Hi. I have just bought a second hand house. The doors, architraves, skirting boards and stairs are painted white. I am changing the doors to shaker oak. As it is quite expensive to change the architraves and skirtings to oak I'm wondering could I paint the architraves and skirting an off white or cream? Would they all have to be sanded down first? Is it a big job. Anyone know how much roughly a painter would charge to do it?