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HeatAlgo

Heat lossroom by room.

Heat loss calculations in minutes, not hours.

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HeatAlgo - the building's heat loss result, room by room

What it is

HeatAlgo's heat loss calculation runs in the browser and complies with EN 12831-1 (ISO 6946, ISO 13370), room by room - for installers and homeowners. See every wall layer, every U-value, the split between transmission and ventilation losses. Nothing is hidden.

The quote says 12 kW.Where does it come from?

The heat source, the radiators and the underfloor heating follow from the heat loss of one particular house, not from a figure per square metre. Until now, calculating it meant licensed desktop software or commissioning an engineer for every project.

An estimate per square metrea W/m² figure does not say what one room loses - and that is what the sizing depends on
Commissioned for every changean engineer calculates once, and a different window or thicker insulation starts the calculation over
A result with no reasoninga number in a quote without the layers, the U-values and the room-by-room split - nothing to check it against

From your house plansto a figure in kW.

Three minutes on a made-up house: Algo AI reads the floor plan and the building elements, you check every step, and the answer is 4.87 kW for 102 m². The same heat loss calculation the steps below describe.

All recordings →

English narration, English and Polish subtitles

From your house plans

How to calculatethe heat loss.

1 / 5
Guide: every step of the heat loss calculation →
Algo AI in HeatAlgo - a new conversation beside the heat loss result: check the project, upload a documentBuilding step in the heat loss calculation - heated area, design outdoor temperature, and the data shared by the whole buildingRoom editor in the heat loss calculation - the building elements section with each element and its U-valueHeat loss calculation result - one room's details: envelope elements, windows and doors, and the load componentsHeat loss PDF report - cover page and the room-by-room summary

Which U-value?Ask Algo AI.

Algo AI knows your project - the building elements, the rooms, the building data - and answers in that context. It suggests values, explains the result and watches for gaps. The algorithm always does the calculation, to EN 12831-1.

Meet Algo AI →
AlgoThis projectFeedback

What U-value for a wall of 24 cm hollow brick and 15 cm EPS?

THINKING

Work it out from the layers, not from a table: 24 cm ceramic hollow brick (λ about 0.30 W/mK) and 15 cm EPS (λ 0.040) give U ≈ 0.21 W/m²K to ISO 6946. Enter both layers on the 'External wall' element - if the EPS label says a different λ, use that and the result recalculates.

Ask about an element, a room or the result…

Everythingthe standard asks for.

Heat loss calculation result in the HeatAlgo app - heat loss room by room
Heat loss in full compliance with EN 12831-1.

Transmission, ventilation, and thermal bridges per EN 12831-1, U-values per ISO 6946, ground losses per ISO 13370. An empty floor-on-ground perimeter is worked out from the rooms' walls (EN 12831-1 Annex E, ISO 13370).

See every layer of the wall, not just the result.

Wall composition layer by layer: thickness, lambda, U-value. You can always check where the result comes from. The constructions include timber frame: cellulose, gypsum fibre board and two ready assemblies (a wall and a ceiling under the attic), and you can add your own material to the list.

A complete heat loss calculation in minutes, not hours.

Simple forms, typical constructions to pick from a list, and an instant result. No training sessions or thick manuals.

One result feeds every other module.

The heat loss directly drives the underfloor heating design and the heat pump sizing. One data source for the whole project.

A clear split between transmission and ventilation.

See how much heat escapes through the envelope and how much through ventilation. Easier to show the client what to improve in the building. A room 2 K or more warmer than the rest of the house, with no building element to a colder heated neighbour, gets a warning.

A client-ready PDF report in one click.

Full calculations in a clear report for the client and the project documentation. Ready to send the moment the calculation is done. The app and the report are in Polish, English, German, French and Dutch.

HeatAlgo vstraditional software.

Traditional software

  • PriceA per-seat licence
  • InstallationPC (Windows)
  • TrainingWeeks
  • MethodologyVaries
  • TransparencyOften a black box
  • PDF reportYes, complex

HeatAlgofree

  • PriceFree forever, reports from €19
  • InstallationBrowser
  • TrainingNone
  • MethodologyEN 12831-1 + ISO 6946 + ISO 13370
  • TransparencyEvery step visible
  • PDF reportYes, simple and readable
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a free account · full results and PDF after purchaseSee the method: a reference house calculated in full →

Frequently asked questions

The heat loss calculation implements EN 12831-1 (room-by-room building heat loss) with EN ISO 6946 (thermal resistance of building components) and EN ISO 13370 (ground). The result includes heat losses, U-values, the transmission/ventilation split and an additive thermal-bridge surcharge per EN 12831-1 Annex B.2.1 (ΔU_TB). Useful for quick building assessment and client presentations - a certified energy audit may still be required for formal grant applications. Full compliance covers residential buildings with natural, mechanical, or MVHR ventilation, without air transfer devices (ATDs).

Other tools

Heat pump selection10 power classes, radiator checkUnderfloor heatingzones on the plan, loops from geometryAI client formclient data without the phone calls
← See all tools

Calculate your first heat loss today

Register, enter the building data, and see a result compliant with EN 12831-1 in minutes.

Create a free accountSee how it works

No payment card. Your projects and data stay in your account.