For safety, motion sensor lights are useful outside, but wasteful inside. It's challenging to sell because not all homeowners want them inside.
Carpet cleaning is expensive, especially if you have allergies. Many people today prefer hardwood floors.
Many homes replace water heaters and roofs. You won't regain much of your investment when reselling.
Murals and wallpaper can seem like a cheap home upgrade, but it's not the best investment if you plan to sell your space in the future.
Mixing styles will devalue your home. A rustic kitchen and a modern living room will make your home feel inconsistent, so select complementary styles and fittings.
Unique items, like a built-in aquarium, may bring your personal joy, but as it requires a lot of maintenance, it can become a hindrance when selling the space.
Having a sun room can be a lovely idea, as it's a room one can use all year round. But it can take away a lot of yard space, which for some may be a negative thing.