The NumFOCUS DISCOVER Cookbook (Diverse & Inclusive Spaces and Conferences: Overall Vision and Essential Resources). A guide for organizing more diverse and inclusive events and conferences, produced by the NumFOCUS Diversity & Inclusion in Scientific Computing (DISC) Program, with support from the Moore Foundation.
These are the guild-lines I've learned from running events with significant numbers of wheel-chair users.
2.5m corridors. Both between rooms and marked in the ground to stop people from blocking the space people need to move through chattering