Q. What is a "Pitch Raise"?
A. When a piano has been neglected and not tuned as often as it should be, the instrument will fall flat from standard pitch. The longer it has been neglected, the farther away from pitch it will fall. Smaller, lighter built pianos seem to fall more quickly than the bigger, older, heavier pianos.
When the instrument is found to be significantly below pitch, special care must be given in adding tension to the scale to bring it back up to proper pitch. With skill, care, experience and patience, many pianos can be brought back up to pitch with a minimum of risk of string breakage, soundboard damage or other structural complications. The neglect that the piano suffered is responsible for these risks of damage but a skilled technician can reduce (but not eliminate) the risk and associated repair costs.
While the tuning that is associated with the pitch raise should leave the piano sounding considerably better that it sounded before, the piano will sound better yet and the tuning should be more stable after the next tuning which usually should be done within 3-6 months of the pitch raise (and sometimes considerably sooner.) Different piano technicians have differing price strategies but most will have some sort of extra fees that the piano owner should expect to pay for the extra efforts and care expended to carefully restore their piano to proper pitch.