Heat loss calculation

Heat loss calculation for your home

Know exactly how much heat your home needs, room by room — the basis for a well-sized heat pump and smart insulation.

In short

The essentials at a glance

A heat loss calculation shows how much heat each room of a home loses through walls, windows, roof, floor and ventilation, and therefore how much capacity the heating must deliver. You need it to size a heat pump or low-temperature heating correctly. At Hasibo a heat loss calculation costs from €425 including VAT.

Price: from €425 incl. VAT
Standard: ISSO 51 / NEN-EN 12831
Result: heat loss per room in watts
Useful for: heat pump, insulation, comfort issues

Clear prices

Fixed prices including VAT, no hidden costs.

Apartment

€425

Terraced or corner house

€475

Detached house

€550

All prices include VAT (BTW).

Why a heat loss calculation for a heat pump?

A heat pump must match the heat loss of the home, not the capacity of the old gas boiler. Too small, and the home won't get warm enough in winter. Too big, and it switches on and off often and efficiency drops. A calculation under ISSO 51 / NEN-EN 12831 prevents both.

You may be eligible for an ISDE subsidy when buying a heat pump. Check the current conditions with RVO.

What do you get?

The heating capacity needed for the whole home
Heat loss per room, so radiators or underfloor heating are sized correctly
Insight into thermal weak spots: which walls, windows or floors lose the most heat
A solid basis to share with your installer

How it works

1
Inspection
We measure the home and record insulation, glazing, ventilation and temperature requirements per room.
2
Calculation
We calculate transmission and ventilation losses per room at a design outdoor temperature.
3
Report
You receive the report with the required capacity, ready for your installer.

Insulate first?

The better a home is insulated, the smaller (and cheaper) the heat pump can be. Unsure about the right order? Combine the calculation with tailored energy advice or read improve your energy label.

Frequently Asked Questions

Answers to the questions we are asked most about this topic.

1. How much does a heat loss calculation cost?

At Hasibo a heat loss calculation costs €425 for an apartment, €475 for a terraced or corner house and €550 for a detached house, including VAT.

2. Is a heat loss calculation mandatory?

Not by law, but it is the only reliable way to determine the right capacity for a heat pump. Many installers ask for one.

3. Which standard do you use?

We calculate according to ISSO 51 and NEN-EN 12831, the common methods for residential heat loss calculations in the Netherlands.

4. Can't the installer do this?

They can, but an independent calculation makes sure the capacity is matched to your home rather than to a product.

Last updated: 7 October 2026 · by Hasibo Ingenieurs & Adviesbureau

Sources: RVO — ISDE subsidy (Dutch)