You can upgrade directly after you have saved enough gold coins.

Twin apartments have one big plot, two small plots. On the big plot, a high-grade vegetable market will be built, and on the small plot, a grocery store and a hospital will be built. There is a lot of spare money at this stage, so you can consider raising the facilities first and then slowly opening the room to upgrade the furniture. When recruiting tenants, if you recruit a certain occupation+unemployed people, you can consider driving them away, because the rate of return of unemployed people is not as high as other occupations.

Introduction:

1. When the room completion is greater than 35%, the unemployed will automatically check out, making room for you to recruit other tenants.

2. The infrastructure has two plots of land, one big and one small. Please build a restaurant on the big plot and a express booth on the small plot.

3. Before your restaurant is upgraded to a "Chinese restaurant", try not to recruit tenants who need to eat, because the "breakfast stand" can't fully meet their needs and will give bad reviews.

4. After the restaurant is upgraded, employees recruited before the upgrade will leave their jobs and need to be recruited again. So don't make too many employees before upgrading, you will lose money.

5. Career balance is very important. If you have too many people in a certain profession, you may not be able to meet your needs and get bad reviews, thus reducing your income.

6. Facilities upgrade gives priority to "commodity price" and "queue number", and the efficiency can be delayed, because customers will wait for you no matter how slow you are.