Project

CHILI

part of Indoor air quality and Citizen Science

Schools and nurseries make up 15% of carbon emissions from UK public buildings. To reach net zero, this needs to be reduced, through retrofit options and better insulation. However, such measures could have unintended effects on indoor air quality. Through CHILI, led by University College London, we will monitor how adapting school buildings for energy efficiency changes the indoor environment, model likely impacts on children’s health and education, and evaluate potential mitigations.

Photo: Compassionate Eye Foundation/Chris Ryan / Getty Images

Active project

2025–2029

Project contact

Lucy Way / lucy.way@sei.org

Background

The UK aims to reach net zero by 2050, meaning that it will not put more carbon emissions (which lead to global warming) into the atmosphere than it takes out.

To meet this target, we need to make buildings in the UK more energy efficient. This is currently achieved through retrofit options such as replacing boilers with heat pumps, and better insulating buildings. This means less energy is required to heat buildings, but it may also have unintended effects such as more indoor air pollution becoming trapped indoors, or making it very hot indoors. Respiratory infections also spread more easily in airtight buildings.

Schools and nurseries make up 15% of carbon emissions from public buildings in the UK and so are likely to be targeted for energy efficiency adaptations. Children and young people spend a significant proportion of the time at school, most of that indoors. The indoor environment at school can affect children’s physical and mental health, and their education, so it’s important that we understand how the indoor environment in schools changes during adaptations for energy efficiency.

CHILI

Delivering a zero-carbon future, whilst responding to the urgent threat of poor indoor air quality and climate change on children and young people’s physical and mental health, requires transformative, scaled-up solutions. To propose impactful solutions and develop effective interventions, we need first to understand the complex relationships between net zero building adaptations, indoor air quality, high temperature and health.

CHILI is short for Child and adolescent Health Impacts of Learning Indoor environments under net zero. CHILI will lay the foundation for developing these solutions through a comprehensive research programme, co-created with stakeholders, children and young people and school communities, and build a sustainable research community in this emerging research area.

We’ll monitor how adapting school buildings for energy efficiency changes the indoor environment, model likely impacts on children’s health and school attendance, and evaluate potential mitigations, including changing ventilation behavior and using air cleaning devices. Ultimately, we aim to ensure that children’s health and education is supported and improved as school buildings are being made environmentally sustainable.

CHILI logo

Logo: CHILI project

Workstreams

CHILI has six workstreams:

Map. We’ll measure indoor and outdoor air quality in schools in England and Wales, building on the work we’ve done on SAMHE, and work closely with 20 schools to get a more detailed understanding of air quality. This will help us develop indicators of indoor environments in schools that can be compared between areas.
Understand. We’ll combine these school indoor environment indicators with national data on children’s health and education, collected by hospitals, pharmacies and schools in England and Wales. We will research the link between indoor air pollution or heat in schools and children’s health and school non-attendance.
Model. We’ll develop combined building and health impact assessment models, which describe the impact of climate change and energy efficient building alterations on indoor environments in schools. We’ll use these models to work out how these changes will affect children’s health in the future.
Test and evaluate. We’ll evaluate whether existing technology and behaviors to improve the indoor environment support children’s health. We’ll achieve this by investigating a) whether installation of air cleaning filters in schools affects children’s use of health services, and b) if increased opening of classroom windows impacts children’s comfort in classrooms.
Involve. SEI York is co-leading this work package with the University of Swansea. We will work with young people and teachers to develop data collection methods to measure the impact of the indoor environment on children’s health and education. We’ll also explore the efficacy of different methods for engaging pupils with net zero.
Engage. We’ll set up a network of individuals and organizations who are working to make school buildings meet the net zero target or will be affected by that work. We will work with this group to identify and describe any barriers to making school buildings energy efficient. We’ll also work closely with policy makers, school leaders and staff, parents and carers and young people to ensure our findings improve health and education for all young people.

Join us for the third CHILI seminar

On 12 May 2026, Sarah West will unpack what citizen science really is (and what it isn’t), and explore how citizen science approaches can be used to deepen our understanding of both natural and built environments.

People sitting and standing round a table engaged in a group activity.

Citizen science: what it is and what it isn’t (CHILI seminar)

Event on 12 May / In this third CHILI seminar, Sarah West will talk about citizen science and its growing role in understanding the environments we live in.

00:00 BST / Available online

Watch the second CHILI seminar

Watch the seminar

Watch the inaugural CHILI seminar

A group of primary school children in blue school jumpers sitting at desks in a classroom and facing a teacher.

CHILI inaugural seminar

Past event / Watch the first in the CHILI seminar series, which brought together experts to explore children’s learning environments and health.

23 January 2026 / About Cities, Climate policy and Pollution

Co-designing the CHILI logo

Year 4 & 5 students from a primary school in Swansea worked with Graphic Designer Aaron Hill to co-design the CHILI logo (below). The co-design session was organized by CHILI partner HAPPEN.

The pupils were curious and excited as they navigated ideas like Net Zero, air quality, logo symbolism and the design process. Through a series of activities, from playing word association games to brainstorming ideas, the students expressed their understandings and concerns about the natural environment through vivid imagery and phrases.

With the wide range of student ideas, drawing inspiration even from Minecraft (a common question we got asked was if we had seen the movie yet!), it was going to be quite an artistic challenge to condense the student insights into a single logo. However, Aaron did a tremendous job, drawing inspiration from the smoke-themed bubble writing one pupil drew and incorporating a nod to the ‘climate stripes’ in the colour shades.

CHILI logo Logo: CHILI project

SEI Team

Members of Inclusive Citizen Science, SEI York’s citizen science research group, are leading on stakeholder engagement, including co-design and project communications.