importantly, make sure that everything that can go wrong is covered. with the right resources and the right training, the longer they have been offering the cleaning services the more the chance they will deliver a great quality. the kind of services that you are looking for and the kind that they have been offering need to have some relevance or else the long experience will not matter. a look at their portfolio will give you an idea of what they have been doing and how.
you need a budget for this, and the prices therefore are something that you will have to look at. the prices will vary depending on 