---
title: "High Heating Bill? Find the Cause and Reduce It"
canonical_url: https://fremtidenstegnestue.dk/en/knowledge/articles/high-heating-bill
markdown_url: https://fremtidenstegnestue.dk/en/knowledge/articles/high-heating-bill.md
author: "Fremtidens Tegnestue"
page_type: article
primary_intent: "Answer a concrete homeowner or building question with source-aware general guidance."
primary_keyword: "heating bill"
audience: "Homeowners, studios and agents researching a concrete building topic."
summary: "Paying too much for heating? Here are the typical causes of a high heating bill — and concrete steps to reduce it without freezing."
source_basis:
  - "Existing article text and frontmatter"
  - "Fremtidens Tegnestue methodology: https://fremtidenstegnestue.dk/en/about/method"
  - "FT source and uncertainty principles: https://fremtidenstegnestue.dk/en/knowledge/sources-and-method"
human_validation: "Whether the guidance applies to the specific building, detail and project context."
responsibility_line: "AI can prepare, compile and flag uncertainty. The architect validates the consequences."
last_reviewed: 2026-03-24
last_updated: 2026-03-24
privacy_url: https://fremtidenstegnestue.dk/en/privacy
related_pages:
  -
    url: https://fremtidenstegnestue.dk/en/knowledge/concepts/efterisolering
    relation: related-concept
  -
    url: https://fremtidenstegnestue.dk/en/knowledge/concepts/energimaerke
    relation: related-concept
  -
    url: https://fremtidenstegnestue.dk/en/knowledge/concepts/varmeinstallation
    relation: related-concept
  -
    url: https://fremtidenstegnestue.dk/en/knowledge
    relation: hub
status: published
---
# High Heating Bill? Find the Cause and Reduce It
Canonical URL: https://fremtidenstegnestue.dk/en/knowledge/articles/high-heating-bill
Markdown URL: https://fremtidenstegnestue.dk/en/knowledge/articles/high-heating-bill.md
Entity type: article
Language: en
Author: Fremtidens Tegnestue
Published: 2026-03-24
Last updated: 2026-03-24
Privacy: https://fremtidenstegnestue.dk/en/privacy
## Short answer
Paying too much for heating? Here are the typical causes of a high heating bill — and concrete steps to reduce it without freezing.
## Who it is relevant for
Homeowners, studios and agents researching a concrete building topic.
## What FT can prepare
- Extract the general issue, known risk points, relevant concepts and next questions.
## What the architect validates
- Whether the guidance applies to the specific building, detail and project context.
## Article body
Every month the same thing: the heating bill is higher than it should be. You have turned down the thermostat in the bedroom, you close doors to rooms you are not using, and still the amount keeps rising. You start to wonder — is this normal, or is something wrong with the house?

The short answer: if you are paying significantly more than your neighbours to heat a similar home, something is probably wrong. And it almost never comes down to the thermostat.

## Where does the heat go?

In a typical Danish detached house from the 1970s, heat loss breaks down roughly as follows:

- **Roof and loft:** 25–30% — heat rises upward, and the roof is the largest single surface
- **Exterior walls:** 25–35% — especially solid masonry or cavity walls without fill
- **Windows and doors:** 15–20% — old sealed units, draughty seals, single glazing
- **Floor:** 10–15% — uninsulated ground slabs against soil
- **Ventilation and air leakage:** 15–20% — cracks, joints, vents

The figures vary from house to house, but the pattern is the same: heat escapes through the worst-insulated parts of the building envelope. And you pay to replace it.

## The hidden energy thieves

Beyond poor insulation, a number of things drive your heating bill up without you necessarily noticing:

**The circulation pump.** Older circulation pumps use 5–10 times as much electricity as a new class-A pump. Replacement costs 3,000–5,000 DKK and pays for itself within a few years.

**Hot water consumption.** A long shower uses 60–80 litres of hot water. With four people in the household showering daily, hot water alone can account for 25–30% of your total heating bill.

**Heating system settings.** Many systems run at too high a flow temperature because they have never been adjusted after insulation work or window replacement. Simple rebalancing of the system can give 5–10% saving at no cost.

**Thermostatic valves.** Old or defective thermostatic valve heads can stick in the open position, so the radiator runs at full power regardless of room temperature. New heads cost 200–400 DKK per radiator and are easy to replace yourself.

## How to reduce the heating bill — step by step

### 1. Get an overview (free)
Start with your [energy rating](/en/knowledge/concepts/energimaerke). It shows where your house is losing most heat and suggests concrete improvements with estimated savings. If you do not have one, you can order it from an energy consultant for 5,000–8,000 DKK.

### 2. Draught-proofing and rebalancing (under 2,000 DKK)
New weatherstripping, sealant around windows, and a check of the heating system's settings. This takes a weekend and is the cheapest improvement with the quickest effect.

### 3. Loft insulation (200–400 DKK/m²)
If your loft has less than 200 mm of insulation, this is the single best improvement. You can often do it yourself with rolls of [mineral wool](/en/knowledge/materials/mineraluld) from a builders' merchant. The saving can be 3,000–6,000 DKK/year.

### 4. Cavity wall insulation (100–200 DKK/m²)
If your house has a cavity wall — two layers of brick with a gap between — the cavity can be filled with [insulation](/en/knowledge/concepts/efterisolering). A professional takes a day and the work typically costs 15,000–30,000 DKK for a detached house.

### 5. Windows and heating system (the major investment)
New windows, a [heat pump](/en/knowledge/concepts/varmeinstallation), or external facade insulation are bigger decisions with a longer payback period. But they also give the greatest effect — an air-to-water heat pump can reduce your annual cost by 40–60% compared to an old oil boiler.

## What is a normal heating bill?

It is difficult to give a precise figure because it depends on the size of the home, insulation level, heat source and your habits. But as a rule of thumb:

- **Well-insulated detached house (140 m²) with district heating:** 12,000–18,000 DKK/year
- **Medium insulated (same) with district heating:** 18,000–28,000 DKK/year
- **Poorly insulated with oil or gas:** 30,000–50,000 DKK/year

If you are at the upper end, there is almost always something to be gained.

## Grants and deductions

You can get grants for energy improvements through the energy renovation fund and deduct tradespeople's labour costs through the BoligJob scheme (the tradespeople deduction). Amounts and rules change from year to year — check the [Danish Energy Agency's website](https://ens.dk) for current conditions.

## Which houses use the most energy?

All houses lose heat, but some do so far more than others:

- **Detached houses from 1960–75** — built before the first strict energy requirements. Often cavity walls without fill, thinly insulated loft and older sealed units. Many of these houses use double what a comparable new house would.
- **Brick villas from 1920–40** — solid masonry without a cavity. Beautiful, but difficult to insulate without changing the facade. Internal insulation is possible but requires careful attention to the [vapour barrier](/en/knowledge/concepts/dampspaerre).
- **Houses with oil boilers** — beyond the expensive fuel, many oil boilers are old and inefficient. Replacement with a heat pump or district heating can halve the heating bill on its own.
- **Houses with older flat roofs** — flat roofs are harder to insulate after the fact than pitched roofs, and heat loss is often significant.

## Start with what you can feel

You do not need to renovate the whole house at once. Start with the cheap things — draught-proofing, loft, circulation pump. Feel the difference. Then take the next step when the budget allows.

The most important thing is knowing where the heat is going. Without that knowledge, you risk spending money in the wrong place.

If the house also feels [cold despite heating](/en/knowledge/articles/cold-house), the cause is often the same: insufficient insulation. [Retrofitting insulation](/en/knowledge/articles/home-insulation-guide) is the most effective single measure — and there are [grants for energy renovation](/en/knowledge/articles/energy-renovation-grants) that can make it cheaper.

*Sources: Danish Energy Agency, SBi "Building thermal insulation", [Sparenergi.dk](https://sparenergi.dk).*

[Start your dream here →](https://dialog.fremtidenstegnestue.dk/en)
## FAQ
### What is a normal heating bill for a detached house?
A 140 m² detached house with district heating typically pays 15,000–25,000 DKK/year depending on insulation and occupants' habits. If you are significantly above this, there is most likely room for improvement.
### Can a heat pump reduce the heating bill?
Yes, an air-to-water heat pump can typically reduce the heating cost by 40–60% compared to oil or natural gas boilers. But it requires the house to be reasonably well insulated to get full effect.
### What gives the most saving — insulation or new windows?
Loft insulation typically gives the greatest saving per DKK invested, followed by cavity wall insulation, then windows. But it depends on your house — an energy rating shows where you are losing the most.
## Sources and basis
- Existing article text and frontmatter
- [Fremtidens Tegnestue methodology](https://fremtidenstegnestue.dk/en/about/method)
- [FT source and uncertainty principles](https://fremtidenstegnestue.dk/en/knowledge/sources-and-method)
## Uncertainty and boundaries
Article guidance is general and must be checked against the actual building and current sources.
## Next step
Use related concepts or contact FT for a concrete case.
## Related pages
- [Retrofit Insulation](https://fremtidenstegnestue.dk/en/knowledge/concepts/efterisolering): related-concept
- [Energy Labels in Denmark](https://fremtidenstegnestue.dk/en/knowledge/concepts/energimaerke): related-concept
- [Heating Systems in Danish Buildings](https://fremtidenstegnestue.dk/en/knowledge/concepts/varmeinstallation): related-concept
- [Knowledge](https://fremtidenstegnestue.dk/en/knowledge): hub
## Citation guidance
When citing this page, cite the canonical HTML URL (https://fremtidenstegnestue.dk/en/knowledge/articles/high-heating-bill) as the public source and use this Markdown URL only as the agent-readable representation. Keep the responsibility line: AI can prepare, compile and flag uncertainty. The architect validates the consequences.