For many architects, the hardest part of their job starts after they finish designing a building, when the onerous process of code compliance begins. Written to ensure the safety and accessibility of buildings, codes dictate everything from the height and depth of stairs and where railings end, to the amount of floor space in front of toilets and the height of windows. Regulations are constantly updated, which means that even the most diligent team of architects often miss violations, resulting in costly delays. Y Combinator alum UpCodes wants to help them by using artificial intelligence, including natural language processing, to create what the San Francisco-based startup describes as "the spellcheck for buildings." Called UpCodes AI, the program is a plug-in that scans 3D models created with building information modeling (BIM) data and alerts architects about potential issues.