Structural Insulated Panels
Although log building and timber framing are both time-honoured methods of construction,
they can employ state-of-the-art materials. Of these, one of the most prominent materials
is the structural insulated panel, or SIP. The energy-star rated, sandwitch-like panels consist of two
layers of sheathing separated by a rigid foam core. The foam core provides the insulation while
the sheathing maintains the panel's rigidity and strength. In a conventially framed house, heat is
conducted through the framing members, buth with SIPs, a house is virtually wrapped with a continuous
and uninterrupted layer of insulation, achieving a remarkable degree of energy-efficiency. SIPs offer an
insulating value of approximately R-6 for every inch of thickness. This means a 4-inch thick wall offers
an average insulating value of R-24, while a conventional stud wall with fiberglass insulation rates between
R-12 and R-14. Because SIPs actually combine four steps of the home building process - framing, sheathing,
insulating, and vapour-barrier - into one, the result is a drastic reduction in on-site construction time and
decrease in labour costs. This makes the combination of timber framing and SIPs an economical choice. Another
advantage of SIPs is the reduction of external noise. The dense foam core of the panels helps prevent
sound travel form one side of the panel to the other. Of course, SIPs can also be used on their own, without
the log or timber structure. They are compatible with all types of conventional construction, making them an
excellent choice for additions and renovations. Currently the London Home Builder's Association, with support
from Natural Resources Canada and the Federation of Canadian Municipalities has begun a program researching
and promoting energy-efficient technologies. This program, London's Energy Efficiency Partnership (LEEP)
has listed SIPs as one of the top new technologies devoted to improving energy efficiency in home building.
For more information on LEEP please call the Air Quality Management Division of the City of London at
519-661-2500 or email
jskimmin@londonon.ca.