Project Progress Update

January 2026

Work Package One

Key Activities Completed

  • We have created a new dataset which has not previously existed. We identified addresses of 66,345 properties created through PD. Our dataset of PD addresses across England is now completed as far as we can take it.

  • We will now conduct some basic descriptive analysis of this dataset, e.g. number of homes created by each type of PD, average scheme size and so on.

  • We have begun the process of linking addresses to health data.

Current Status & Outputs

  • We will analyse issues such as access to green space, shops/services and morbidity (e.g. asthma prevalence) and mortality data.

  • We will profile the neighbourhood locations (e.g. neighbourhood deprivation data) to produce a portrait of PD housing across England and comparison with national average housing locations.

  • We will undertake additional enhanced analysis using WP2 survey data to explore in greater detail the health and well-being impacts of PDR housing participants. We will further explore the research question of what are the health needs of populations living in PD housing which cannot be obtained through data linkage with hospital episode statistics.

  • We will conduct additional analyses of health conditions using data collected on physical and mental health and subjective wellbeing that have been identified as key themes in the qualitative research.

Work Package Two

Key Activities Completed

  • Quantitative Phase: A large-scale cross-sectional survey was successfully completed, collecting data from 1,029 residents across England.

  • Qualitative Phase: Rich qualitative data was gathered through:
    - 6 focus groups with 36 participants.
    - 75 semi-structured interviews and home assessments.

Current Status & Outputs

  • The analysis of the WP2 data is complete, and the initial results are currently being disseminated and prepared for publication.

  • Initial results have been successfully presented at two conferences. Several outputs are currently under review and in preparation for submission to peer-reviewed journals.
    We anticipate having further details on the final publication status and full findings available on the website soon    .

Work Package Three

Key Activities Completed

  • Indoor Environmental monitoring of 50 resident participant homes. Collecting data on Indoor environmental factors: carbon dioxide (CO2), carbon monoxide (CO), nitrous oxide (NO2), air temperature, relative humidity.

  • Building surveys for 50 homes - collecting information on building fabric characteristics and dwelling layout.

  • Seasonal resident questionnaires - collecting information on thermal comfort, indoor air quality, and lighting and acoustic comfort.

  • Indoor Environmental monitoring of 50 resident participant homes - collecting data on carbon dioxide (CO2), carbon monoxide (CO), nitrous oxide (NO2), particulate matter (PM), formaldehyde, air temperature, and relative humidity.

Current Status & Outputs

  • The WP3 data collected are currently being cleaned and analysed, and initial results are emerging.

  • PDR housing (archetypes) developed based on conversion type/age, building fabric characteristics, thermal efficiency and dwelling geometry, and are currently being refined based on their representativeness of the PDR stock in the UK.

  • The modelling and validation process is currently being set up to extract energy, temperature and pollutant output per archetype under current and future climates, while testing retrofit interventions and occupant profiles representing different vulnerable groups.

  • PD housing (archetype) are being developed, including building geometry, construction and conversion type/age, building fabric characteristics (with a focus on thermal efficiency of the building envelope), but also and occupant characteristics, including tenure type and household socioeconomic characteristics.

  • Conference Presentations:  Conference contributions planned to present preliminary findings from the monitoring of PDR homes and from the development and validation of PDR archetypes.

    Publications Pipeline: Several papers are planned on the findings from the monitored and modelled thermal comfort and indoor air quality parameters, the testing of interventions to improve the indoor environment, as well as the impact of occupant behaviour. 

Work Package Four

Key Activities Completed

  • Development of an integrated health impact and health-economic assessment framework linking indoor exposures and population health outcomes.

  • Identification and synthesis of epidemiological evidence, concentration–response functions, and baseline health data relevant to PD-related exposures.

  • Integration of WP4 methods with empirical monitoring data (WP2) and exposure modelling outputs (WP3).

 Current Status & Outputs:

  • The Analysis: Health risk and health-economic modelling are underway, integrating indoor exposure estimates with epidemiological evidence to quantify disease burden, mortality, and economic costs under baseline and alternative regulatory scenarios.

  • Publications Pipeline: Peer-reviewed manuscripts in preparation on (i) integrated health risk assessment of ambient air pollution in Great Britain and (ii) health-economic and policy-relevant cost–benefit analyses.

Work Package Five

Key Activities Completed

  • TCPA roundtables - Following a short online survey sent to 317 local authorities in England, we recieved 49 responses from across all 9 regions, including from planners, public health and environmental health officers. Six online roundtables took place with 32 participants from eight out of the nine regions

  • Interviews - Five semi-structured interviews were conducted, targeting representatives from national professional bodies and recommended experts.

  • TCPA parliamentary briefing: An oral question was raised in the House of Lords about the government’s position on PDR housing, by Lord Nigel Crisp on 18 December 2024: Permitted development rights, health and housing – parliamentary briefing - Town and Country Planning Association

  • Presentation at Westminster Forum event on Planning reform – April 2025

  • Joint presentation with WP2 and WP5 at Healthy City Design Congress – October 2025

  • Supporting LGA open letter and article in Guardian: Ministers urged to put brakes on offices in England being turned into homes | Housing | The Guardian

  • (Currently) Submission of evidence to National Planning Policy Framework (NPPF) consultation: - lobbying for a revision of the NPPF requirements on ‘Article 4 directions’ - which currently restricts the ability of local authorities to decide where PDR conversion can take place.

 Current Status & Outputs:

News and Publications

News and Publications