How much does weight affect a house?
The total weight of materials in a room is not really the question. The concern, if any is how many pounds per square foot. This will vary depending on what size joists are supporting the floor. Common residential construction is build to handle a dead load (materials/fixtures) of 40 to 60 psf averaged over the entire floor not counting load bearing wall materials. Live load is people.  Lets say you have a 10ft X 10ft room @40psf, the total load rating would be 4,000 pounds averaged. This link has some charts if you want to read more. http://www.assakkaf.com/Courses/ENCE355/Lectures/Part2/Chapter2a.pdf

In your case, there should be no structural changes or issues at all.