Those pesky building codes!
Not many things can wreck your building floor plans like code requirements that sneak up on you. Overlooking a seemingly innocuous requirement can set you back hours in the beginning of design and days at the end of design.
The only solution is to review the code early and often. This doesn’t have to be as overwhelming as it sounds. Use a checklist at the earliest opportunity to document the requirements that will apply to your project and how your design complies. At the end of the design phase, read over the checklist and update any changes that have occurred, making sure that you are still in compliance.
The designer needs to be the one who checks the code, even though most designers hate this. It is the only way to avoid constant re-designs to correct code problems uncovered by your in-house expert (after too much time has been spent doing it wrong).
There are a few checklists out there on the Internet that you could use*. Those rarely seem that useful. You could create your own. If your work is repetitive, this will save time. Even if your work is not repetitive, customizing the checklist to your needs will save time in the long run. The checklist below is for the International Building Code. It covers the issues that we usually need to check; your need is probably different! Use this one as a guide to make your own.
* Here is one checklist that does seem useful.
Modified 9/6/2016 with full images of checklist and one new link.