1. If It's your primary residence you want to be comfortable , you need more space , need a brand new garage and have the money ......you should do it!
2. if you are looking to remodel a property (flip ) and don't know what to do .........you need to do the numbers first and than talk to a good Realtor who can have a CMA and some suggestions!
In the end...we need more info so we can answer properly your question!
If someone is looking to do a job like this and they don't have the cash, there are renovation loans out there that can help you do a project like this without needing all the equity in your home "now" to do it (especially important now after equity many homeowners used to have has evaporated partially or in some cases completely).
Hopefully other readers of this post learned something other than this person didn't give us additional details and the question is three years old as of when I type this. :)
There are other factors involved, but you have not given me much information.