The 5 piece bathroom is also a full bath, but the only difference is an added sink. It has similar features of a full bath; toilet, shower, bathtub, sink, and another sink.
A five-piece bathroom is most common nowadays. Most master bedrooms have an attached 5 piece bathroom.
For a working couple, getting ready in the morning gets quicker and convenient with two sinks.
Does a 5 piece bathroom increase property value?
The answer is simply, NO.
Do not fall for any broker claiming a house to be pricey because all the full baths are 5 piece. Adding another sink for convenience should not affect the price.
However, in reality, if a property has more attached bathrooms with bedrooms, the buyers may have to pay more due to the higher demand for such properties.
Should you build 5 piece bathrooms?
I don’t see why not. If your house is under construction, you might want to add another sink to make a five-piece full bath. What if you don’t feel the need for it right now?
It is possible for you do not have a need right now, but houses require long term planning, and you might need it in the future.
Thus, there is no harm in adding another sink, even if you don’t need it currently.