Timber building systems enable high performance out of the box – but what are the insulation options for a bespoke project?

Chris Batesmith investigates

When you buy a timber home, you’re usually commissioning at least the house shell and insulation package. If a single firm’s delivering this, it means they’re responsible for ensuring a core part of your project achieves the expected performance. “The beauty of options like timber frame is the insulation is part of the system,” says Simon Orrells, MD at Frame Technologies. “But you will still get choice: as long as it’s tested, we can put any insulation in it.”

Of course, insulation isn’t the only factor at play. There’s airtightness; thermal mass (a building’s ability to absorb and retain heat); cold bridging (where energy can escape via junctions in the structural fabric); overheating risk; and how the other components installed into the main house shell support the whole picture. Recent changes to the Building Regulations mean greater attention is now paid to cold bridging (psi values), in particular. Dealing with this should be part of the system supplier’s remit, so ask how they’re addressing this. Nevertheless, insulation remains a key consideration for delivering the U-values required, both under the regs and if you’re aiming for more stringent eco standards, such as Passivhaus.

Whatever your energy efficiency target, early supplier engagement is key to a joined-up approach. “For 90% of our projects, we do all the detailed design,” says Simon. By connecting your house designer and system provider before you even get to planning application stage, you can get the very best out of the product, as well as more control over the decisions that are important to you.