Implementing Building Integrated Photovoltaics

The concept of Building Integrated Photovoltaics (or BIPV) has been around for a while.  The idea behind BIPV is that an effort is made by the solar panel company to supply panels that don't look like an ugly after thought when placed on the roof or the wall of a structure.  For a long time arrays have often sat, somewhat insect-like, on the skin of a building.

Despite laudable efforts in the past decade, the problem of thinking about solar panels in a truly integrated way persists.  In short, it has just been very difficult to incorporate a mass produced mechanistic object into the esthetic fabric of the domestic environment.  Much of this can be blamed on the cultural schism that often exists between the worlds of architecture and engineering.

I've heard it said that good architects start off "knowing very little about many things until they know nothing about everything."  Good engineers, by contrast, are suppose to "know a great deal about very little, until they know everything about nothing."

This is a basic difference between the two disciplines and photovoltaic solar panels were conceived by engineers with the initial specific goal of providing solar power.  This undertaking required a great deal of expertise and specialization.

In the world of architecture, on the other hand, every building element is commonly asked to have "stacked" functions.  In other words, one building element should perform many functions.  This is not always true, and one can argue that the world of architecture is becoming increasingly engineering oriented.   Buildings are increasingly populated with elements that perform discrete functions. Not too long ago a wood floor simply sat on floor joists and performed the "stacked" functions of structural element, insulation, moisture retarder and finished floor etc.  This way of stacking functions has an efficiency about it that is wholly different from the efficiency of the engineering world.  The engineered solution tends to introduce specialized elements that address the individual design challenges; plywood subfloors perform the structural task, a finished wood floor for esthetic and wear issues and to protect the subfloor from wear and tear, and a possible vapor retarder between or under these two elements if one is specifically concerned about moisture.

This subject of "general" versus "specialized" design approaches is an intriguing one.  The environmental design movement today is taking a decidedly "specialized" approach vis a vis the LEED rating system.  This "point" system  is very much an engineering approach to the business of environmental stewardship and it can be argued that this specialized way of addressing our environmental problems is exactly what got us into this environmental mess in the first place.  After all, some of the most wasteful design solutions are the ones that, while efficiently executing their specific task, are inefficient in the breadth of their capabilities.

This project was intended to take the solar panel to a level beyond the BIPV approach.  We didn't want the solar panel integrated with the building only in the sense that it "plays nice."  On this project we wanted the solar panels to actively contribute to other functions on the project, namely to provide shade and a modicum of shelter.

If a pool is an ingredient of a project, it can be an organic place to utilize solar in this way since it gets good sun exposure and can benefit from an elevated structure that also provides a modicum of shade.   One sees this being done with carports as well and this is the strategy we implemented here.

The two biggest construction challenges with this installation were the wire management and getting all the team members to realize - conceptually -  that we weren't just installing solar panels; we were installing a shade structure.  

It turns out it is typical to install solar panels wires in a leap-frogging daisy chain fashion utilizing the wire whip that comes with the individual solar panel from the factory.  This practice avoids introducing an extraneous wire at the end of the run to bring the circuit back to the beginning.  This extra wire also adds a little cost and reduces the efficiency by a very minor amount.  But if you are making a shade structure and not just a photovoltaic array, this cost is minuscule compared with the cost of an entirely discrete trellis element.  This is exactly what we were trying to accomplish.  For this reason, Solarworks installed an extra circuit-completing cable (in addition to the whips provided by the factory) to keep the wire pattern consistent.  This strategy was facilitated by the presence of tube steel trellis members that provided a concealed manner for routing the wires as well as the mounting mechanism for the panels themselves.  A big thank you to Mark Rechin at Total Concepts for coordinating the final effort to fine tune this wiring issue.

figure 2

Left to their own devices, and in the absence of some clearly articulated alternate objective, any solar panel installer is going to install solar panels with about a 20° tilt at this latitude to maximize productivity.

These panels were installed with a 1/2" drop across their 5' length.  The reason for the minor tilt is to simply get standing water and grime off the panel and to prevent this scum from hampering energy production.  This array had two parallel rows of solar panels along its length and we simply pitched them to either side of the main axis with the peak running lengthwise down the array's ridge (see figure 2 and 3). The solar panels need to be cleaned with a hose once a year to maintain reasonable efficiency. 

figure 3

On this project we pursued a strong connection between the grape fields and the pool site work. The solar "trellis" was an element that was striking in its similarity in both form and function to the stakes and metal wires that supported the grapes and aided in their harvest.  This idea of harvesting energy became a strong force in designing this solar trellis and we wanted to create a real harmony between the geometry of the grape fields and the pool terrace with its solar-harvesting shade element.  We had wanted to design a building that had an authentic connection and harmony with its environment and this seemed like a strong way to pursue this connection.  A shade structure that was not pitched, but virtually flat, would resonate strongly with the layered planer geometry of the project (e.g. the pool surface, the terrace and the fields themselves).  It is true that there was a minor loss in power production associated with this strategy but in a more macroscopic sense for the project we had also built a shade structure where we could have simply built a solar array .  This is the basic idea behind building integrated photovoltaics.

I was happy to hear this week that the eight kilowatt solar panel array is currently running a credit with the electric company for the entire Diaz facility.  

My Father's Home in Willits

With the down turn in the economy there are understandably a lot of questions from potential clients about how to build things on a tight budget.  I frequently point them to a project done up in Willits for my father several years ago.

A lot is written about square footage cost.  This is a coefficient that can be readily applied to just about any project and because of this it is a popular way for people to get their head around building cost and compare relative costs.  But there are a lot of hidden costs to a project that are either included or not include in this figure depending on the point someone is trying to make and the nature of the building type.

In the residential world for example, when one speaks of the square footage cost of a home, one often takes the construction cost of the building itself and divides it by the heated space square footage.  The cost of the garage and the other "servant spaces" go along for the ride and contribute to the square footage cost of the residence proper.  To include square footage costs that are not actually the square foot in question often strikes people as odd.  This is understandable but it is important to realize people are trying to focus on the cost per square foot of living space with all the building related prerequisites.  Conversely it is quite typical (though not categorically so) to not include the cost of the sitework (driveway, utility trenching etc.). This is part of a civil engineering universe that usually doesn't apply to the construction cost of the home itself.  The whole thing can get quite convoluted.  

Having said all this, we did my fathers house for roughly $150 a square foot.  This was done back in the mid 90's.  Even back then, that number was eye-catchingly low for a custom residence.  I don't want to frame our solution as a recipe for how anyone can build a home for $150 a square foot.  The real answer is that you use all the resources you have at your disposal and you don't invest in anything that you don't deem necessary.  

Its important to realize that most spec homes are not built this way.  At least not this second criteria dealing with neccessity.  Why?  Because a spec home needs to appeal to a broad enough audience to stay marketable out of the gate and different people have surprising tolerances for inexpensive solutions.  They also want surprising amenities and I like to believe that you can build pretty affordably if you don't try and trick your house out with every amenity to a middle-of-the-bell-curve-or-greater extent.  

My father, for example, did not need a dishwasher, a door bell, an enclosed garage or a ducted forced air system.  His house was 900 square feet and a carport with a large closet was sufficient for his "garage" needs.  Because this two bedroom house is so small there is virtually no hallway.  Everything is built around a central music-making living room.  

We also went radically light on the floor.  Except in the bathroom and the kitchen (where we used linoleum) we used floor paint over his plywood subfloor.  We didn't put down any additional carpet or wood flooring down.  He uses area rugs. The outside of the house is simply painted exterior grade plywood siding with battens applied at 12" on center.  We debated the need for the battens but the fact is they help to conceal the nails and plywood joints.  Most custom homes these days add a layer of siding.

My father also hired a general contractor as the job foreman and took on the general contracting responsibilities himself.  This avoided the usual 15% to 20% markup.  I wouldn't recommend this approach for everyone.  He and I talked a lot and he was a conscientious presence on the site.  He is also someone who has gone all his life with little to no health insurance so he is use to avoiding the moral hazards associated with lots of liability protection.

On the flip side of things we invested in a couple things he really cared about.  He got a nice wood stove and a 24 gage painted corrugated metal roof that was expressed on the interior of the house as a vaulted ceiling.  Fine Homebuilding had an article several years ago that opined that a vaulted ceiling usually increases the building's typical square footage cost by 50% in that area.  Part of the reason for this is the expense usually associated with more complicated drywall installation or the finished lumber work involved with exposed beams. We tried to offset this tendency by simply using conventional framed lumber in the ceiling.  This included simply exposing the framing plywood.  But this roof was still expensive.  The insulation of a vaulted ceiling is typically complicated and this house was not exception.  We had to sandwich a layer of polyisocyanurate insulation on top of the interior plywood and a second layer of plywood to which the metal roof itself was attached.  At the end of it all he got a long lasting roof with good acoustics in the living room due to the high ceiling.  The clerestory windows also act as a cooling chimney for the house.

All in all the project was a study in surgically installing your wants and needs and dispensing with the unnecessary things.  In many ways this summarizes the undertaking of design.

The Interior Under Construction

CalGreen: The Pros and Cons of the New California Building Code.

After spending the day in seminars going over the new California CalGreen Code a while back, I feel I can finally shoot my mouth off a bit without feeling like I haven't "done my homework."  Here are my take away points from the new regs:

First let me say that getting a famously diverse state like California to march in lock step over building codes must be a daunting challenge for any codesmith.  The task boggles my mind.  Also, whether we like it or not, we have big appettites here in California.  We like our scenic highways, our beautiful real estate, our cuisine and our nice weather.  While we care about the environment, we also like our bonvivant lifestyle.  Its not exactly a state of deprivation.

Getting the code officials, let alone the construction industry to realize that environmental issues are also health and safety issues is a challenge I never thought would see the popular light of day.  Up until now I've had the sense the code was a life safety apparatus in the most blunt sense of the word.  It might waste tons of embodied energy in the name of lonely ADA bathrooms sprinkled across the US but at least at the point of use, the mission is clear.  Seeing a code with more big picture environmental concerns is a relief.  It might still be couched in self interested terms, but there is something laudable about treating the environment as something to be preserved.  So bravo on that.  This code is a big step toward recognizing in a conscious way, what many tribal people know intuitively: The environment is worthy of respect and - in some hard-to-define measure - our own well being (i.e. health and safety) is tied up in it.

Having said all that, there are a couple things that really rub the wrong way about this new code.  For now,  let me confine myself to the subject of fireplaces.

There are a lot of people who say they won't buy a house without a fireplace and yet it is ILLEGAL to build a house with a wood fireplace in modern California.  I get there is an indoor air quality issue.  I understand that wood smoke can dirty the air.  Nevertheless, this in itself is not a sufficient reason to outlaw open fires inside a home.  Burning wood has many benefits that driving a car or burning yard waste on burn day lack.  This is especially true in Rural areas. You are replacing the consumption of gas, oil or electric energy with a locally available - potentially FREE fuel that, among other things  - has the added benefit of clearing the underbrush in fire prone areas.

I get that there are certain areas with precipitous terrain or "dead air" that suffer inordinately from wood fires and it makes sense that these areas be considered too dense for fireplace use.  But it seems wrong that everyone should lack the option of a fireplace because of these areas.  We are not headed for the kind of congestion that merits a blanket code on this front.  Marc Reisner, the author of Cadilllac Dessert, would have us believe water usage will curtail growth long before fireplace pollution would have this effect.

The other reason that gets paraded around for public viewing when we talk about abolishing fireplaces is indoor air quality.  The dirty little secret that is implicit in this argument is the fact the code has been pushing the industry, wrongly in my opinion, toward more air tight construction for some time.  It is not without irony that buildings have also been having issues with mold in the past couple decades.  Even the requisite energy calcs mandated by the state of California completely neglect the reality of thermal mass in association with thermal comfort.  Objects (like fireplaces and concrete floors) allow heat to be dissipate over time in a manner that continues to function even when the doors are open or you are in a space with a high ceiling.  Objects with high thermal mass do this primarily by radiating heat via infra red radiation and conducting heat to the surrounding air.  Thermal mass located near the human body is a tremendously effective way to stay warm.

A complaint voiced about fireplaces has been the general draftiness and extremely local comfort afforded by their heat inside a house.  Like this is a big surprise?  Many people know that opening a window or door can help keep a fire going.  The fresh air is also good and, because the fire is a radiant heat source, this isn't, per se, a problem.  If you wanted to be warmer you had to "huddle" by the fire.  Because the code is only now becoming somewhat sensitive to thermal mass, the construction industry has been obsessed with heating the entire mass of air inside a house and then sealing up the house tightly in some kind of strange hoarding idea that should not be given more credence than some - arguably more valid -other ideas.  An equally valid instinct is this abiding "huddle" idea and it seems wrong this idea should be given so little validity when a more worthy goal would be to rectify this deficit in the virtues of a breezy house with high thermal mass in the present code.

Also, the fact that gas fireplaces and EPA approved wood stoves are allowed is suspicious.  All these appliances just seem to be a further step toward disposable materials that work out well for big business.  Gas fireplaces might burn efficiently at the point of use but there is no reliable way to quantify the embodied energy associated with the exploration, extraction, production, transport, storage and distribution of this fuel.  One thing is certain: It's a whole lot greater than a dead piece of wood.

Academics might attempt it, but the reality is: you and I will never know.  It bothers me that this form of fuel use is so causally detached from me.  The beauty of a fireplace is not only the way the flames can lick so deliciously at the dead wood but the fact that people understand it.  Too much smoke can make you choke.  There is no doubt about this.  But the fact you understand exactly what is polluting your environment has merits in itself.  It is too easy to displace the pollution to central locations where its effects go largely unnoticed or understood.  It seems better to regulate the usage of open fireplaces in a community-by-community way where the effects of usage patterns can be suitably addressed along side the obvious economic and larger environmental benefits of avoiding the use of a processed fuel source.

A Roof Under Spared Trees

Last week I visited a beautiful retreat called Four Springs in Middletown.  Their main lodge had recently burned down.  Based on the folks I spoke with, the lodge was a place of many memories and its lose will be something that will take some time to heal.  While the place clearly has its own ethos, it reminded me of several places I have visited in California as both a child and as an adult.

These retreats are literally what California poet Robinson Jeffers called "A roof under spared trees."  Something about this kind of place captures an enduring side of California life.  Tucked away in the forest, the retreat is a spiritual place with no discernible ambition to take its spirituality "on the road."  From all appearances what is taking place at this retreat is sustained largely on the power of the environment itself, both human and nonhuman. A worthy mode of operation.

Most of the cabins are simple and rudimentary in nature and serve mostly as sleeping quarters for the guests who gather at the lodge or other hubs located throughout the woods.  It has the effect of subduing the built environment while celebrating the natural beauty of the place.

Not all retreats are explicitly spiritual.  I can recall going to a retreat like this in the redwoods north of San Francisco as a kid and later as an adult my family and I journeyed to Camp Mather near Yosemite.  It is interesting to recall that a distinction of many early American protestant faiths was the concept of a meeting house.  This was  a radical departure from the more european catholic notion of a church and its designation as a "house of God."

As a child I remember being encouraged by many adults to acknowledge the beauty of nature as something spiritual and to be sure to get out "in it."  There was always this sense that if God could be found anywhere, the natural world was as good a place as any.  This early american idea that one did not need a cathedral or church to find God certainly resonates today in many of the faiths people continue to pursue here in the west.

In 1911 George Santayana wrote, "I am struck in California, by the deep almost religious affection which people have for nature and by the sensitiveness they show for its influence...It is their spontaneous substitute for articulate art and articulate religion."

It has been argued by far western writers like William Everson that to call nature a "substitute" for art and religion is to give nature less import than it deserves.  Whatever the case, it is my sense that Satayana was accurate in his observation of nature and the mythic role it plays in the far western collective unconscious.  This retreat is certainly a meaningful example of a spiritual space that possesses a dominant natural beauty.

Diaz Vegetable Garden Taking Off

It was good to see see the Diaz vegetable garden taking off in the wake of all the recent construction.  So often the area around recent construction is kind of a DMZ.  It usually takes a while for plants to repopulate this zone where vegetation and the built environment intermingle.  The subject of how buildings relate to landscape is an interesting one and this intermediate zone can be a real testament to our attitudes.  In the spectrum of residential projects that come across our desk at Studio Ecesis, this one is interesting because it is a home on a working farm.

There have been a several articles over the years that critique designer residences in the rural landscape and their tragic detachment from any useful or authentic connection to their surroundings.  Greg Brown, the folk singer says: "All this stuff about intentional community is a bunch of crap. You’ve got to need each other."   Getaways can be wonderful esthetic pieces but they are also understandably prone to dilapidation.  With our recent rains and the concerns about grape shatter, the need for a surveilling residence on a farm is pretty self evident.

As an architect, can you design a house that forces people to be connected to the land?  I thought so in architecture school.  Giving up on the power of this idea was a bit of a let down initially.  But in reality, while designer's can't "force" anything, they can "inspire" behaviors.  There is nothing like a diving board to make one want to jump in the water.  The truth is that clients come to you with a dream and you are either lucky enough to resonate with it or you are not.  If you resonate with it, inspiration is a whole lot easier.  

In architecture school you are, in a strange way, the client too.  You create, or at least interpret, the program and then you give it voice through a building.  There is something deeply self involved and at the same time deeply expressive about this.  Something akin to a composer conducting his own music. With this kind of control, the architecture student is more the academic equivalent of a developer, not an architect.  

Once you get out of school you switch from the naturally didactic world of academia to another world.  In this world (some people call it "the real world")  members of the community "need each other."  

It is frequently the case that the architecturally designed rural home puts a big premium on the view of the landscape without actually engaging it.  A worthy question:  What kind of rural home showcases a generous view of the land without a convenient means to join it?

In this project we were lucky enough to have clients that explicitly wanted to connect to the land.  Their temperament recalled an atavistic belief that this connection to land is an abiding thing worthy of incorporation into a residential design despite its less cinematic experience.  

Starting with the residence itself, this home transitions first to a wrap around veranda and screened-in porch, second to a vegetable garden and yard and finally to eighteen acres of grapes. The area around the house was a wonderful intermediate space between domesticity and agriculture.  A big thank you to Mike Lucas for helping to get this garden off the ground and another one to the Diaz for making such a welcoming and connected residence.