Panel Installation is Underway /
Ready to Go. /
The Diaz Farm Massing Model /
The Agriboard panels on the Diaz Farm Residence will look something like this massing model when they are assembled.
The building regulates sunlight intake with a deep eave over the main living space and west facing exterior retractable shades. Coupled with the excellent insulation properties of the Agriboard, it is our hope this building will have superior thermal performance.
In working on this project and others like it, we've found the language of crisp edges to be the most natural expression of a panelized building system.
Waiting for the Rain to Stop /
Agriboard! /
Enter Agriboard. As a byproduct of the wheat and rice harvest, Agriboard manufactures a pressed wheat and rice panel they call a CAF (compressed agricultural fiber) panel. Instead of burning the wheat and rice fields after their harvest, a second crop is afforded by harvesting stalks for CAF panels. The CAF panel replaces the styrofoam in the SIP panel assembly and actually has a negative carbon footprint due to the manner in which it is harvested. The panel for the Diaz Residence is 8" thick and has a R value of 24! This is about twice the R value of a 2x4 wall with batt insulation. The panel's fire rating is 2 1/2 hours and this has allowed us to build closer to the property line than a traditional 2x4 wall assembly would have permitted.
This panel also provides a viable alternative to the present straw-bale quandry in California. Straw-bale, like rammed earth, is an affordable and readily available building material that has been essentially legislated out of existence in the affordable housing market. Isn't affordable housing the place to use these relatively unprocessed low cost materials? To build with straw-bale in California today requires a steel structure to handle seismic issues. The code considers straw-bale too risky a material in and of itself. This steel work is usually too expensive for affordable housing. The place we are far more likely to see rammed earth and straw-bale these days is in higher end homes. By coupling the use of straw with conventional wood construction elements (i.e. OSB) there is a real opportunity with Agriboard to provide a structurally sound building solution here in California that is energy efficient, healthy and renewable.
This panel also provides a viable alternative to the present straw-bale quandry in California. Straw-bale, like rammed earth, is an affordable and readily available building material that has been essentially legislated out of existence in the affordable housing market. Isn't affordable housing the place to use these relatively unprocessed low cost materials? To build with straw-bale in California today requires a steel structure to handle seismic issues. The code considers straw-bale too risky a material in and of itself. This steel work is usually too expensive for affordable housing. The place we are far more likely to see rammed earth and straw-bale these days is in higher end homes. By coupling the use of straw with conventional wood construction elements (i.e. OSB) there is a real opportunity with Agriboard to provide a structurally sound building solution here in California that is energy efficient, healthy and renewable.
We are pretty excited about this project. With the approval of an "Application for Alternate Method or Material," the Diaz Residence will be the first Agriboard structure constructed in California. Its 8" thick walls will allow the use of exterior shades in the window pocket. More photos to come.
A Passive Cooling Asset: Exterior Retractable Shades /
How far can one go improving the cooling properties of one’s house? Whether it’s a remodel or a new house design, it’s an interesting question with a lot of creative answers. Air conditioning is one stalwart solution, but there are other ways to improve the comfort of your home. It frequently surprises people to hear that “passive cooling” options should really be exhausted before exploring air conditioning.
"Passive cooling" is a term applied to any cooling srategy that uses few mechanical parts. Allowing cool air to flush a house at night while closing up the house during the day, is an everyday example of a passive cooling strategy. Increasing a building’s thermal mass, improving insulation and strategically planting deciduous trees are also good examples. But exterior retractable shades are another solution. Because they are simply placed above the window on the outside of a building, they are a flexible solution that can be elegantly incorporated into most floor plans with minimal impact on the homes basic layout. Furthermore, you can still see through them when they are deployed. With all these design assets, they represent a highly efficient solution that is wrongly neglected.
When dropped, exterior shades cool a house far more effectively than interior shades. Living passively does require a certain tolerance of seasonal temperature swings. In the winter a house is going to be cooler than it is in the summer. But if one considers the reduction or elimination of energy use, one starts to appreciate the possibilities. Should we really expect the house to be as warm in the winter as it is in the summer?
The ideas of the Slow Food movement and seasonal eating resonate with our Sonoma County way of life and the architectural parallels are worth exploring. Retractable shades, like most passive systems, heighten your awareness of the outdoor environment. If the building system is too highly processed we lose a sense of where we are. The cost associated with living this way is not sustainable. In a building on a thermostat it’s possible to exist without ever registering the change in the seasons or the character of our natural environment. Good architecture should be about tempering your environment, not disowning it.
The following conditions imply a project that is a good candidate for retractable exterior shades:
• A home with glass that receives a lot of summer sun (i.e. windows that face eastern, western and southern exposure)
• A home where the summer sun shine through a window onto thermal mass inside your home (e.g. a concrete floor or a tiled wall).
• A home that has a potential view that would be desirable in the winter but presents a cooling challenge during summer months.
If you meet any of these conditions consider these questions before installing exterior shades:
• Does your home have sliding or double hung windows on your building? Are you interested in using such windows? Retractable exterior shades work best with sliders and double hung windows because they don’t interfere with the window’s operability. Other windows like casements or awnings can be used but one is sometimes forced to choose between an open window and a shaded window because these window types swing outward.
• What size fabric is necessary to minimize the seams visible in your opening? If you have a large opening, certain screen fabric selections are hard to use without having a noticeable seam in the middle of the field of view. Check out your fabric capabilities before you incorporating it into your design.
• How much transparency is desired for sun protection and privacy? If you have a view you would like to see through the fabric, there is usually a trade off here. Be sure of your priorities before finalizing the fabric selection.
• What color of fabric is desired for sun protection, esthetics and privacy? Is it worth investing in a two sided fabric?
• Should the screen be motorized or manually operated. Motorized shades are an additional expense that can make sense if there are a lot of windows that need to be closed all at once or a particular window that is difficult to reach from the outside.
• Will the screen be mounted in the window opening, on the wall above the window or in the roof eave? This can effect whether your shade will run on tracks or cables. If the screen is mounted on the face of the wall, the shade looks better running on cables. Cables are less obtrusive than the track. If the shade is mounted in an eave space you can avoid the manufacturer’s housing and go with something more integrated by building your own recessed box. Our firm recently did this on a contemporary residence and we found it could be designed to fit into roof visor pretty easily (see figure) and also accomplished a very integrated look.
• Is there a good unobtrusive place to mount a wind sensor? Wind sensors are not always necessary. If the shade is mounted in the window opening, or simply on tracks, a wind sensor is not as necessary. But for a screen that is cable mounted on a wall face, one should consider a wind sensor.
• Do I need my exterior shade to function as a bug screen? This can simplify both the interior look and functionality of a building but it usually works best with a track system. A cable system always has a little clearance around the shade. If you’re serious about your aversion to bugs, this might not be enough protection.
I find many of my clients are surprised to discover they are a lot better off investing in a good passive cooling design than a good passive (solar) heating one. Why? The short answer is that heating a home is considered more of a life safety concern in the United States. Legislation, industry and our northern California climate have joined together to provide you the homeowner with many widely available and effective options in this regard. The same can not be said of passive cooling. Retractable shades are an attractive option.
In many ways exterior retractable screens are doing for a contemporary residence what traditional shutters did for older homes and it can be said that good architecture makes an esthetic out of the human response to the environment. Exterior retractable shades are an intriguing contemporary response that begs further expression and refinement.
Septic Systems Designs /
I recently found myself in the familiar position of waiting on a septic system design before I could call a project feasible and today I dealt with a new wrinkle in the complex Sonoma County septic regulations. One of the hurdles you must vault on your way to approval is to be at least 100' away from the 10 year flood line. On this particular project there was an existing septic system. It turns out that the 10 year flood line has changed from what was considered the flood line several years ago. Not only can the regulations change but the facts about nature can too! A lot of times I'll counsel a client to have a topo survey done without including a lot line survey because the project may be safely away from setbacks and the premium for the lot line information can run well over ten grand. But if you are doing a topographic survey and you are near the russian river, you should consider including a (re)evaluation of the floodlines. The information is invaluable for a septic and system anytime and they are may have changed recently. It is worth the cost of this piece of knowledge to avoid a project-stopping conflict late in the game.