Material assignment to the different objects. Shader nodes

Hi,

Excuse my technical vocabulary I am fairly new to Blender. So I am following tutorial and modelling a house. I came to shader point and somehow selected the whole house to a single node effect. I wonder how to select and assign node effect to specific part of the house only. Hope it makes sense.

Thanks

Make the material single for the chosen object. Click the number shown in the picture. Make the same with the other parts if you want an individual material.