Firstly at the end of the day it's the AHJ's (inspectors) call - however from my experience they usually rely on what are referred to 'prescriptive' methods for design (ie: IRC, span tables for joist sizing, tables that dictate minimum design requirements, etc) and if those prescriptive requirements do not meet an application, that's when often they will either require an engineer, or give some direction if they are comfortable.When using a sister to an existing framing member, the capacity of the new member should be evaluated but also how it is attached to the existing, as a shearing failure of the screws/lags can occur. 

A lot of the answers in this thread remind me of a part from Charlie Munger's speech "How to Guarantee a Life of Misery" "My second prescription for misery is to learn everything you possibly can from your own personal experience, minimizing what you learn vicariously from the good and bad experience of others, living and dead.

@Kevin Moules - One of the reasons I self manage is that management companies need to be prescriptive in their approaches.  

It's the trades equivalent of asking a doctor for a blank prescription pad.

You cannot tell anyone they aren't allowed to have a legal substance like alcohol or prescription drugs in your house.

If you don't, they'll get an ESA "prescription" and then you'll have to accept the dog for free.CLICK HERE to educate yourself on ESAs.Just because you have to allow an ESA doesn't mean it gets free rein.

I believe it's called a prescriptive easement. 

They are an aggressive breed, and aggressive breeds are not generally allowed to be service dogs.If you are trying to verify whether a service dog is legitimate, the key is to ask for the prescription for the dog. 

However, VA might provide more in terms of retirement benefits, such as no taxes on prescription drugs.

These are then deductible by the individual taxpayer.Also, consider a Health Savings Account (HSA) to pay other medical expenses, such as doctor's visits, prescription drugs, dentist, etc.