LaHouse Building Systems and Features (East Wing)

Structural Insulated Panel System

SIPS roof

SIPS roofing

East Wing (dining, home office, part of kitchen)

Structural Insulated Panel System (SIPS)

  • Factory made panels of insulating foam core with ½ in. thick oriented strand board (OSB) panel skins
    • Borate-treated EPS foam & OSB for termite resistance
    • Panels form structure and insulation in one step
    • Openings lined with studs
    • Panel size from 4 x 8 to 8 x 24 ft.
    • Precut chases for wiring
  • Very fast assembly with less skilled labor, fewer trades – but requires crane to lift large panels
  • Can be fully precut in factory or openings cut on site
  • Highly energy efficient system
    • Continuous insulation (no gaps from framing) outperforms higher R-values between studs
    • Creates airtight building envelope
    • Panels glued and nailed to insulated spline joints
  • High strength, stability, shear resistance
  • Little construction waste – less to landfills
  • OSB is efficient use of renewable wood resource
  • Cost 0-3% more than standard wood frame
    • higher material cost, lower labor & finance costs
    • transportation cost – distance from factory matters
    • simple designs on 4 ft. grid, model plans cost less

SIPS Roof and Attic

Two options exhibited:

  • SIPS ceiling creates airtight, fully insulated, walkable attic floor (see attic over home office from exhibit room)
  • SIPS roof creates unvented, semi-air conditioned attic (see attic over dining area in exhibit room)
    • No HVAC, duct losses + climate-controlled storage space

Weather Barriers

  • Triple sill gasket – air seal plus adhesive flashing in one
  • Hot-humid climate housewrap installed shingle fashion
    • Water vapor retarder (ideal 6 perm, semi-permeable)
    • Strong, tear-resistant, well fastened
      •  Withstood Katrina and Rita
    • Non-perforated; surfactants won’t cause leakage
  • Plastic window sill pan flashing with sloped channels drains to outside (see semi-circle window in exhibit room)
    • Protects vulnerable corners, sills from water leaks
    • Fast, easy installation; no need for slope, backdam
  • Mortar dropping collection system behind brick veneer to protect weep hole drainage

SIPS Energy-saving features

  • Exceptionally airtight system without added air barrier
  • Continuous insulation throughout building envelope
    • 4 in. wall = R-15 - outperforms R-19 between studs
    • 8 in. panels (R-30) for roof (see exhibit room over dining) or ceiling (see attic floor over home office)

Fortified SIPS features (to resist 130 mph wind & flood damage)


  • Anchor bolts tie bottom plate to slab every 16 in.
  • Metal connector plates secure wall panels to sole plate to resist both uplift and shear (racking) forces
  • Panels provide inherent resistance to lateral wind forces


  • Hurricane straps tie wall panels and plates to rafters, wrap over every rafter (framed roof over home office)
  • Close spacing of fastening screws tie roof panels to wall panels
  • Rafter 2x8 splines between roof panels extend full length of roof porch overhang
  • Peel & stick membrane roof underlayment – secondary water barrier for storm protection
  • Breezeway roof reinforced with micro-laminated beams and bolted through both building walls for high uplift resistance

12/18/2008 12:34:28 AM
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