One of city centre’s largest rooftop solar installations completed at The Cambridge Building Society

One of the largest rooftop solar installations in the centre of the city has been completed at The Cambridge Building Society’s headquarters – and it is also working on a residential installation.

Some 258 panels have been installed at the society’s head office in Newmarket Road following five weeks of work.

They will generate a massive 116,000 kWh of electricity per year - the same energy required to power about 40 three-bedroom houses for a year.

The installation will help The Cambridge cut its own carbon footprint, but it is also keen to showcase to its members and the wider community how domestic changes can be made to improve the sustainability of our homes.

The mutual is retrofitting a 1930s semi-detached home in Ferndale Rise – a project the Cambridge Independent is following. The Cambridge will be sharing the lessons it learns from the work to help others decide what to do with their own properties.

The latest work there involves installing 10 solar panels on to an upgraded roof at the home. This is expected to generate 3000kWh of electricity per year, the same as the average usage of a three-bedroom home or, to put it another way, enough energy to power a kettle for more than 100 days without turning it off!

Richard Brockbank, chief financial officer at The Cambridge, said: “We’re committed to supporting our members now and the generations to come, to create a sustainable future for us all. Through addressing our own carbon footprint, we hope to encourage others to do more.

“Renewable energy sources such as solar offer a really effective way to make that positive change and our head office becoming solar powered is just the beginning for our sustainability journey.”

Depending on the set-up and usage, solar systems typically pay for themselves in as little as four or five years to around a decade, and the panels themselves generally last 25 to 30.

Work on both projects was carried out by Sparktek.

Duncan Turner, project manager at The Cambridge, explained: “More people are wanting to make environmentally positive upgrades to their homes, often driven by wanting to save money on their energy bills and do their bit for the environment. It’s often difficult to know where to start. Our retrofit case study using a typical semi-detached property aims to show what can be done while providing practical, affordable solutions.

“We’re on a steep learning curve and we want to share the lessons learned and tips for our members and the wider Cambridge community so they might consider implementing energy efficient solutions for their homes. Spartek has proved to be a great partner for us to deliver these projects in a genuinely collaborative way.”

Lee Watson, Spartek’s managing director, said: “The Cambridge head office project is the largest slate roof solar panel installation we have completed to date and is one of the largest rooftop solar panel examples in central Cambridge. It highlights perfectly what can be achieved in a commercial setting with relatively little disruption.”

But the solar panels are only part of the work at the Ferndale Rise property.

Over the coming weeks, excavation will be completed for the foundations for the single-storey extension with rainwater harvester installed, while core structural work will continue inside the property.

The Cambridge will be sharing what it learns with tips and advice from industry experts and links to skilled local tradespeople, including project partners Koru Construction, Pip Architecture, Rethink Buildings, and RHBC Ltd Building Control.

And when the house retrofit is completed, the property will be added to The Cambridge’s unique Rent To Home scheme, under which it rents out homes to aspiring first time buyers at just below market value and then after a few returns up to 70 per cent of the rental payments to use as a deposit when they buy their first home.

Visit cambridgebs.co.uk/ sustainable-living for more details.

Key sustainability improvements considered at Ferndale Rise include:

Insulation (wall, floor, roof)
Improved glazing
Air source heat pump
Mechanical ventilation system with heat recovery
Electric underfloor heating
Solar panels
Rainwater harvesting
Green roof on rear extension

Spartek’s top 3 tips for homeowners considering solar panels

1. Find a reputable company to manage the process of your solar installation from start to finish.
2. Do some research on a few companies such as reading customer reviews and checking they are MCS before choosing one.
3. Consider that you’re effectively installing a ‘mini power station’ on the roof of your home – the cheapest option may not be the best and it is an investment which should pay back after four to five years if designed correctly.