Earth Support Corp

Cost guide · Boston

What underpinning and basement dig-outs cost in Boston

Conventional pit-and-pour underpinning budgets at $1,700–3,100 per foot of wall, or $7,000–12,500 per pit, plus mobilization. One 40 ft rowhouse party wall comes to $76,750–142,250 with mobilization.

Written for builders, developers and engineers. ESC prices the underpinning as the builder’s subcontractor; the dig-out, slab and waterproofing around it stay with the builder.

  • Per pit

    $7,000–12,500

    One pit about 4 ft wide, about 4 ft below the footing. Typical $8,900.

    UP-PIT-POUR-EA

  • Per foot of wall

    $1,700–3,100

    Per LF of underpinned wall, from the wall plan. Typical $2,200.

    UP-PIT-POUR-LF

  • One 40 ft party wall

    $76,750–142,250

    A whole job, with mobilization. Typical $100,500.

    See the arithmetic

Whole jobs, with mobilization

Budget, not a quote.Computed from ESC’s Unit Price Package rev 1, issued Sep 14, 2026, valid through Dec 13, 2026.See the rates in the book

01 · How it's priced

How pit-and-pour underpinning is priced

Pit-and-pour is the conventional way to underpin a masonry wall: dig a short pit under the footing by hand, shore it, fill it with concrete, and dry-pack the gap tight to the old footing. Pits go one round at a time in the engineer’s sequence, so no two neighbors are open together. The book prices the same work three ways.

  • Per pit

    UP-PIT-POUR-EA

    $7,000–12,500per pit

    typical $8,900 †

    About 4 ft wide pit to about 4 ft below the existing footing: hand dig, pit shoring, dowels, concrete, dry-pack.

    Use it when: You can count the pits on the engineer’s plan.

  • Per foot of wall

    UP-PIT-POUR-LF

    $1,700–3,100per LF

    typical $2,200 †

    Per LF of underpinned wall at about 4 ft below the footing, for estimating from the wall plan.

    Use it when: You have the wall plan but not the pit layout yet.

  • Per cubic yard

    UP-PIT-POUR

    $3,550–6,450per CY

    typical $4,550 †

    Per CY of underpinning concrete placed, incl. hand excavation, pit shoring and dry-pack.

    Use it when: Pits go deeper than about 4 ft below the footing, or the engineer gives a concrete quantity.

One pit, in the book’s terms

Width along the wall
About 4 ft, the segment engineers usually detail.
Depth below the old footing
About 4 ft, to the design bearing.
Concrete
About 2 CY a pit, or about 0.5 CY a foot of wall: the per-pit and per-foot prices divided by the per-CY price.
Minimum charge
$8,900 a job, whichever unit you price in.
Mobilization
$8,750–18,250 for each continuous visit (MOB-COMPACT), a separate line.

Budget figure. Depends strongly on ground and configuration; confirm with a firm quote.

Section through an underpinned wallThe existing wall and footing, with a pit dug by hand under the footing to about 4 ft below it, filled with concrete and dry-packed tight to the footing. The new basement floor is lower than the old one.about 4 ftbelow footingNeighbor’s sideYour basementOld floorOld floor (removed)Existing wallExisting footingDry-packPit concreteNew floor (builder)
Section, not to scale. The pit takes the footing down to new bearing below the new floor; the builder digs the basement out and pours the new slab.
Pits along the wall, dug in roundsEight pits about 4 ft wide under a wall, numbered 1, 2 and 3. Pits with the same number are dug and poured in the same round and are never side by side.Existing wall and footing12312312one pit, about 4 ft wideSame number: dug together, never side by side
Elevation, not to scale. The engineer of record sets the real width, depth, dowels and sequence; the 1-2-3 rounds here are one common pattern.

Why pits go in rounds

An open pit takes the ground out from under about 4 ft of footing. Dug in rounds, never two side by side, the wall stays carried by the soil and the finished pits around each open one.

Every round is dug, shored, poured and dry-packed before the pits beside it open. That is why the count of pits, not only the length of wall, sets the price and the schedule.

02 · Worked examples

Four Boston jobs, priced from the book

Each job is the book’s unit price times the quantity shown, plus one mobilization per visit, at the book’s low, typical and high prices. Swap in your own wall lengths and the arithmetic still holds.

Not in these figures: the engineer’s design, inspections and monitoring; the builder’s dig-out, new slab and waterproofing; permits; dewatering beyond a pit sump; and off-site haul of spoil.

Example 1 · priced per foot of wall

One rowhouse party wall

A rowhouse basement going down, with one party wall underpinned along its length.

Wall
40 ft
Pits
10 (40 ft ÷ 4 ft per pit)
Depth
about 4 ft below the old footing, as the book prices it
Priced
per foot of wall
Visits
1, so one mobilization

  • Underpinning, per foot of wall

    40 LF × $1,700 / $2,200 / $3,100

    UP-PIT-POUR-LF

    Low
    $68,000
    Typical
    $88,000
    High
    $124,000

  • Mobilization, compact spread

    1 visit × $8,750 / $12,500 / $18,250

    MOB-COMPACT

    Low
    $8,750
    Typical
    $12,500
    High
    $18,250

  • Design, inspection and monitoring

    Engineer of record and the owner's team. Not in ESC's price.

Budget for the underpinning

Low
$76,750
Typical
$100,500
High
$142,250

Budget: $76,750–142,250 · typical $100,500

  • Front and rear walls that need it too add at the same rate per foot.
  • The wall is shared, so the neighbor will want the engineer's plan, a condition survey and monitoring in writing, carried by the owner's team.

Example 2 · priced per foot of wall

Both party walls of a rowhouse

The same basement with both party walls underpinned in one continuous visit.

Walls
2 × 40 ft = 80 ft
Pits
20 (80 ft ÷ 4 ft per pit)
Depth
about 4 ft below the old footing, as the book prices it
Priced
per foot of wall
Visits
1, so one mobilization

  • Underpinning, per foot of wall

    80 LF × $1,700 / $2,200 / $3,100

    UP-PIT-POUR-LF

    Low
    $136,000
    Typical
    $176,000
    High
    $248,000

  • Mobilization, compact spread

    1 visit × $8,750 / $12,500 / $18,250

    MOB-COMPACT

    Low
    $8,750
    Typical
    $12,500
    High
    $18,250

  • Design, inspection and monitoring

    Engineer of record and the owner's team. Not in ESC's price.

Budget for the underpinning

Low
$144,750
Typical
$188,500
High
$266,250

Budget: $144,750–266,250 · typical $188,500

  • One mobilization covers both walls when they are done in one visit. Phase them apart (one side now, the other once the neighbor signs off) and the second visit carries its own.

Example 3 · priced per foot of wall

Lowering a triple-decker basement

Taking a detached triple-decker's basement floor down, with every perimeter wall underpinned.

Footprint
25 × 50 ft
Perimeter wall
150 ft = 2 × (25 + 50)
Pits
38 (150 ft ÷ 4 ft per pit, rounded up)
Depth
about 4 ft below the old footing, as the book prices it
Priced
per foot of wall
Visits
1, so one mobilization

  • Underpinning, per foot of wall

    150 LF × $1,700 / $2,200 / $3,100

    UP-PIT-POUR-LF

    Low
    $255,000
    Typical
    $330,000
    High
    $465,000

  • Mobilization, compact spread

    1 visit × $8,750 / $12,500 / $18,250

    MOB-COMPACT

    Low
    $8,750
    Typical
    $12,500
    High
    $18,250

  • Design, inspection and monitoring

    Engineer of record and the owner's team. Not in ESC's price.

Budget for the underpinning

Low
$263,750
Typical
$342,500
High
$483,250

Budget: $263,750–483,250 · typical $342,500

  • Perimeter walls only. Interior column footings are separate: usually new footings by the builder, or underpinned to the engineer's detail and priced per pit.
  • Past about $250,000, the book itself says to get a firm quote from the drawings rather than carry a budget.

Example 4 · priced per pit

One wall at a new addition or opening

A 20 ft run of existing foundation beside an addition whose footings go deeper, or under a new opening.

Wall
20 ft
Pits
5 (20 ft ÷ 4 ft per pit)
Depth
about 4 ft below the old footing, as the book prices it
Priced
per pit
Visits
1, so one mobilization

  • Underpinning, per pit

    5 pits × $7,000 / $8,900 / $12,500

    UP-PIT-POUR-EA

    Low
    $35,000
    Typical
    $44,500
    High
    $62,500

  • Mobilization, compact spread

    1 visit × $8,750 / $12,500 / $18,250

    MOB-COMPACT

    Low
    $8,750
    Typical
    $12,500
    High
    $18,250

  • Design, inspection and monitoring

    Engineer of record and the owner's team. Not in ESC's price.

Budget for the underpinning

Low
$43,750
Typical
$57,000
High
$80,750

Budget: $43,750–80,750 · typical $57,000

  • Short runs are easiest to count in pits: take the count off the engineer's plan and use the per-pit price.

03 · What moves the number

What moves an underpinning number

Where the book prices the condition, its figure is shown. Where it doesn't, the factor says who carries it.

  1. How deep you lower

    The per-pit and per-foot prices assume pits about 4 ft below the old footing. Take the floor lower and the pits go deeper, so price them by the cubic yard: at the book’s per-CY rate, each extra foot adds about $1,750–3,150 per pit.

    In the book · UP-PIT-POUR: $3,550–6,450 per CY

  2. Pit width and count

    The engineer sets the pit width and the sequence. Narrower pits mean more of them per foot of wall, and every pit carries its own setup, shoring, dowels and dry-pack. Count the pits on the plan and price them per pit.

  3. Hand or machine access

    The pits are dug by hand either way. Access decides everything around them: whether a small machine can reach the basement for the dig-out, how concrete gets to each pit (pump line or buggies), and how far everything is carried. The book’s range reads it this way: “Low end: open site, repetitive work, good ground, larger quantities. High end: tight access, obstructions, variable ground, small quantities.”

  4. Getting the spoil out

    In a rowhouse, soil leaves by bucket, by conveyor through a window or bulkhead, or by machine where one fits, and how far it is carried moves the number. Off-site haul of clean spoil is an allowance line billed against tickets; contaminated soil is handled by others.

    In the book · SPOIL-HAUL: $71.50–100 per ton

  5. Groundwater and the GCOD

    Pumping a sump inside ESC’s own pits is a book item; wellpoints, treatment and discharge permits are by others. In Boston’s Groundwater Conservation Overlay District, many buildings stand on wood piles that have to stay wet. A dig-out there typically has to show it will not lower groundwater, and any wood-pile cutoff the lowering reaches is the engineer’s detail, priced per job. Building below grade in the GCOD

    In the book · DW-SUMP: $510–855 per day, minimum $2,700

  6. Rock, ledge or an old foundation

    The pit price assumes soil you can dig by hand. Ledge, boulders, rubble or an old foundation in a pit is a changed condition: paid at the book’s unit prices where one fits, otherwise at its time-and-materials rates.

  7. How many visits

    One mobilization covers one continuous visit. Phasing the work (one party wall now and the other later, or pits held while the neighbor’s engineer reviews) adds a mobilization each time the crew comes back.

    In the book · MOB-COMPACT: $8,750–18,250 per visit

  8. Engineering and monitoring

    The engineer of record designs the underpinning and inspects the bearing at each pit. The neighbors will want a pre-construction condition survey and monitoring. All of it sits outside ESC’s price. What the neighbors will ask for

  9. Permits

    Permits and fees are by others, and a basement lowering in Boston can need several. A dumpster, conveyor or concrete pump in the street usually needs a street occupancy permit of its own. Permits for below-grade work in Boston

  10. Winter concrete

    Pouring pits in cold weather means heated water, blankets and enclosures. The book carries that as a percentage on the affected items, only when the weather calls for it.

    In the book · ADD-WINTER: 4–12% on the affected items

Ground and groundwater change block by block. For what to expect in a neighborhood, see Back Bay, South Boston and Beacon Hill.

04 · Who carries what

Who carries what on a basement lowering

ESC's scope is the underpinning. The builder or GC carries the job around it, the way the book scopes its items.

ESC: the underpinning

ESC's scope as the book prices it.

  • Hand excavation of each pit, in the engineer's sequenceUP-PIT-POUR
  • Timber shoring in the pit as it goes downUP-PIT-POUR
  • Dowels, concrete, and dry-pack tight to the old footingUP-PIT-POUR-EA
  • A sump pump in ESC's own pits when water comes inDW-SUMP
  • One mobilization for each continuous visitMOB-COMPACT
  • A competent person on site; excavation to OSHA Subpart PGeneral Conditions §2
  • Installation logs and concrete tickets for every pitGeneral Conditions §2

The builder or GC: everything around it

Not in ESC's figures. Carry it in your own budget.

  • Breaking out the old slab and digging the basement down§4: excavation by others
  • The new slab, footings and structure§4: concrete structures by others
  • Waterproofing and under-slab drainageNo ESC item
  • Shoring or needling the building aboveNot in the pit price
  • Utilities: finding, supporting and relocating them§4: utilities by others
  • Dewatering beyond a pit sump, treatment and discharge§4: dewatering by others
  • Design and stamp by the engineer of record; testing and inspection§4 and §9
  • Condition surveys of the neighbors, and monitoring§4: by others
  • Permits, survey and layout§4: by others

Checked against the book: the pit-and-pour item’s own description sets what its price includes, and the book’s General Conditions list what is by others. Nothing in ESC’s price covers waterproofing or shoring the building above, so those stay with the builder.

05 · National figures

Why national cost websites show much lower numbers

Search for underpinning costs and most national figures price a different job: helical or push piers set beside a settling suburban house. Lowering a Boston basement under its party walls is sequenced hand work inside the building, so the two do not compare per pier.

What national cost figures usually price

The method
Helical piers screwed in, or push piers jacked in, beside the old footing
The goal
Stop a settling house from going down further
Where the crew works
Outside, from the yard, often with a machine
The pace
A handful of piers
Who it is built for
Sold to the homeowner

What a Boston basement lowering needs

The method
Pits dug by hand under the old footing, shored, filled with concrete and dry-packed
The goal
Take the basement floor below the old footings without moving the building
Where the crew works
Inside the basement, under the building's own walls, often party walls shared with a neighbor
The pace
One round of pits at a time, in the engineer's sequence, often dozens of pits
Who it is built for
Built for the builder or GC, to the engineer of record's stamped design

06 · What we need

What ESC needs to price yours

Four things turn this budget into a firm number for your job.

  1. 01

    The address

    It tells us the ground, the neighbors, and whether the GCOD applies.

  2. 02

    The drawings

    Architectural and structural, with the engineer's underpinning plan, sections and pit sequence.

  3. 03

    Borings or test pits

    Or the geotechnical report, if there is one.

  4. 04

    The depth of lowering

    Existing floor and footing elevations, and the new floor level.

Send them and ESC returns a firm, itemized underpinning quote within 3 business days.

Helpful too: how crews and concrete get in (bulkhead, front door or rear yard), the headroom, and your schedule.

Send drawings for a firm quote

Or email plans to bids@earthsupportcorp.com

Homeowner? ESC works as the underpinning subcontractor to your builder or general contractor. Ask them to send us the drawings.

Budgeting the rest of a below-grade job, such as soldier piles, soil nails or drilled piers? The budget estimator prices those from the same book

07 · FAQ

Underpinning costs in Boston: common questions

How much does underpinning cost in Boston?
Conventional pit-and-pour underpinning budgets at $1,700–3,100 per foot of wall, or $7,000–12,500 per pit, plus mobilization, in ESC's published price book (rev 1, issued Sep 14, 2026). One 40 ft rowhouse party wall comes to $76,750–142,250 with mobilization. These are budget figures, not a quote.
How much does it cost to lower a basement in Boston?
The underpinning is the part ESC prices. Underpinning both party walls of a rowhouse budgets at $144,750–266,250, and the full perimeter of a 25 × 50 ft triple-decker at $263,750–483,250, each with mobilization. The builder's dig-out, new slab, waterproofing, engineering and permits come on top and are not in these figures.
What does the per-pit price include?
One pit about 4 ft wide, dug by hand to about 4 ft below the existing footing, with timber shoring in the pit, dowels, concrete and dry-pack tight to the underside of the footing. It budgets at $7,000–12,500 per pit, with a minimum charge of $8,900 per job. Design, the basement dig-out, the slab, waterproofing, dewatering beyond a pit sump and off-site haul are not included.
What makes underpinning cost more?
Depth first: each foot deeper than the book's pit adds about $1,750–3,150 per pit at the per-cubic-yard rate. Then narrower pits (more of them per foot of wall), tight access and a long carry out, water in the pit, rock or old foundations in the pit, and extra visits, each of which carries its own mobilization.
Why do national underpinning cost figures look so much lower?
National cost sites mostly price helical or push piers set beside a settling suburban house, a few at a time, from outside. Lowering a Boston basement is different work: sequenced pits dug by hand under the building's own walls, often party walls shared with a neighbor, each shored and filled with concrete. The two should not be compared per pier.
Who designs the underpinning?
The project's structural engineer of record. The engineer sets the pit width, depth, dowels and sequence and stamps the drawings, and ESC builds to that design. The engineer's fee, inspections and any monitoring are carried outside ESC's price.
Does ESC work directly for homeowners?
No. ESC is the underpinning subcontractor to builders and general contractors. If you are a homeowner planning a dig-out, ask your builder or GC to send us the drawings, and we will price the underpinning for them.
Do you price micropiles or line drilling?
Not from the book. Neither is in the current edition, so both are priced per job from the drawings.
How current are these prices?
They are computed from rev 1 of ESC's Unit Price Package, issued Sep 14, 2026 and valid through Dec 13, 2026. For a firm, itemized number, send drawings and borings: ESC returns a quote within 3 business days.

Send the drawings. Get a firm number.

Plans, borings and the depth you are lowering to. ESC returns a firm, itemized underpinning quote within 3 business days, to the builder or general contractor.

Get a firm underpinning quote+1 978 846 6851

Or email plans to bids@earthsupportcorp.com

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