u/Factory-Chad

Finally finished this solid oak vanity. Pretty happy with how the grain wrap came out on the stiles.

Hi everyone,

I’m currently doing a DIY renovation on a property in Hokkaido, Japan and I’m designing my insulation detail. Given the winters here, I’m concerned about getting the vapor barrier setup right to avoid condensation and rot.

Does anyone know of a building body, a freelance architect, or a consultant in Japan who offers professional review services for DIY details?

• Structure: Traditional wooden frame (Image 1), Stucco render externally.
• Current Plan:
  • Air Gap: 20mm packers/furring strips fixed against the external sheathing to create a 20mm ventilation gap (See Image 2).
  • Internal Layer: 50mm rigid foam insulation fitted between the studs/horizontal members (niku) (See Image 2).
  • Continuous Layer: 20mm rigid foam installed over the entire face of the studs to break thermal bridging (See Image 3).
  • Vapor Barrier: 0.2mm polyethylene plastic sheet covering the final foam layer before the interior finish (See Image 3).

The Dilemma: I’m debating whether to install a dedicated plastic vapor barrier (Bousou-shīto / 防湿シート) on the interior side before the drywall goes up.

I’ve heard conflicting things: some say the plastic is "non-negotiable" in Hokkaido to stop indoor moisture from hitting the cold exterior sheathing, while others warn about "trapping" moisture if the wall can't breathe through the drywall or the stucco render?

Thanks in advance!

Client asked us if we could use real timber (he has a curved island and wanted profiled doors) to match the melamine their interoir designer had specified - We got pretty close IMO!

All solid timber and veneer. Still mid-install but starting to come together nicely.