AECB CarbonLite Retrofit Standard

AECB lifetime carbon modelling suggests that either of our two retrofit standards should deliver dramatically lower lifetime carbon emissions for homes – compared to not retrofitting. Over time we imagine two waves of retrofit happening, with some step-by-step projects progressing to full retrofit, depending on future policy and financial developments.

CarbonLite Retrofit Step-By-Step

Our Retrofit Standard can be done step-by-step with a minimum first step called ‘Step1’ – This recognises the practical and financial challenges faced by ‘early adopter’ retrofitters in the absence of a working UK retrofit programme. They offer a pragmatic and flexible approach to retrofitting existing buildings, and the new Approved Certifier scheme streamlines and strengthens the AECB’s approach to Quality Assurance.

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A Tale of Two Retrofits

A quick delve into the contrasting approaches of Greater Manchester’s first two AECB CarbonLite Retrofit Level 2 Projects; One an Edwardian manor house, the other a 1980s bungalow.

Hannah Dixon is the founder of Progress in Practice, a small and innovative architecture practice in Greater Manchester, specialising in Passivhaus, retrofit and low energy homes and buildings. The practice delivered the first two AECB certified retrofit projects in Greater Manchester in 2023 and are advocates for the Passivhaus and AECB approach. Hannah is passionate about inclusivity in design and sits on the board of the GM Community Led Homes hub

CarbonLite Retrofit

The energy and non-energy benefits of a deeper retrofit may justify adopting the full Retrofit standard for some projects, whereas the faster and lower capital cost Step 1 may be more appropriate for other projects. Completing a step 1 retrofit does not lock out later works to take the building to a cost-effective full Retrofit.

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AECB standard – what it is, how to undertake it, a case study

Certification

In order to maintain the integrity of the standards and ensure consistency of application, the AECB uses Approved Certifiers to confirm that projects have met the AECB CarbonLite Standards.

All our certifiers are AECB members, approved by us to carry out project certification. Certifiers undertake regular AECB CarbonLite CPD.

The AECB Standards are based on the Passivhaus methodology, and certifiers use the Passivhaus Planning Package software (PHPP)
The certifier may choose to appoint a separate PHPP modeller as part of their certification service, or may do this in-house
Once modelled in PHPP, certifiers use the AECB CarbonLite LEBD Uploader software to collate project data and evidence and automatically upload the certified project to the Low Energy Buildings Database

Our other CarbonLite Standards & Guidance

CarbonLite New Build

More in-depth information about the standard can be found here

Water Standard

Learn more about delivering buildings with excellent water energy performance.

Daylight Guidance

Creating a well- lit building is vital for the occupants and for reducing energy demand and carbon emissions.

Airtightness Guidance

Achieving excellent airtightness