On the "Genshin Impact" 1.5 update, you can now build their own houses using the Serenitea Pot.
The said item will transport you into a pocket dimension where you can start making your own home. However, obtaining the Serenitea Pot will have you roaming around Liyue and talking to other NPCs.
How to Get the Serenitea Pot in 'Genshin Impact'
According to IBT, you need to meet the requirements first of having a level 35 Adventure Rank or higher and completing the "Chapter I: Act III: A New Star Approaches" Main Story Quest before you can start building a house.
If the required level is met, you can activate the quest "A Teapot to Call Home" from the Events page of the Paimon Menu.
From there, you can talk to Madame Ping to start the quest. You need to roam around Liyue to speak with other NPCs and the new playable character, Yanfei, before heading back to Madame Ping. Once you head back to Madame Ping, the Serenitea Pot will be yours.
Once the Serenitea Pot is obtained, you can activate it by selecting the gadget in the inventory. From there, you will choose from three-pocket dimension spaces: the Floating Abode, Emerald Peak, and Cool Isle. Once you decide on a location, you will be teleported to the selected place.
How to Build a House in 'Genshin Impact'
To start construction, you will need to place a forge on your chosen property. Note that you cannot construct houses or other materials in the Serenitea Pot dimension without Blueprints and materials. For that, you must go into the "Genshin Impact" world and gather the materials there.
According to Games Radar, blueprints can be obtained by leveling up the Trust Rank from Tubby, the pot butler. To level up the Trust Rank, you must craft furniture learned by the given blueprints from Tubby. Simultaneously, completing several missions from the Serenitea Pot journal will get you new blueprints to make new appliances.
If completing quests is a hassle for you, Tubby also sells blueprints of its own. You can purchase the blueprints in exchange for Realm Currency, which is generated in the Serenitea Pot. You can collect Realm Currency by the hour based on the your Adeptal Energy.
Also, blueprints can be found in Mondstadt and Liyue, which you can purchase for 50,000 Mora each. In Mondstandt, the blueprint vendor is an oldman named Goth and you can find him in the city by the beach southeast of the city's western teleport point and will appear during the daytime. In Liyue, the old man named Master Lu can be found at the southern tip of Qingce Village.
For the materials, you can collect them outside of the Serenitea Pot world, and heading into the wilderness of "Genshin Impact" will be a good start. According to Realsport101, the materials you will commonly need are different classes of Wood--like Birch, Cuihua. Pine, Sandbearer, Bamboo, Cedar, and Fir--which are abundant in the game.
For the Fabric, you will need 10 Silk Flowers and dyes. Different dyes will need different materials. For the Blue dye, you will need one Mint and one Wolfhook. To make Yellow dye, you will need one Berry and one Cor Lapis, while the Red dye will need Sunsettia, Carrots, and Valberries, as Game Rant added.