Hi there to all This is my first post to this forum so bear with me about my lack of knowledge I have been doing some research on the net on installing vinyl siding and every site says to start your starter strip level around your house and start at the lowest corner, now I have never installed siding before. MY QUESTION IS How do you determine the lowest corner of the house, what procedure do the pros use? where do they measure from to determine this? my house is 25 years old and it is not straight and square, as it used to be I also would like to know if I could remove the old siding off of 1 wall at a time and side it? or should I remove it off of all the walls before I start to side.