Karuizawa has several town regulations to protect its tranquility and scenery.
Picture above was taken at the Seven Eleven convenience store in the town. Can you see a difference from what you usually see in your vicinity? Yes, a color of the signboard. Original Seven Eleven color of ”Orange-Red-Green" stripe conflicts with the town regulation of "Chroma level must be equal to or less than 4 and brightness level must be equal to or less than 7 for colors being used in the signboards" in this district. So, even Seven Eleven had to follow that regulation to operate its stores here.
There is also operation hours regulation for commercial facilities in the town. Convenience stores, restaurants, and bars must close at 11:00pm at night. There are two big supermarkets in the town, and one closes at 8:00pm while the other closes at 10:00pm. Most gas stations close by 7:00pm while some of them close at 6:00pm. To be honest, I felt inconvenient when I first came to the town and saw them, but now understand that they are all for keeping night tranquility and protecting environment.
If you want to buy or build a permanent or seasonal house here, you have to care the town's house building regulations, too.
See this city planning map (caution: it is 1.5MB jpeg file) issued by the town administration. You do not have to read Japanese characters but should care colors and numbers in circle. You can see the green and white districts are marked with the number "50/30" in the circle while the yellow districts are marked with "200/60." The upper number is called "floor area ratio" while the lower one is called "building coverage (or building-to-land) ratio." For example, if you purchase 1000 sqm of land (it's a bit huge, but common in Karuizawa.) in the green or white "50/30" areas, you can build a house which occupies 300 sqm (30%) as a building site area and has 500 sqm (50%) of total floor space in the house.
"50/30" is a regulation by Nagano prefecture, and actually the Karuizawa town administration further regulates it to make them "20/20." So, in reality, one is only allowed to build a house with 200 sqm (20%) of total floor space and building site occupation in 1000 sqm of land in these "50/30" areas. As far as I know, this is one of the most strict house building regulation in Japan.
Town first enforced this regulation in 1972, and it has served to protect town scenery with villas and cottages in the spacious gardens and forest. It has also served to keep the town's "premier" status and real estate prices as well.