Blog

The construction of a clients high performance house, near Parry Sound is coming along quickly!  The walls and roof are up and the enclosure will be protected soon to receive the upcoming winter weather.
At this stage, when the walls and roof are being constructed, it is exciting to see the design becoming a reality.  Our clients were inspired by Frank Lloyd Wright and think the impressive overhangs with their bare bone structure look stunning: they already have begun imaging themselves in the spaces, relaxing, cooking, and entertaining.
  

Elements envisioned back in the design stage are starting to materialize, like the three picture windows facing the lake that provide a fantastic view (see below). The location is pristine and we wanted to maximize the visual interaction between the interior and the exterior.
  

The tall window on the side frames an oak tree in front of it.  The 14′ high ceiling in the central living space is impressive and bright.

  
We have four high performance wall assemblies that we have designed at the firm.  But we know that each client-contractor have their preferences, so we were  able to accommodate different options according to site or their labour availability. We explored the use of prefab walls and SIP  (Structural Insulated Panels of OSB sandwiched between Extruded Polyestyrene), but the contractor felt comfortable with the double stud walls and these also provided the better cost. We are loving the double stud walls and the contractor is fully on board with the non conventional detailing to minimize thermal bridges, air leaks, and durable.  For example the contractor suggested having the studs staggered which will maximize the effective r-value of the walls.
  

Due to the slope on the site, 3/4 of the house is on TJI  (truss joists) floors sitting on piers. The rest of the house is on a slab on top of the rocky “Canadian Shield”, as our client loves to say. The TJIs will be filled with insulation, but the perimeter concrete wall of the slab needed a more intricate detailing to reduce the heat losses. The interior wall of the double stud wall is non-load bearing and to break the thermal bridge 6″ of high compression strength insulation was added below the wall sill plate. You can see the gravel and lime layer exposed awaiting the insulation before pouring the slab.

 

The detailing of the enclosure is key to achieve a high air tightness levels and the continuity of the Air Control Layer (OSB board) on the exterior of the wall is properly connected with high quality tape as you can see on the image above. Once the roof trusses are installed, the Air Control Layer will continue at the interior with an OSB ceiling properly connected to the OSB extension above the top plate. The air control layer will hold the loose insulation down enough to leave a vented cavity between the insulation and the roof keeping it dry.
    

The roof was a challenge because we had to accommodate 16″ of insulation, the low slope, and the continuity of the air and thermal control layers. The open web roof trusses provide very low thermal bridging and long spans make the interior column free. These trusses also provided strength for the long overhangs that the design required. The photos below show the high quality tape and spray foam insulation applied at difficult locations. The contractor is looking closely at all the nooks and crannies to guarantee the lowest amount of thermal bridges. It is important to the have the contractor on-board when creating a high performance house design!
  

If you would like to begin construction your dream home this spring contact us soon to start the process. Give us a call for a free consultation 416-868-9227 or email us to info@coolearth.ca