Coffee-ground insulation is a promising area of materials research, but the name covers several distinct products and experiments. A European construction-sector report described KA-RZ, an insulation material made from recycled coffee grounds. Separately, a 2026 peer-reviewed study measured the thermal conductivity of a lab-made coffee-ground biochar and ethyl-cellulose composite. That result is not a specification for KA-RZ, and neither finding alone establishes a ready-to-specify building product.
What is coffee-ground insulation?
It is not one standardized material. Researchers and developers have explored spent coffee grounds in different forms, including as an ingredient in plaster, as part of a geopolymer, and as biochar within a biodegradable polymer matrix. Because each formulation and manufacturing process differs, performance figures from one study cannot be transferred to another product.
The potential environmental benefit is the reuse of a waste stream. Jeonbuk National University reported that more than 8 million tons of spent coffee grounds are generated annually; that is the university’s figure, not a harmonized global inventory. Reuse alone does not establish a lower overall environmental impact: that also depends on processing energy, sourcing and transport, service life, and end-of-life handling.
What is known about KA-RZ?
In a report published on 28 August 2025, the European Commission’s BUILD UP platform identified KA-RZ as insulation made from recycled coffee grounds. It attributed the idea to Olaf Elze, director of German firm K-MÄLEON and a partner in the GreeNest project. The report described possible applications in exterior walls, gallery ceilings, and roofs, and said the material was then poised for market launch. Read the BUILD UP report on KA-RZ.
Quick wins for a faster PC:
Clear out junk files and repair common Windows errorsFree Scan →Fix the driver behind crashes, sound loss and screen glitchesFind Drivers →#1 Best Overall
- Premium Material: The double-sided insulation roll is made of high-quality reflective aluminum film and polyethylene air bubble cushion, with a surface round hole design to increase reflectivity. The RV window insulation is durable and long-lasting, resistant to scratches.
- Temperature Protection: The reflective insulation roll reduces heat transfer for year-round comfort, while the reflective bubble sheet provides energy-saving, window insulation and privacy protection.
- Excellent Performance: The window insulation for summer has excellent waterproof performance, allowing worry-free outdoor use. It is easy to clean with a simple wipe. When not in use, it can be easily folded up for space-saving and convenient carrying.
- Wide Usage: Our insulation sheet is versatile and can be used for various spaces, including windows, RVs, roofs, garage doors, and more as a heat blocker.
- Easy Installation: The usage of the foil insulation roll is easy and convenient. Simply cut it to the desired size with a utility knife or scissors, then use the provided double-sided tape for easy installation.
The report does not provide a thermal-conductivity measurement, detailed formulation, technical datasheet, certification, or confirmation of current sales. Its 2025 reference to a planned launch should not be treated as proof that the product is available now.
What performance has laboratory research measured?
Biochar and ethyl-cellulose composite
A separate 2026 study by Sung Jin Kim and Seong Yun Kim tested a composite made from biochar produced by carbonizing spent coffee grounds and biodegradable ethyl cellulose. The researchers reported thermal conductivity of 0.04 W m−1 K−1, which they described as comparable to commercial expanded polystyrene (EPS). This is a result for their research specimen, not a measured value for KA-RZ or a complete comparison of building products. Read the 2026 study in Biochar.
Rank #2
- R-13 faced insulation, easy exterior/interior 2x4 wall install
- Fiberglass insulation roll helps maintain temps and control noise
- Pink fiberglass insulation is formaldehyde free and soft to touch
- The greater R-value provides greater insulation performance.
The optimized biochar filler had a reported porosity of 71%. To make it, the researchers carbonized discarded coffee-capsule grounds at 700 °C under ambient atmosphere and used a pore-restoration process. They formed the composite with a laboratory heating press at 150 °C and 15 MPa, then vacuum-dried it. Those steps describe a controlled research process, not evidence of routine commercial manufacturing.
Other coffee-ground formulations
Earlier work also tested coffee grounds in different building materials. The results illustrate why each formulation needs to be judged on its own evidence.
What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
Rank #3
- SPECS - (1) Foil Reflective Insulation Roll | Width: 48" | Length: 125' | 500 sq.ft. | White/Foil | Thickness: Approximately 1/8" | Reflects 96% and 4% Emissive | Class 1 / Class A Fire Rating | Non-Toxic, Non-Carcinogenic, Fiber Free, No Off Gassing
- REDUCE ENERGY USE - Our lightweight thermal insulation reduces heating and air conditioning costs by blocking 96% radiant heat. Single bubble insulation keeps indoor spaces warm in the winter and cool in the summer. Made in USA.
- EASY TO INSTALL - EcoFoil's foil bubble wrap insulation roll is lightweight, easy to handle, and cuts easily. Requires no special clothing. The heat reflective insulation is difficult to tear, but can be easily cut with scissors or sharp knife.
- VERSATILE – Use foil bubble insulation for home insulation and in pole barns, metal buildings, basement walls, crawl spaces, storage units, and more. Works in any climate, but best suited for warmer regions where snow/ice is minimal.
- VAPOR BARRIER - The reflective bubble insulation acts as a vapor barrier when properly installed with tape, prevent the passage of moisture and other unwanted particles.
| Study and material | Reported result | What the figure represents |
|---|---|---|
| Lachheb et al., Journal of Cleaner Production, 2019: plaster with spent coffee grounds | Thermal conductivity fell from 0.5 to 0.31 W/m·K with 6 wt% coffee grounds. | A result for the tested plaster formulation. The authors also modeled a typical house in Marrakech, Morocco, estimating up to 20% lower heating and cooling loads and up to 1,500 kg less CO2 annually. Those are modeled scenario results, not measured savings from an occupied home. |
| Saeli et al., Energy and Buildings, 2023: geopolymeric materials made with biomass fly ash and spent coffee grounds | Up to about 19% annual building-envelope energy improvement and up to 37% manufacturing-cost saving for a formulation containing 17.5% spent coffee grounds. | Study-specific modeled building and formulation estimates, not retail product specifications or verified savings from a KA-RZ installation. |
Do the experiments prove that coffee-ground insulation is eco-friendly?
They establish that researchers can make and test materials incorporating spent coffee grounds; they do not establish that every such material has a lower life-cycle impact than conventional insulation. The 2026 paper also reports small-scale thermal demonstrations, a scaled-down building-integrated photovoltaic setup, finite-element simulation, and enzymatic degradation behavior over a three-week test. These bounded experiments do not establish whole-building code compliance, long-term field durability, fire performance, moisture behavior, or an environmental advantage across all manufacturing conditions.
A credible environmental comparison would need to account for the energy and materials used to collect, prepare, and process the grounds, as well as transport, useful service life, and end-of-life treatment. A biodegradable ingredient or recycled feedstock is relevant, but neither by itself settles the full comparison.
Rank #4
- Package Contents: HADOR Reflective Window Insulation kit has everything you need. It includes a 48 inch x 10 foot insulation foil, suitable for most windows. It comes with 65 small round hook and loop adhesive pads to ensure a secure fit, along with a roll of heavy duty aluminum foil tape for extra strong fixation.
- All Season Comfort Maintenance: Our reflective insulation board, with a foam core between double aluminum foil, offers great thermal insulation. It effectively blocks the sun's rays in summer, keeps out the sweltering heat, and in winter, it prevents heat loss, ensuring your home stays cozy and warm.
- Durable Quality: HADOR RV window insulation has a three layer structure, with aluminum foil on both sides and 3mm polyethylene foamed cotton in the middle. The foil surface design boosts heat reflectivity, offers sun protection, waterproofing, and thermal insulation. Built to last, you can rely on it for years to come.
- Easy Installation: Installing our window insulation is a breeze. All you need is a utility knife or a pair of scissors to cut it to the perfect size for your window, garage door, or any other area you want to insulate. Simply attach it using the provided accessories, and you're done.
- Wide Application: The reflective insulation roll is highly versatile. It can be used in many indoor and outdoor places such as windows, attics, garages, sheds, RVs, greenhouses, and cars. By reducing heat transfer, it not only helps you stay comfortable but also saves you energy and money on heating and cooling bills.
Can coffee-ground insulation be used in a house?
The studies show research potential, but the available KA-RZ report does not establish a product that a homeowner or builder can currently buy and specify. For any emerging insulation, first confirm the product’s local availability and obtain product-level documentation for the intended assembly. Key items include:
- Thermal performance: measured conductivity and the resulting thermal resistance at the proposed installed thickness, with test conditions stated.
- Moisture behavior: water absorption, vapor permeability, and suitability for the wall, roof, or ceiling assembly.
- Fire performance: applicable fire classification and evidence for the installed system.
- Strength and durability: resistance to settling, damage, and degradation over the expected service life.
- Compliance: applicable certification and building-code status for the project’s jurisdiction.
- Environmental and cost evidence: a documented comparison that covers manufacturing, transport, service life, end of life, and actual local price.
The 0.04 W m−1 K−1 laboratory result may help assess that particular composite against other materials on conductivity, but it cannot substitute for the rest of a building-product specification. A conductivity value alone does not establish installed performance, safety, approval, or availability.
Free tools Windows power users keep installed
One-click scans. No signup required.
Quick Recap
Best Value
- Temperature Stabilization: Thermalized bubble roll that keeps indoor temperatures stable reducing the use of heating and cooling systems. This packaging supply is a versatile packaging option that can be used for all types of business and personal applications
- Made in the USA Quality: Top quality packaging that can be used as an insulated barrier to keep the temperature of items stable. Its bubble layers can be used as a home climate control during winter or summer
- 3/16 Inch Bubble Layer Construction: Features a 3/16 inch bubble layer with foil outer layer that keeps items cushioned and insulated. Suitable for garage ceilings, greenhouses, building insulation, and product packaging since it can be installed easily
- Thermal Resistance Performance: One-sided thermoflex insulated bubble made of polyethylene material designed with interior bubble rolls. Keeps your products and items cushioned with a thermal resistance R-value of 4.9 to 14.1
- Easy Installation Process: Can be installed easily since it can be cut with a scissor or with a knife. You can apply it on basements, metal buildings, under concrete, walls, roofs, shipping cold products, crawl spaces, attics, and more
What to take from the current evidence
- KA-RZ is a named recycled-coffee-ground insulation development associated with K-MÄLEON and GreeNest; the August 2025 report does not confirm current availability or publish measured product specifications.
- A separate 2026 research composite of coffee-ground biochar and ethyl cellulose measured 0.04 W m−1 K−1 conductivity. That value belongs to the tested specimen, not KA-RZ.
- Plaster and geopolymer studies report promising formulation-specific experimental or modeled results, not universal savings or field performance.
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
