Better Together

Tennex confidently address your net zero challenges.

With our network of experts, we build great teams, combining skills and experience with proven track record or working together.

We make mole-hills out of mountains.

Meet (some of) the Team

  • Richard McWilliams

    Founder & Director

    Richard is a specialist management consultant with 15+ years’ experience in leading large public sector decarbonisation programmes. His clients include DESNZ, GLA, Midlothian Energy Ltd and Salix Finance. These programmes have deployed multi-Bn capital, upgraded 1,000+ buildings, 100,000+ homes and established a large-scale demand for heat networks.

  • Chris Spicer

    Project Management Specialist

    Chris has nearly 20 years’ experience in energy, carbon and sustainability consulting. He has led major projects across multiple sectors, including a £200m business case for the UK’s oldest heat network and a multi-million-pound retrofit programme for the City of London, covering iconic sites like Barbican and Mansion House. He founded a specialist consultancy and has worked with organisations including SDCL, Bouygues and Turner & Townsend.

  • Jamie Abbott

    Housing Decarbonisation Specialist

    Jamie Abbott has 20+ years’ experience in housing decarbonisation, funding strategy, stakeholder engagement, and programme governance. He leads major initiatives including DESNZ’s SHDF2 & HUG2 Technical Assistance Facility, and has served as Chief Commercial Officer at Sero and Strategy Advisor for Bristol City Leap. Jamie previously built and led a 70+ person housing retrofit consultancy.

  • Georganne Toomey

    Capital Projects & Change Specialist

    Georgeanne has 20+years experience of programme and project management for capital and change programmes across real estate, health and government. Projects include the politically sensitive listed building Palace of Westminster restoration, £100+m commercial fit-out projects, and DHSC Contract Management for £180m/yr spend. Georganne combines stakeholder engagement and risk mitigation to ensures cost-efficient, transformative solutions.

  • Chris Joyce

    Technical Specialist

    Chris is a Chartered energy and carbon reduction consultant with a strong track record across public and private sectors. He has delivered over 400 energy audits, secured £72m+ in grant funding, and co-authored the NHS Wales decarbonisation strategy. Key clients Chris has worked with include TfL, University of Reading, CBRE and Coventry University, with deep expertise in retrofit strategy and delivery.

  • Louise Trenchard

    Retrofit Delivery Specialist

    Louise has supported public sector organisations for over a decade, delivering £1Bn of grant-funded retrofit programmes. Her leadership roles include for the Salix Delivery Partner and RISE, alongside hands-on delivery in East Sussex, providing expertise in funding, risk management, resident engagement, and compliance—ensuring practical solutions to everyday challenges in sustainable project delivery.

  • Mark Williams

    Finance Specialist

    Mark is a Chartered Accountant and specialist in public sector financial and business cases for net zero. He has provided HM Treasury ‘Better Business Case’ / ‘Green Book’ training to circa 3,000 public servants in the UK and internationally. Previously a Big-5 Partner, Mark has led Government finance and audit teams and recent role include as interim Finance Director for a London Borough.

What People Are Saying

“Richard has demonstrated a deep understanding of government dynamics, the environmental and retrofit industries, and brings advanced expertise in strategy and operating model creation. His work on our three-year strategy plan was especially impactful, reflecting a strong grasp of external challenges and a talent for guiding the design of agile, future-ready strategies.”

— Salix Finance

Chris Joyce has an exceptional work ethic and really adds great value from his prior working experience. Where we started, to where we are now in understanding the carbon emissions baseline of our diverse and complex built environment estate is directly correlated to having had Chris working with our team

— Transport for London

“Chris Spicer has shown incredible tenacity and diplomacy in driving progress the Westminster Heat Network business case to the secure real financial and political commitment to proceed. He made it happen.”

— Westminster City Council