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February 28, 2022

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5 concepts to crack the retrofit challenge - Energiesprong UK hackathon

What do an extended reality student, a journalist and an architects’ firm have in common?

Don’t worry, it’s not the start of a bad joke. Instead, it’s a taster of the diverse attendee list from our hackathon last week.

Bringing together students and professionals across sectors, backgrounds, age groups and even countries, we had one aim: catalyse concepts for making retrofit more scalable and appealing.

What’s in a hack?

Today’s IPPC report says we must halve emissions by 2030 if we are to stand a chance of limiting warming to 1.5 degrees. Without retrofit, we will not achieve our climate goals. It’s a simple as that.

We desperately need to find solutions to decarbonise our homes that can be scaled quickly. Yet currently, these don’t exist.

We believe that we need to shake up the sector – bringing in new ideas, new people and new ways of thinking to create an industrialised, efficient industry that’s well-resourced, focused on performance, and fit for the future.

So this was reflected in the hackathon challenge: to come up with net zero concepts for different housing archetypes that draw on digital technologies to make retrofit more appealing to people or easier for the sector to implement.  

Each team had a different archetype with a specific ‘pain point’ outlined, along with some other prompts.

As with any good hackathon, the ideas that emerged went in quite a few different directions with this brief. But they all had one thing in common: an absolute focus on cracking the retrofit challenge.

(If you’re at Futurebuild 2022 this week - join us in the Whole House Retrofit Zone at 1.15pm – 2pm to hear from the teams themselves!)

5 concepts to crack the retrofit challenge

Team #1: “TeamMate” – VR and AR for skills building

Identifying the industry pain point of upskilling, this team’s concept was a suite of apps covering the whole retrofit process – from design and survey to construction and tenant engagement.

Each is uniquely designed to increase the efficiency of the retrofit process as well as train professionals in a risk-free environment. This idea won our “inter-industry innovation category” due to its proposal to use digital twins, VR and AR technologies.

We also loved the idea of incorporating standards like PAS2035 to notify when designs are not meeting required airtightness so would also tackle the challenge of the building performance gap.

The video below illustrates how AR could be used onsite to inform and upskill, drawing on BIM modelling for detail and gamification principles to make it fun and engaging!

Team 1's members: Ele Clemens, Alexis Olubunmi-Oke, Chris Forster, Dylan Fardon, George Appleby and Yuzhu Chen.

Team #2: No fines, no problem

Around 300,000 Wimpey No Fines homes were built between 1940s and 1960s often in large estates, using common archetype patterns. This makes it an ideal housing type for a standardised net zero retrofit design to be rolled out at scale.

Team 2 from Constructive Thinking Studio focused specifically on creating a design for their archetype, with emphasis on making it appealing for residents.

Identifying the challenges of air leakage, shallow roof pitches and voids making fixings difficult, the team’s design outlined a fabric first approach with appropriate ventilation and heating systems, powered by renewables. With this focus, the team won the 'Solving your archetype’s pain points' category.

The team also proposed removing the roof and replacing with an offsite constructed, modular extension that increases living space, and therefore property price.

Team 2's members: Adam Hill, Sophie Chapple, Joseph Willoughby, Emily Niven, Jon Moorhouse, Yashna Calleechurn.

Team #3: People-first retrofit

With a flatted archetype, Team 3 (including a cohort from Grounded Practice) identified a fabric first solution to achieve net-zero but concentrated specifically on taking residents through the whole retrofit journey with an app.

From initial engagement and consultation, through to post-occupancy, this app would allow tenants to feedback on design, choose modular components for their retrofit and keep them updated on progress.  

Drawing on gamification principles to incentive engagement with the app, the team also focused on developing opportunities for residents by offering training and potential jobs.

We were impressed to see that the team had identified that residents require detailed support on new technologies to ensure performance is achieved, as well as the scope for enabling them to share data on performance for ongoing monitoring. View their full presentation.

Team 3's members: Sam Pywell, Claire Brown, Beth Day, Chloe Phelps, Sarah Hutchison, Sophie Whinney, Joey Aoun

Team #4: HomeHackers: a plugin for real estate websites

Team 4 dealt with an archetype that is often owned privately. Their focus was therefore on making “retrofit the new renovation,” and making it aspirational to a much wider market.

Thinking about the ‘trigger points” at which people might consider retrofit, they proposed adding additional features into real estate websites like Zoopla that places retrofit at the heart of the homebuying journey.

This included reports for properties on their “retrofit status” ie retrofitted or ‘retrofit ready’, information about the potential savings post-retrofitting and linking prospective buyers with more information about retrofit, including finance providers.

Many of the judges felt this concept would be a real game changer which could make retrofit much more visible and demonstrate its impact on house value, and the team won the ‘Making retrofit desirable’ category. View their full presentation.

Team 4's members: Bushra Al Jahwari, Jiamin Chen, Ryan Barclay, James Harrington, Anne-Marie Tomchak.

Team #5: Rethinking facades

The cross-wall archetype which Team 5 focussed on has inherent structural challenges making it complex to retrofit, but due to this is well-suited to offsite facades.


Team 5 developed concepts for modular facades which incorporated services, but were lightweight enabling them to be assembled onsite without a crane, therefore reducing cost.


With their focus on their particular archetype, as well as building physics, cost detail and replicability, Team 5 won the ‘Optimising solutions to archetypes’ category.

Team 5's members: Nao Shibata, Barbara Sledz, Divyanshu Sood, Veronica Rocha.

What's next?

Our teams achieved so much in just 2 days. We’ll be working with them to see how their ideas can be progressed, from finding the right connections to sharing the ideas widely with our networks to be tested in real-life.

With a fantastic array of coaches and judges, we’ve already seen a couple of new avenues open up and we can’t wait to see what happens next.

And don't forget, if you’re at Futurebuild 2022 this week - join us in the Whole House Retrofit Zone at 1.15pm – 2pm to hear from the teams themselves!

Whole House Retrofit Nottingham is led by Nottingham City Homes, Nottingham City Council and Energiesprong UK. It’s funded by the Department for Business, Energy and Industrial Strategy.