The quality of every thing put on site is you chose and to the standard you require - you can even change your mind with any of the materials as you go along - perhaps a newer product comes out or prices on something is available cheaper elsewhere. This is what we call an organic building process, it allows for change as the project grows and perception of the end result develops with the building process. Contractors quotations may need reviewing during this period, however you know that what you have initially agreed is a fixed figure that can be adjusted at your discretion should you needs change.