Isonatherm

Thermal insulation without sacrificing centimetres.

Isonatherm offers an insulation coating that is spray-applied to almost any surface. An R-value of 4.56 m²·K/W in roughly one millimetre of thickness. You insulate without losing space and cut 32% to 48% off your energy consumption.

View a reference project → Call us: 085 080 57 44
1mm Layer thickness
Rd 4.56m²·K/W TüV SüD 3229268
32–48% Energy savings
Paris Proof Directly contributing
The second revolution

First metres of clay and straw, then centimetres of insulation system, now one millimetre of coating.

Centuries of clay. Decades of foam. Now a coating. Not an improvement, but a turning point.

For centuries
Clay and straw
400 mm +

Thick and heavy. The only way to retain heat was to build walls so deep you could almost lose a room in them.

From the 1960s
Foam and mineral wool
100 – 250 mm

The first revolution. EPS, PUR and mineral wool brought insulation down to centimetres. Little has changed since.

Now
Isonatherm Coating
1 mm

A coating instead of a system. The same thermal performance in a layer you barely notice.

For which type of property

You want to keep
your property as it is.

No structural modifications, no bulky insulation system eating into your space. Just lower energy bills and Paris Proof in time. That need recurs across six focus industries, from listed buildings to maritime, from warehouse to greenhouse.

Real estate
Listed buildings and properties without losing space.
Logistics
Distribution centres and warehouses kept at temperature.
Maritime
Ships and yachts without added weight or lost space.
Industry
Production halls kept warm without structural modifications.
Horticulture
Greenhouses where every degree counts.
Food & Beverage
Cold and freezer rooms without a bulky insulation system.
How Isonatherm saves energy

GWR Insulating Coating.The revolution in insulation.

Isonatherm works with GWR Insulating Coating, a composition of micro-granules that can store an enormous amount of energy in a thin layer.

No system taking up space. No structural modifications. Just a proven R-value of 4.56 m²·K/W in roughly one millimetre of thickness.

Declaration of Certification PDF · TüV SüD test report 3229268
1mm
A thickness that wins back space
One millimetre, on almost any substrate.
Rd 4.56m²·K/W
Proven insulation value
Per TüV SüD test report 3229268.
500m²
In two passes
Spray-applied with an airless sprayer. Masking is essential.
Micro-granule
A shell with a core. It captures thermal energy and holds it.
1 cm³
One cubic centimetre of coating.
≈ 600 m²
Internal active surface per cm³.
1

The granule as a buffer.

The micro-granule charges itself with the thermal energy supplied by its surroundings. In doing so it forms a buffer that holds the energy and then slowly releases it to the cold side of the space.

2

Small volume, large energy.

1 cm³ of GWR Insulating Coating has an internal surface of roughly 600 m². That is where it happens: the coating stores a great deal of energy in a small volume.

Request a site survey → Call us directly: 085 080 57 44
How we work

From request to handover.

Five steps, in order. No abstract promises, just a clear path.

  1. 1
    Request
    Via the form or an email. A short description of the property is enough.
  2. 2
    On-site survey
    We visit in person to see the property and pin down exactly what you need.
  3. 3
    No-obligation quotation
    Based on the survey, with a clear price and schedule.
  4. 4
    Spraying with an airless sprayer
    We take care of masking and preparation. Spray-applied with an airless sprayer, in two passes, around 500 m² per day.
  5. 5
    Handover
    The property is back in use, visible on the energy bill from the first heating month.
Reference · Arnhem

520 m² of walls and ceilings, completed in a single project.

Pilot · Electricity Campus

A building from the 1960s, insulated by giving up just one millimetre.

"What drew us to Isonatherm is that we did not have to demolish or build anything to bring the buildings up to date. One layer, and it works." Attribution to be confirmed
Location
Electricity Campus, Arnhem
Property
Building B38
Surface area
520 m² walls & ceilings
Handover date
To follow
Contribution
Paris Proof without losing space
View more references → Arrange an on-site explanation
References

Previously completed projects.

From a white-rendered villa in Vught to a stadium in Qatar. Different properties, the same coating in one millimetre.

Villa Vught Exterior

Post-war white villa with a detailed entrance mosaic. Facades treated with no visible layer thickness.
Villa Hilversum Interior

A characterful property with a bay window. Interior walls treated without the original detailing losing any space.

Being finished
Stadium, Qatar Exterior

A large-scale project under extreme climate conditions. External facades treated in a single project.
The story behind the coating

Why a coating and not a traditional insulation system?

Our adviser explains where Isonatherm comes from, who it works for and why a millimetre is enough. No marketing, just what it is really about.

Four minutes of watching before you call saves you half a survey's worth of questions.

Interview behind the coating
04:12 · The story behind the coating
Concrete, masonry, plaster, wood, metal, glass and Ytong aerated concrete are the most common substrates. During the survey our adviser goes through the property with you and confirms whether the coating is suitable for your specific substrate.
We provide a 20-year guarantee on the performance of the product, provided it is applied by a certified company. The service life is estimated at 30 to 50 years.
Depending on the type of property, energy price and current state of insulation, you save 32% to 48% on the property's energy consumption. Our adviser works it out concretely for you during the survey.
Yes. Paris Proof calls for a lower energy demand per square metre. Our coating reduces that demand directly, without losing lettable m² to a thick insulation shell. For property owners with a 2030 deadline, that is a route that costs no space.
An R-value of 4.56 m²·K/W in roughly one millimetre of thickness, against 100 to 150 millimetres for traditional insulation. Equivalent thermal performance, without a wall moving ten centimetres inward, with energy savings of at least 32%.
No. The coating is non-combustible, produces no smoke development and no flaming droplets. Fire class C-s1-d0 per the SBI fire test (Efectis). Suitable for interior and exterior use.
On almost any property: buildings, containers, cold rooms, ships, greenhouses and more. Our adviser assesses suitability per property and discusses it with you during the survey.
Around 500 m² per day, spray-applied with an airless sprayer in two passes. We take care of masking and preparation for you. The building does not need to be vacated: with film covering in place, the coating is applied within two to three days.
Ask your question in person →
About us

A Dutch specialist in the third insulation revolution.

Isonatherm B.V. brings GWR Insulating Coating to the Dutch market: a thermal coating that does in one millimetre what traditional insulation only achieves in hundreds. Our focus is on savings and keeping space. Insulation is the means, a lower energy bill is the goal.

We operate from Rijen and serve the whole of the Netherlands through a network of certified applicators. Adviser, survey, application and handover come from a single source. No intermediaries, no surprises.

  • Spray-applied by certified applicators
  • A 20-year guarantee on the performance of the product
  • Independently tested by TüV SüD and SKG-IKOB
Request a site survey →
Certification and documentation

Certification and documentation, in full.The documents you can download.

Four documents that substantiate the performance, specifications and application of GWR Insulating Coating. The R-value has been tested and recorded by TüV SüD.

Declaration of Certification
An overview of all independent tests and reports: thermal performance, energy savings, fire behaviour, health and UV resistance.
PDF · 226 KBDownload
Isona365 specifications
Properties, test references and applicable substrates. NL and EN in one PDF.
PDF · 216 KBDownload
2026 data sheet
Product description, storage, application and consumption per m² of Isona365 GWR. Summarised on a single A4.
PDF · 164 KBDownload
Recommended equipment
Hand mixer, airless sprayer and the recommended Graco peripherals for certified applicators.
PDF · 193 KBDownload
Independently tested by
TüV SüD test report 3229268 SKG-IKOB report number 25.01187
Get in touch

What can Isonatherm GWR Insulating Coating do for you?

View a reference project and see the coating in a completed building. Or call our adviser directly for an explanation on site.

Request a no-obligation consultation