Since the detached casita was appraised 5 months ago with a $60 per square foot value, a new appraisal giving you a value of $180 per square foot will increase your value an estimated $48,000 (I took the square foot price difference, $120 and multiplied it by 400 square feet).

How much value does a Casita add?

If your guest house is detached, it will be considered a “line-item adjustment.” This has the potential to add anywhere from $10,000 to as much as $30,000 to your total asking price when you're ready to sell.

What is the difference between a guest house and a casita?

A detached house that serves as a guest house, studio or home office is often referred to as a Casita. In the main house, an in-law suite can be found in the lower level, first floor, main bedroom level and even the loft.