Libraries NI Sets New Standard for Sustainable Public Buildings December 2025

In the Libraries NI Corporate Plan for 2025 -2030, there is a clear objective for the organisation to actively respond to the climate change challenge. This is a clear direction for the organisation and in many ways, this is embraced in delivering services on a daily basis. At the heart of a library is book borrowing; a system that reduces the environmental impact of reading by sharing resources instead of people buying their own copies. One of the biggest environmental improvements though for the organisation has been in our buildings and three rural libraries shine as environmental beacons, showing how limited capital budget can be used to achieve significant environmental improvements.

Killyleagh Library

Setting the Standard: Libraries NI Leads the Way with UK’s First EnerPHit Certified Public Building

When Libraries NI set out to refurbish a trio of rural libraries—Ballymoney, Killyleagh, and Bessbrook—the goal was clear: transform old and tired spaces into modern, sustainable and welcoming community hubs. 
A focus on this clear goal and a collective desire to create environmentally efficient library spaces led to a benchmark-setting achievement. Ballymoney Library became the first public building in the UK to achieve the prestigious EnerPHit standard—an accolade that would earn recognition in several awards:

• Chartered Institute of Architectural Technologists (CIAT), Winner - Retrofit of the Year, 2025.
• Construction Employers Federation (CEF) Construction Excellence Award, Winner - Energy Efficiency Project of the Year, 2025.
• Edge Awards 2025, Category – Physical, Shortlisted
• Construction Employers Federation (CEF) Construction Excellence Award, Shortlisted – Social/Community Construction Project of the Year, below £2m, 2024

These transformations were facilitated by the Department for Communities and supported by capital funding provided through the Department for the Economy Energy Invest to Save Programme 2023/24. This funding, specifically earmarked for energy efficiency projects, enabled the libraries to meet the stringent EnerPHit standard.

Teamwork: The Engine Behind the Transformation

Delivering these ambitious projects relied on seamless collaboration between departments across Libraries NI and external organisations. Libraries NI’s team managed the physical element of the builds from conception to completion, ensuring that every technical detail met the rigorous EnerPHit standard. Working closely with architects, contractors and specialist consultants, the team managed each stage of the process to deliver high-performing, sustainable buildings that met both design ambitions and environmental targets.

The projects also benefited from the expertise of a range of staff across Libraries NI, including frontline library staff who advised on layout and customer needs. This collaborative approach helped ensure the retrofitted buildings not only worked well behind the scenes but also met the needs of the people using them — from the layout and technology to the promotion and implementation of services and activities.

From the outset, customer engagement played a central role to the plans as feedback was gathered at multiple points to help shape internal layouts, improve accessibility, and enhance comfort.

Raising the Bar with EnerPHit

The EnerPHit standard is the retrofit counterpart to the world-renowned Passivhaus standard which demands exceptional energy performance, airtightness, and comfort. This criterion is rarely applied to existing public buildings so meeting the benchmarks in older library structures was a complex challenge.

Through innovative design and meticulous attention to detail, Ballymoney, Killyleagh, and Bessbrook Libraries were transformed. Each was fitted with triple-glazed windows, high-performance insulation, and airtight building envelopes. Central to the upgrades were MVHR (Mechanical Ventilation with Heat Recovery) systems, which improve air quality while drastically reducing energy loss.

The fresh look libraries also include subtle design nods to sustainability with for example purposely planted birch trees at the entrance of Ballymoney Library, to greet visitors whilst also reinforcing the green ethos.
 
Improving the energy performance of each library went hand-in-hand with enhancing the customer experience. The projects were not just about numbers on a meter but rather creating warm, bright, welcoming places where people want to spend time. Library staff and customers alike have noticed the difference— improved natural light, air quality, and steady indoor temperatures have made a noticeable impact, with filtered fresh air circulation being a key factor.

However, the improved energy efficiency was also clearly obvious and the environmental and operational benefits of the refurbishment were immediate and measurable. Energy use at the retrofitted libraries dropped by up to 65% and CO₂ emissions were reduced by approximately 22 tonnes annually across the three sites.

Refurbishing libraries to the EnerPHit standard has not only improved energy efficiency but also transformed how services are delivered. Better lighting, insulation, and ventilation have created a more comfortable environment, while clearer zoning helps customers navigate the space with ease. These improvements enable Libraries NI to deliver services more efficiently and with greater focus on customer needs.

Overcoming Obstacles with Innovation

Retrofitting existing buildings to such an exacting standard was not without its difficulties. Integrating new systems into decades-old infrastructure required a level of problem-solving that tested the limits of traditional project delivery.

Airtightness, for example, is a central requirement of EnerPHit but notoriously difficult to achieve in buildings not originally designed with that in mind. The solution involved painstaking detailing by contractors, with input from engineers, architects, and library staff to ensure every gap was sealed and every solution tested.

Additionally, the need to keep library services accessible during works required careful decanting, storage planning, and community engagement. Temporary relocations were arranged with minimal disruption, and regular updates reassured customers that their library service was not only continuing—it was evolving.

Figures!!

Post-retrofit, Ballymoney Library achieved an energy demand of 21kWh/m²/year (down from over 120kWh/m²/ year), a DEC rating improvement of an E to an A+, and a measured airtightness of 0.68 ach @50Pa. It was the first certified EnerPHit non-domestic public sector project in the UK.

Energy saving statistics for one year:

Ballymoney Library Figures

• Total energy saving: 17,227 kWh
• Space heating energy saving: 13,968 kWh
• CO2e saving: 3,887 kg
• 51% reduction total energy consumption
• 60% reduction in energy consumption

Bessbrook Library

• Total energy saving: 21,706 kWh
• Space heating energy saving: 18,194 kWh
• CO2e saving: 4,656 kg
• 70% reduction total energy consumption
• 85% reduction in energy consumption for space heating

Killyleagh Library

• Total energy saving: 13,607 kWh
• CO2e saving: 2,919 kg
• 65% reduction total energy consumption

Watch the full video to hear the architect share his thoughts on the refurbishment of Ballymoney and Killyleagh libraries.