> For the complete documentation index, see [llms.txt](https://docs.betterbuilding.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.betterbuilding.io/sign-up-and-plans/news-and-updates/2026/ncc-2025-the-facade-calculator.md). # NCC 2025: The Facade Calculator V 1.2 {% embed url="" %} Better Building has released version 1.2 of its NCC 2025 Facade Calculator, building on the original with more features and a wider set of export options, all aimed at meeting the code in a way that's simple to use but robust enough to stand behind. {% hint style="success" %} Grab your copy of the [NCC 2025 Facade Calculator here.](https://files.betterbuilding.io/docs/ncc_facade_calculator_v1_2.html) {% endhint %} It's built primarily for architects who want fast access to Deemed to Satisfy design pathways under NCC 2025, but it also does real work for sustainability consultants. The tool makes clear just how demanding the reference building becomes under the J1V3 verification method once window to wall ratio climbs above 40%. Which raises the obvious question. Are the days of large curtain wall glazing ratios numbered? Early signs point that way. If DTS won't carry a high-glazing design, the only real offset left is running the J1V3 pathway and leaning hard on optimised building services, and that's a significantly bigger undertaking than sticking within DTS limits from the outset. --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation by asking a question. Perform an HTTP GET request on the following URL with the `ask` and `goal` query parameters: ``` GET https://docs.betterbuilding.io/sign-up-and-plans/news-and-updates/2026/ncc-2025-the-facade-calculator.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is what the user is ultimately trying to achieve, the reason they need the answer. Sharing it helps GitBook give you a better, more relevant answer. A goal is most helpful when it describes the outcome the user wants rather than restating the question. For example, with `ask=how do I create an API token`, a goal like `automate deployments from our CI pipeline` lets GitBook tailor the answer to that use case. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.