Niche substance · structure
Structural or cosmetic, and why it decides everything
Finishes are the visible money. Load paths are the real money. Work out which tier your project sits in before you price a single tile, because moving between tiers changes the number by an order of magnitude.
Cosmetic
No engineerFinishes change, nothing that holds the house up is touched. Floors, paint, trim, fixtures replaced in place, cabinetry in the same footprint.
- Cost impact
- Baseline
- Schedule impact
- Baseline
How you can tell
- No wall is being removed or moved
- No opening is being widened
- Nothing is being added above an existing floor
- Plumbing and electrical stay where they are
What it triggers
- No structural review
- No stamped drawings
- No framing inspection
- Often no permit at all
Non-bearing wall
No engineer, still a permitA partition that carries only itself. Removing one changes the plan but not the load path. It is still a permit job, because the services inside it have to be relocated properly.
- Cost impact
- +$6,000 to $18,000 per wall (sample)
- Schedule impact
- +1 to 2 weeks
How you can tell
- Joists above run parallel to the wall, not across it
- No wall, beam or footing sits directly below it
- Nothing bears on it in the attic
- It is often a closet wall or a single-storey interior divider
What it triggers
- Building permit
- Electrical, plumbing and mechanical sub-permits for anything in the wall
- Framing and rough inspections
Load-bearing wall
Engineer stamp requiredThe wall carries floor or roof load. Removing it means a header or beam, posts, a continuous load path through the floor framing, and a footing at the bottom of it.
- Cost impact
- +$28,000 to $95,000 per opening (sample)
- Schedule impact
- +6 to 14 weeks, most of it permit review
How you can tell
- Joists above run perpendicular to the wall and lap over it
- There is a beam, girder or footing directly below it in the crawlspace or basement
- It sits near the middle of the house, roughly parallel to the ridge
- A wall above it lines up with it on the next floor
What it triggers
- Stamped structural calculations
- Temporary shoring on both sides during the work
- Footing inspection before any pour is covered
- Framing inspection of beam, posts and hardware
- Shear nailing inspection where sheathing replaces lost bracing
Envelope and roof
Engineer plus energy codeDormers, raised ceilings, new large openings in an exterior wall, or anything that changes the roof structure. Both structure and energy compliance come into play.
- Cost impact
- +$35,000 to $140,000 (sample)
- Schedule impact
- +8 to 18 weeks
How you can tell
- Rafters or trusses are being cut or altered
- A new window or slider is wider than the existing rough opening
- A flat ceiling is being opened up to the rafters
- The roof line changes shape
What it triggers
- Structural review of rafters, ridge and collar ties, or a truss modification letter from the truss manufacturer
- Shear wall recalculation where a large opening removes bracing
- Energy-code compliance for the altered envelope
- Weather protection plan while the roof is open
Foundation
Geotechnical territoryNew footings, underpinning, lowering a basement slab, or extending a foundation for an addition. The most expensive and the least visible money in any renovation.
- Cost impact
- +$45,000 to $220,000 (sample)
- Schedule impact
- +10 to 24 weeks
How you can tell
- New square footage on new ground
- A post landing where there is no footing below
- A basement being dug down for height
- Existing settlement, sloping floors or stair-step cracking in the foundation wall
What it triggers
- Structural engineering, and a geotechnical report on sloped or fill sites
- Excavation and shoring plan
- Footing and foundation wall inspections before backfill
- Drainage and damp-proofing detail
Illustrative header and beam guide
Sample sizes only, for orientation. Your engineer sizes members from the actual loads on your house. Nobody should quote a beam size from a photograph.
| Clear span | Carrying roof only | Carrying roof and one floor | Note |
|---|---|---|---|
| Up to 6 ft | (2) 2x10 Douglas fir | (2) 2x12 Douglas fir | Typical interior closet or doorway widening. |
| Up to 8 ft | (2) 2x12 Douglas fir | 3.5 x 9.25 in LVL | A standard single-door-to-cased-opening upgrade. |
| Up to 12 ft | 3.5 x 9.25 in LVL | 3.5 x 11.875 in LVL | The most common kitchen-to-dining opening we build. |
| Up to 16 ft | 3.5 x 11.875 in LVL | 5.25 x 11.875 in PSL | Usually needs a dedicated pad footing at each end. |
| Up to 20 ft | 5.25 x 11.875 in PSL | 5.25 x 14 in PSL or W10x26 steel | Steel is often chosen to keep the beam flush with the ceiling. |
| Up to 26 ft | 5.25 x 14 in PSL | W12x40 steel or glulam | Crane or multi-person set. Access to the room matters as much as the span. |
The load path
Five links, and the house only works if all five hold
Remove a bearing wall and the load it carried has to go somewhere. It follows a chain from the opening to the ground. Skip a link and the failure is gradual: drywall cracks at the corners of the opening within a year, then doors on the floor below stop latching.
- 01
The opening
A header or beam spans the gap, sized by the engineer from the actual tributary load above it, not from a rule of thumb or a photograph.
- 02
The posts
The beam bears on posts at each end. Those posts are specified by material and size, with named hardware connecting beam to post.
- 03
Through the floor
The load has to travel down through the floor framing. That means solid blocking or a squash block under each post, so the joists below are not crushed over time.
- 04
The footing
At the bottom there is a footing sized for the load and the soil. If one does not exist under your post, you are pouring one, and it is inspected before it is covered.
- 05
Lateral bracing
Walls also brace the house against wind and seismic force. A large opening removes bracing that has to be replaced, usually by re-sheathing adjacent walls with structural panel and adding hold-downs anchored to the foundation.
Before you call anyone
Four checks you can do yourself in ten minutes
01 · Look at the joists
From the crawlspace or basement, note which way the floor joists run. A wall that sits perpendicular to them, with joists lapping over it, is very likely bearing.
02 · Look directly below
Is there a beam, a girder, a post or a footing under the wall? A bearing wall almost always has something underneath continuing the load path down.
03 · Look directly above
In the attic, does anything bear on the wall? Rafters, a purlin, a strongback or a wall above lining up with it are all signals.
04 · Look at the plan
Bearing walls tend to sit near the middle of the house, roughly parallel to the ridge, and run most of its length. Closet walls near an outside corner rarely do.
These four checks tell you whether to worry. They do not replace an engineer, and no beam should ever be sized from them.
No, and be wary of anyone who does. The size follows from a load calculation the engineer runs on your actual framing, spans and roof. What we can tell you at the first meeting is whether the wall is bearing.
A flush beam keeps the ceiling plane continuous but costs more, because the joists have to be hung off the side of it with concealed hangers. A dropped beam wrapped in drywall reads as a deliberate architectural line when the trim is right. We price both.
Usually one to three weeks: from the day the temporary walls go up to the day the framing inspection passes. The shoring is in the way for all of it.
We document it, have it engineered, and legalise it. It is not optional at sale, and correcting it while the ceiling is already open is far cheaper than doing it later.
Not linearly. A 12 ft and a 22 ft opening are different structural systems, not different sizes of the same one. The second may need steel, a crane or a multi-person set, and larger footings at each end.
No. The web members do calculated work. The only legitimate routes are a modification design from the original truss manufacturer or replacement trusses, and both take weeks.
Next step
Find out which tier you are in, before you budget
The walk-through includes the crawlspace and the attic. That is usually enough to say whether your plan is cosmetic, non-bearing or structural.