Destroying a building, house or any structure is one of the most difficult decisions you will have to make. Demolition can be done for various purposes. Below are some situations in which you would have to take this bold step:
Re-building a house: If you have just bought a very old house that cannot be renovated, and not even parts of it can be replaced, then it might be good to demolish it and start new construction from scratch.
Unsafe building: In case the building has been shown to be unsafe then its demolition should be considered, even though you otherwise like to stay in it and would like to keep it as is.
Damage due to fire: If the damage caused by fire or any other disaster cannot be fixed then it will have to be re-built. When the cost of repair turns out to be more than the value of building itself then demolition is a good option.
Selective renovation: Sometimes renovation requires part demolition of a structure. Of course, if you are renovating your kitchen, garage, swimming pool or patio then it has to be done precisely so that other parts of the house are not damaged.
No matter what the reason for the demolition is, it must be done with precaution and following proper safety measures. It needs proper planning and preparation so that no other surrounding areas are damaged.  A trained and experienced professional should be consulted to make sure demolition is the right path for your building or home.