> 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/bb-hamt-demo-now-available.md). # BB HAMT Demo - Now Available {% embed url="" %} Better Building used to lean on EnergyPlus, specifically the finite element heat transfer solver that showed up in version 9.5. It was fine for walls, using the same Kunzel equations that underpin WUFI, but it started falling over for roofs and anything beyond the basics. The team ended up engineering workarounds just to match capabilities WUFI already had natively, which is the kind of thing you do reluctantly as no one likes a workaround. . So towards the end of last year they decided to just build their own solver instead of patching around someone else's. ## BB HAMT The result is BB HAMT, a cloud-based heat and moisture solver that's now the only moisture modeling option on the platform (EnergyPlus has been cut over entirely). It's been validated against the HAMSTAD benchmarks and EN 15026, with results tracking closely against reference temperature and moisture profiles. ## **Demo Summary** The demo covered: * **Materials**: drag-and-drop with hydrothermal data attached, with a private material directory coming for users to manage their own datasets (thermal, moisture, carbon, etc). * **Climate files**: upload your own EPW, get automatic data quality warnings (mostly precipitation-related, which is the perennial headache with weather files), plus a "drying potential" view by facade to help you pick your critical orientation before you've even started modeling. * **The input form**: analogous to WUFI or Delphin, covering objectives, orientation, run periods, mould growth targets (NCC default of 3), initial conditions, and equilibrium moisture content. Worth noting: the 90% x 2 EMC requirement for concrete is often physically impossible since it exceeds the material's actual moisture storage capacity, so expect to tweak that one. * **Cavity ventilation**: dynamic air change modeling based on high/low openings, discharge coefficients, and inlet area. * **Driving rain**: 1% source method off the climate file, standard exposure and deposition factors. * **Results**: high-level summary reports (mould growth, RH, water content, flux) plus a detailed point-selection tool for pulling hourly data at specific depths within the assembly. --- # 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/bb-hamt-demo-now-available.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.