This quote is on point. It is so key to remember when you are working on a space, that the shell of the space is important too! The shell is going to limit what you can do to some extent, just as your client will limit what you can do based on their tastes. Work to balance these boundaries. Show the client how great the space can be. Work within that shell and give it a whole new image.
After all in the world of design, this is our life. Meeting the needs of both client and space, while seeing how far we can push the boundaries to create something truly beautiful that functions well and suits the needs of those using it to make everyone happy!