There are 12 houses in astrology, and each house rules a different part of your life. The 1st house is the self, the 2nd house is money, the 3rd house is communication, and on and on.
If you're looking for which house rules friendships, the kinds of friends you have, that is governed by the 11th house. It's the 11th house of hopes, dreams, the future, and friendships!
The 11th House of Friends: Planets
When you're analyzing your 11th house for friendships, you'll want to look at the sign on the 11th house cusp, planets in the 11th house, and house and sign location and condition of the 11th house ruler.
With the Sun in the 11th house, you feel very comfortable around your friends, and usually have an easy time making new friends. The Moon in the 11th house can show your friends are like your family, and that you need them for emotional support. Mercury in the 11th house shows an ability to express yourself with your friends.
With Venus in the 11th house, you can have an easy time making friends, and you may attract many people of different backgrounds to you. You may also focus on friendship in your romantic relationships. With Mars in the 11th house, you can be extra driven to have lots of friends, and you can feel more motivated with your friends or in groups.
With Jupiter in the 11th house, this can make you someone with a ton of friends, and it can be easy for you to meet new people. You can feel comfortable with your friends, and find more opportunities when with them.
Saturn in the 11th house can be the hardest for friendships since you likely have a difficult time making friends and opening up to new people. You may have an easier time with this when you get older. No matter what, you're probably someone who only has one or two really close friends, and don't care to extend beyond that.
Uranus in the 11th house puts Uranus in the house it naturally rules, so you can focus on having a wide, diverse social circle, and lots of friends at all times. Neptune in the 11th house makes you more empathetic with your friends, and you may attract artistic friends, spiritual friends, or friends who need your help.
Pluto in the 11th house can bring some power struggles in your friendships, and you may attract people who want to control and dominate you. Asserting yourself becomes important. If you're comfortable with your own strength, you can attract powerful people to you.
The 11th House of Friends: Signs
Fire (Aries, Leo, Sagittarius) and air (Gemini, Libra, Aquarius) signs on the 11th house cusp tend to have an easier time making friends, attracting new friends, being sociable, and enjoying company. This is just in general though (if Saturn or Pluto are in the 11th house or conjunct the 11th house ruler, then it's probably not the case!).
Earth (Taurus, Virgo, Capricorn) and water (Cancer, Scorpio, Pisces) sign on the 11th house cusp tend to have more difficulty with friends. The earth signs may be too wrapped up in other stuff while the water signs may be too sensitive and easily hurt. Again, this is just in general, and personal planet (Sun, Moon, Mercury, Venus, Mars) or Jupiter in the 11th house or positively aspecting (sextile or trine) the 11th house ruler or cusp can mitigate the challenges. Unless Saturn is there too!
The 11th House Ruler
The sign and house location of your 11th house ruler (the natural planetary ruler of the sign on the cusp) can also impact your friendships. If it's conjunct a personal planet or Jupiter, friendships can be more important to you as a person. Saturn conjunct can make friendships most difficult and hard to find or keep.
Uranus conjunct can make your friendships more erratic, and people may come and go as friends. Neptune conjunct can make you more easily taken advantage of by friends, so you have to work on better boundaries. Pluto conjunct can make friendships volatile at times, and you may need to transform in order to make good friends.
If your 11th house ruler is anaretic (at 29 degrees of any sign), this may show some issues that impact your friendships or ability to make friends. If your 11th house ruler is intercepted (contained within a house), friends may be cut off for you, or there may be a subconscious block getting in the way of you being able to make friends.
Additional Astrology to Consider: Your Aquarius Houses
The house that has Aquarius on the cusp, the sign naturally ruling the 11th house and friends, can also add show some more about your views of friendship.
Aquarius on the 1st house can show friendships are very important for you in life;
the 2nd house can show you place a lot of value and find a lot of worth in your friendships;
the 3rd house can show needing a mental connection, being drawn to intellects, having friends younger than yourself, or treating them like a sibling (or they are one);
the 4th house can show viewing your friends as family, and include them in your support system;
the 5th house can show a real love for your friends, being generous with them, wanting attention from them, and you can find help romantically through them;
the 6th house can show you do a lot for your friends, are practical in your view of friendship, and don’t get too emotionally-invested;
the 7th house can show you commit to your friendships, try to balance all of them evenly, and want to constantly improve them;
the 8th house can show you’re intense and possessive of your friends, and want to be friends with powerful people;
the 9th house can show you’re gregarious and easy with friends, make lots of them, and like friends who expose you to other ways of thinking;
the 10th house can show you want your friends to live up to certain standards, or that you aspire to be like your friends;
and the 12th house can show you’re shy with making friends but will do anything for your friends, sacrificing yourself for them.
Suggested Reading: Aquarius Houses: Where You're Different