As long as there isn't any foreseeable danger, he is provided with the necessities while you are gone, has no medical issues and there is an emergency contact nearby in case there is a need for same there shouldn't be an issue.
In theory a 17 year old is well capable of staying alone but be aware that the parents and homeowners may be liable for any 3rd parties who visit while you are gone and if any parties are thrown and alcohol is served. It happens all the time.
This information is a general answer and is not specific to any particular case. Carin Manders Constantine, Esq. 727-456-0032/ 727-488-8272 familylawyer411.com/about-carin https://www.facebook.com/pages/The-Law-Offices-of-Carin-M-Constantine/125967577416313 http://www.linkedin.com/pub/carin-constantine/b/861/445
You should not be leaving a 17 year old home alone for a week. When I first read this question, it seemed obvious that a 17 year old can be at home alone - but a week is too long. Even leaving a child home alone for the entire night is a bit much. Do not risk leaving him home alone for a week - very bad idea.
This answer is for general informational purposes only and should not be relied upon for your particular case nor is it intended as legal advice. I have not reviewed your case nor have I met with you and the answer to this question does not in any manner whatsoever establish an attorney/client relationship.