Construction Progress: Week of Mar 11

This week saw the final module (the living module) coming together. Now, framing and interior sheathing have been completed on all three modules. While the interior sheathing was been put up on the third module, plumbing hookups were run to the bathroom. Also this week, the insulation professional responsible for installing all the insulation in the ELEMENT came in to do trials.

The insulation is a sprayed foam called polyurethane. The insulation is referred to as “spray foam” because of its installation method. As seen in the picture below, the insulation is blown into place where it clings to the wood surfaces and expands. This method offers substantially more resistance to heat transfer (referred to as R-Value) when compared to the commonly used batt insulation. This construction method is similar to Structurally Insulated Panels, or SIPs for short. SIPs are prefabricated wall units which are comprised of high density rigid foam insulation (most commonly polyurethane) sandwiched between to sheets of sheathing (commonly OSB or fiberboard). The best thing about SIPs is the lack of thermal bridges. Thermal bridges are created when a direct path is given through which heat can be transferred (aka through wall studs). SIPs have no thermal bridges because the loads are transferred through the sheathing, not through studs or other areas where insulation cannot be placed. If a scenario arises where more structural support is needed, studs can be placed to help carry a heavier load (from solar panels on the roof for example), but again SIPs effectiveness means that the studs can be spaced further apart when compared to standard construction.

The insulation should offer an overall wall R-Value of aproximately R-15. As you may see in the picture above, after the exterior sheathing is applied there will be an air gap between the exterior sheathing and the insulation. This will make the overall R-Value of the wall assembly drop because there will be air moving around behind the exterior sheathing where there should be insulation. To overcome this problem, one common solution is to put up the exterior before spraying the insulation. A circle is then cut out of the exterior sheathing and the foam is then blown in. This method insures that foam fills ever corner and thus maximizes the possible R-Value of the wall assembly. Another common solution would be to spray the foam without the exterior sheathing on and wait for the foam to expand past the joists (that would be the plane were the exterior sheathing should be), then cut off and disregard the excess foam. This should create a relatively even surface in the insulation after which the exterior sheathing is attached. This method, while often successful, generates much more waste. This can become an issue both in terms of efficient construction practice and cost.

The week of March 18^th the construction will be put on hold due to spring break. The following week the insulation professional will come and spray in the insulation. The entry “Construction Progress the week of March 25^th” should be able to give a detailed account of which method was used to spray in the insulation.

Construction Progress: Week of Mar 4

This framing was completed for all exterior and interior walls. With all the exterior walls framed out, work began on framing out the bathroom and the inverter closet in the bedroom module. This work was accomplished while the floors for the third and final living module were being squared and leveled.

Once the living modules floor is completed the framed walls can be secured to the floor. This process should only take a day or two. So hopefully early next week the full house will be coming into reality.

As touched upon in the entry form “Construction Progress: Week of Feb 25,” the panoramic windows have been framed out. While not erect, the solution to both the structural and energy lose issues can be seen. In order to carry the load from the roof down to the ground and also to help minimize the energy which was bound to occur through this panoramic window, the solution was to frame out the window in the corner by continuing the stud through to the floor joists. This process is covered more in deeply in the entry “ELEMENT Design Development: Panoramic Window.”

Construction Progress: Week of Feb 25

Construction this week has been progressing slowly but steadily. With the kitchen module framed, sheathing began on the interior and the module’s space is really coming into form. Work has also begun on the last module, the living module. Framing for the walls is coming along and should be completed by next week.

As for the panoramic window questions which have been arising; details have been worked out. If this has been unclear in the plans shown thus far, there will be two corner “panoramic” windows in the living module. One window faces northeast while the other faces northwest.

The framing for these windows should begin by the end of the week or early next week. However, based on the construction details described this week, the framing for one of the corners should resemble something like this sketch:

Sketch of "panoramic" window from interior looking northwest

Construction the week of March 11^th should result in the full framing of the living module. Hopefully then there will be an actual photograph of this detail. Perhaps by the end of the week of March 11^th there will also be a photograph of the three modules sitting side-by-side.

ELEMENT Design Development: Layout

The layout change occurred for a number of reasons. Namely, when the module shift occurred (for more information on why the module shift took place see ELEMENT Design Development: Module Shift) the fact was brought to light that perhaps the bedroom should not take up 1/3 of the total square footage. In the initial design, the bathroom and kitchen were located in the same module. This was excellent because all the plumbing could take place in a very small area saving time and money on construction and material costs. This kitchen / bathroom module was then referred to as the “Wet” module. However, to fit both the bathroom and kitchen in the same module led to a very small and uncomfortable kitchen.

Based on modern home layouts we developed the current layout in which the kitchen and living area are open to one another, making the space seem larger and more inviting. Since the home is only 500 square feet and it is to be marketed as a single family residence, we found it understandable to reduce the size of the bedroom and place the bathroom in the bedroom unit. While it may be a pain to have guests walk into your bedroom to use the bathroom, here is one way to rationalize it:

By keeping the bathroom outside the bedroom (as done in the initial design) you only have the small 12 foot by 18 foot living room area to use as entertainment space. Without a larger, more open kitchen this space will become uncomfortable with even a small number of guests. Therefore, we found it more pleasing to open the layout between the living and kitchen modules so that the house would seem more inviting and a more suitable space for entertaining guests.

The only “real” positive aspect of combining the kitchen and bathroom was (as mentioned above) the “wet” module aspect. However, by placing the larger “wet” kitchen appliances opposite the bathroom, the distance to run plumbing materials remained very short.

ELEMENT Design Development: Module Shift

The transition from the original design (talked about in the "Initial Design Concept" entry) to the current design took place during the first half of the Fall 2006 semester. The issues with the past design were resolved, or at least attempted to be resolved, in the development of the current ELEMENT design.

One of the first issues to be tackled was the reduction of exterior surface area. By changing the module layout, the surface to volume ratio was reduced 12%. Obviously, a straight rectangular layout with only 4 corners would have formed the most efficient surface to volume. However, by using the current layout, we were able to add more architectural interest and create a more flowing circulation path through the house.

The initial design idea for the module concept was creating each module based on a 4 foot grid. The reason being, sheets of building material most commonly come in 4 foot by 8 foot sheets. Therefore, constructing each module would produce less waste and lead to a more efficient construction process. However, when the initial design was developed, this 4 foot grid was only seen in the dimensions of the modules, know where else. In order to return to the 4 grid, the modules were offset and laid out based on this grid system.

The module shift created several other benefits to the design as well. By decreasing the exterior surface area of the walls, the shift also increased the available roof area for solar panels. An additional 3 solar panels were added due to this increase. To learn more about the design of the solar panels, see the “ELEMENT Design Development: Solar Panels” entry.

Construction Progress: Week of Feb 18

View out the north window of the Kitchen Module

Construction has been going along well. The bedroom module's exterior framing and interior sheathing is complete. Work on the kitchen module has been going well this week with sheathing scheduled to be complete by the end of the week.

With framing about to begin on the third living module, the framing for the corner window was coming into question. As the current design was being developed, the idea for a corner window was brought to life. The window came from the desire to have a panoramic view from the living module's workstation. However, putting a window in the corner of a building can have negative affects on the building's energy performance. It is said that the majority of a building's heat loss occurs at corners and around windows and doors. This corner window thus would have a very negative impact on the building's energy performance. This strong desire to keep this window also led to several other challenges including the building's structural capabilities as well as the physical construction of the window itself. For more information about the development process of this window see "ELEMENT Design Development: Panoramic Window" entry.

This week it is said that the window in question will be framed out in the corner to solve both the structural and fabrication issues while also helping to negating some of the efficiency issues which had come into question. Aesthetically, the panoramic feel of the window is sure to be damaged by placing a stud and two frames in the middle of the view. While details of the window were not available on the day of the site visit, next weeks entry should discuss how the window framing comes together.