"Should I stay or Should I go"?

The main reason to move, of course, is that you would be getting a bigger, nicer house. On the other hand, the main reason to stay where you are and expand is that you already know the home and neighborhood, have friends in the community and love where you are. You can sometimes solve a problem with a reasonably priced renovation. This option might be more affordable than moving and buying a new home.

However, there are some major drawbacks to renovating that are easily overlooked. First, additions to older homes have a way of becoming more expensive than originally budgeted which we affectionately refer to as “cost creep.” Builders don't always know what they are going to find until they open up the walls, dig foundations, etc. Second, homes are generally built with a consistent aesthetic, and the design/flow of the home makes sense given its scale. Additions, particularly big ones, can compromise the home's flow and congruency, and can sometimes create awkward spaces, dark rooms or partially blocked views. Third, sometimes an owner's taste-specific customizations make the home less desirable for future buyers. Finally, there are cost/inconveniences to living through a renovation or moving out temporarily.

One prudent thing to do if you’re considering a major renovation or expansion is to determine if the increased value of the home will be more or less than the “all-in” cost of the renovation. The truth is that in the majority of cases, the renovation costs exceed the increased value to the home. The NAR puts out a cost/value report every year that shows that an owner gets between 60% to 90% of every dollar put into a renovation. 

In other words, not a good investment.