Building Physics Engineer (United Kingdom)

Shape the future of sustainable buildings with re:sustain Role overview: Embedded in science and fuelled by a passion for tangible change, we\’re a rapidly growing team at the forefront of building analytics, dedicated to rewriting the story of energy consumption and carbon reduction in commercial real estate. We leverage cutting-edge BMS data streaming solutions interfaced with our proprietary calibrated digital twin technology to empower clients to manage their facilities with unparalleled efficiency and drive significant carbon reduction. This is a brand-new role in our scaling impact technology business. We are seeking a highly skilled and detail-oriented Building Physics Engineer to take a pivotal role in developing, calibrating, and maintaining the energy models that power our digital twin platform. Your work will be instrumental in ensuring our virtual models accurately reflect real-world energy performance and building behaviour. If you\’re a curious and driven engineer with a solid grasp of building physics, thermodynamics, and systems modelling, and you\’re ready to apply that knowledge to a unique digital twin platform that’s already making a tangible impact, this role is a genuine opportunity to step up and make your mark. What you’ll do – your impact: As a Building Physics Engineer at re:sustain, you will be instrumental in ensuring our virtual models are precise, dynamic reflections of real-world building behaviour. You\’ll be empowered to: Digital Twin development: Create and maintain sophisticated dynamic energy models of commercial buildings, meticulously incorporating HVAC systems, envelope properties, occupancy patterns, and internal loads. Develop detailed geometry for energy models. Construct comprehensive energy models, including intricate HVAC systems (training on our advanced in-house tools will be provided). Drive accuracy through data-driven calibration: Utilise real-time and historical building performance data, including metered data and utility bills, to meticulously calibrate digital twin models, ensuring exceptional accuracy. Conduct thorough analysis of utility bills and metered data to inform model refinement. Unlock performance insights & optimisation strategies: Simulate diverse operational strategies (e.g., HVAC schedules, retrofit scenarios) to accurately predict energy, carbon, and comfort outcomes. Run multiple scenarios through the energy model to identify and quantify potential savings. Analyse building control patterns to identify inefficiencies and opportunities for optimisation. Partner with clients to translate complex model outputs and energy data into clear, actionable strategies, empowering them to achieve their sustainability goals and enhance operational efficiency. Champion service excellence & continuous improvement: Regularly monitor streamed BMS data, proactively responding to alerts and ensuring optimal system performance. Oversee the quarterly recommissioning of controls to maintain peak efficiency. Maintain a meticulous audit trail of all control interactions. Collect and manage monthly/quarterly metered data readings and utility bills. Commitment to technical learning, collaboration & knowledge contribution: Remain at the forefront of advances in digital twin frameworks, building simulation tools, and energy modelling standards (e.g., ASHRAE, CIBSE). Collaborate closely with building engineers, software developers, and sustainability consultants to interpret model results, refine our platform, and continuously improve asset performance for our clients. Contribute to internal knowledge sharing, potentially including training colleagues on energy modelling best practices. Who you are – your expertise: We\’re looking for a proactive, analytical, and solutions-oriented engineer who is excited by the prospect of working with advanced technology to deliver tangible sustainability outcomes. Essential: A Bachelor\’s or Master\’s degree in Mechanical Engineering, Building Physics, Architectural Engineering, Sustainable Design, or a closely related field. 2-3+ years of dedicated experience in dynamic building energy modelling, with hands-on proficiency using leading simulation tools. A strong fundamental grasp of thermodynamics, heat transfer, fluid dynamics, and the operational principles of diverse HVAC systems. Experience working with building automation systems (BMS), IoT sensor data, or time-series energy data. Proven ability to analyse building performance data and diagnose system inefficiencies. Excellent problem-solving skills and meticulous attention to detail. Strong communication and interpersonal skills, comfortable liaising with technical and non-technical stakeholders, including clients. Proficient user of Microsoft Excel for data analysis. A genuine passion for sustainability and making a positive environmental impact. Desirable (these skills are a bonus, and we\’re passionate about your growth and learning on the journey with us!): Proficiency in Python or MATLAB for scripting, data analysis, or model integration. Direct experience with the installation, configuration, or commissioning of BMS systems and familiarity with protocols like BACnet, Modbus, or LON. Knowledge of specific BMS platforms (e.g., Honeywell, Schneider, Siemens, Tridium Niagara). Familiarity with cloud platforms and data analytics tools. Experience with digital twin concepts or platforms. Relevant professional certifications or licensures (e.g., CEng, CEM, BEMP, BCIA qualifications). Additional language skills Why re:sustain – what we offer: This isn\’t just another role; it\’s a chance to be at the heart of a company where your work has purpose, your ideas are valued, and your growth is paramount. Make a tangible impact: Join a mission-driven company where your work directly contributes to reducing carbon emissions and creating more sustainable commercial buildings. Innovate and grow: Be part of an innovative and fast-growing PropTech business at the cutting edge of digital twin technology. As this is a brand-new role, you have an unparalleled opportunity to not only define your impact but also to sculpt your career trajectory within a rapidly scaling business. Collaborative & supportive culture: Join a dynamic, supportive, and close-knit team where collaboration, open knowledge sharing, and mutual respect are foundational. We celebrate curiosity and empower you to make your voice heard. Professional development: We are committed to your growth, offering opportunities for ongoing learning, training (including on our bespoke tools), and professional development. Flexible work environment: Enjoy the benefits of a remote-first role with flexibility, balanced with valuable in-person team collaboration. Competitive rewards: Receive a competitive salary, a discretionary company bonus, and a comprehensive benefits package. To apply: Ready to make an impact? We\’re excited to learn more about you. Please submit your CV and a covering letter, detailing your relevant experience and how you envision contributing to re:sustain’s mission, to michelle@resustain.com.