How Kensington and Chelsea cut heat loss and engaged pupils at Colville Primary School

Colville Primary School is a Grade II listed, late-Victorian building in Notting Hill, serving 480 children. Constructed in 1879, its large sash windows once maximised natural light in pre-electric classrooms. Over time they degraded to the point where they were causing significant heat loss and higher running costs, and the Royal Borough of Kensington and Chelsea needed to replace them without closing a school that is in use almost every day of the year.

The problem

Ageing windows, heat loss and a school that rarely closes

The school’s original sash windows had reached the end of their life. As well as looking tired, they were causing severely degraded thermal performance in both summer and winter, driving up running costs and leaving classrooms uncomfortable for pupils and staff.

Replacing more than 160 windows and external doors in a live primary school is not a simple job. Colville serves 480 children, uses its limited outdoor space for staggered breaks and lunchtimes, and runs clubs through the holidays, so the building is occupied almost all year round. Its Grade II listed status added a further requirement, with any work needing to protect the building’s historic character while improving comfort and energy performance.

The council needed a compliant route to an experienced supplier that could deliver a large fabric programme safely, around a working school, without losing time or control of the budget.

The solution

A compliant route to an experienced supplier, with social value built in

The Royal Borough of Kensington and Chelsea used our Planned Works Framework, Lot 17: Whole House Works, to appoint McConnell Group through a compliant procurement route, with support from our team. The framework gave the council direct access to an experienced supplier and helped keep the £1.64 million programme moving within a tight delivery window.

Over 35 weeks, from August 2025 to April 2026, McConnell replaced more than 160 windows and external doors with new double-glazed sash units, chosen to improve thermal performance and reduce running costs while respecting the building’s appearance. The programme also included façade repairs and repairs to drainage and rainwater goods.

To keep pupils safe, the works were timed to start in the school holidays and then continued carefully through term time. The team held regular meetings with school leaders to plan around lessons and activities, closing specific zones as needed.

Social value was built into how McConnell worked, not added on afterwards. The team ran a construction safety assembly, with a spot-the-hazard competition and a site safety clothing demonstration, so children understood the risks of a live building site. Pupils designed their own safety posters, and the winning designs were turned into signage displayed on the site hoarding. Two classes took part in McConnell’s Raising Aspirations programme, forming their own construction companies and taking on roles from architect and quantity surveyor to buyer, safety manager and site manager. The team also turned used hard hats into planted hanging baskets, which were donated to the school, and supplied and fitted new kitchen units for the school’s daycare, contributing nearly £2,000 in labour and materials.

The results

Better buildings, safer pupils and clear value for money

The programme delivered the replacement of more than 160 windows and external doors, alongside façade and rainwater repairs, improving the condition, comfort and energy performance of the school and helping its low-carbon heating work harder.

It also delivered clear value for money. When the team found failing brickwork during the works, they carried out the additional repairs using scaffolding that was already in place. That avoided a separate mobilisation, protected the original programme and saved the council money. The project finished on time and within budget.

The most visible outcome was the impact on pupils. What could have been a disruptive year became something the school community was part of, from safety posters on the hoarding to careers learning in the classroom.

“The Procurement for Housing Planned Works Framework provided a compliant, efficient, and reliable route to market, enabling us to appoint an experienced contractor within a challenging delivery timeframe. The framework gave us confidence that we could achieve value for money while maintaining high standards of quality, safety, and governance. Through close collaboration with McConnell Group and the project team, we successfully delivered a complex programme in a live, Grade II listed school environment, improving the building’s energy performance and comfort for pupils and staff while also generating meaningful social value for the school community.”

Nana Penseh, Commercial Manager, Procurement & Commercial Services, Westminster City Council

Together, the Royal Borough of Kensington and Chelsea, McConnell Group and PfH delivered more than a set of new windows. The right framework and the right supplier improved the school building and left a lasting benefit for the pupils, staff and community who use it every day.