House Overlays

House overlays answer a question cross-aspects don't: which area of my life does this person activate? You take the other person's planets and see which of your houses they fall into. Their Sun in your 7th house, their Mars in your 10th, their Moon in your 4th.

Where cross-aspects show how two psyches touch, overlays show where in your life the other person lands — which department of your existence lights up when they walk into it. It is one of the most immediately practical techniques in all of synastry.

Overlays follow directly from the house system and from synastry's core method of laying one chart over another. The logic is old and simple: your houses are the twelve arenas of your life, and when another person's planet falls into one of them, that planet's energy is brought into that arena. Their Venus in your 2nd brings their love and values into your realm of money and self-worth. Their Saturn in your 7th brings weight and commitment into your house of partnership.

The tradition read this as where the other person becomes significant in your life — not how you relate abstractly, but what part of your world they occupy and change.

The method: take Person B's planets by degree and sign, and see which of Person A's houses each falls into (using A's house cusps). Then reverse it — A's planets into B's houses. You get two overlays, one for each direction, and they are usually different.

Read each planet-in-house as "they bring [planet] into my [house]":

• Their planet in your 1st — they profoundly affect your sense of self and how you show up; you may become more like them.
• Their planet in your 4th — they touch your home, roots, emotional foundation; a "family" feeling.
• Their planet in your 5th — romance, play, creativity, children; a classic romantic overlay.
• Their planet in your 7th — partnership; they feel like a natural partner. The marriage overlay.
• Their planet in your 8th — deep intimacy, shared resources, transformation, the psychologically or sexually profound.
• Their planet in your 10th — they affect your public life, reputation, direction; can feel like a mentor or a figure who shapes your standing.
• Their planet in your 12th — the hidden, the unconscious, the spiritual or the self-undoing; a subtle, sometimes elusive or karmic connection.

Which planet lands matters as much as which house. Their Saturn in your 5th (weight on romance and play) is very different from their Venus in your 5th (delight in it).

Overlays and cross-aspects together. Cross-aspects say how you interact; overlays say where. A person whose planets fall heavily in your 7th and who also has Sun–Moon contacts with you is a partner in both wiring and placement — a strong marriage signature. Read the two layers together.

Take your two charts. Work out which of your houses the other person's planets fall into, then which of their houses yours fall into. Two overlays.

Ask, for each direction: which house of mine holds the most of their planets? That is the area of my life they most activate. And where do my planets cluster in their chart — what part of their world do I light up?

Then compare the two directions. Relationships are often asymmetric — one person lands in the other's 7th (partnership) while the other lands in their 5th (romance) or 12th (the hidden). That asymmetry is often the truest thing the overlay reveals: the two people may be in subtly different relationships with each other.

Consider a relationship where their planets fall heavily in your 12th house while yours fall in their 7th.

You experience them through your 12th — the hidden, the unconscious, the dissolving, the place of things that don't quite come into daylight. They feel elusive, dreamlike, spiritually or karmically significant, hard to pin down, possibly a source of both transcendence and confusion. Meanwhile they experience you through their 7th — as a clear partner, a natural other, someone squarely in the frame of committed relationship.

That asymmetry is the whole story: one person is having a partnership, the other is having something veiled and half-conscious. Neither is wrong about their experience, and the overlay shows exactly why they don't match — you are not, in a real sense, in the same relationship. Naming that can be painful and clarifying at once, which is what synastry at its best does: it shows you the actual shape of the thing, including the parts two people were never quite saying to each other.

• Stephen Arroyo, Relationships and Life Cycles — house overlays in practice.
• Sue Tompkins, The Contemporary Astrologer's Handbook — the houses, which carry directly into overlay work.
• Read alongside: the whole Houses subsection in Foundations.