if this model was imported from a CAD software (Sketchup, Rhino… ), in most cases the UVs generated from those software are not good enough for texturing process.
However, a final solution for your problem is to correctly UV unwrap your model. To do this, just follow these steps:
- apply the scale of the object (this is necessary to avoid distortions while projection)
create a Color Grid texture map (1024 is enough)
switch to Blender Render engine, and active Textured Solid shading (just because it's easier to have a nice preview of how your texture is projected onto the surface)
start unwrap your model, and set the color grid as active texture in the UV/Image Editor, so you can see how the texture is projected onto the surface
The main reason of following this procedure is that you can immediately see the distortions of the texture of your model. The color grid checker is used to check errors/distortions during unwrap. When you don’t see correct squared numbers, it means that you have some distortions along an axis (first image below). It’s also useful to see if several objects have the same UV scale by checking the dimension of the squares (second image below). The first image is the same of your case: the UVs of the left object are stretched along one direction (U or V), so you will see that long thiny bricks instead of regular bricks. The following images visually explain these concepts:
My advice is to create a correct UVMap once for all objects, so you won’t care about the position/scale/orientation when you apply the textures.
Remember this: any other texture will be projected onto the surface in the same way as the color grid is projected. So, if the color grid is correctly projected, that means that every other texture will be correctly projected, with the same size, the same orientation and the same distortions (you can be as good as you can during unwrap, but a little bit of distortion is difficult to avoid, mostly for organic models). If the color grid checker has some distortions, any other texture will be projected with the same distortions.