Does anyone know why my 7 year old dog would be constantly hiding under the couch?

She's been acting strange ever since we got our kitchen remodeled and she spent a week with a friend because the amount of noise the contracter made irritated her. She has been hiding under the sofa a lot and I can no longer coax her out with a treat. Does she just miss her family? Has anyone else had this problem? Is there something seriously wrong? What should I Do? Please HELP!