Stand alone vinyl pergola kits are unique and gives a beautiful appearance, though it is a little difficult to construct than an attached pergola. This type needs a safe and secure foundation and to achieve this, four holes will need to be dug and posts fixed into the ground. The only risk is damaging any utilities, such as cables or plumbing pipes. Be sure to take care of locating & avoiding these. This can be taken care of by informing local authorities beforehand so that they can come and mark where such cables and pipes are buried. If all this sounds like too much, the assistance of a contractor to help installation should be sought.