improve the accuracy of its footprint.

Business travel mileage from the practice's travel portal could be used directly rather than relying on spend data, providing a better representation of the actual activities generating emissions.

Seedling also incorporated the practice's biomass energy generation by accounting for the kilograms of wood pellets used to produce energy.

3) Turned carbon measurement into actionable reduction

Measuring emissions is only useful if it informs action. Stride Treglown has implemented a wide range of initiatives to reduce the emissions associated with its offices and operations.

These include improving energy efficiency through LED lighting, upgrading heating systems, improving insulation, installing solar PV at its Plymouth and Cardiff locations, and upgrading servers and IT equipment. The practice has also moved 90% of its electricity contracts to tariffs providing 100% renewable electricity.

With seven of its UK sites already on renewable energy tariffs, energy procurement and building efficiency have become important parts of its reduction strategy.

The practice has also introduced a salary sacrifice scheme for electric vehicles to encourage lower-carbon employee travel.

4) Made carbon data useful for clients

For Stride Treglown, its carbon footprint is not only an internal reporting exercise. As clients look to understand and reduce their Scope 3 emissions, the emissions associated with the services they purchase from suppliers can form part of their own carbon footprint.

Seedling helps Stride Treglown apportion its emissions to individual clients on a revenue basis. This allows the practice to provide clients with an estimate of the emissions associated with the services they purchase, helping those organisations improve the accuracy of their own Scope 3 reporting.

This makes Stride Treglown's carbon data useful beyond its own impact reporting and supports the growing demand for better primary emissions data across supply chains.

The Impact

Between 2018 and 2025, Stride Treglown reduced its emissions per employee by:

• 62% in Scope 2 emissions

• 33% in Scope 1 emissions

• 76% in Scope 3 business travel emissions

• 33% in Scope 3 employee commuting and homeworking emissions

The practice now has a structured carbon management process, historical data retained from its 2018 baseline, and a clearer view of the operational activities driving its emissions.

This carbon data also forms an important part of Stride Treglown's annual Positive Impact Report, feeding into its reporting on environmental performance and progress against its climate commitments.

Its latest Positive Impact Report sets out its SBTi-verified targets and identifies further opportunities to reduce emissions from areas including business travel, waste and commuting.

Looking Ahead

Stride Treglown is continuing to work towards its science-based climate targets while improving the quality and granularity of its emissions data.

The practice's approach reflects the role that carbon accounting increasingly plays for professional services businesses: not simply as a way to understand their own environmental impact, but as a source of data that clients can use to understand the emissions associated with their supply chains.

For an architecture practice whose work is closely connected to the transition towards a lower-carbon built environment, reducing its own operational emissions provides an important foundation for the wider sustainability work it delivers for clients.