> For the complete documentation index, see [llms.txt](https://docs.enercalc.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.enercalc.com/sel-faq/using-the-software/calculation-modules/walls/concrete-shear-walls/why-cant-i-vary-wall-lengths.md). # Why Can't I Vary Wall Lengths by Story? Why concrete shear wall lengths can no longer vary by story and how this affects existing calculations. Why was the ability to vary wall lengths on a story-by-story basis removed? Based on discussions with industry experts, the interpretation of 'hw' and 'Lw' for the purposes of calculating 'αc' has been standardized. To ensure consistency, wall lengths and offsets are now uniform across all stories, and the shear wall aspect ratio (Hw/Lw) is calculated using the global dimensions of the entire wall stack. How does this change affect my existing Concrete Shear Wall calculations? When opening calculations created before this update, the following changes will occur: * Wall Length values from the *Story Data* tab will be automatically updated to match the Length value from the General tab. * Wall Offset values from the *Story Data* tab will be reset to zero. Additionally, a warning message will appear when you open the calculation to notify you of these changes. What should I do if I need to reference my older calculations? If needed, legacy calculation data can be accessed by using an older build of SEL which predates this update. Contact for help. However, it is strongly recommended to use the updated module moving forward as all other shear wall layouts fall outside the scope and intent of this module. --- # 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.enercalc.com/sel-faq/using-the-software/calculation-modules/walls/concrete-shear-walls/why-cant-i-vary-wall-lengths.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.