Trusted research environments (TREs) are necessary for the ethical and secure management of sensitive data. Designing and operating a TRE in the cloud requires considerable custom work, with a challenging learning curve for operations staff. The implementation, maintenance and development of TREs requires unique skillsets for which there is a current shortage. Upskilling of new and existing staff is crucial for the continued growth and development of Data Science in the UK. The Health Informatics Centre (HIC) have been running a TRE for over a decade and have recently collaborated with AWS to develop a Cloud TRE which is now in production. The TREEHOOSE proposal was to create and share an open-source infrastructure-as-code implementation, with documentation, for both operating and performing research within a modern cloud TRE. The aim of the open source architecture was to: Reduce the learning curve for TRE operators and users alike. Reduce the cost of migration to the cloud for other TREs. Aid portability of code between TREs. Make federation more straightforward through the use of common cloud deployments. The TREEHOOSE project also upskilled project team members for the benefit of future research projects. None of this work is possible nor sensible without engagement with the public and patients as they are the final arbiters of acceptable reuse of their data. TREEHOOSE ran workshops on the trustworthiness of cloud computing with research data and generated reports on our findings. This work was funded by UK Research & Innovation, Grant Number MC_PC_21032, as part of Phase 1 of the DARE UK (Data and Analytics Research Environments UK) programme, delivered in partnership with Health Data Research UK (HDR UK) and ADR UK (Administrative Data Research UK).