Agar Grove is a multi-award-winning development, created by 5-star housebuilder, The Hill Group for Camden Council, as part of their Community Investment Programme. With a proposed 507 new homes, once complete Agar Grove will be the largest Passivhaus development in the UK.

Knauf Insulation’s glass blowing mineral wool Supafil® has been specified for Phase 1C of the project, which comprises 125 homes. We spoke to Hill’s Senior Technical Coordinator, Ben Clarke and Senior Contract Surveyor, Matthew Bricknell about the needs of the project.

Prioritising real performance

Passivhaus is an internationally recognised building standard, resulting in very high energy efficiency. For the residents of Agar Grove, this will mean greater thermal comfort, alongside reduced energy bills.

Achieving the Passivhaus standard requires a complex balance of design factors to create high levels of insulation and airtightness. To ensure their designs would deliver in the real world, it was therefore important for Hill to specify products which would perform as well in situ as they did on paper.

As Ben explains, “We chose to use blown-in insulation because of its real-world thermal performance. Installing insulation boards can sometimes mean gaps are left between them, which leads to cold bridges in the build. But that can be more easily avoided with a blown-in product.”

To provide further quality assurance, Hill has appointed contractors from Knauf Insulation’s network of Approved Supafil® Installers. Trained by Knauf Insulation’s own Regional Technical Managers, they have the necessary product knowledge and expertise to ensure a quality installation.

Using Supafil® will also mean that less product is wasted on-site. When rigid insulation boards are cut to size, offcuts are often discarded because they are difficult to use elsewhere. By contrast, Supafil® has a zero-waste potential. When the cavity is full any excess product remains in the insulation blowing machine hopper, ready to be installed on the next plot, and when the job is complete Supafil®’s packaging can be recycled. Ben says: “As a responsible business, Hill is always looking for ways to reduce waste on our projects wherever we can, and this solution will help us to do that”.

Evidencing quality

The Passivhaus accreditation requires Hill to demonstrate the energy efficiency of Agar Grove, which will involve data collection throughout the build and thermal imaging of the finished product. As Matt explains, “We have a significant quality assurance requirement. We need to be able to show Camden Council that we have insulated the building as specified and that’s not always a simple task – particularly with blown-in solutions which by their nature, are hidden within the cavity.”

To help meet this challenge, Hill’s Approved Supafil® Installers will use Knauf Insulation’s app-based site reporting system, KinetiK®. The app allows the installer to select their site and plot number on their mobile device, photograph the elevation, and then scan each pack of Supafil® as it’s installed.

Matt continues, “KinetiK® will enable us to confirm that the insulation has gone in as specified. This is essential for our client, but it also gives us confidence too. If areas are missed during an install, there are time and cost implications, so having a tool like KinetiK® will provide us with added assurance that the cavity has been fully filled.”

Agar Grove will be the latest in a number of Passivhaus projects which Knauf Insulation has supported. Read more about Preston Springs, North Yorkshire here and Denby Dale, one of the first certified Passivhaus homes in the UK, here.