What Are the Benefits of Hempcrete?

With rising energy bills, changing climates, and a strong push towards sustainability, we need to be extra meticulous about the materials we use to build our homes. 

What you need is efficient insulation that doesn’t back down. 

Enter hempcrete: a natural alternative to conventional insulation products. It offers incredible thermal performance, breathability, and eco-credibility. But how does it really stack up against traditional materials like fibreglass, polystyrene, concrete blocks, and spray foam?

Hempcrete Insulation R Value (Blocks)

Thermal resistance, or R-value, is the gold standard for insulation. The higher the R-value, the better the material resists heat transfer. Hempcrete blocks come in several sizes with impressive performance figures.

Compare that to:

• Brick Veneer: ~0.51 R-value

• Weatherboard: ~0.54 R-Value

• Concrete blocks: ~0.08 R-value

• Polystyrene panels: ~R2.0–R3.5 (but prone to off-gassing and flammability)

• Fibreglass batts: ~R2.5–R3.7 (but degrade and sag over time)

• Spray foam: ~R3.5–R6.5 depending on type, but has serious environmental and health trade-offs

Even the smallest hempcrete blocks outperform concrete by over 10x. Plus, hempcrete insulation properties go beyond R-values—it regulates moisture, prevents mould, and contributes to healthier indoor air.

Hempcrete as Insulation Solutions

1. Hempcrete for Walls

Walls are crucial for keeping interiors cool in summer and warm in winter. Traditional insulation like fibreglass batts may tick the thermal box, but they can trap moisture, support mould growth, and lose performance over time. Polystyrene offers a high R-value but has flammability risks and environmental concerns. Concrete walls? Great for strength, poor for insulation.

Spray foam, on the other hand, fills wall cavities tightly and offers high R-values. But it’s made from petrochemicals, emits VOCs during installation, and is so airtight that it can actually encourage moisture buildup without proper ventilation. Once installed, it’s difficult to alter or remove.

In contrast, hempcrete does wonders for your walls: 

• Offers natural vapour permeability and breathability

• Regulates internal humidity and reduces condensation risk

• Provides thermal mass for cooler summers and warmer winters

• Easy to handle and install with no toxic chemicals

• Carbon-negative—absorbs CO₂ as it cures

• A long-term, sustainable solution for comfort and indoor health

2. Hempcrete Roof Insulation

Heat rises—so your roof plays a massive role in your home’s energy performance. Traditional materials like mineral wool and fibreglass offer fair thermal performance, but they compress over time and may become home to pests or dust.

Spray foam insulation is often applied directly to roof sheeting to air-seal and insulate in one go. While it does block airflow effectively, this can lead to timber rot if internal humidity isn’t managed. And with high chemical content and questionable recyclability, it’s not the greenest solution.

Here’s why hempcrete is perfect for roof insulation:

• Combines solid thermal mass with breathable comfort

• Does not sag, degrade, or require synthetic vapour barriers

• Can be cast into panels or used as loose-fill

• Keeps attic temperatures regulated in all seasons

• Naturally wicks away moisture, eliminating condensation issues

• Pest-resistant, adding to its durability and reliability

• Offers natural temperature regulation, humidity control, and inherent fire resistance

• Ideal for homes in Australia’s bushfire-prone areas

• Lowers energy costs for heating and cooling by up to 70%

3. Hempcrete Floor Insulation

When it comes to floor insulation, most Australian homes rely on polystyrene panels or fibreglass rolls beneath suspended timber floors. These do provide insulation, but they often compress, deteriorate, and aren’t recyclable. They can also trap moisture under your flooring, leading to timber decay.

Spray foam insulation, often applied beneath floorboards in hard-to-access crawlspaces, does air-seal well. However, it is notoriously hard to remove if repairs are needed, and moisture can still build up between the foam and timber if the area isn’t ventilated. Plus, it’s highly flammable and not biodegradable.

Here’s how hempcrete floors other traditional insulation options: 

• Provides a breathable and mould-resistant alternative

• Can be poured in place or laid in block form
  Adds thermal resistance while allowing vapour to pass through

• Helps reduce condensation risk beneath floorboards

• Safe, sustainable, and breathable—ideal for healthy indoor environments

• While it may not match the ultra-high R-values of closed-cell spray foam, it delivers consistent comfort and long-term performance

4. Hempcrete Sound Insulation

Wherever there’s modern urban living, noise pollution follows. Whether it’s traffic, neighbours, or internal echoes, sound insulation is crucial for comfort.

Materials like acoustic plasterboard, foam panels, and fibreglass can help—but they often need layering and aren’t sustainable. Spray foam does offer some sound-dampening, but it’s most effective against air transmission (like drafts), not low-frequency vibrations.

Why hempcrete is a sound choice: 

• Naturally absorbs a broad range of sound frequencies
  Its fibrous texture and density reduce echo and airborne noise

• Helps muffle external sounds, enhancing indoor tranquillity

• Functions without chemical additives or synthetic linings

• Ideal for:

  • Multi-residential buildings

  • Home offices

  • Any space needing noise reduction

• Quiet, sustainable, and long-lasting—a top performer across the board

Dream Up Efficient, Eco-Friendly Homes with Respirabuilt

If you’re dreaming of a home that’s cooler in summer, warmer in winter, quieter year-round, and kinder to the planet, hempcrete will help you achieve all that and more.. From walls to roofs and even floors, this natural powerhouse outperforms traditional materials across key categories—without compromising on comfort or sustainability.

Ready to build smarter? Explore premium hempcrete solutions at Respirabuilt—Australia’s trusted leader in eco-conscious construction.

Explore our other blogs for more expert tips:

• What Are the Benefits of Hempcrete?

• Hempcrete vs Concrete

• Sustainable Building Materials Australia