How Pixeled Eggs Built the Money Saving Boiler Challenge for Nesta

Nesta, the not-for-profit UK innovation agency for social good, created a tool to help households make a simple change to their boiler settings, cutting both bills and carbon emissions. Pixeled Eggs built the website that hosts it, with a step-by-step guide.

The Challenge

Household heating produces 16% of UK carbon emissions, and the campaign tackled the cost of living crisis and climate change together. The goal was to reach one million households. Pixeled Eggs had nine weeks to get the site ready for the heating season.

Nesta first trialled the tool with more than 3,500 users of an energy advice app, to test whether households would turn down their combi boiler flow temperature, use less energy and still stay warm. The positive results fed into the UX and UI design.

The site had to be resilient and accessible for a national audience. Not everyone is comfortable changing their boiler, and the advice applied only to combi boilers, which some users would not know they had.

The Approach

Mobile-first. People were likely to open the site on a phone while standing in front of the boiler, so it was designed mobile-first, to high accessibility standards.

A guided walkthrough. Visual references let users click through to personalised instructions. A simple, lightweight landing page used solid colours rather than imagery to keep attention on the call to action. Blog, FAQ and evidence pages answer questions before steering users back to the walkthrough.

Sharing and a live total. A share button creates a ready-made social post when a user finishes. A live totaliser on the homepage shows how many boilers have been optimised against the campaign target.

Built light. To keep the site's own footprint low, it has no video, sparing use of images, minified code and fewer server requests.

The Outcome

The campaign won Campaign of the Year at The Energy Awards 2023 and a PRCA Consumer Award, and Martin Lewis recommended the website on primetime television. It reached more than 31 million UK adults. Between October 2022 and March 2023, more than 214,000 people used the tool and told Nesta they had turned down their boiler. Nesta estimates this saved more than £20m on energy bills and 37,000 tonnes of CO2 a year.

Nesta's tracking surveys found the share of people who had lowered their boiler flow temperature rose from 21% in October 2022 to 32% in March 2023. That equates to an estimated 3.1 million households, £300m in household savings and 500,000 tonnes of CO2, well past the original goal of one million households. Nesta's radio campaign and its work with government and energy companies widened the reach further. The site is still live.