How close should I plant my hydrangea to my house
Do not know how big it will get and want to leave enough room for it.
There are many types, and many sizes, of hydrangeas. The information on size at maturity should be on the plant tag. If there's no plant tag, request the information from the plant store. If they don't know, (even if they do should you want to do further research,) get the name of the grower and the name of the cultivar. After you get your hydrangea planted, we have several article to help you keep it healthy and beautiful. Start here: https://www.gardeningknowhow.com/ornamental/shrubs/hydrangea/growing-hydrangeas-hydrangea-care-guide.htm