The Alton Downs Vineyard Home is a beautifully designed, high-end architectural residence located in the Marlborough District of New Zealand. This spacious five-bedroom home features skillion roof construction, ensuring a striking and functional design.

To be able to achieve stringent H1 compliance and building code requirements, Earthwool glasswool: Skillion batts were specified, providing superior thermal performance and energy efficiency. The thoughtful integration of high-quality insulation and modern design elements creates a comfortable, sustainable living environment in one of New Zealand’s most picturesque regions.

The builder, Peter Ray Homes designed the skillion roof structure of the Alton Downs Vineyard home using 290mm rafters at 450mm centres. The New Zealand Building Code requires a 25mm air gap between the top of the insulation and the roof purlins, while achieving high R-Values is necessary to meet H1 requirements. Achieving these goals requires a balance of insulation performance, air circulation, and thermal efficiency, ensuring the building’s overall comfort and energy efficiency.

For the Alton Downs Vineyard Home, the builder has used a 290mm rafter. To insulate this area, Knauf Insulation has proposed the use of the Earthwool glasswool: R7.4 Skillion batt.

The nominal thickness of the R7.4 Skillion batt is 265mm which means it will friction fit nicely while also maintaining the 25mm air gap under the roof purlins. The Earthwool Glasswool: Skillion batt boasts a high density and thermal resistance rating, which ensures excellent thermal performance by significantly reducing heat transfer. This makes it ideal for skillion roofs, where a higher R-Value is essential for H1 Compliance.

“We chose to specify and use Knauf Insulation’s skillion batts because their design perfectly met the building code requirements," says John Pile, Living House NZ Ltd. "Unlike many other insulation products, Knauf’s skillion batts were able to maintain the crucial 25mm air gap needed for proper ventilation, without compromising the performance of the insulation. Their friction-fit design ensures a secure and efficient installation, making them the ideal choice to meet both the H1 requirements and the strict air gap specifications of the building code.”

The unique thickness of Earthwool Glasswool insulation was specifically chosen to accommodate the critical ventilation requirements of the roof design. This allows for the necessary 25mm air gap under the roof underlay, which is vital for maintaining airflow and ensuring the building remains comfortable and energy-efficient. Many insulation products on the market do not account for this crucial ventilation pathway, but Knauf Insulation’s Earthwool glasswool: Skillion batts are designed to fit securely and friction-fit neatly between the rafters, keeping the air gap intact.

The nominal thickness of 265mm is not only key to maintaining the air gap but also allows for easy installation. The batt width and thickness have been carefully considered to provide a seamless fit, ensuring that the installation process is straightforward and efficient.

The R7.4 Skillion batts will friction fit into place creating a complete thermal envelope for the home helping maintain a comfortable temperature inside the home year-round.

The Earthwool glasswool insulation range of skillion products are manufactured using DriTherm Technology, a silicone treatment, improving their durability and resistance to moisture. They are also tested to be non-combustible in accordance with AS 1530.1, ensuring the highest standards of fire safety.

Knauf Insulation’s Earthwool glasswool provided a highly effective solution for the Alton Downs Vineyard Home. The Earthwool glasswool: Skillion batt was the ideal choice to meet both the functional and environmental demands of the project whilst also meeting the stringent H1 and Building Code requirements.