To add friends in SimCity BuildIt, you can connect your game to Facebook or Game Center. Once connected, you can invite friends from your social network to become your in-game friends. You can also join a Club in the game and make friends with other players in the Club. By adding friends, you can visit each other's cities, trade resources, and help each other progress in the game. **

In SimCity BuildIt, you can build skyscrapers by first reaching a high enough population level in your city. As your city's population grows, you can unlock more advanced buildings and services, including skyscrapers. Additionally, you will need to provide your citizens with the necessary utilities and services, such as power, water, and transportation, to support the construction of skyscrapers. Finally, you can also use special items and resources to upgrade existing buildings into taller and more advanced skyscrapers. **

To earn money faster in SimCity BuildIt, you can focus on increasing your population by building residential zones and upgrading them to maximize the number of Sims living in your city. This will increase the tax revenue you collect. You can also sell excess items on the Global Trade HQ to earn Simoleons quickly. Additionally, participating in contests and completing cargo shipments can also provide a boost to your income. Finally, investing in commercial and industrial buildings to produce and sell goods can also help increase your city's income. **

No, the houses in SimCity BuildIt cannot be further expanded. Each house has a set size and capacity that cannot be increased. Players can, however, upgrade their houses to increase their population capacity and appearance. Additionally, players can build more houses to accommodate a larger population in their city. **

One way to earn money faster in SimCity BuildIt is by focusing on increasing your population. The more residents you have, the more taxes you can collect. Another way is by completing cargo shipments and selling items in the Trade Depot for a profit. Additionally, participating in contests and completing disaster challenges can also provide a quick influx of cash. **

In SimCity BuildIt, houses cannot be expanded further beyond their maximum capacity. Players can upgrade their houses to increase their population capacity and appearance, but there is a limit to how much a house can be expanded. To accommodate more residents, players can build additional houses or upgrade existing ones to higher levels. **

The Trade HQ in SimCity BuildIt will be unlocked once you reach level 18 in the game. This building allows you to trade with other players, buy items from the Global Trade HQ, and sell items to earn Simoleons and other resources. It is an important feature for expanding your city and acquiring rare items. Keep progressing through the game to unlock the Trade HQ and take advantage of its benefits. **

To unlock the Trade HQ in SimCity BuildIt, you need to reach level 17 in the game. Once you reach this level, the Trade HQ will become available for you to build. You can then place the Trade HQ in your city and start using it to trade with other players for resources and items. Keep developing your city and leveling up to unlock more features and buildings in the game. **