Before installing a pergola, the main points to be considered are location, position of the sun, budget, size and shape. Vinyl pergolas offer a focal point or attraction and must be placed in the prime place of the garden or yard. They should be installed in such a place that they can catch either morning or afternoon sun and give off necessary shade. The size of the pergola should be such that it does not cause obstruction and the exact measurement needs to be taken. Though round shaped pergolas are good looking, square and rectangle shaped ones are more cost effective.