Does anyone know the average amount you would get in SOM?

I guess it depends what you do for them, but I'd assume more than the average for the job.

Usually Architects earn around 10% of the capital-construction cost.

% dpends on the complexity of the job, and geography I guess.

In the UK about 6% would be right for a commercial job - office etc.
Anything up to 15% for complicated residential.

I worked for SOM, and salaries vary depending on many factors, like what type of work you do (architecture, engineering, interior design, etc) and also on your level of experience, licenses, seniority in the firm, etc. It also depends under what regional office your payroll is (salaries in the UK are different from the US for example)