Even in-use chimneys are only sometimes the best option as a primary heating source. Wood-burning fireplaces send 85% of their energy out of the chimney. Gas fireplaces aren't much better, with new literature linking natural gas appliances to dangerous levels of nitrogen oxide and carbon monoxide.

Losing heat through the chimney flue: An unused and unsealed chimney wastes energy like a small opened window. Even a sealed chimney is losing air through the masonry or any gaps in the seal.

Losing heat through conduction from heating the thermal mass of the chimney stack: Stonework is a fantastic conductor of indoor space heating, which is wasted when the chimney stack is sticking out the top of your roof.

Reclaiming wasted space in the home: Chimneys can take up large amounts of floor space inside a house, particularly larger chimneys. Removing the chimney breast from multiple floors can be a game-changer for homes short of space.

Roof leakage: Chimneys are one of the most common causes of roof leaks, and this risk increases as the chimney ages.

A damaged chimney stack: Chimneys are skinny pillars exposed to the elements, so, unsurprisingly, they are prone to damage. A damaged chimney can cause water leaks, air leaks, and the risk of falling debris.

Ordinances and certifications: Since chimneys are often a source of emissions and pollution, some cities don't allow them in their building code. If you're seeking a home certification like LEED, check to make sure the fuel source for your fireplace doesn't cost you LEED points. 

A structural expert can explain any concerns with removing the breast from one or more floors. They might tell you where to put up temporary walls during demolition, what type of structural support you'll need to install after removal, or they might even tell you not to take out the chimney.

A masonry expert can help you decide between removing or repairing your chimney. They can also help you find a suitable second home for the stone and brick debris.

A local code administrator can ensure you obtain the correct documents and permits to remove your chimney. Historical homes, for example, might need special permission from a Preservation Review Board.

And lastly, find a contractor that's on the same page as you. Since chimney removal can be such an involved job, especially if you're removing the flue and breast from inside the house, prioritize a contractor who's done this type of job before. If you're renovating your home and hoping to pursue a home rating like LEED, Net Zero, or Passive House, look for a contractor who understands these programs and shares your goals for your home.

A building permit: make sure you have permission from your city, your housing association, your local heritage office, or anyone with authority to tell you what to do on your property.

Blueprints: this can warn you of any structural considerations, including any shared wall concerns if you don't have a fully detached home. Your local public official's office might be able to help you track this down since the original building permit for your home would have needed to include blueprints.

Liability insurance: any contractor you hire needs to have at least liability insurance to avoid all liability falling on you in the case of an accident or injury. This includes events during the renovation or demolition and problems with the completed job for months or years afterward.

A disposal permit: Some jurisdictions require a disposal permit if you're disposing of any material that might endanger workers or the environment. This might include roof shingles, asbestos-containing materials, sharp things like broken glass, and oil-soaked material. The fee is usually small, so check the solid waste commission in your area before renting a dumpster.

Certifications: check that your chosen contractor has credentials or experience that qualify them for a challenging chimney removal. Also, consider if you're trying to qualify your home for certifications like Net Zero, LEED, or Passive House - your contractor should be familiar with these programs to ensure the chimney removal project doesn't disqualify you.

Removing a chimney can be a simple or complicated project. In either case, please consult with the right experts before taking it on.