The bathroom is one of the most important rooms of your home and will add a substantial amount of value to it as long as you take care of it. Remodeling an old bathroom and bringing it up to date can also add a lot of value to the house, especially if you add some unique features to it.
If you do decide to remodel your bathroom, try to stay with the current layout if you can, since rearranging the plumbing can be fairly expensive. If you have money to spend, though, and your master plan just has to have a brand new layout, then go for it. It is not likely to hurt anything to change the layout of the bathroom, especially if it is a unique one.
The most important feature of the room will be the type of flooring that you choose to put down. You can have all different types of flooring, but the one thing that you never want to put down in this room is carpet. This is a huge mistake and if you do it once, you will never do it again.
Carpet will become molded after a fairly short period of time due to the amount of moisture in the room and you will eventually have to completely get rid of it. Put down ceramic tile or stone and this will last a lifetime and longer as long as you take care of it properly. More expensive stone will make it worth more.
A bathroom that has a bath tub and a shower that are separate from each other is likely to add a lot of value to the room. A large number of homes have this feature in the master bathrooms, but not skimping on the features of the guest bathroom also shows not only that you care about your guests, but also about adding value to the house.
The toilet is also a primary feature in the room and you should try to purchase the right model for you. Dual flush toilets save a lot of money on the water bill, since they offer two different water quantities that you can flush it with. Energy efficient appliances anywhere in the house can help with the value.
You should also consider the fixtures in the room. They should all be the same finish, such as brass or brushed nickel, as this will unify the space and help bring it all together.