Low carbon loan guidance for building developments

What can the development finance industry do to reduce the carbon impact of the construction of buildings? Earlier this month, we published a report titled ‘Low Carbon Loan Guidance for Building Developments‘ looking into this issue. We embarked on this project because we were working with funders who were trying to condition their development loans based on the upfront embodied carbon performance of new developments they were funding, but there was no agreed guidance or case studies on how to do that.

Why we wrote this

Our mission at Construction Carbon is to simplify carbon reduction during the construction phase. Most of the funders we spoke with understood the big impact from their construction projects’, however, most of the funding products with sustainability incentives for new buildings have historically been centred around EPC ratings or other green building certification schemes.

We worked with Built by Nature to pull together funders, developers, contractors and consultants to understand what challenges people had encountered and what best practice might look like.

How we developed the guidance

We ran a series of structured workshops, starting with development funders, before expanding the conversation to developers, contractors and consultants. We had some leading organisations input into the project, from major banks and smaller specialist lenders, lawyers and main contractors to standard creators, and developers specialising in lower carbon developments. The result is a document grounded in real world delivery experience, reflecting the lessons learned from people who have actually tried to implement low carbon finance products.

What the guidance contains

Key Takeaways:

1. Finance can drive embodied carbon reduction: Development loans can meaningfully incentivise lower upfront embodied carbon (A1–A5) when incentives are directly tied to verified carbon outcomes rather than broader green certifications or operational EPCs.
2. Standardised measurement is essential: Anchoring loan products to a single recognised standard, such as the UK Net Zero Carbon Buildings Standard, provides clear KPIs, comparability across projects, and third‑party verification to reduce greenwashing risk.
3. Early design decisions matter most: Carbon performance and the viability of timber and bio‑based systems are highly path‑dependent, requiring ‘timber‑first’ and low carbon design choices to be made at the earliest stages.
4. Simple, capped incentives work best: Performance‑linked rebates assessed at completion offer a clear, lender‑friendly incentive that aligns developers, contractors, and funders without undermining credit risk or returns.
5. Delivery controls must match finance conditions: Carbon targets only remain credible when supported by procurement controls, staged assessments, and consistent site‑level data throughout design and construction.

What comes next?

We know this guidance is not perfect. We are looking to expand engagement to government bodies, equity funders, development lenders and planning authorities. Recent signals are encouraging. The Department for Education has already released employers requirements referencing the UKNZCBS embodied carbon limits for new builds, which points towards potential broader government adoption. Our ambition is to build a growing body of case studies from the development finance world as more lenders and organisations get comfortable with embodied carbon limits.

Now that the UK Net Zero Carbon Building Standard is properly established, we hope more funders and government bodies will get behind this initiative and feature in the next piece of work. We believe that the fastest way to make a real difference before hard legislation is implemented is to focus on funding. Getting funders aligned around consistent, auditable embodied carbon metrics and giving them the tools to act is where we believe industry change can be made.

How it can help you

This guidance is designed for lenders, investors, developers, contractors, and advisors who want to embed embodied‑carbon performance into development finance without creating unworkable complexity. It helps finance providers design loan products that are robust, auditable, and aligned with emerging regulation, while giving developers clarity on what is required to unlock financial incentives. It links financial incentives to embodied‑carbon performance, with a particular focus on enabling and de‑risking the use of bio‑based materials.