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Rule 12: Keep Housing Around 30% of Your Gross Pay

BY GIANCARLO STA CRUZ · NOVEMBER 2026 · FROM THE 12TH FLOOR

Every budget has one line that decides the rest, and it isn’t coffee. It’s housing. If you limit your housing cost to a reasonable amount — around 30% of your gross pay — the road to success will be much easier to achieve. Saving through latte deprivation is not the answer. Limiting housing overhead is.

THE CHEAPEST SQUARE FOOT IS VERTICAL

I live in about 500 square feet on the 12th floor of a 12-story building in National City — technically, the penthouse. When I needed more room, I didn’t buy a bigger place. I built upward: a $4,000 loft bed against roughly $633,000 of added housing costs to solve the same problem any other way. Same problem, 1/158th the price.

WHY THIS RULE DOES THE HEAVY LIFTING

Housing is the one expense that repeats at full size every month for decades. Keep it near 30% of gross and the surplus has somewhere to go — mine goes to the retirement account, at 31.5% of pay. Let housing creep to 40 or 50% and no amount of skipped lattes closes the gap; the math simply runs out of month. Wealth is what you don’t see — and what you don’t see starts with the rent or the mortgage you didn’t take on.

Build upward. The cheapest square foot is vertical.

From The 12th Floor — How a GS-8 Retired at 57 with $5 Million (Without Working a Day Past 56). Out November 28, 2026 — paperback $12.99, ebook $4.99. Read Chapter 1 free · All articles
This is my story, not financial advice. I’m an anesthesia tech who kept a spreadsheet for twenty years — not a financial advisor, and this book won’t make me one.