By Legal Futures Associate Landmark Information Group
Following the publication of the Law Society’s Climate Change and Property Practice Note in May 2025, The Chancery Lane Project (TCLP) updated its existing Marni’s Clause to reflect the terminology and guidance in the new Practice Note. In addition, TCLP introduced a new clause, Isabella’s Clause, specifically for residential properties. Marni’s Clause now focuses exclusively on commercial transactions.
The Need for Two Clauses
Originally, Marni’s Clause was designed to support both commercial and residential property transactions. However, the release of the Practice Note highlighted the distinct legal, practical, and client communication needs of these two sectors. TCLP recognised that separating the clauses would simplify the drafting process for property lawyers and allow for more tailored, sector-specific language.
As a result, two clauses were developed:
- Marni’s Clause – for commercial properties.
- Isabella’s Clause – for residential properties.
Robert Lee, Professor of Environmental Law at the University of Birmingham and Simon Boyle, Environmental Law Director at Landmark Information were invited to assist with the drafting of both clauses, having previously contributed to the development of the Law Society’s Practice Note.
Comparison of Marni’s Clause and Isabella’s Clause
| Feature | Marni’s Clause (Commercial) | Isabella’s Clause (Residential) |
| Property Type | Commercial properties | Residential properties |
| Original Purpose | To reference climate risk searches in reports on title for commercial transactions | To provide a tailored equivalent for residential conveyancing, aligned with the Law Society’s Practice Note |
| Trigger for Use | When a climate risk search has been conducted or is unavailable, to ensure climate risks are properly referenced in the report on title | Same trigger, adapted for residential property context and client communication needs |
| Risk Categories Addressed | Physical, transition, and liability risks (aligned with TCFD and PRA SS3/19 guidance) | Same categories, with simplified language and examples relevant to residential buyers |
| Alignment with Law Society Practice Note | Updated to ensure consistency with the Practice Note’s guidance and sample wording | Developed concurrently to complement the Practice Note’s residential guidance |
| Level of Detail | More technical and detailed, suitable for commercial clients and institutional investors | More accessible language, designed for individual homeowners and residential buyers |
| Drafting Contributors | Updated by TCLP with input from Professor Robert Lee and Simon Boyle | Created as a new clause by the same team to address residential-specific needs |
Summary
Climate risks, both physical and transitional, are already affecting UK properties. As global temperatures continue to rise, the impacts of climate change will become more severe and widespread. Property lawyers have a responsibility to report on these risks clearly and effectively. Marni’s and Isabella’s Clauses are designed to support that responsibility, helping lawyers communicate climate risks to clients with precision and confidence.
Our role in shaping the Law Society’s guidance
Members of Landmark’s Sustainability Team played a key role in the development of the Practice Note. Robert Lee, Professor of Environmental Law at the University of Birmingham and Simon Boyle, Environmental Law Director at Landmark Information were both contributors to the Practice Note and co-authors of the accompanying Technical Note. Their insights helped ensure the Practice Note guidance is both practical and proportionate. For further guidance, explore Landmarks essential resource on navigating the practice note here.
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