Roofing a House, 2-roofing techniques to improve lego homes

I have already brought up some basic house building techniques in a previous post.
In this post i will continue with the basic roofing of houses.

Lego just recently released info on another one of their big sets for next year.
This time it was the                                      

10243 Parisian Restaurant. After taking a closer look at this model i realized that the roofing was rather abnormal for Lego. This model featured some large sloping elements to form the roof. Often techniques like these are excluded from official lego sets. 

Now, as mentioned before, most lego houses are designed for a beginner's age group. so, more complex roof designs are excellent to find in new sets. 

with this all said, it's time to get to the building tech part of this post:
House roofing techniques....

The five basic tips every house builder should know.

    

Recently, lego creator saw the release of the new Family House. I personally have had a chance to mess around with this set and I find it disappointing. Although it may "look cool" it has a low piece count (756p.) and price per piece is high averaging at 9 cents a piece. This includes all the minifig elements and accessories. so i do not fancy this decline in value of lego sets.

Now I could go on and on about how awful a set this is, including the fact that the garage opens directly into the living room where a kitchen should exist, but I have a different point to make.

The standard for lego houses could be so much better. Take the modular buildings for example.
The 10218-1: Pet Shop has neat techniques and lots of space for it's size. If you haven't seen this model displayed before, it's HUGE! So, why aren't Lego houses this good?

The two reasons I figure are: