Skip to content
Wood framing for a room addition going up beside an attached garage

Home Additions

Bump-Out Additions

Sometimes a few feet is all a room needs. A bump-out pushes one wall outward to make room for a tub, an island, a breakfast nook or a bigger closet.

Get a Free Estimate Call (805) 921-0405
BBB Accredited Business A+ rating5.017 Google reviews

Request a Free Quote

Licensed CSLB #920095 · Free estimates

Bump-Out Additions

A bump-out is a small addition, often just two to eight feet deep, that extends one room. It is a common way to fit a freestanding tub in a primary bathroom, a dining nook beside a kitchen, or a wider closet. One of our clients had us take out a bay window and a slider and extend an exterior wall to make room for a standalone tub and more closet space.

Small as it is, a bump-out is still an addition. It needs structure underneath, a roof above, a permit and an exterior that matches the house. What makes it attractive is that it changes one room a lot without the cost and disruption of a full addition.

Foundation or cantilever

Most bump-outs sit on a new footing like any addition. In raised-floor houses, a very shallow bump-out can sometimes be cantilevered, with the floor framing extended past the existing wall and no new foundation, if the engineer approves it for the span and load. Cantilevers are limited in depth, so they suit window seats and small extensions better than a full room enlargement.

Roof and exterior

A bump-out usually gets a small shed roof tied into the wall or the main roof, with flashing to keep water out of the joint. The exterior is finished to match: stucco texture, siding, trim and window style. On a small addition, a mismatch is easy to see, so we test finishes before completing the wall.

  • Bathrooms

    Room for a freestanding tub, a larger shower or a double vanity.

  • Kitchens

    Space for an island, a pantry wall or a breakfast nook.

  • Closets and dining

    A walk-in closet or a dining area that fits the table.

Permits and setbacks

Even a few feet counts toward setbacks and lot coverage, and side setbacks on narrow lots are often the limiting factor. Coastal and design review can apply as with any addition. A bump-out rarely crosses the 500-square-foot threshold for school fees. We check the rules before you design around a specific depth.

From our clients

Real Google reviews from LE Construction clients, quoted word for word.

EXCELLENT

5.0 out of 5, based on 17 Google reviews

  • Richard Torres

    April 2024 · Google review

    "All work was constructed via architect design. We eliminated a bay window and slider and extended an exterior wall making room for a stand alone tub and facilities relocation to accommodate more closet space. All new tile was installed throughout."
  • Teresa Bucio

    June 2025 · Google review

    "He shows up exactly when he says he will every time which is a rare and much-appreciated quality in this industry. His pricing is fair and transparent, with no surprises along the way."

Read all reviews on Google

Find the few feet you need

Tell us which room is too tight. We will see whether a bump-out solves it and price it in writing.

Get a Free Estimate

Bump-Out Additions: FAQs

How much space can a bump-out add?

Typically a few feet in one direction across the width of a room, which might mean anywhere from a small window seat to roughly 60 to 100 square feet or more. The limit is usually setbacks, the roof connection and budget. We measure and show you what depth works for your goal.

Is a bump-out cheaper than a full addition?

In total, yes, because it is smaller. Per square foot, it can be expensive, since it still needs a foundation, roof, exterior finish, permit and the cost of opening an existing wall. It makes the most sense when a few feet solves a specific problem.

Does a bump-out need a permit?

Yes. It changes the structure, the exterior and usually the roof, so it needs a building permit and inspections. Setbacks and lot coverage still apply, and coastal or design review may too, depending on location.

Can a bump-out be cantilevered without a foundation?

Sometimes, in raised-floor homes, for shallow extensions approved by an engineer. The floor joists are extended past the wall to carry the bump-out. Deeper bump-outs, heavy loads like a stone tub, and slab homes need a footing. We check your framing first.

Related services

Home Additions near you

Related pages

Call NowFree Estimate