ITV Wales' Mike Griffiths spoke to Doug Hughes, the managing director of Hughes Architects who is revamping the Victorian marvel.
A long neglected Victorian mansion is getting a makeover which will transform it into an eco-conscious events venue that will minimise its reliance on the conventional power grid.
The Bronllys Hall in Powys will be converted into an events venue. The team behind the project want it to draw most of its power from renewable sources - such as solar and biomass.
Bronllys Hall has collaborated with Brill Power that originated from Oxford University.
Dr Christoph Birkl is the CEO of Brill Power and he is the man behind this new cutting edge technology
They are working on a renovation project to breathe new life into this 18th-century architectural gem.
Dr Christoph Birkl, CEO of Brill Power, is the man behind this new cutting edge technology.
Dr Birkl gave details about how this technology can work all year round, adding: "The need of the client was to maximise the renewable energy that is generated on site.
"So, there will be a lot of solar panels installed on site to utilise as much energy as possible.
"But the sun doesn't always shine, so we'll need to buffer that energy somewhere. They needed a battery and in our case we needed a Lithium ion battery.
He continued: "Our control systems make batteries live as long as the renewable energy technology are connected with. In that way you avoid a lot of expensive replacements and you avoid a lot of scarce material and energy that goes into making more batteries.
"So, that helps the venue of the client here to have a sustainable way of storing lot of renewable energy."
The mansion house at Bronllys, near Brecon, used to be the home of the Powys Teaching Health Board before falling into disrepair.
Hughes Architects is looking after renovating the Bronllys Hall and bringing it back to life.
Doug Hughes, the firm's managing director said: "Previously, it was called Pont-y-wal House and It has got an incredibly rich heritage.
"It started being built in the 15th century but really came into it's maturity in the 1850s where you see this wonderful Victorian architecture coming in to play here.
"The strategic masterplan for Bronllys Hall is a very ambitious plan. We are looking at retaining the existing building of fabric as much as we can and converting this into a hotel- conference facility.
"We are also looking at extending the additional bedroom accommodation. But what I find magical is converting the Garden's cottage into a holiday net.
"We're starting (the revamp) with the big house. It has its heritage in the 1750s and has been extended every 100 years or so. Now it is our turn to look after this building for the next generation and bring it back into a viable reuse."
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