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Wasted Space in House Plans

Wasted space in house plans: how to find it and what it costs you

A hallway costs about as much per square foot as a bedroom. Here's where wasted space hides in a floor plan, how to measure it, what it adds to your build cost and how to turn it into space you'll actually use.

By the CostToBuildHouse design team · Updated September 2026
Sample reviewMarked-up floor plan
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What wasted space really costs

Every square foot of a house costs roughly the same to build, whether it's a bedroom you love or a hallway you walk through twice a day. Foundation, framing, roof, drywall, flooring, heating and cooling all scale with area.

Wasted areaAt $150/sq ftAt $200/sq ftAt $250/sq ft
50 sq ft$7,500$10,000$12,500
100 sq ft$15,000$20,000$25,000
200 sq ft$30,000$40,000$50,000

Rough cost per square foot varies by state and finish level. Get yours with a build cost estimate — then you know exactly what each wasted foot is worth. And you pay again every year in heating, cooling, taxes and cleaning.

Where wasted space hides in a floor plan

WhereWhat to look for
HallwaysLong central halls, halls that serve only one or two doors, double-loaded corridors in a one-story house.
Formal roomsA formal living and a formal dining room you'll use a few times a year.
Oversized roomsA secondary bedroom at 14×16 when 11×12 works, a 200 sq ft laundry.
Foyers and landingsTwo-story entries and wide stair landings that add area but no use.
Awkward shapesAngled walls and bump-outs that leave corners no furniture fits.
Duplicate spacesA bonus room, a loft and a den all doing the same job.
Closets you can't useDeep closets with no shelving plan, closets under stairs with no access.
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How to measure wasted space on your plan

  1. Shade every hallway, landing and foyer on a printout.
  2. Add up the shaded area using the plan's dimensions.
  3. Divide by the total heated area.

In efficient plans, circulation usually lands under about 10% of the heated area. Above about 15% is a sign there's room to tighten the plan. Then do the same for rooms you'll rarely use and ask whether the space could work harder somewhere else.

Not all “extra” space is waste. A wider hall for aging in place, a generous mudroom for a busy family or a big great room for hosting can be exactly right. Waste is space that doesn't do anything for how you live.

How to reclaim wasted space

  • Open the hall into a room. Bedrooms can open off the living area or a short vestibule instead of a long corridor.
  • Turn hall into storage. A short hall can become a walk-in pantry, linen wall or drop zone.
  • Combine formal rooms. One flexible dining area next to the kitchen beats two rarely used rooms.
  • Right-size secondary rooms and move the saved area to where you live every day.
  • Simplify the footprint. Fewer corners mean less foundation, framing and siding for the same area.
  • Stack and share walls. Back-to-back bathrooms and laundry save plumbing and space.
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A smaller plan that feels bigger

Cutting waste lets you build less square footage without feeling cramped: long sightlines, higher ceilings in the main room, big openings to the outdoors and built-in storage all make a compact plan feel generous.

More ideas in how to design a small house that doesn't feel small and simple house plans that are cheaper to build.

Next steps

  1. Get your cost per square foot with a state-adjusted estimate.
  2. Measure the circulation on your plan with the steps above.
  3. Have the plan professionally reviewed — wasted space and cost drivers are part of every review, and the Complete Review estimates the cost impact of each change.

Frequently asked questions

How much hallway space is normal in a house plan?

In efficient plans, hallways and circulation usually take under about 10% of the heated area. Above about 15% suggests room to tighten the layout.

How much does wasted space cost?

About the same as any other space: your cost per square foot. At $200 per square foot, 100 square feet of unnecessary hallway is roughly $20,000 to build.

How can I make my house plan more efficient?

Shorten or eliminate hallways, combine rarely used rooms, right-size secondary bedrooms, simplify the footprint and stack plumbing walls.

Will cutting square footage make my house feel small?

Not if the saved space is removed from circulation and rarely used rooms. Open sightlines, taller ceilings in the main room and good storage keep a compact plan feeling generous.

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