At Citu we’re all about using cutting edge tech to be as sustainable as possible. 

That means using the best insulation technology, thermal envelopes, MVHR systems and advanced building modelling to make sure everything is ultra-efficient and can run on 100% renewable energy.

That works fine when we’re building new places from scratch- we can create homes that require ten times less heating than conventionally built houses, making them so efficient it’s possible to heat them with electricity from renewable sources. 

But what about when it comes to restoring historic buildings?

We want to bring back the best of an area’s iconic architecture, rather than knock it all done and start afresh. 

When you’re working with historic buildings, you’ve got beautiful exposed Brickwork, huge heritage windows and 200-year-old timbers that all give these buildings their unique character.

But these places weren’t built with climate change in mind – they’re not ultra-air tight or super-insulated, so we can’t install MVHR systems and a few electric heat mats. 

To heat these spaces with 100% renewable energy would be expensive for the people living in them, because electric heating costs more than gas. 

So we had to find another way. 

We weren’t going to just whack in some gas boilers and be done with it.

Sure, it’d be easy. But it would also keep the place dependant on fossil fuels, and if we’re going to prevent dangerous levels of climate change, we need to be net carbon neutral in 10-20 years.

What’s the point of building someone’s home with a fossil fuel based heating system that’ll be obsolete in just a decade or two?

It’s bad economics, and it’s bad for the environment.

Renewable and carbon neutral: Biomass

To find a solution, we turned to nature. Sustainably sourced biomass provides a way to heat buildings that’s totally renewable and carbon neutral.

It’s also a similar price per unit of heat to gas, so that means we can heat historic places without it costing a fortune.

How does it work?  

We’re using biomass boilers to heat water for radiators and hot water in the historic buildings that we’ve restored at Little Kelham. Two boilers in Eagle Works, two in the Riverside to heat the Riverside Apartments and the Green Lane Works Clocktower, and 1 in the Gatehouse. These biomass boilers are far, far more efficient than your typical wood fire, and are able to operate at 90% efficiency- which means 90% of the energy in the biomass is converted into useful heat. You can see one of the biomass boilers installed in the bowels of Eagle Works below. 

Residents of the Riverside building will have hot water provided from the boilers, metered through a heat exchanger, and managed via Actuate. So they can still manage their home from their phone, and be billed only for what they use. Businesses in our Citu Commercial spaces will also be able to manage their heating and energy use via Actuate. 

Why is biomass better than gas?  

Gas boilers use gas that’s been pumped out from under the North Sea, or under the deserts of Qatar, or under the Russian Steppe. When it’s burnt it releases CO2, which warms the planet.

Biomass uses energy from plants, which absorb CO2 from the atmosphere. The amount of CO2 the biomass gives off when burnt is directly off-set by the amount absorbed by the plant to create the biomass in the first place. That makes it carbon neutral, and, so long as it’s sourced from sustainable sources, it’s completely renewable. Unlike gas, which will one day run out, we can always grow more plant matter.

So thanks to nature’s sweet bounty, we can restore these historic buildings to their former glory, and do it in a way that won’t harm the planet. It’s future-proofing the past, with the power of nature.

Read more from us