Case Study: The Shirt Factory, Gloucester

The Shirt Factory

161.1 kWp (358 panel) installation

From factory floor to powerhouse

The Shirt Factory is a historic industrial building in the heart of Gloucester, currently being redeveloped into a modern, multi-let commercial business hub. As part of an extensive renovation programme run by County to County Property Group, a bespoke construction and development company based in the heart of Gloucestershire, the team wanted to maximise the value of the building’s large roof space while embedding sustainability into the fabric of the development.

Stitching sustainability into a landmark building

Originally a shirt manufacturing facility and then later an optical lenses factory by Norvilles, the building had stood as a key employer in Gloucester for decades. When County to County acquired the site from administrators, the vision was to transform it into a thriving commercial centre with strong sustainability credentials that would appeal to modern tenants.

The challenge was twofold:

To futureproof the building in line with rising tenant expectations around energy performance and sustainability.
To design a solar PV system that worked around a complex site layout, made up of 17 different roof areas, while preserving the buildings premium office views and avoiding shading issues.

Cutting a system that fits

Working closely with the Mypower team, multiple system layouts were assessed during the design phase. While early designs explored installing solar across several roof areas, a detailed analysis of access requirements, structural loading, shading and cost ultimately led to a refined solution. By concentrating the system on the site’s largest, most accessible roof, Mypower was able to deliver the strongest return on investment without unnecessary complexity. An East–West panel configuration was selected to keep the panel pitch low, ensuring uninterrupted views from the building’s premium office

spaces towards Gloucester Cathedral and the city centre. Throughout the process, Mypower worked collaboratively with the wider construction team to ensure the installation integrated seamlessly into the live redevelopment site.

Built to perform, designed to last

The solar PV installation forms part of a much wider sustainability strategy for The Shirt Factory redevelopment. Each unit within the building is being designed to achieve an EPC B rating, supported by:

Up to 130mm of roof insulation
Fully insulated internal walls
Strong thermal performance even prior to heating installation

In addition, waste management on site has been exemplary, with less than 1% of waste sent to landfill, helping to significantly reduce the environmental impact of the renovation works.

The finished product

The completed 161.10 kWp solar PV system now makes productive use of The Shirt Factory’s expansive roof space, generating renewable electricity on-site and delivering long-term value for both the building owner and future tenants.

The system comprises 358 Trina solar panels, paired with 2x Solis inverters, and is expected to generate 148,979 kWh of clean electricity annually. This will help the site avoid approximately 30.8 tonnes of CO2 emissions every year, supporting the development’s wider sustainability goals. For a multi-let commercial development such as The Shirt Factory, the solar PV system enhances the site’s appeal to sustainability-conscious tenants who are increasingly asking how their electricity is generated, while also improving energy resilience and reducing reliance on grid-supplied power. By generating clean

electricity on site, the system helps protect the development against rising energy costs over the long term and provides a clear, credible sustainability USP for a landmark redevelopment in the heart of Gloucester.

Key facts and predictions

161.1 kWp (358 panels) installed.
149,979 kWh units of energy produced per annum.
£27,189 projected first year income and savings.
27.3% projected first year return on capital invested, before capital allowance benefits.
4.31p/kWh - the equivalent forward purchase price of 3.4 million units of electricity over 25 years including estimated operating & maintenance costs.
3.7 years - system payback before finance, tax and capital allowance and grant benefit.
£848,962 - a 25-year income and savings after indexation.
80% saving per unit from solar PV electricity compared to grid supplied electricity at 24p/kWh.
30.8 tonnes of CO2 emissions avoided per annum.

“We’ve obviously got these big roofs and wanted to get the best value from them. There are also growing expectations from tenants around how their electricity is generated, and we see that as a real positive. We got on really well with the team, the installation slotted in seamlessly alongside the wider construction works, and everything ran smoothly. Overall, we’re really pleased and would highly recommend Mypower to any business considering solar.”

Tom Waldron, Director, County to County Property Group

“The success of this project came down to collaboration. We worked closely with Tom and the wider construction team to ensure the installation integrated smoothly into a live redevelopment site, delivering a high-quality system that will support the building’s sustainability goals for years to come.”

Tom Sivil, Mypower's Project Manager