A 38 m2 modular home with a heat pump averages 380 kWh of electricity and 6 m3 of water per month — about EUR 100 in bills for a couple. We show real consumption by season, size and finish level so you know what living in your home will actually cost.
This is the first surprise for most customers: a modern modular home with proper insulation and a heat pump uses less energy than an old 70 m2 cottage with a coal stove. Three reasons: a small footprint, good thermal insulation, and a factory-built envelope.
This article shows estimated consumption: what you pay each month for electricity and water, how it depends on season and size, and how a solar array plus a heat pump cut the bill to a minimum. All numbers are calculated at 2026 retail prices: EUR 0.21 per kWh for electricity (retail rate after the price cap ends) and EUR 3.10 per cubic meter for water with sewage.
Heating is the main driver. In summer, electricity goes only to lighting, cooking, air conditioning and hot water. In winter you add the heat pump or electric heaters — and those dominate the bill.
The table below shows real monthly electricity use for a 38 m2 Premium home (energy class A, air-to-water heat pump):
| Season | Monthly kWh | Bill (EUR 0.21 per kWh) |
|---|---|---|
| Winter (Dec – Feb) | 620 – 720 kWh | EUR 131 – 152 |
| Spring-autumn (Mar – May, Sep – Nov) | 320 – 420 kWh | EUR 68 – 89 |
| Summer (Jun – Aug) | 180 – 240 kWh | EUR 38 – 51 |
| Yearly monthly average | ~380 kWh | ~EUR 80 |
The key to a lower winter bill is proper insulation and air tightness. In Year-round modular home — how insulation works we show exactly where a modular home loses energy and how to fix it at the ordering stage.
Size is the main variable. The table below collects the yearly monthly average for all five models in our lineup:
| Model | Size | Avg. kWh/mo | Avg. bill/mo |
|---|---|---|---|
| Container 14 m2 (seasonal) | 14 m2 | 90 – 150 kWh | EUR 19 – 32 |
| Container 29 m2 (year-round) | 29 m2 | 240 – 320 kWh | EUR 51 – 68 |
| Home 38 m2 Standard | 38 m2 | 340 – 420 kWh | EUR 72 – 89 |
| Home 38 m2 Premium (heat pump) | 38 m2 | 300 – 380 kWh | EUR 63 – 80 |
| Home 74 m2 Standard | 74 m2 | 620 – 780 kWh | EUR 131 – 165 |
We treat the 14 m2 container as a seasonal object — used from April to October. In winter, if you want to live in it full time, consumption climbs to ~380 kWh/mo due to heat losses (less thermal mass than a 38 m2 home).
More on heating and how to compare heat sources in Heating in a modular home — heat pump, air conditioning or radiators?
Water use does not depend on the home type — it depends on the number of residents and their habits. A modular home with one bathroom and standard fittings (aerator taps, 3/6 L WC) generates:
| People | Monthly m3 | Bill (EUR 3.10 per m3) |
|---|---|---|
| 1 person (single) | 2.5 – 3.5 m3 | EUR 8 – 11 |
| 2 people (couple) | 5 – 7 m3 | EUR 16 – 22 |
| 3 people | 8 – 10 m3 | EUR 24 – 31 |
| 4 people | 10 – 14 m3 | EUR 31 – 43 |
| Container 14 m2 rented on weekends | 1 – 2 m3 | EUR 3 – 7 |
A private well brings the drinking-water bill to zero (aside from ~EUR 1/mo for pump electricity), but adds the cost of a septic tank or home wastewater treatment plant: EUR 9 to 18 per month for emptying every 4 to 6 weeks. For a family of four in an off-grid location this makes sense when a water-main connection would cost more than EUR 4,400.
The table below collects annual utility costs for four typical scenarios — full-time living and seasonal rental:
| Scenario | Electricity/yr | Water/yr | Sewage | Total/yr | Monthly |
|---|---|---|---|---|---|
| Home 38 m2 Standard, 2 ppl year-round | EUR 960 | EUR 160 | EUR 80 | EUR 1,200 | EUR 100 |
| Home 38 m2 Premium (HP + PV 4 kW), 2 ppl | EUR 265 | EUR 160 | EUR 80 | EUR 505 | EUR 42 |
| Home 74 m2 Standard, 4 ppl year-round | EUR 1,785 | EUR 400 | EUR 160 | EUR 2,345 | EUR 195 |
| Home 14 m2 seasonal (May – Sep), 2 ppl weekends | EUR 160 | EUR 40 | EUR 55 | EUR 255 | EUR 21 |
The gap between Standard and Premium (about 58 percent lower annual bill for the same size) comes from two things: the heat pump (COP ~4, so 1 kWh of electricity makes 4 kWh of heat) and the 4 kW solar array (production about 4,000 kWh per year, offsetting 80 to 95 percent of yearly consumption).
4 kW solar array — cost about EUR 4,000, production ~4,000 kWh per year. For a 38 m2 home the yearly offset is 80 to 95 percent. Payback: four to six years at 2026 electricity prices. Full details in Solar panels for a modular home — cost and payback.
Air-to-water heat pump — a EUR 7,800 upgrade over electric heaters. Winter savings: EUR 67 to 111 per month, under EUR 25 in summer. Payback: six to eight years, but it guarantees thermal comfort at -20 C outside.
Private well plus home wastewater treatment plant — cost EUR 5,500 to 8,900. Makes sense when the plot is off-grid or when a water-main connection costs more than EUR 4,400. In the Rumia, Reda and Wejherowska area the ground is often suitable for a well starting from a 20 meter depth.
Small things that work:
The real monthly electricity + water bill for a 38 m2 Standard modular home for two people is about EUR 100 per month — roughly EUR 3.30 per day. Less than a typical car loan payment. A Premium home with a solar array and heat pump drops to EUR 42 per month, which is essentially just fixed fees plus water.
These are 2026 numbers, at electricity prices of EUR 0.21 per kWh (retail rate after the price cap ends) and water at EUR 3.10 per cubic meter (average for the Gdynia, Reda, Rumia and Gdańsk area). Looking ahead: electricity — further increases of 3 to 5 percent per year, so solar becomes ever more attractive; water — increases of 5 to 8 percent per year, so a private well pays back faster than it did three years ago.
Want an exact forecast for your model and location? Contact us — we prepare an annual utilities estimate for a similar climate zone.
On average 340 to 420 kWh per month for a Standard home with electric heaters, or 300 to 380 kWh for a Premium with a heat pump. That is about EUR 72 to 89 per month at the 2026 retail price of EUR 0.21 per kWh.
The winter bill (December to February) runs EUR 131 to 152 per month for a 38 m2 home with a heat pump. Electric heaters without a heat pump: EUR 178 to 244 per month. The key is insulation and air tightness, not just size.
Ten to fourteen cubic meters per month, or EUR 31 to 43 at EUR 3.10 per cubic meter (water with sewage). Consumption depends on habits, not on home type — a modular home does not use more than a brick one.
Yes, especially for year-round homes. A 4 kW system for EUR 4,000 produces about 4,000 kWh per year and offsets 80 to 95 percent of consumption. Payback: four to six years at 2026 electricity prices.
About EUR 2,345 per year (EUR 195 per month) for a family of four in a Standard home with electric heaters. The Premium version with a heat pump and solar array: EUR 930 to 1,110 per year.
We prepare a yearly utilities estimate. No obligation.
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