This is the ‘Nailed It Build Mode Basics Set' which is essential for the modern simmie. It features Board & Batten wall paneling in blue and greyscale hues, hardwood plank flooring in two sizes and trending wood tones, and a whole lot of doors: three styles, both single and double, and both modern colors and wood tones. The simmie with style is going to want to start here.
This mod changes seasonal parameters such as flower growth, color shift, and leaf accumulation to better match the temperature and seasonal changes in that world.