An off-centre fireplace on a wall can make the whole wall look awkward. When we look at this type of wall the fireplace will tend to feel heavier and darker than the rest of the wall. Sometimes the imbalance can be reduced by lightening and neutralising the paint colour of both the wall and the fireplace. Other ways to balance the feeling of the room is to bring a large piece of art to balance the weight. This can often produce striking visual results.
Paint the wall and fireplace in complementary neutral tones. Use crisp trim colours such as white or off white. If your fireplace is floor-to-ceiling brick or stone, consider covering the weight of the masonry with drywall that you can paint in the same colours as the rest of the room.
Update standing hearths by covering them with modern tiles or granite slab in the same palette as the rest of the room. The fireplace should look like an intentional feature that has been mounted in that position for a good reason. When possible, avoid mounting a television adjacent to the fireplace as this often creates a disjointed coupling of unlike objects that leads to a feeling of visual discord.
Highlight the open wall space next to the fireplace with directional recessed lights. Place a piece of large art on the space. This will immediately create the visual message that the space was designed to showcase large art. The art on the wall and decorating the fireplace should relate in some way (such as colour). Avoid placing several little pictures on the wall or fireplace as this feels like visual clutter and does nothing to solve the wall problem.
Position chairs or couches toward the fireplace as well as toward any view or a television. Incorporate the fireplace as an important part of your seating arrangement. It is often essential to pull furniture off the walls so that it floats in the room and to use armless chairs and lounges to bridge more than one seating arrangement. Be willing to move your furniture several times to achieve seating and visual balance.
Hang draperies that will unify windows on the fireplace wall. If the wall space is unusually large, draperies can be positioned so that some of the wall space is covered. Place a taller, heavier piece of furniture directly opposite the fireplace. This will tend to counter the visual weight of the awkwardly placed fireplace.
Consider extending the mantle and hearth of the fireplace in more modern style homes creating linear shelves on the wider expanse of walls. Decorate these shelves with a select few high-impact art pieces. This makes the shelves an extension of the architecture as well as a further decorating opportunity.
Your best result occurs when the off-centre fireplace looks intentional and well designed.