St. Mary’s School is an independent girl’s school in Cambridge that prides itself on nurturing students and cultivating individuals with a broad social vision after the example of Mary Ward, its founder. in 2024, we completed a refurbishment and new build intervention for the School, to improve facilities for existing students, provide the spaces essential to teaching a modern curriculum, and to support a forward-thinking pedagogical approach. It was necessary to carefully think through our sustainability options for this project as it encompassed a variety of works within the overall masterplan, with each element requiring a bespoke approach. The project rationalises and refurbishes the internal spaces of the key teaching block to create larger classrooms and improve spatial use, signage and accessibility. We also designed a new CLT frame two-storey insertion, expanding classroom spaces on both floors. The upper half of the classroom block is clad in a light copper-alloy, bringing a bit of light and colour to the new extension, while the thermal performance of the building fabric is improved at each point of intervention.