I think it's okay to give my parents a key to my new house if they visit me frequently. But if my parents are far away from my new house and don't visit often, a key is optional.
If after moving into a new house, your parents are still very uneasy about themselves and often want to come to see them, it's okay to give them a key. Because they will inevitably have things not at home, and parents come to see their own words, no one to open the door is not waiting outside the door, there are keys will be able to facilitate a lot of parents can be timely to the house side to rest. And parents are certainly not outsiders, fortunate to bring us up, we give our parents the key to the new house is also deserved. If your own key is left in the house, the key to your parents can also be used as a spare key, so that you are not afraid of being locked out of the house.
Of course, if your parents live far away from your new house and don't come to see you often, you'll be able to call them beforehand to make sure they're not home when they come to see you. In addition, if you give your parents the key, in the case of their own unawareness, parents come to see their own, after returning home to find someone at home will also be worried about who is in their own home, of course, finally found that it is their own parents, at most, is to make a mess. Although it will not be a big thing, but their own house such a situation will still be nervous. You don't have to give your parents a key if you live far away, but it's okay to give them a key, and it's good to have a spare key.
Also, if your parents are living in a new house with you, there's no reason not to give your parents a key, but if you don't give your parents a key, don't you want to keep them at home. In this case it would be unreasonable not to give your parents a key, and it's just too inconvenient not to have a key. If you live together, you should give your parents a key, so that they can go out and buy food, and if they want to go to the neighbor's house, it's also convenient for them to do so.
The situation should be analyzed on a case-by-case basis. Giving your parents a key can be inconvenient at times, but not giving them a key can also be inconvenient. Give parents the key on the one hand is to believe that the parents on the other hand is also to give the family a convenient, if you often need to take care of their parents, you can consider giving their parents a key or two, so that they can receive parental care, but also to ease their parents miss their own, but also in the necessary time to solve their own did not bring the key to the trouble. If you are more independent and your parents only come to see you once in a while, you can consider not giving your parents a key or giving them a key as a spare key, which can bring convenience to you.