Insulating a detached house is one of the biggest investments you will make as a homeowner. Prices range from 300,000 to 800,000 Kč - and yet many people go into it blind. They get a quote from an insulation company, nod, and pay. Without knowing where the heat is actually escaping.
A thermographic inspection solves this problem before you even start comparing quotes.
What thermal bridges are and why they matter
A thermal bridge is a point in the external structure where heat passes outward significantly faster than in the surrounding area. Typically these are:
- Corner joints of walls - geometric thermal bridges, unavoidable, but they can be minimised
- Steel and concrete elements - lintels, ring beams, columns; concrete conducts heat 30 times better than aerated concrete
- Balcony slabs - a classic weak point. A balcony embedded into the floor structure is a thermal channel straight outward
- Window reveals - the point where the frame touches the masonry; poor execution means condensation and mould
- Parapets and roof overhangs - often neglected, but critical on flat roofs
The problem with thermal bridges: they show up on the gas bill, but they are not visible to the eye. Without thermal imaging, you will not find them.
Thermal imaging versus a visual impression
An insulation company will carry out a survey - a technician comes, looks at the façade, taps the wall, checks the drawings. Based on that, they propose an insulation scheme. This is standard practice.
But a technician without a thermal camera simply cannot see what is happening inside the structure. He does not know whether a corner joint has a cold zone of 4°C or 12°C. He does not know whether water ingress on the façade is causing moisture inside the masonry (in which case insulating over it could seal the problem in and make it worse). He does not know exactly where the ring beam runs and how much it affects the wall’s temperature profile.
A thermal camera shows this in real time.
How a drone-based thermographic inspection works
Our drone flies around the whole building at a distance of roughly 2-5 metres from the façade. The thermal camera measures surface temperatures to within a tenth of a degree. The result is a set of thermograms - colour images in which blue tones mean cool (heat-losing) areas and red tones mean warm ones.
Ideal measuring conditions:
- At night or early morning - outside temperature below 5°C, the house heated to at least 20°C
- No precipitation - rain cools the façade and distorts the results
- No direct sunlight - solar radiation warms surfaces so that they “look warm” regardless of the state of the insulation
In Prague and the Central Bohemian Region we have optimal conditions from October to March.
What thermal imaging tells you
Before deciding on insulation:
- A real map of thermal bridges - you know exactly where the problem is. The insulation company gets a specific brief.
- The state of any dampness - wet masonry behaves differently from dry masonry; insulating a damp wall is counterproductive.
- Prioritisation - not every part of the façade needs the same solution. You save where insulation would achieve little, and invest where the benefit is greatest.
- An independent benchmark - you do not turn up to a meeting with the insulation company empty-handed. You know what you want fixed.
After insulation (a follow-up inspection):
- You confirm that thermal bridges have been properly addressed
- You reveal any workmanship defects (gaps in the insulation, poorly thought-through transitions)
- You have documentation to support a warranty claim
How much it costs and when it pays for itself
A thermographic inspection of a detached house costs from 4,700 Kč with us (up to 200 m² of built-up area). It includes a drone flight, thermograms of the whole façade, identification of thermal bridges, and a report in PDF format.
Compare that with an insulation job costing 400,000 Kč. If thermal imaging helps you design a better insulation scheme, or reveals a problem that would otherwise have led to a 50,000 Kč claim, the investment pays for itself many times over.
For NZÚ 2026 you will also need supporting documentation for the renovation passport. A thermographic report is one of the inputs an energy specialist will use.
Practical tips before you book
- Book your thermal imaging in winter - summer is unsuitable for façade inspections
- Have the house heated for at least 24 hours beforehand - the temperature difference between inside and outside must be at least 10-15°C
- Prepare a plan of the house - even a sketch will do; it helps match the thermograms to specific rooms
- Let your neighbours know - the drone will also fly close to the boundary of the plot; this prevents misunderstandings
Interested in a thermographic inspection before insulating? Send us your enquiry - we reply within 24 hours with a price and the nearest available date.