I know what you are saying. The problem is that unless you create your uvs with a 1:1 ratio and apply a single material with a single texture map you wont be able to repeat any particular texture on the one texture map.

You have two choices:

1) create uvs within a 1:1 ratio and then take the uv map into your paint package and adjust the textures so they are different sizes and look fine in the 3d space

or

2) create separate maps and different materials. If its a door for example create 1:1 as suggested above or if its a brick wall created a tileable texture where you can just dial in how many times it repaeats over your model.

But bear in mind also that a door texture will look different to a brick texture specular wise etc...so one texture map or material will not necessarily be useful

Hope this helps
Jay