DESNZ is seeking to procure a contractor/s to deliver Phase 3 of the Homes for Net Zero research programme (HfNZ P3). This is a continuation of our multiyear, largescale research and demonstration trial, building on the existing cohort of approximately 1,250 owner-occupied homes. Among other tasks the appointed contractor(s) will be responsible for trial management and coordination, longitudinal monitoring, data collection and processing, and participant engagement – including physical measurements in homes and social research with occupants. It will include research on practical, scalable pathways to decarbonising owner-occupied homes, particularly complex-to-decarbonise and space constrained properties, with a focus on low carbon heating. This includes evaluating the real-world performance, costs, and user experience of heat pumps (including reversible air-to-air systems), alternative electric heating and domestic hot water solutions. Consumer engagement approaches, and measures to improve resilience to a future climate, such as overheating mitigation, are also key elements of HfNZ P3. The programme will require delivery through competitively procured work packages (lots); • Lot 1: Trial management and co-ordination – including programme management of whole trial, collecting data from monitoring devices and ensuring high data quality, managing trial participants, supporting additional technology trials through an innovation test bed; • Lot 2: Data analysis and research – including technical analysis of in-home monitoring data to answer the research questions, and collaboration with Lots 3 and 4 to ensure methods are designed to address those questions. • Lot 3: Consumer engagement and social research – establishing best practice consumer engagement approaches to transition homes to low carbon heating and using these to support the delivery of measures in Lot 4, carrying out social research to support the research objectives in collaboration with Lot 2. • Lot 4: Design and installation of low carbon heating measures in homes – including, air-source heat pumps, reversible air-air heat pumps, alternative approaches to electric domestic hot water in space constrained homes and the specification and installation of monitoring equipment. Contractors will need to work collaboratively across the work packages as well as with DESNZ and possibly with linked programmes, notably Built Environment Adaptation and Resilience (BEAR) and Heat Pump Ready Programme (info here: https://www.gov.uk/government/publications/heat-pump-ready-programme/information-about-the-heat-pump-ready-programme#latest-opportunity-from-2026). Outputs are likely to include regular, publicly accessible research publications; including two annual reports with research findings, an annual trial delivery summary, and publication of datasets (subject to GDPR). The programme will also deliver thematic research briefs and a final report at project completion, with outputs designed to directly inform DESNZ policy development and analysis on clean heat, energy efficiency, and climate resilience. DESNZ is holding a supplier event on MS Teams on Wednesday 29th April 2026 from 1400 - 1600, consisting of presentations by DESNZ and interactive feedback sessions. – Lot nr.: 1 Trial Management and Coordination Provides programme-wide trial management, participant engagement, data operations and coordination across all work packages to ensure effective delivery, reporting and governance. 19. The appointed supplier for Lot 1 will be required to work with the suppliers awarded the other three lots, as well as coordinating input from suppliers delivering two other programmes, whose objectives overlap with, but will be commissioned separately from, HfNZ Phase 3 Duration contract start date : 11/10/2026 11:00:00 PM Duration contract end date : 31/03/2029 10:59:59 PM Criteria definitions: Quality: 40 (Meeting the Requirements) Quality: 15 (Skills and Capability) Quality: 15 (Project Management and Risk) Quality: 10 (Lot Specific - Managing a programme with Mulitplwe contractors) Cost: 10 (Cost) Quality: 10 (Social Value) – Lot nr.: 2 Data Analysis and Research Delivers the analytical framework, data integration and technical research needed to turn monitoring, survey and intervention data into robust evidence and publishable findings Duration contract start date : 11/10/2026 11:00:00 PM Duration contract end date : 31/03/2029 10:59:59 PM Criteria definitions: Quality: 40 (Meeting the Requirments) Quality: 15 (Skills and Capability) Quality: 5 (Project Management and Risk) Quality: 20 (Lot Specific - Research Methodology) Cost: 10 (Cost) Quality: 10 (Social Value) – Lot nr.: 3 Consumer Engagement and Social Research Designs consumer engagement, tailored roadmap advice and social research to improve understanding, support decision-making and evaluate barriers to low carbon heating uptake. Duration contract start date : 11/10/2026 11:00:00 PM Duration contract end date : 31/03/2029 10:59:59 PM Criteria definitions: Quality: 40 (Meeting the Requirments) Quality: 15 (Skills and Capability) Quality: 5 (Project Management and Risk) Quality: 20 (Lot specific - Research Methodology) Cost: 10 (Cost) Quality: 10 (Social Value) – Lot nr.: 4 Heat Pump Design and Installation Designs, installs, commissions and maintains heat pumps and related electric heating solutions, including monitoring, to test performance and participant experience in trial homes. Duration contract start date : 11/10/2026 11:00:00 PM Duration contract end date : 31/03/2029 10:59:59 PM Criteria definitions: Quality: 40 (Meeting the Requirements) Quality: 20 (Skills and Capability) Quality: 15 (Project Management and Risk) Quality: 5 (Resource Availability) Cost: 10 (Cost) Quality: 10 (Social Value)