Worked examples · October 2026 gas prices
Three fictional but realistic facilities – a warehouse, a supermarket and a workshop – each with three levels: a small local leak, a medium leak and a large, widespread one. Energy, forints, the one-off fix cost and the five-year result, with ranges and an open method.
01 / Basis of the calculation
Estimate 9 October 2026
40.4Ft/kWh
October 2026 business natural-gas price: net, marginal, all-in
Range: 32.1–56.9 Ft/kWh · ≈ 338–599 Ft/m³ (central ≈ 425 Ft/m³)
The “invoice kWh” is the unit on the Hungarian gas invoice (MJ/3.2504); 1 m³ = 10.52 invoice kWh. The fixed capacity fee cannot be saved and is excluded. The contract mark-up is an assumption: always treat your own invoice as authoritative.
Sources: TTF quotes · MVM Basic · NAV · ERA5 / Open-Meteo
Ft per invoice kWh. “Flat price” and “curve” are the upper and lower bound of the five-year result.
02 / The examples
Illustrative example – not real measurement data.
60 × 40 m, 9 m high, sandwich-panel walls and roof (older, U ≈ 0.35), 16 °C, gas radiant-tube heating, 4 dock doors + 2 sectional doors, Nyíregyháza area.
One dock-seal side pad torn, one sectional-door bottom seal missing, 6 m² wet roof insulation.
Cost in one heating season
HUF 120,000
price range HUF 93–160k · with weather, efficiency and defect size (P10–P90): HUF 82–190k
Heat loss
0.6 kW
season average · 47 W/K
Heat and gas
2,100 kWh
≈ 270 m³ natural gas
Share of the heating bill
1.5%
≈ 530 kg CO₂
One-off fix
HUF 520,000
range HUF 0.3–1.0M
Payback (fix only)
54 mo
on the forward curve: 70 mo · best–worst: 19–187
5-year net (savings − fix)
+HUF 61k
flat price · curve: −HUF 67k
| Finding (quantity) | Mean W | kWh | m³ | Ft/season | Fix | Payback | Prio. |
|---|---|---|---|---|---|---|---|
| Dock 3: side pad torn (2.8 m × 40 mm) | 170 | 630 | 83 | 35,000 | 300,000 | 103 mo | C · slow |
| Sectional door 1: bottom seal missing (4.0 m × 15 mm) | 230 | 890 | 120 | 50,000 | 90,000 | 22 mo | A · quick |
| Wet roof insulation near a drain (6 m²) | 150 | 570 | 75 | 32,000 | 130,000 | 50 mo | B · medium |
| Total (joint effect*) | 550 | 2,100 | 270 | 120,000 | 520,000 | 54 mo |
The loss of one gap depends on the others (the air must also get out), so rows and total can differ slightly beyond rounding. *Fix and payback columns of the total row use the sum of the item fix costs. Prio.: A ≤ 24 months, B ≤ 60 months, C otherwise.
| year | Flat gas price (40.4 Ft/kWh) | Forward curve (falling) | Quick wins (A) only, flat price |
|---|---|---|---|
| 0 | −HUF 520k | −HUF 520k | −HUF 90k |
| 1 | −HUF 410k | −HUF 410k | −HUF 40k |
| 2 | −HUF 290k | −HUF 300k | +HUF 10k |
| 3 | −HUF 170k | −HUF 220k | +HUF 59k |
| 4 | −HUF 55k | −HUF 150k | +HUF 110k |
| 5 | +HUF 61k | −HUF 67k | +HUF 160k |
| Payback | ≈ 54 mo | no payback within 5 years | ≈ 22 mo |
Cumulative savings minus the one-off fix (and optionally the survey). The solid orange line is the flat price, the dashed indigo line the falling forward curve; the shaded area between them is the price uncertainty. The point where a line crosses zero is the payback.
1 of 3 items: Sectional door 1: bottom seal missing (4.0 m × 15 mm)
Probably not worth it
The survey price alone exceeds what the findings save over five years. If you order a survey for another reason anyway, the quick wins are worth fixing.
3 dock seals faulty, 2 sectional doors with worn seals, 35 m of failed wall-panel joint, 35 m² wet roof insulation, 45 m eaves / slab-edge thermal-bridge run.
Cost in one heating season
HUF 620,000
price range HUF 490–880k · with weather, efficiency and defect size (P10–P90): HUF 0.4–1.1M
Heat loss
2.9 kW
season average · 250 W/K
Heat and gas
11,000 kWh
≈ 1,500 m³ natural gas
Share of the heating bill
7.6%
≈ 2,800 kg CO₂
One-off fix
HUF 2,700,000
range HUF 1.4–5.2M
Payback (fix only)
52 mo
on the forward curve: 67 mo · best–worst: 19–178
5-year net (savings − fix)
+HUF 430k
flat price · curve: −HUF 260k
| Finding (quantity) | Mean W | kWh | m³ | Ft/season | Fix | Payback | Prio. |
|---|---|---|---|---|---|---|---|
| Dock 1: both side pads compressed (5.6 m × 30 mm) | 76 | 290 | 38 | 16,000 | 300,000 | 223 mo | C · slow |
| Dock 2: both side pads compressed (5.6 m × 30 mm) | 76 | 290 | 38 | 16,000 | 300,000 | 223 mo | C · slow |
| Dock 3: head curtain missing (2.6 m × 80 mm) | 99 | 380 | 50 | 21,000 | 300,000 | 171 mo | C · slow |
| Sectional door 1: worn perimeter seals (17 m × 8 mm) | 200 | 770 | 100 | 43,000 | 90,000 | 25 mo | B · medium |
| Sectional door 2: worn perimeter seals (17 m × 8 mm) | 200 | 770 | 100 | 43,000 | 90,000 | 25 mo | B · medium |
| Wall-panel joints open (35 m × 2 mm) | 1,300 | 4,800 | 630 | 270,000 | 160,000 | 7 mo | A · quick |
| Wet roof insulation (35 m²) | 870 | 3,300 | 440 | 190,000 | 770,000 | 50 mo | B · medium |
| Eaves / base thermal-bridge run (45 m) | 130 | 500 | 65 | 28,000 | 680,000 | 292 mo | C · slow |
| Total (joint effect*) | 2,900 | 11,000 | 1,500 | 620,000 | 2,700,000 | 52 mo |
The loss of one gap depends on the others (the air must also get out), so rows and total can differ slightly beyond rounding. *Fix and payback columns of the total row use the sum of the item fix costs. Prio.: A ≤ 24 months, B ≤ 60 months, C otherwise.
| year | Flat gas price (40.4 Ft/kWh) | Forward curve (falling) | Quick wins (A) only, flat price |
|---|---|---|---|
| 0 | −HUF 2.7M | −HUF 2.7M | −HUF 160k |
| 1 | −HUF 2.1M | −HUF 2.1M | +HUF 110k |
| 2 | −HUF 1.4M | −HUF 1.5M | +HUF 380k |
| 3 | −HUF 820k | −HUF 1.1M | +HUF 650k |
| 4 | −HUF 190k | −HUF 680k | +HUF 920k |
| 5 | +HUF 430k | −HUF 260k | +HUF 1.2M |
| Payback | ≈ 52 mo | no payback within 5 years | ≈ 7 mo |
Cumulative savings minus the one-off fix (and optionally the survey). The solid orange line is the flat price, the dashed indigo line the falling forward curve; the shaded area between them is the price uncertainty. The point where a line crosses zero is the payback.
1 of 8 items: Wall-panel joints open (35 m × 2 mm)
Probably not worth it
The survey price alone exceeds what the findings save over five years. If you order a survey for another reason anyway, the quick wins are worth fixing.
All 4 dock seals failed + leveler pits, all door seals poor, ridge and skylight gaps, 90 m of wall-panel joints, 140 m² wet roof insulation (≈ 6% of the roof), 120 m of thermal bridges (column bases, eaves).
Cost in one heating season
HUF 2,700,000
price range HUF 2.2–3.9M · with weather, efficiency and defect size (P10–P90): HUF 1.9–4.5M
Heat loss
13.0 kW
season average · 1,100 W/K
Heat and gas
49,000 kWh
≈ 6,400 m³ natural gas
Share of the heating bill
26.6%
≈ 12,000 kg CO₂
One-off fix
HUF 8,900,000
range HUF 5–17M
Payback (fix only)
39 mo
on the forward curve: 48 mo · best–worst: 15–131
5-year net (savings − fix)
+HUF 4.8M
flat price · curve: +HUF 1.8M
| Finding (quantity) | Mean W | kWh | m³ | Ft/season | Fix | Payback | Prio. |
|---|---|---|---|---|---|---|---|
| Dock 1: seal failed (7.6 m × 26 mm) | 87 | 330 | 43 | 18,000 | 300,000 | 196 mo | C · slow |
| Dock 2: seal failed (7.6 m × 26 mm) | 87 | 330 | 43 | 18,000 | 300,000 | 196 mo | C · slow |
| Dock 3: seal failed (7.6 m × 26 mm) | 87 | 330 | 43 | 18,000 | 300,000 | 196 mo | C · slow |
| Dock 4: seal failed (7.6 m × 26 mm) | 87 | 330 | 43 | 18,000 | 300,000 | 196 mo | C · slow |
| 4 leveler-pit side gaps (4 × 3.0 m × 15 mm) | 310 | 1,200 | 160 | 66,000 | 600,000 | 109 mo | C · slow |
| Sectional door 1: perimeter seals (17 m × 8 mm) | 200 | 750 | 99 | 42,000 | 90,000 | 26 mo | B · medium |
| Sectional door 2: perimeter seals (17 m × 8 mm) | 200 | 750 | 99 | 42,000 | 90,000 | 26 mo | B · medium |
| 4 dock-door perimeter gaps when closed (4 × 8.2 m × 5 mm) | 180 | 680 | 90 | 38,000 | 360,000 | 113 mo | C · slow |
| Roof-ridge gap (60 m × 3 mm) | 3,200 | 12,000 | 1,600 | 690,000 | 270,000 | 5 mo | A · quick |
| 8 skylight perimeter gaps (80 m × 2 mm) | 2,900 | 11,000 | 1,400 | 610,000 | 960,000 | 19 mo | A · quick |
| Wall-panel joints open (90 m × 2 mm) | 1,700 | 6,400 | 840 | 360,000 | 410,000 | 14 mo | A · quick |
| Wet / missing roof insulation (140 m²) | 3,500 | 13,000 | 1,700 | 740,000 | 3,100,000 | 50 mo | B · medium |
| Column-base and eaves thermal bridges (120 m) | 350 | 1,300 | 170 | 74,000 | 1,800,000 | 292 mo | C · slow |
| Total (joint effect*) | 13,000 | 49,000 | 6,400 | 2,700,000 | 8,900,000 | 39 mo |
The loss of one gap depends on the others (the air must also get out), so rows and total can differ slightly beyond rounding. *Fix and payback columns of the total row use the sum of the item fix costs. Prio.: A ≤ 24 months, B ≤ 60 months, C otherwise.
| year | Flat gas price (40.4 Ft/kWh) | Forward curve (falling) | Quick wins (A) only, flat price |
|---|---|---|---|
| 0 | −HUF 8.9M | −HUF 8.9M | −HUF 1.6M |
| 1 | −HUF 6.1M | −HUF 6.1M | +HUF 21k |
| 2 | −HUF 3.4M | −HUF 3.7M | +HUF 1.7M |
| 3 | −HUF 650k | −HUF 1.9M | +HUF 3.3M |
| 4 | +HUF 2.1M | −HUF 31k | +HUF 5.0M |
| 5 | +HUF 4.8M | +HUF 1.8M | +HUF 6.6M |
| Payback | ≈ 39 mo | ≈ 48 mo | ≈ 12 mo |
Cumulative savings minus the one-off fix (and optionally the survey). The solid orange line is the flat price, the dashed indigo line the falling forward curve; the shaded area between them is the price uncertainty. The point where a line crosses zero is the payback.
3 of 13 items: Roof-ridge gap (60 m × 3 mm); 8 skylight perimeter gaps (80 m × 2 mm); Wall-panel joints open (90 m × 2 mm)
Probably worth it
Even on the falling gas curve the 5-year net including the survey fee stays positive. The condition: the defects exist and are actually fixed.
50 × 36 m (1,500 m² sales + 300 m² back room), 5 m high, 20 °C, condensing gas boiler + AHU with heat recovery, vestibule entrance with air curtain, 1 rear dock door. Refrigeration waste heat enters only through the lower 12 °C balance temperature.
Rear dock-door bottom seal missing, 8 m² wet flat-roof insulation.
Cost in one heating season
HUF 120,000
price range HUF 94–170k · with weather, efficiency and defect size (P10–P90): HUF 75–190k
Heat loss
0.6 kW
season average · 36 W/K
Heat and gas
2,500 kWh
≈ 280 m³ natural gas
Share of the heating bill
1.6%
≈ 530 kg CO₂
One-off fix
HUF 270,000
range HUF 140–500k
Payback (fix only)
27 mo
on the forward curve: 31 mo · best–worst: 10–86
5-year net (savings − fix)
+HUF 320k
flat price · curve: +HUF 190k
| Finding (quantity) | Mean W | kWh | m³ | Ft/season | Fix | Payback | Prio. |
|---|---|---|---|---|---|---|---|
| Rear dock door: bottom seal missing (2.6 m × 20 mm) | 290 | 1,300 | 140 | 60,000 | 90,000 | 18 mo | A · quick |
| Wet flat-roof insulation (8 m²) | 270 | 1,200 | 140 | 58,000 | 180,000 | 37 mo | B · medium |
| Total (joint effect*) | 560 | 2,500 | 280 | 120,000 | 270,000 | 27 mo |
The loss of one gap depends on the others (the air must also get out), so rows and total can differ slightly beyond rounding. *Fix and payback columns of the total row use the sum of the item fix costs. Prio.: A ≤ 24 months, B ≤ 60 months, C otherwise.
| year | Flat gas price (40.4 Ft/kWh) | Forward curve (falling) | Quick wins (A) only, flat price |
|---|---|---|---|
| 0 | −HUF 270k | −HUF 270k | −HUF 90k |
| 1 | −HUF 150k | −HUF 150k | −HUF 30k |
| 2 | −HUF 30k | −HUF 43k | +HUF 31k |
| 3 | +HUF 88k | +HUF 36k | +HUF 91k |
| 4 | +HUF 210k | +HUF 120k | +HUF 150k |
| 5 | +HUF 320k | +HUF 190k | +HUF 210k |
| Payback | ≈ 27 mo | ≈ 31 mo | ≈ 18 mo |
Cumulative savings minus the one-off fix (and optionally the survey). The solid orange line is the flat price, the dashed indigo line the falling forward curve; the shaded area between them is the price uncertainty. The point where a line crosses zero is the payback.
1 of 2 items: Rear dock door: bottom seal missing (2.6 m × 20 mm)
Probably not worth it
The survey price alone exceeds what the findings save over five years. If you order a survey for another reason anyway, the quick wins are worth fixing.
Dock-door and staff-door seals faulty, entrance air curtain under-performing, 24 m of shopfront-to-wall junction open, 45 m² wet flat roof, 40 m parapet thermal bridge.
Cost in one heating season
HUF 760,000
price range HUF 0.6–1.1M · with weather, efficiency and defect size (P10–P90): HUF 0.5–1.2M
Heat loss
3.6 kW
season average · 230 W/K
Heat and gas
16,000 kWh
≈ 1,800 m³ natural gas
Share of the heating bill
9.3%
≈ 3,400 kg CO₂
One-off fix
HUF 1,900,000
range HUF 1.0–3.5M
Payback (fix only)
29 mo
on the forward curve: 34 mo · best–worst: 11–95
5-year net (savings − fix)
+HUF 1.9M
flat price · curve: +HUF 1.1M
| Finding (quantity) | Mean W | kWh | m³ | Ft/season | Fix | Payback | Prio. |
|---|---|---|---|---|---|---|---|
| Rear dock door: perimeter seals (10.7 m × 6 mm) | 310 | 1,400 | 150 | 65,000 | 90,000 | 17 mo | A · quick |
| Staff door threshold / side gap (5 m × 4 mm) | 91 | 410 | 45 | 19,000 | 30,000 | 19 mo | A · quick |
| Entrance air curtain under-performing (residual 0.28 → 0.60) | 790 | 3,500 | 390 | 170,000 | 45,000 | 3 mo | A · quick |
| Shopfront-to-wall junction open (24 m × 3 mm) | 710 | 3,200 | 350 | 150,000 | 110,000 | 9 mo | A · quick |
| Wet flat-roof insulation (45 m²) | 1,500 | 6,900 | 760 | 330,000 | 990,000 | 37 mo | B · medium |
| Parapet thermal bridge (40 m) | 160 | 700 | 77 | 33,000 | 600,000 | 219 mo | C · slow |
| Total (joint effect*) | 3,600 | 16,000 | 1,800 | 760,000 | 1,900,000 | 29 mo |
The loss of one gap depends on the others (the air must also get out), so rows and total can differ slightly beyond rounding. *Fix and payback columns of the total row use the sum of the item fix costs. Prio.: A ≤ 24 months, B ≤ 60 months, C otherwise.
| year | Flat gas price (40.4 Ft/kWh) | Forward curve (falling) | Quick wins (A) only, flat price |
|---|---|---|---|
| 0 | −HUF 1.9M | −HUF 1.9M | −HUF 270k |
| 1 | −HUF 1.1M | −HUF 1.1M | +HUF 130k |
| 2 | −HUF 350k | −HUF 430k | +HUF 530k |
| 3 | +HUF 410k | +HUF 75k | +HUF 930k |
| 4 | +HUF 1.2M | +HUF 580k | +HUF 1.3M |
| 5 | +HUF 1.9M | +HUF 1.1M | +HUF 1.7M |
| Payback | ≈ 29 mo | ≈ 34 mo | ≈ 8 mo |
Cumulative savings minus the one-off fix (and optionally the survey). The solid orange line is the flat price, the dashed indigo line the falling forward curve; the shaded area between them is the price uncertainty. The point where a line crosses zero is the payback.
4 of 6 items: Rear dock door: perimeter seals (10.7 m × 6 mm); Staff door threshold / side gap (5 m × 4 mm); Entrance air curtain under-performing (residual 0.28 → 0.60); Shopfront-to-wall junction open (24 m × 3 mm)
Probably worth it
Even on the falling gas curve the 5-year net including the survey fee stays positive. The condition: the defects exist and are actually fixed.
Air curtain not working and vestibule inner door left open, all door seals poor, 80 m of open shopfront junction, roof-penetration gaps, 160 m² wet flat roof (≈ 9%), 110 m parapet thermal bridge.
Cost in one heating season
HUF 2,400,000
price range HUF 1.9–3.3M · with weather, efficiency and defect size (P10–P90): HUF 1.5–3.9M
Heat loss
11.0 kW
season average · 720 W/K
Heat and gas
50,000 kWh
≈ 5,600 m³ natural gas
Share of the heating bill
24.2%
≈ 11,000 kg CO₂
One-off fix
HUF 6,300,000
range HUF 3–12M
Payback (fix only)
32 mo
on the forward curve: 38 mo · best–worst: 12–103
5-year net (savings − fix)
+HUF 5.5M
flat price · curve: +HUF 2.9M
| Finding (quantity) | Mean W | kWh | m³ | Ft/season | Fix | Payback | Prio. |
|---|---|---|---|---|---|---|---|
| Rear dock door: perimeter seals (10.7 m × 6 mm) | 520 | 2,300 | 260 | 110,000 | 90,000 | 10 mo | A · quick |
| Staff door threshold / side gap (5 m × 4 mm) | 170 | 750 | 84 | 36,000 | 30,000 | 10 mo | A · quick |
| Air curtain off and vestibule door held open (residual 0.28 → 1.0) | 1,800 | 8,000 | 880 | 380,000 | 500,000 | 16 mo | A · quick |
| Shopfront-to-wall junction open (80 m × 3 mm) | 2,000 | 9,000 | 1,000 | 430,000 | 360,000 | 10 mo | A · quick |
| 4 roof-penetration gaps (8 m × 10 mm) | 810 | 3,600 | 400 | 170,000 | 200,000 | 14 mo | A · quick |
| Wet flat-roof insulation (160 m²) | 5,500 | 25,000 | 2,700 | 1,200,000 | 3,500,000 | 37 mo | B · medium |
| Parapet thermal bridge (110 m) | 430 | 1,900 | 210 | 90,000 | 1,700,000 | 219 mo | C · slow |
| Total (joint effect*) | 11,000 | 50,000 | 5,600 | 2,400,000 | 6,300,000 | 32 mo |
The loss of one gap depends on the others (the air must also get out), so rows and total can differ slightly beyond rounding. *Fix and payback columns of the total row use the sum of the item fix costs. Prio.: A ≤ 24 months, B ≤ 60 months, C otherwise.
| year | Flat gas price (40.4 Ft/kWh) | Forward curve (falling) | Quick wins (A) only, flat price |
|---|---|---|---|
| 0 | −HUF 6.3M | −HUF 6.3M | −HUF 1.2M |
| 1 | −HUF 4.0M | −HUF 4.0M | −HUF 58k |
| 2 | −HUF 1.6M | −HUF 1.9M | +HUF 1.1M |
| 3 | +HUF 740k | −HUF 300k | +HUF 2.2M |
| 4 | +HUF 3.1M | +HUF 1.3M | +HUF 3.3M |
| 5 | +HUF 5.5M | +HUF 2.9M | +HUF 4.4M |
| Payback | ≈ 32 mo | ≈ 38 mo | ≈ 13 mo |
Cumulative savings minus the one-off fix (and optionally the survey). The solid orange line is the flat price, the dashed indigo line the falling forward curve; the shaded area between them is the price uncertainty. The point where a line crosses zero is the payback.
5 of 7 items: Rear dock door: perimeter seals (10.7 m × 6 mm); Staff door threshold / side gap (5 m × 4 mm); Air curtain off and vestibule door held open (residual 0.28 → 1.0); Shopfront-to-wall junction open (80 m × 3 mm); 4 roof-penetration gaps (8 m × 10 mm)
Probably worth it
Even on the falling gas curve the 5-year net including the survey fee stays positive. The condition: the defects exist and are actually fixed.
40 × 25 m, 7 m high, 18 °C, gas warm-air heaters, 1 roller door (4.0 × 4.5 m) + 1 sectional door (3.5 × 3.5 m), process extraction.
Roller-door brush seal worn, 5 m² wet roof insulation.
Cost in one heating season
HUF 99,000
price range HUF 79–140k · with weather, efficiency and defect size (P10–P90): HUF 70–160k
Heat loss
0.5 kW
season average · 39 W/K
Heat and gas
1,900 kWh
≈ 230 m³ natural gas
Share of the heating bill
1.8%
≈ 450 kg CO₂
One-off fix
HUF 140,000
range HUF 75–260k
Payback (fix only)
17 mo
on the forward curve: 18 mo · best–worst: 6–49
5-year net (savings − fix)
+HUF 360k
flat price · curve: +HUF 250k
| Finding (quantity) | Mean W | kWh | m³ | Ft/season | Fix | Payback | Prio. |
|---|---|---|---|---|---|---|---|
| Roller door: brush seal worn (13 m × 6 mm) | 380 | 1,400 | 170 | 72,000 | 30,000 | 5 mo | A · quick |
| Wet roof insulation (5 m²) | 150 | 520 | 65 | 28,000 | 110,000 | 48 mo | B · medium |
| Total (joint effect*) | 530 | 1,900 | 230 | 99,000 | 140,000 | 17 mo |
The loss of one gap depends on the others (the air must also get out), so rows and total can differ slightly beyond rounding. *Fix and payback columns of the total row use the sum of the item fix costs. Prio.: A ≤ 24 months, B ≤ 60 months, C otherwise.
| year | Flat gas price (40.4 Ft/kWh) | Forward curve (falling) | Quick wins (A) only, flat price |
|---|---|---|---|
| 0 | −HUF 140k | −HUF 140k | −HUF 30k |
| 1 | −HUF 41k | −HUF 41k | +HUF 42k |
| 2 | +HUF 59k | +HUF 48k | +HUF 110k |
| 3 | +HUF 160k | +HUF 110k | +HUF 190k |
| 4 | +HUF 260k | +HUF 180k | +HUF 260k |
| 5 | +HUF 360k | +HUF 250k | +HUF 330k |
| Payback | ≈ 17 mo | ≈ 18 mo | ≈ 5 mo |
Cumulative savings minus the one-off fix (and optionally the survey). The solid orange line is the flat price, the dashed indigo line the falling forward curve; the shaded area between them is the price uncertainty. The point where a line crosses zero is the payback.
1 of 2 items: Roller door: brush seal worn (13 m × 6 mm)
Borderline
Positive but thin: with the uncertainty in gas price and defect size it can fall below zero.
Both door seals poor, 25 m of wall-panel joint, 30 m² wet roof, 30 m eaves thermal bridge.
Cost in one heating season
HUF 420,000
price range HUF 330–590k · with weather, efficiency and defect size (P10–P90): HUF 270–730k
Heat loss
2.2 kW
season average · 160 W/K
Heat and gas
7,900 kWh
≈ 980 m³ natural gas
Share of the heating bill
7.3%
≈ 1,900 kg CO₂
One-off fix
HUF 1,300,000
range HUF 0.7–2.5M
Payback (fix only)
39 mo
on the forward curve: 48 mo · best–worst: 15–127
5-year net (savings − fix)
+HUF 750k
flat price · curve: +HUF 290k
| Finding (quantity) | Mean W | kWh | m³ | Ft/season | Fix | Payback | Prio. |
|---|---|---|---|---|---|---|---|
| Roller door: perimeter seals (13 m × 10 mm) | 350 | 1,200 | 150 | 65,000 | 30,000 | 6 mo | A · quick |
| Sectional door: perimeter seals (13 m × 8 mm) | 260 | 940 | 120 | 50,000 | 90,000 | 22 mo | A · quick |
| Wall-panel joints (25 m × 2 mm) | 630 | 2,300 | 280 | 120,000 | 110,000 | 11 mo | A · quick |
| Wet roof insulation (30 m²) | 880 | 3,100 | 390 | 170,000 | 660,000 | 48 mo | B · medium |
| Eaves thermal bridge (30 m) | 100 | 360 | 45 | 19,000 | 450,000 | 281 mo | C · slow |
| Total (joint effect*) | 2,200 | 7,900 | 980 | 420,000 | 1,300,000 | 39 mo |
The loss of one gap depends on the others (the air must also get out), so rows and total can differ slightly beyond rounding. *Fix and payback columns of the total row use the sum of the item fix costs. Prio.: A ≤ 24 months, B ≤ 60 months, C otherwise.
| year | Flat gas price (40.4 Ft/kWh) | Forward curve (falling) | Quick wins (A) only, flat price |
|---|---|---|---|
| 0 | −HUF 1.3M | −HUF 1.3M | −HUF 230k |
| 1 | −HUF 920k | −HUF 920k | +HUF 1k |
| 2 | −HUF 510k | −HUF 550k | +HUF 240k |
| 3 | −HUF 88k | −HUF 270k | +HUF 470k |
| 4 | +HUF 330k | +HUF 7k | +HUF 700k |
| 5 | +HUF 750k | +HUF 290k | +HUF 940k |
| Payback | ≈ 39 mo | ≈ 48 mo | ≈ 12 mo |
Cumulative savings minus the one-off fix (and optionally the survey). The solid orange line is the flat price, the dashed indigo line the falling forward curve; the shaded area between them is the price uncertainty. The point where a line crosses zero is the payback.
3 of 5 items: Roller door: perimeter seals (13 m × 10 mm); Sectional door: perimeter seals (13 m × 8 mm); Wall-panel joints (25 m × 2 mm)
Probably worth it
Even on the falling gas curve the 5-year net including the survey fee stays positive. The condition: the defects exist and are actually fixed.
All door seals poor, ridge gap, 70 m of panel joints, 100 m² wet roof (10%), 80 m of thermal bridges.
Cost in one heating season
HUF 1,300,000
price range HUF 1.0–1.9M · with weather, efficiency and defect size (P10–P90): HUF 0.8–2.3M
Heat loss
7.0 kW
season average · 520 W/K
Heat and gas
25,000 kWh
≈ 3,100 m³ natural gas
Share of the heating bill
19.8%
≈ 6,000 kg CO₂
One-off fix
HUF 4,000,000
range HUF 2.2–7.5M
Payback (fix only)
36 mo
on the forward curve: 45 mo · best–worst: 14–118
5-year net (savings − fix)
+HUF 2.6M
flat price · curve: +HUF 1.1M
| Finding (quantity) | Mean W | kWh | m³ | Ft/season | Fix | Payback | Prio. |
|---|---|---|---|---|---|---|---|
| Roller door: perimeter seals (13 m × 10 mm) | 710 | 2,500 | 310 | 130,000 | 30,000 | 3 mo | A · quick |
| Sectional door: perimeter seals (13 m × 8 mm) | 560 | 2,000 | 250 | 110,000 | 90,000 | 10 mo | A · quick |
| Roof-ridge gap (40 m × 3 mm) | 1,500 | 5,300 | 660 | 280,000 | 180,000 | 8 mo | A · quick |
| Wall-panel joints (70 m × 2 mm) | 1,100 | 3,800 | 470 | 200,000 | 320,000 | 19 mo | A · quick |
| Wet roof insulation (100 m²) | 2,900 | 10,000 | 1,300 | 550,000 | 2,200,000 | 48 mo | B · medium |
| Column-base and eaves thermal bridges (80 m) | 270 | 970 | 120 | 51,000 | 1,200,000 | 281 mo | C · slow |
| Total (joint effect*) | 7,000 | 25,000 | 3,100 | 1,300,000 | 4,000,000 | 36 mo |
The loss of one gap depends on the others (the air must also get out), so rows and total can differ slightly beyond rounding. *Fix and payback columns of the total row use the sum of the item fix costs. Prio.: A ≤ 24 months, B ≤ 60 months, C otherwise.
| year | Flat gas price (40.4 Ft/kWh) | Forward curve (falling) | Quick wins (A) only, flat price |
|---|---|---|---|
| 0 | −HUF 4.0M | −HUF 4.0M | −HUF 620k |
| 1 | −HUF 2.7M | −HUF 2.7M | +HUF 100k |
| 2 | −HUF 1.4M | −HUF 1.5M | +HUF 820k |
| 3 | −HUF 53k | −HUF 640k | +HUF 1.5M |
| 4 | +HUF 1.3M | +HUF 250k | +HUF 2.3M |
| 5 | +HUF 2.6M | +HUF 1.1M | +HUF 3.0M |
| Payback | ≈ 36 mo | ≈ 45 mo | ≈ 10 mo |
Cumulative savings minus the one-off fix (and optionally the survey). The solid orange line is the flat price, the dashed indigo line the falling forward curve; the shaded area between them is the price uncertainty. The point where a line crosses zero is the payback.
4 of 6 items: Roller door: perimeter seals (13 m × 10 mm); Sectional door: perimeter seals (13 m × 8 mm); Roof-ridge gap (40 m × 3 mm); Wall-panel joints (70 m × 2 mm)
Probably worth it
Even on the falling gas curve the 5-year net including the survey fee stays positive. The condition: the defects exist and are actually fixed.
03 / The honest overall picture
The numbers do not argue for our survey; they argue for scale: the loss covers the cost of a survey and the repairs only when enough defects add up.
| Facility | Small (localised) | Medium | Large, widespread |
|---|---|---|---|
| Warehouse / logistics hall · HUF 489,000 | Probably not worth it −HUF 430k | −HUF 560k payback 104 mo | Probably not worth it −HUF 62k | −HUF 750k payback 61 mo | Probably worth it +HUF 4.3M | +HUF 1.3M payback 41 mo |
| Supermarket / retail unit · HUF 423,000 | Probably not worth it −HUF 98k | −HUF 230k payback 70 mo | Probably worth it +HUF 1.5M | +HUF 670k payback 36 mo | Probably worth it +HUF 5.0M | +HUF 2.4M payback 34 mo |
| Workshop / small production hall · HUF 190,000 | Borderline +HUF 170k | +HUF 58k payback 40 mo | Probably worth it +HUF 560k | +HUF 98k payback 44 mo | Probably worth it +HUF 2.4M | +HUF 940k payback 38 mo |
The verdict uses the survey list price and assumes the defects exist – which you cannot know before the survey. “Borderline” means: positive, but on the forward curve less than half the survey fee.
HUF 99–120k per season – 1.5–1.8% of the heating bill. The one-off fix is HUF 140–520k, and the survey price is 2–4 times one season’s loss. So small leaks rarely justify a survey on their own; on the bill they are almost invisible.
HUF 1.3–2.7M per season (20–27% of the bill). The survey price is only 14–18% of the first season’s loss; survey and repairs together pay back in 34–41 months. Over five years the net is +HUF 2.4M to +HUF 5.0M on a flat gas price, and still +HUF 940k to +HUF 2.4M on the falling curve – provided the defects are actually fixed.
A dock gap loses only HUF 16–66k per season, while the repair costs HUF 300,000 per dock: a payback of 103–223 months. Two reasons: the gap only leaks while a trailer is docked with the door open (25% of heated hours, assumption); and air that comes in must also get out, so openings in series pass less than the sum of their parts. A dock seal can have other value (snow, water, dust, pests, comfort, protecting goods) – but that is not energy saving and is not counted here.
From all example findings (52 items, each calculated on its own). The bar spans the smallest to the largest simple payback (flat price), the dot is the middle value. Vertical lines: 24 and 60 months (A/B/C limits).
| Item group | n | Loss/item | Fix/item | Payback (months) |
|---|---|---|---|---|
| Ridge, skylight and roof-penetration gaps | 4 | HUF 280k | HUF 200k | 5–19 mo (mid 8) |
| Panel and façade joints | 6 | HUF 200k | HUF 160k | 7–19 mo (mid 10) |
| Entrance air curtain / vestibule | 2 | HUF 170k | HUF 45k | 3–16 mo (mid 3) |
| Door and gate seals | 16 | HUF 50k | HUF 90k | 3–113 mo (mid 18) |
| Wet roof / wall insulation | 9 | HUF 190k | HUF 770k | 37–50 mo (mid 48) |
| Dock seals and shelters | 9 | HUF 18k | HUF 300k | 103–223 mo (mid 196) |
| Thermal bridges (columns, eaves, parapet) | 6 | HUF 33k | HUF 680k | 219–292 mo (mid 281) |
Quick payback (middle value ≤ 24 months): Ridge, skylight and roof-penetration gaps; Panel and façade joints; Entrance air curtain / vestibule; Door and gate seals. The slow or never-paying items (docks, thermal bridges) are worth fixing for other reasons – fabric protection, comfort, operations – not for the energy bill.
04 / Pipes and electrical
25 m of wetted pre-insulated (PUR) hot line between two buildings (district heat / hot water, 80 °C supply). The leak is DOWNSTREAM of the heat meter, so the loss is billed 1:1.
| Leak | Cost/season | Fix | Payback |
|---|---|---|---|
| 5 l/h | HUF 1.1M(HUF 0.6–1.4M) | HUF 3.0M | 33 mo |
| 50 l/h | HUF 2.1M(HUF 1.2–2.9M) | HUF 3.0M | 17 mo |
| 500 l/h | HUF 13M(HUF 7–18M) | HUF 3.0M | 3 mo |
Heating season (5,342 h), 25 m wetted section, 200 W/m (100–380). The repair (locate, excavate, fix, reinstate) is HUF 1.5M–HUF 6.0M. In year-round operation the cost is ~1.6 times higher. The district-heat fee is a Budapest proxy – we did not find the local tariff.
Phase terminal carrying 160 A with +0.5 mΩ extra contact resistance (one phase; the all-three-phase case is shown separately). 3,000 h per year at that load (assumption).
The energy is negligible. The stake is failure and fire risk, which we do not put a monetary figure on because we have no reliable source for downtime cost. The one sourced fact: of 736 fires investigated in Hungary in 2022, 73 (9.9%) were caused by electrical energy (OKF sample, all building types). This is not an electrical safety inspection.
05 / The data
The tables are generated from the calculation engine’s output; no number is typed by hand. Check them, or recompute with your own prices.
Values in net HUF, excluding VAT. Money and energy are given unrounded (integers) so you can recompute; the page shows 2 significant digits because the estimates are no more precise than that.
The calculator runs the same model with your dimensions and gas price – and tells you whether a survey is worth ordering at all.