Just because I happen to have looked at this before–WUSTL is pretty transparent about their 3+2 engineering admissions requirements, down to specific requirements for specific majors:
https://engineering.wustl.edu/academics/dual-degree-program/admissions.html
In addition to doing the required courses (and it is a comprehensive list including what might be called gen ed requirements) and getting the required grades, you also need to make sure you are working with the “Dual Degree liaison officer” at your first college who will need to certify you.
However, the good news is they say in their FAQs:
https://engineering.wustl.edu/academics/dual-degree-program/FAQs.html
Is admission guaranteed?
All applicants are admitted as long as the candidate:
- is currently attending one of our affiliations schools
- completes all of the course requirements for admission and achieves a 3.25 GPA or above (overall and math/science)
- is endorsed by their current institution certifying aptitude for engineering study and the completion of a bachelor’s level, non-engineering degree at the current institution no later than receipt of the engineering degree from WashU
The only reason a student would not be accepted after meeting the above requirements is if they had an anomaly on their record such as a felony or a severe academic integrity violation, for example.
As I understand it, this is one of the nice things about going to an affiliated school for WUSTL’s program, that it isn’t capacity limited and so as long as you can jump through all the hoops (and to be sure there are a lot of them) you will not then also need to worry about whether they will have enough space to admit you.