Hi gonna make a little tutorial on how it is simple to make a very low polygon simple house.
with mostly only 3 shape for the main part.
Step 1:
Draw a box 3.0 x 3.0 x 2.5 high (screen1)
Step 2:
then clone* this box and lower its sides per 0.1 minus each side (2.8 x 2.8 x 3.0) high (screen2)
make sure it goes further down up and down (this is why 3.0 high)
Step 3:
Select your 3 x 3 x 2.5 box (screen3)
Goes in the menu of primitive shape and select Compound objects , click on Pro boolean, substraction and click start picking and select the inner smaller box
you get (screen 4) as result.
Step 4:
draw a big box, bigger than your 3x3 mesh and angle it at 30%. place it so the edge arrive at middle of the house, clone it , turn the new one at 180 degres on horiz line. Place it at same distance the other side. (screen 5)
Go back in the primitive menu and go select Compound objects, Pro boolean, susbtraction, click on picking objects and select the 2 big boxes in 30 angle... (screen6)
you should get (screen 7) as result.
Step 5:
Lets put some material texture to it. press "M" (material) click on diffuse, select a texture, click view in viewport and apply the texture to the selection.
and you see all the walls of the house. in 1 single box (screen8)
Step 6:
Lets do all the windows and door.
draw 6 little boxes of 0.6 x 0.6 x 1.2 high for the door, and 0,4 x 0,4 x 0,6 high for the windows. place them where you want to have your holes. (screen9)
Step 7:
Go in Compound Objects, pro boolean, substraction, start picking and select all your little boxes 1 after the others.... (screen10)
as you can see in screen11, you have now 1 box with empty in middle, walls inside too, with door and windows openings... in 1 single box.
Step 8:
With your building selected , go in 2nd icon "modify" and open the scroll list and select Unwrap UVW.
in that window , top right open the box and select your texture. now click the red square at the right of the screen and select each side and move around the red selected zone to make it stand ontop of a "wood beam" and do this for all the not good little sides (screen 11)
Step 9:
once all the windows and door fixed with nice wood beams... lets do the roof.
a box of 3.2 long X 1.8 width and 0,3 high should be good. give it the roof texture in the "M" material menu. apply to it, and then go in 2nd icon "modify" and select in the scroll box "Unwrap UWV".
Place the thick sides (0.3 high) so it stands on a side on the texture, 1 row of shingles, rotate if need... (screen 12)
Step 10:
rotate it with a 30 degres angle, place it to 1 side of your building , clone it, rotate that clone at 180 degres horiz, place it the other side. make them meet together in the middle of your building (screen 13)
move the lower bottom parts to make the sync vertically for better looking... (screen14)
And then you have a very nice , very simple form with only 3 boxes (1 for walls, 2 for the roof) with almost nothing as polygons amount (screen 15)
Step 11:
and then you can start to add some doors and windows like the the next screen.... (screen 16)
so .. that was very simple to do something more than correct with almost no polygons

Enjoy!