Live ground-source payback with a dig-vs-drill loop field sketch - because the buried loop is usually the real project, not the indoor unit sticker.
Planning sketch only. Not a soil test, Manual J load, or drilling bid.
By Ahmet C. Toplutaş·Site owner & editor · Energy & home tools
Last updated May 21, 2026 · Reviewed May 21, 2026 · Planning estimates only - not tax, medical, or investment advice
01
People search “geothermal heat pump cost” and picture swapping a furnace for a box in the basement. Ground-source systems bury a large share of the spend in the ground loop - horizontal trenches or vertical boreholes - plus design, drilling access, restoration, and commissioning. An equipment sticker without the loop field is not a bid you can sign.
Loop cost scales with home load (roughly tons of capacity), soil and rock conditions, and whether the lot can absorb horizontal runs or needs vertical depth. The indoor heat pump is one line item; the field is often the dominant line on rural and cold-climate quotes. This page keeps that split visible so payback math does not pretend the loop is free.
Capacity here uses a planning rule (~550 sq ft per ton) from square footage and climate HDD/CDD presets - not Manual J. Use the sketch to compare dig vs drill and incumbent fuels; paste a contractor total into the override when you have one.
Decision framing: “Can my lot dig or must I drill - and what does that do to payback?” - not “the heat pump listing online is $X, so that is the project.” Anchor usage with home energy if sq ft alone feels thin.
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The panel’s loop field sketch is the unique control. Horizontal (“dig”) converts tons into trench feet (~500 ft per ton planning rule) and checks whether a typical open-yard run (~180 ft usable length in the panel) can absorb the layout without stacking loops unrealistically. Vertical (“drill”) budgets total bore depth (~175 ft per ton) when surface area is the bottleneck - city lots, rocky yards, or preserved landscaping.
Digging is not automatically cheaper than drilling - soft soil long trenches can beat multiple deep bores, while hard rock makes horizontal impractical at any price. The sketch flags yard-fit (enough linear feet) separately from dollar cost so you do not force horizontal geometry onto a lot that physically cannot host it.
That yard-fit teaching moment is why this page is not a macro plate remix or battery runtime clock - you are sizing buried pipe, not reshuffling grams or outage hours.
Wetlands, utility easements, and setback rules can veto a trench run that looks fine on paper. Vertical bore fields still need staging room for drill rigs and grout trucks - “drill” is not zero surface footprint. Loop designers add header pits, manifold vaults, and fusion joints that never appear on heat-pump spec sheets.
03
Annual operating cost compares geothermal COP assumptions (roughly 3.9 heat / 4.5 cool in the panel) against what you would have paid with gas, oil, propane, electric resistance, or a modern air-source heat pump. Savings = incumbent bill − GSHP bill. There is no universal “geothermal saves $2,000” - only savings versus your baseline fuel and tariff.
Versus a modern air-source heat pump (ASHP), geothermal’s bill advantage shrinks - COP gaps narrow, equipment cost is lower on ASHP, and you may still buy loop longevity and cold-climate steadiness, but payback lengthens. Versus oil, propane, or resistance heat, the sketch usually looks sharper because incumbent $/MMBtu is punishing.
Cooling-heavy southern homes still pay loop cost for heating-capable fields even when cooling dominates - check the Cooling-heavy preset and compare incumbent electric AC + gas backup stories honestly.
Fuel price inputs ($/MMBtu sketches for gas, oil, propane) move annual savings faster than COP tweaks. A cold winter with propane spike can shorten payback; mild winters with cheap gas do the opposite. Re-run the panel when your utility bill proves the incumbent line wrong - do not trust default fuel forever.
04
The incentive % reduces net installed cost for simple payback (years = net cost ÷ annual savings). Federal residential clean-energy credits, state rebates, and utility programs change with legislation and income limits - the dial is a planning knob, not eligibility verification.
Paste a contractor’s all-in installed total into the override when you have a proposal. Soil conductivity, groundwater, existing duct condition, and asbestos abatement laugh at spreadsheet defaults. Domestic-content adders and itemized loop vs equipment credits may apply differently than one flat % - read your quote’s line items.
Simple payback ignores financing cost, maintenance, and rising fuel prices - it is a first filter, not a lifecycle NPV. Pair with efficiency upgrades if the home leaks more heat than the loop can afford to overcome cheaply.
05
Example A - Suburb 2k, horizontal dig. Tap Suburb 2k preset: 2,000 sq ft · mixed climate · dig · gas incumbent.
Tons ≈ 2,000 ÷ 550 = ~3.6 tons · Trench ≈ 3.6 × 500 = ~1,800 ft · Typical yard run ~180 ft → sketch flags whether horizontal layout fits without fantasy stacking. Note loop vs equipment $ split on the panel before you trust payback.
Flip Dig → Drill on the same home: bore ≈ 3.6 × 175 = ~630 ft vertical depth budget - loop cost and field geometry change while sq ft stays put.
Example B - Tight lot, vertical. Urban preset: 1,600 sq ft · cold · drill.
Tons ≈ ~2.9 · Bore ≈ 2.9 × 175 = ~508 ft - the sketch exists so you do not force 1,450 ft of horizontal trench onto a city lot that only has driveway margins.
Example C - Vs air-source incumbent. Same Suburb preset; switch incumbent to Air-source HP.
Annual savings shrink because baseline COP improves (panel uses ~2.6 heat / 3.5 cool for ASHP vs ~3.9 / 4.5 for GSHP on the same loads). Payback stretches - that honesty prevents buying a loop project while comparing against outdated resistance heat math.
Large home preset (3,200 sq ft · oil incumbent) pushes tons toward ~5.8 and trench toward ~2,900 ft on dig - loop share of installed cost dominates. Use that preset when someone says “geothermal is just a fancy furnace” without quoting the field.
Maintenance sketches often assume long loop life with indoor unit service every few years - neglected filters and flow issues erode COP before the loop fails. Operating savings in the panel are steady-state; they do not include financing interest or major duct retrofits.
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No. Ground-source systems bury most of the money in the ground loop (trenching or boreholes), not only in the indoor unit. The panel splits equipment vs loop on purpose so a “heat pump quote” is never mistaken for a turnkey geothermal install.
Horizontal loops need long shallow trenches and open yard. Vertical loops need deep boreholes and much less surface area. The field sketch converts tonnage into trench feet or bore feet and flags whether a typical suburban lot can absorb a horizontal layout - that yard-fit check is the unique job of this page.
Roughly 1 ton per 500–600 sq ft is a planning sketch, not a Manual J load calculation. Insulation, windows, orientation, and duct design can swing sizing. Treat tons as editable; replace them with an HVAC design load before you bid.
Not always. Payback vs your incumbent fuel is one lens. Comfort, quiet operation, long equipment life, and incentive timing matter too. If you already have a high-efficiency cold-climate air-source heat pump, savings versus geothermal shrink - compare honestly.
No. Federal ITC / state rebates / utility programs change by year and eligibility. The incentive % dial is a planning lever - paste your actual net after credits before calling the number a deal.
No. Soil conductivity, rock, groundwater, permitting, and drilling access dominate real bids. Use this page to learn dig-vs-drill tradeoffs and order-of-magnitude payback, then get a site-specific geothermal contractor estimate.
LIVE GSHP SKETCH
Sticker ≠ loop ↓Home presets
Dig vs drill
Climate
Incumbent system
Updates live. Heat-pump sticker ≠ ground-loop project. Planning sketch — not a drill bid.
Simple payback
24.8 yr
$722/yr vs Gas furnace + AC · net $17,885 after 30% · ~3.5 ton
LOOP FIELD SKETCH · DIG
≈ 9.7 passes of a 180 ft yard run. Yard-fit looks tight — vertical bores (drill) are usually the honest path.
EQUIPMENT
$15,750
LOOP FIELD
$9,800
38% of plant+loop
INCUMBENT $/YR
$3,388
GSHP $/YR
$2,667
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