Problem is blender . need a solution

Hello Guys I am facing a problem in blender … So I created a house in blender , then I separated the different things with different names , windows , door, roof etc … but when I select one thing lets say ground and I go into materials and apply shadders or change the color, it gets applied to the whole house even though I select only a certain part … help needed

If the object had a material before you split into different parts then all the parts will have the same material. If you change a setting of that material then it applies to all objects that have that material.

Next to the name of the material there may be a number telling you how many objects use that material. Mouse click on the number to make a new single user.

I suggest you read the manual or watch some beginner tutorials so you start to understand the basics before doing anything else

Also please use the appropriate support forum for support questions. There is a Support / Materials and Textures forum if you actually scroll down the page