Sustainable Hydrogenated Vegetable Oil (HVO) Technology to heat Victorian mansion event venue – in what is believed to be another UK-first

Bronllys Hall in Powys, Wales is on a journey to become a sustainable events venue powered by vegetable oil, solar, wind and batteries.

As part of the work to transform Bronllys Hall, a Victorian mansion in Powys, into a sustainable events venue, an innovative new boiler system has been fitted that enables the building to be heated using vegetable oil. It’s believed to be the first heating solution of its kind fitted into a UK events venue.

HVO (Hydrogenated Vegetable Oil) is made from 100% renewable and sustainable waste-derived raw materials and has one of the lowest carbon emission levels for off-grid heating solutions.

Work underway at Bronllys Hall, parts of which date back to the 18th and 16th centuries, will create 40 ensuite bedrooms and various entertainment areas – a lot of space to heat. It was important to find a boiler solution that was suitable for the job, so Hughes Architects, the conservation architecture specialists who are managing the Bronllys project, teamed up with Suffolk-based Hounsfield Boilers to tackle the challenge. The company’s founder Andrew Hounsfield has long been a trailblazer in the field of HVO heating.

The systems integrators for Bronllys Hall, working with a local plumbing company, have connected Hounsfield’s highly efficient UK HVO boiler technology into a thermal storage system provided by Baxi, another UK company. Manufactured in the UK, the Megaflo 1,000 litre cylinder is highly insulated to achieve low heat losses, constructed of duplex stainless steel for longevity, and maintenance-free with no sacrificial anodes.


Richard Whittington, technical sales manager – commercial at Baxi said:

“The very low heat losses of our Megaflo hot water cylinders, their renowned quality and reduced carbon footprint dovetail perfectly with the carbon neutral aims of this project as well as meeting the requirements for a long-term low-maintenance solution. We are extremely proud to be playing a part in this ground-breaking sustainable events venue which exemplifies UK innovation at its best.”


It’s a key step forward in the major renovation project at Bronllys, which aims to transform the deteriorated 18th-century structure, which retains elements from the 16th century, into a five-star events venue that operates sustainably and uses only renewable energy sources.


Doug Hughes, principal architect and managing director of Mid Wales-based Hughes Architects said:

“Along with our other partners in this expansive project, Hounsfield’s technology and Oil4Wales’ logistics enable HVO heating to work at scale with high availability – another step in creating a fully sustainable historical building alongside our work with battery technology from Brill Power, whose battery management system will extend the lifespan of the building’s battery system. The batteries are charged by sustainable sources, with minimal reliance on renewable power from the grid.

“HVO is a highly effective way to solve the difficult issue of decarbonising heating, with options to scale for the future and deliver on our collective commitment to sustainability. This approach not only gives incredible projects like this a competitive edge through delinking from carbon-intensive fossil fuels and their price swings, but also adds further to its core eco credentials, aligning with the team’s sustainability targets.”


The team aims to complete the first stage of Bronllys Hall’s transformation into a carbon-neutral event venue by the end of 2024, setting new precedent for event venues, hotels and businesses. In the process, Bronllys Hall is intended to become a showcase for UK homegrown cleantech innovation, giving confidence to commercial building owners and developers seeking to install renewable and sustainable integrated systems.

This need has become more pressing now that the UK Government’s Energy Efficiency Standards, which came into force on April 1, require all commercial buildings to be rated at Grade C or higher by 2027 and Grade B by 2030.


The project’s relevance is set to become wider still: the Minimum Energy Performance of Buildings Bill, which is currently being considered by Parliament, will require all residential properties to meet at least EPC C by 2035 where practical, cost-effective and affordable. Wales has also recently introduced recycling and sustainability targets, all of which the Bronllys Hall Team aim to deliver on, meet or exceeded by the end of 2024.


Andrew Hounsfield said:

“We have been producing HVO-ready boilers for a few years now, with a focus on long life through quality British-made parts.

“Energy prices remain stubbornly high (although the price of HVO has been stable). We need to decarbonise and HVO provides a sustainable green energy source. Adopting this fuel more widely will reduce our reliance on foreign fuel.”

Although HVO is produced from 100% sustainable resources, is low carbon and reduces emissions, it is still being taxed as road diesel, due to the way it is distilled, and that attracts a 57.95ppl duty as a result.


Sally Williams from Oil4Wales commented:

“The cost of HVO is currently about twice the price of heating oil. If the government were to reduce the tax this would drive demand and enable the industry to make economies of scale, bring the price down, and boost uptake of HVO as a low-carbon heating fuel.

“Converting from Kerosene to HVO can be very cheap and easy. Some boilers may require more costly modifications or replacement.”


Hughes added that as the work at Bronllys Hall progresses, it will continue to showcase the best of British sustainable and renewable systems and technologies.

“Bronllys Hall is an older historic building that we, with the owners and skilled local tradesmen have sought to conserve and safeguard its history, while embracing the best of British technology to deliver sustainable outcomes and efficient operation,” he said.

“We also work closely with our partners to ensure the technologies we use integrate effectively; HVO for heating, sophisticated battery management systems for long life and British Solar panels, along with other innovative technologies and partnerships to be announced over the next few months that when fully integrated will deliver fully on our carbon neutral ambitions.”