IS 440 and Imported Timber Frame: What an Irish Self-Builder Must Check

Importing a frame into Ireland is completely normal — a large share of Irish timber frame has always come from Britain and the Nordics. What is not normal, and what causes real trouble at sign-off, is arriving on site with a frame and no paperwork. Sort the paperwork first.

What IS 440 is

IS 440 is the Irish Standard for timber frame construction in dwellings and other buildings — IS 440:2009, with amendment 1 consolidated in 2014. It sets out design, manufacture, handling and site assembly requirements for timber frame in an Irish context, and it is the reference your engineer and certifier will work from. NSAI operates certification schemes for timber frame manufacture against it.

It is a standard, not a law. Compliance with the Building Regulations is the legal requirement; IS 440 is the route almost everyone uses to demonstrate it for timber frame, which in practice makes it the thing you need.

Why it matters commercially, not just technically

• Your assigned certifier has to be satisfied the structure complies before signing the certificate of compliance on completion.
• Your lender will usually not release the frame stage drawdown without the engineer confirming compliance.
• Structural warranty providers and some insurers have their own timber frame conditions on top of the standard.
• Resale. A future buyer’s solicitor will ask for the completion certificate. Anything unresolved becomes a price negotiation years later.

Ask the supplier for these, in writing, before you pay a deposit

1. Structural design calculations for your specific house, signed by an engineer, to Eurocode 5 with the Irish National Annex, including wind loading for your site.
2. Full specification of the timber: strength class, grading standard, moisture content at manufacture, and preservative treatment where required.
3. CE marking and Declaration of Performance for structural timber, engineered timber components and sheathing boards.
4. The wall, roof and junction build-ups with U-values, and the condensation risk analysis.
5. The airtightness strategy, drawn — not described. Where exactly is the continuous line?
6. Fire performance of the wall and roof build-ups, including cavity barriers and the party wall condition if there is one.
7. Durability and manufacturing quality control: what the factory checks and what it records.
8. Setting-out and tolerance drawings for the foundation, and the erection method statement.
9. Who erects, under whose insurance, and who is responsible for temporary bracing and weather protection during erection.

How Frest handles it

We manufacture in Latvia and erect on your prepared foundation. We supply the structural calculations for your house, the timber and board specifications with their declarations of performance, the build-ups with U-values, the setting-out and tolerance drawings and the erection method statement. We do not certify compliance with the Irish Building Regulations — your engineer and assigned certifier do that, and we give them what they need to do it. We say this plainly because the alternative is a surprise on your site, and we would rather lose an enquiry than cause one.

Frequently asked questions