In April 2013, after several dozens hours of extensive studying of Sims behavior on 3 experimental houses made by me, using two families of 2 and 8 sims, plus the pre-made ones, I made my first (final) house in The Sims 3.
The Sims 3 starter house under $20.000 designed for a family up to 4 sims. For the non-functional items (counters, table, windows, floors, wall paint) I used the cheapest items to save money for the best possible furniture items that fit in a $20.000 house. Similar like Best Starter Home 2×2 made in The Sims 2.
My second The Sims 3 home, inspired by exterior of Tiny House I and interior of Tiny House II built by me in The Sims 2. I used the smallest lot available in Sunset Valley (16×18) instead of regular 20×30 lot, to make it compatible with possible 20×20 lots in other worlds. Feel free to decorate landscape after placing in your desired lot size.
L-Shaped houses were standard homes for my sims during early years of playing The Sims 2. Here is the The Sims 3 version. Ground floor is composed by living, dining, kitchen, hobby rooms and one bath, while second floor is composed by 3 bedrooms, family room and 2 baths. Designed for families of 4-6 sims. Built in November 2015.