Signs say how, houses say where
The twelve houses divide the chart into areas of life: self and appearance, money, siblings and daily talk, home, play and romance, routine and work, partnership, shared resources and intimacy, beliefs and travel, career and reputation, friends and groups, and the private, behind-the-scenes life. The houses pages go through each one.
A useful picture: the chart is a film, the houses are the sets, the planets are the actors, and the signs are the way each actor plays the part. A dominant house is the set where most of the scenes are shot. Someone with a crowded 5th house tends to keep returning to creativity, play and romance. Someone with a crowded 10th tends to measure a year by what they built or achieved in public.
This is why a dominant house can look very different from your Sun sign. Two Taurus Suns can share a steady, sensual temperament while one pours it into a career and the other into a home and family. The sign is the same; the stage is not.
Finding your dominant house
You need an accurate birth time. Houses turn a full circle in about a day, so even an hour off can move planets into a neighboring house. Without a time, skip this and look at your dominant sign instead.
With a time, count the planets in each house, giving the Sun and Moon a little extra weight. Then adjust: the angular houses (1st, 4th, 7th, 10th) count for more, and a planet sitting right on an angle, within a few degrees of the Ascendant or Midheaven, counts most of all. Some astrologers also give weight to the house that holds the ruler of your Rising sign, often called the chart ruler.
For example, say the Sun, Mercury and Venus fall in the 5th house, Mars is in the 1st near the Ascendant, and the rest are spread out. The 5th has three planets, including the Sun, and wins on count. The 1st has only Mars, but sitting on the Ascendant makes it loud. The reading would be a 5th-house chart with a strong Ascendant: someone who invests in play, art and romance, and who meets the world directly.
When an angle carries the chart
Sometimes no single house is crowded, and the weight sits on an angle instead.
A powerful Ascendant. When planets sit close to the Ascendant, or the chart ruler is strong, the person tends to have an unusually clear sense of who they are and to use their personality openly, often on behalf of a cause they believe in. The flip side is that work which doesn’t fit their tastes and talents can feel doubly wrong to them. The Rising sign, its ruler, and any planets in the 1st house describe those talents; see why Rising needs a birth time.
A powerful Midheaven. Planets near the Midheaven, the top of the chart, suggest an appetite for a public role and a real interest in reputation. These people tend to be comfortable around people in charge, do well in supervisory and organizing work, and give their best when the effort is noticed. The sign on the Midheaven and the planets in the 10th describe the style.
What it means for relationships
A dominant house tells you what a person’s life is organized around, which is useful in a relationship even though it isn’t romantic in itself. A strong 7th-house chart treats partnership as a main event. A strong 10th may love you sincerely and still check work email at dinner. A strong 4th wants the home to be the center of things, and a strong 11th wants a calendar full of friends.
When two people’s dominant houses differ, the talk worth having is about time and priority, not about who cares more. A planet gains strength partly from its house, so your dominant house and your dominant planet often point to the same part of the chart. The app counts house position modestly when it works out your strongest planet, and it doesn’t give house readings.