A young eco-warrior who helped win a £100k energy makeover for her school has impressed British Gas auditors with her clever consideration of how to spend the cash.

Niamh, a pupil at Haberdashers’ Monmouth School for Girls, entered the energy supplier’s Generation Green competition as part of the school’s eco project last summer.

Her innovative design for a fuel-efficient school of the future, which was mounted on stilts over a river and featured solar panels, water mills and light-reflecting ideas, was picked from 500 entries across the UK.

Last Wednesday, Niamh and her friend Ellie, both 14, gave auditors a tour of HMSG’s classrooms, sports halls and boiler rooms on their preliminary visit to decide how best to save the school money.

Stephen Hinsley, British Gas energy specialist (schools), said: “The girls had really thought about this before we arrived.

“We come with ideas about what works in schools – I’ve done a lot of these makeovers.

“But the girls had already thought of classrooms with trees covering the windows, meaning the lights are on all the time.

“So they knew those were the ones which would need more efficient lighting.

“It’s very impressive for girls of this age to be thinking that way.”

The tour was the first in a series of visits by British Gas, who will work with the pupils and Nick Meek, Head of Geography at HMSG, to choose which fixtures to update in order to maximise the school’s savings.

LED lights and new boilers are possible options which could save HMSG up to £7,000 a year on its fuel bills.

Niamh said: “I can’t believe this has happened because of me, I’m so happy and excited.

“Just a little extra activity I did in revision time has caused all of this – it’s amazing.

“In the future I would love to go into engineering and it’s so interesting talking to professionals and learning about how things work.”

Work will most likely start on the makeover in Easter next year.

Mr Meek hopes the project will inspire more pupils to join HMSG’s Eco Committee.

“It encompasses everything – science, geography and maths, looking at the data.

“The Eco Committee has done lots of things in the past, like entering competitions and trying to raise awareness of environmental issues, and this opens up more possibilities and opportunities to spread the message.

“It’s about being more energy efficient and broadening the understanding of the girls as to how much things cost in terms of power and heating.

“Those issues are not going to go away. It’s all about looking to the future.”