> 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 dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter: ``` 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 optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. 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.