Launch of Cagni Williams Energy

Newsletter April 2026: Launch of Cagni Williams Energy

In late February we launched Cagni Williams Energy, our new sister company dedicated to helping property owners reach net-zero goals, reduce utility costs and tread more lightly on the planet. As I wrote in this month’s RIBA Journal, we firmly believe that architects have a pivotal role in turning policies into practice. It's not enough to simply deliver a brief, we much take a proactive role in crafting solutions, shaping visions, and then making them real.  We understand the systemic barriers, draw lessons from real world case studies, and foster an open dialogue around innovative strategies.  We build bespoke teams with the best technical consultants, clearly communicate the benefits to stakeholders, and create partnerships that bridge the gap between regulatory ambitions and practical delivery. Decarbonising has always been a natural part of our work - it has felt like our duty as architects. Now with the accelerating climate crisis, it is time to speak up, to share what is possible, and to help inspire wider adoption of grounded, effective solutions. 

– Laura Carrara-Cagni 

In this edition, we share the Cagni Williams Energy mission and take a closer look at  the Sydney Street Heat Network project in London - a community network that has just completed its government-funded feasibility stage. We also feature an interview with pioneering engineer and low-energy expert Sasha Krstanovic, with whom we have been collaborating for years. Finally, we highlight press coverage about the launch of Cagni Williams Energy, including and an in-depth piece on the Sydney Street Heat Network published in Planning In London.

Thing globally, act locally: decarbonising the world one project at a time

We created Cagni Williams Energy with a mission to drive meaningful change in the built environment, by offering advice and delivering practical solutions to help property owners meet net-zero goals through effective technical strategies. From designing ambient loop heat networks for communities, to developing comprehensive energy plans for complex buildings, our team advances ambitious pilot schemes that might otherwise struggle to succeed. We are helping to decarbonise the world one project at a time. 

We work across sectors, residential, commercial, healthcare, education, religious buildings and community developments, to offer expertise in sustainable systems, ambient loop heat networks and holistic plans.Our technical knowledge, paired with a collaborative ethos, allows us to manage complex projects seamlessly - bringing together stakeholders across sectors, including businesses, local authorities, and communities. 

Whether it is  large-scale decarbonisation or a bespoke energy solution, our team is committed to shaping a greener, more sustainable future. If you know of a project where we can help bring the net-zero vision to life - with solutions that deliver impact today and for generations to come -  please do get in touch.

The Sydney Street Heat Network project

The Sydney Street & District Heat Network is an ambitious urban initiative designed to decarbonise heating and cooling for 300 homes, two hospitals, a school, a church, and various commercial spaces. It is a pioneering, community-scale project that brings clean, affordable energy to a historic London neighbourhood -seamlessly integrating modern energy technology into a dense urban landscape. A recently completed, government-funded feasibility study confirmed the viability of a shared ambient loop network running through the public highway, linked to individual Ground Source Heat Pumps (GSHP) that will deliver carbon-free heating and cooling.  

The ambient loop and GSHP system will provide sustainable, low-cost heating and cooling without creating visual or physical clutter in public spaces. It will improve local air quality and play a vital role in helping the community meet its long-term carbon reduction targets. 

This project is a groundbreaking pilot -  the first of its kind to apply proven GSHP technology at scale within a dense, existing urban street network. It demonstrates how sustainable heating can be embedded within existing housing stock,, long viewed as one of the most challenging areas to decarbonise. Already, the initiative is inspiring interest from neighbouring streets, and residents keen to explore similar systems. This ripple effect speaks to the project's potential for replication and wider impact. Our role extends beyond technical design - we are actively engaged in stakeholder collaboration and project coordination to ensure the scheme’s feasibility and long-term success. 

Zero-bills strategy for a countryside home

Nestled in an idyllic English village, this neoclassical house is undergoing an extensive energy retrofit to achieve a zero-bills strategy. We are replacing all single glazing with vacuum glazing and insulating the external walls and roof to enhance thermal performance significantly. 

Heating, cooling, and hot water for the property will be powered by a ground source heat pump system, supported by a solar array and battery storage. Together, these systems can meet the home’s energy needs, with surplus energy fed back into the grid. Underfloor heating and mechanical ventilation (with heat recovery) will ensure year-round comfort, eliminating the need for any gas utilities. 

This ambitious project demonstrates how existing homes can become exemplars of sustainable living. By integrating renewable energy systems while preserving the home’s heritage, we are delivering a solution that meets modern environmental standards without compromising on comfort or style.

In Conversation with Sasha Krstanovic

Sasha is the founder of mstep, an engineering design consultancy dedicated to decarbonising building and spaces. Cagni Williams values working with engineers who share our commitment to creating a more sustainable world - and for nearly two decades Sasha has been one of our most trusted collaborators. 

When she established mstep, we were proud to support the new venture by immediately involving her in our projects. Since then, mstep has delivered cutting-edge designs solutions to improve energy efficiency in private homes, including the integration of heat recovery systems. Thanks to Sasha, we gained deep expertise in Ground Source Heat Pumps (GSHP) technology, and she also introduced us to Chris Davidson, Chairman and CTO of Genius Energy Lab. Together we are now collaborating on the Sidney Street Heat Network project.  

As part of our “In Conversation With” series, we explore the origins of Sasha's passion for sustainable engineering -  and share her insights on how to address scepticism and drive meaningful change. 

Read the interview here

Cagni Williams Energy and the Sydney Street Heat Network project in the news Architecture magazine, Riba Journal and Planning In London

To mark the launch of Cagni Williams Energy, Architectural Magazine featured this exciting new chapter in our journey - one that expands both our capabilities and our vision. 

In Planning In London, Edward presents our groundbreaking project in Chelsea: a feasibility study for a community-based ground source heat pump network, developed in collaboration with the Sydney Street and District Residents' Association, Genius Energy Lab, and Kensa Utilities.  

Meanwhile, in the April 2025 edition of the RIBA Journal, Laura contributes to the Intelligence feature with her article, “If we are to implement net zero, architects need to roll up their sleeves”. She explores the real world challenges of achieving net zero in the built environment—from policy gaps to financial hurdles—and offers a clear-eyed view of how architects can help bridge the divide between regulation, technology, and practical delivery. 

Click on the magazine titles to read the articles.