In2Air - The impact of ‘net-zero’ household energy interventions on indoor air quality, health and wellbeing.

Research question: Can fabric-first energy retrofit interventions bring co-benefits for residents in social housing (tackling climate change whilst maximising health and wellbeing by improving indoor air/environmental quality and reducing fuel poverty) and be efficient to implement?

Background: Energy efficiency renovations have an opportunity to improve both the thermal comfort of homes and indoor air quality (IAQ). Both can have positive outcomes for residents, if appropriately delivered, and reduce GP/hospital visits and NHS costs. A unique contribution of this study is its focus on IAQ, health and wellbeing co-benefits associated with energy efficient refurbishment of social housing.

Aim: To evaluate changes in IAQ, energy consumption, health and wellbeing resulting from ‘fabric-first’ household energy efficiency interventions and to assess the return-on-investment drawing in wider co-benefits.

Methods: The study is a 36-month, non-randomised, natural experiment in partnership with Newcastle City Council. We previously designed the protocols and collected data on 30 homes and residents before retrofit work began (NIHR153617). Now, we want to study these same homes again after the energy efficiency renovations and expand the research to include 1960s blocks of flats and other building typologies. We will measure:

i) outdoor and indoor PM2.5 (our primary outcome metric; exposures to PM are associated with increased mortality from all causes, cardiovascular and respiratory diseases and cancer), temperature and humidity (effect on mould growth and thermal comfort); ii) indoor CO2 (elevated levels are considered a sign of inadequate ventilation);

iii) energy consumption (utility bills),

iv) self-reported general health and wellbeing measured using ICECAP-A, SF-36v2, and Use of Health and Care Services questionnaires.

Statistical modelling will include linear regression, to investigate associations between the various environmental variables as well as between the pre- and post-retrofit monitored data and multiple regression with backwards elimination to explore which monitored environmental variables influence health and wellbeing measures.

Community engagement: Our approach is sensitive to barriers impacting participation in research (e.g. mobility, finance, time, trust, literacy, language). Activities and materials will be informed by a Community Steering Group. Events hosted in the local neighbourhoods will enable the community to contribute, participate, share experiences and feedback. Progress and research findings will be shared through a variety of formats (e.g. newsletter, social media, webpage, leaflet).

Dissemination and impact: Short-term impact will be realised through co-developed materials informing tenant behaviours on ways to get the most benefit out of living in an energy retrofitted home and the potential wider co-benefits. Pathways to national and international impact will be via stakeholder briefings, research outputs, reports and conference presentations.

Medium to longer-term impacts will result from the co-developed retrofit tool-kit, informing evidence-based decision making by council retrofit teams and providing reliable and relevant information on co-benefits. There is currently limited quantitative evidence on the wider societal return of fabric-first retrofit schemes and so our health economic evaluation will provide an important resource to support holistic approaches to retrofit.