Seattle - Epilog
We're coming up on 6 years in the house now, so we have some longer term performance data. The major glitches in our data is that we didn't get our PV till July 2005, and for various reasons our rainwater system has only worked for about eight months. We've had a few hundred people tour the house, and won a couple of awards, but more importantly we love the house. Of course, it's not perfect, and so here we talk about the things we like and the things we think we could have done better.
We've hosted at least five major tours of 50+ people, and numerous other smaller tours. While we are committed to giving them, they are also exhausting. We're doing the solar tour on an intermittent basis, and only very occasional special request tours.
In general, the house works for us. We both love having separate offices, and use them frequently. While we used to fight over the couch a lot, we now both use the window seat far more often, especially when its sunny. Although the dining area is small, we had eleven people around the table for a snack and a roundtable discussion and it worked fine. Having a small bedroom hasn't bothered either of us in the least. Bob hasn't, for various reason used his art studio, so that space has become an art storage area, although the hope is to someday paint again.
Initially we over used the mini-office, but once Bob moved his email to his laptop, this problem went away. The mail sorting area does help with paper clutter, but it doesn't solve it completely, because we didn't give ourselves enough space for "projects". We've struggled a bit with the "living room" part of the great room, and finally (Dec 2005) found a furniture arrangement that works. Kim is not quite happy with it, because in her view its just a few feet too small.
The light switch to the basement is still behind the door (how that happened is beyond me), but the awkward one in the attic has been moved.
The master bath, although functional, has light coming from only the south, and even that is blocked by the linen cabinet. Stylistically, its also our least favorite room, and admittedly we rushed thru the design of it, not thoroughly thinking it all out.
The main annoying downside to our HVAC system is that it only works with very hot water, so we have to keep the tank at 140-160 degrees. To make matters worse, we can't turn the tank temperature down because plumbing code (and possibly sensibility) require a tempering valve if the tank is above 120 degrees. The problem here is that tempering valves lower the hot water temperature by at least 20 degrees, so if you try to turn the tank down to 120 in the summer, the tap hot water is only lukewarm. This problem is further exaggerated by the fact that our "utility closet" in the basement is the only part of our house that isn't super-insulated. The result of this is that our standby losses are probably greater than they should be, although we don't really know what they are.
I've recently discovered that there are now tempering valves that only lower the temperature by 5F, so that would make summer setback much more reasonable.
One side effect of the fan/coil heating system is that it delivers heat very slowly, even with the tank set at 140F. When the outside temperature goes below freezing, the heat runs far too much, so we've started turning the tank up to 160F (which is its max), and alas, unless I remember to turn it back down, we have greater standby losses all winter.
In retrospect, I wish we'd found a cost effective way to do in-floor heat because it can transfer the same amount of heat with lower temperature water. The main question is whether the metal heat spreader plates are really necessary, since they can add thousands to the cost of in-floor heat.
For our energy use, click here.
The thermomax system works like a charm. In the summer the pre-heat tank runs between 110 and 160 degrees, in the winter it often hovers around 60 and in the spring/fall its usually between 80 and 120. If we didn't have to keep our main tank at 140, we'd get a higher percentage of our H/W from solar.
We had one mishap, which was apparently caused by a crow pulling the temperature sensor out of the collector. Its now tied down very securely.
There has been much debate within the Ecobuilding Guild as to whether evacuated tubes make sense, and the general consensus is that for the added expense, you can collect the same heat with a smaller roof footprint.
While the ultimate solar hot water friendly tankless unit has yet to arrive, the units are getting better and improved tempering valves makes the overshoot a moot point. The minimum burn rate on most units is still pretty high for very warm (100F plus) preheated water, and the minimum flow rate to trigger the burner on is getting lower also. My guess is that unless the manufacturers go to a two burner setup (with one have a very low maximum output), or some other significant design change, there will be no further improvement.
I'm still interesting in trying my "small tank" idea, although the issue is now that you're incurring a small standby loss and have to run a pump to keep the small tank at temperature, but with the improved tempering valve, its probably not worth it.
From the carbon-neutral perspective, tankless units are not a great choice, since the only practical ones run on natural gas or propane.
We had 3KW of PV put on our roof in July 2005. To get net metering going, you have to fill out a bunch of paperwork, and once we did, the utility came out in Aug 2005 to give us a meter that will actually run backward. We generate ballpark 2500Kwh a year, which is about 500kwh lower than we could get in Seattle. Our limitation is two trees that shade the system.
The installed price is around $18,000, which as far as I can tell has a payback that is around the life of the system. Based on Seattle's typical max generation of around 3000kwh a year , and assuming its worth 10 cents/kwh (even though our summer rate is more like 4 cents/kwh), the PV generates $300/year of electric. At that rate the payback is around 60 years. I'm assuming here the the discount rate on my $18k investment cancels out the inflation rate for the cost of electric. If the cost of electric goes up significantly faster than the amount I could have earned keeping the $18k invested, then the payback time will shorten.
The state of Washington passed a 15cent/kwh rebate law in Jul 2005, but due to some internal political battle, it wasn't actually implemented till Jul 2006. They did actually make the rebate retroactive, and as a result I got $382.50 for the PV I generated from the time I installed thru July 2006 (2550kwh). Even with this rebate, and using 10 cents/kwh avoided cost, the payback is still 24 years--a long time. I'm declaring myself neutral on the issue of whether subsidies are a good idea. If I had a choice, I'd be putting funding into designing more efficient cells and increases in manufacturing efficiency. More info can probably be found on www.solarwashington.org or at the American solar energy society's site: www.ases.org.
We now participate in Seattle City light's green power program send $72 back to the city to help fund their purchase of green power.
May, 2007: Now that the production program is in place, they'd decided the production meter must be located outside, so they can read it. Unfortunately, we put it in the attic because it was easier, assuming I'd be reading it. It cost a bit over $700 to move it, and then I have to pay a $47 fee for a new meter. So while someday I still expect to save money, that hasn't happened yet. Such is the life of a pioneer. We are still saving carbon, its just that its cost us to do it.
The other issue that has come up is the effect of shading, which reduces output dramatically more than I understood. We had one tree thinned in Jan 2007, and although it should reduce the problem, we apparently took off too little to have any affect. The problem is that even the tiniest amount of shade reduces the output dramatically. I really need to top the tree somewhere near the roof line, but its not my tree.
Jan 2009: Our second rebate was $384.90 (2566kwh) and our third was $325.65 (2171kwh), apparently due to a lot of crappy weather.
Jan 2010: Our forth rebate was back to around $375.
For our electric use, click here.
Although we installed an HRV, we've never used it. We installed a separate ventilation controller to run the HRV directly below the thermostat, but it turned out as dumb luck would have it, the heat rising off the ventilation controller's power supply was heating up the temperature senor in the thermostat because we installed the two really close and the vent for the controller lines up exactly with the inlet for the thermostat sensor. As a result, I snapped the controller off its base to fix the problem, only to discover that the installer didn't leave any slack in the wires, so I'm going to have to break some sheetrock to fix the problem.
In the meanwhile, I looked more into ventilation requirements and bought a humidity meter to try to get any idea of whether the lack of ventilation in our very tight house was a problem. In fact our humidity stays in the 45-50% range all the time, which is considered good. I also tried to reconcile why commercial ventilation is set at 15CFM/person, but residential is expressed as .35 ACH, which in our house translates to around 122 CFM. As it turns out, even the 15CFM is high if you're looking at only the Oxygen necessary for life. The addition ventilation is for diluting other pollutants.
I have no real way to measure how clean our air is, but I can say that we avoid most of the traditional source of indoor pollutants, and use both the bath fan and kitchen fan religiously. The blower door test measured our house at somewhere between 2.8 and 4.5ACH50, with the complication being that the units were measured separately and then combined. The ADU was much tighter than the main house. My general conclusion is that in the winter, we get plenty of natural ventilation, and when its nice enough outside that we don't, we open the windows.
Although we use the bath & kitchen fans pretty religiously, they don't add a whole lot to the daily ventilation amount, probably adding only 8-10CFM over the course of the day.
Ventilation is a much bigger issue in the ADU, where the theoretical natural ventilation is only between 12 and 23CFM, however their ventilation system is the standard bath fan on a timer, and it not serviced by the HRV anyhow.
If I could do it over, I wouldn't put in an HRV or any whole house ventilation system unless I was sure the house was tighter than 2.5ACH50 and/or there was some need for excess dilution air. If I did put one in, I'd want some kind of timer that allowed it to run for a portion of every hour, so the fresh air was distributed evenly over the course of the day.
Since almost no one in Seattle had done a rainwater tank (including us), the project has suffered from a lot of glitches. Our small lot dictated that it had to be under ground (or under the house), so we still feel that cast in place concrete was the right choice. We use the patio on the tank surface whenever the weather allows.
Sealing it required a lot of futzing around, but like anything else one you know exactly what product to use and how to use it, everything becomes much easier. Had we sealed it during the summer, our job would have been easier, because we had a steady stream of groundwater coming in the tank in the seam between the floor and the walls, which complicated sealing the tank significantly. I believe the sealing step could be eliminated with the right concrete mix, since there is apparently a "water tight" concrete.
While the tank itself was ready to go when we moved in, we didn't get our permit to use it flush our toilets till many months later. When we finally did, we promptly burned out the pump, because even though it says that its self-priming, they don't really mean that. Once we found someone to repair it (a few more months: since there are no wells around it was hard to find someone who knew how to fix them), the system run great for about six months and then burned out again. It also turns out that adjusting the turn on/turn off pressure switch is easy to get wrong, and when you do the pump goes into on/off oscillation.
We don't know exactly why the pump burned out, but our theory is that it was because the filter was clogged, creating too much back pressure. We installed a "motor check" device, which was supposed to prevent this, but again, we may have had it adjusted wrong.
We rebuilt the tank inlets so that the water disperses upward to try to keep it from stirring up the silt, and we converted our fixed intake to a floating one, because the cleanest water is generally about 6" or so below the surface. We're also going to build a dam around the hatch cover to stuff from entering that way. I'd recommend raising the hatch cover at least 1/2" above the tank surface for this reason, even though it means you now have to worry about tripping over it. (This hasn't happened because the only effective solutions we've found cost hundreds of dollars). We replaced the shallow well pump/pressure tank with a motor that is made to cycle often and has its own built in pressure switch, and replacing the filter with one that has a cartridge about three times as big as the old one.
As of Jan 2010, our system has been very reliable. We do still have to turn off the toilets in the summer, both because our summers have been hot and dry, and I keep adding plants that need water. The plan is to make the garden more drought tolerant some time in the future.
Since we build our tank, rainwater has become much more popular, and its easier to get a permit as well as to find someone who can build a functioning system.
We're sold on home-run PEX. We get hot water everywhere in the house really fast. We love our ASKO dishwasher, not only because its so energy & water efficient, but because its so quiet. We like our Fisher/Paykel washer also, although it's not so quiet. Having a washer with a spin speed makes the clothes come out much drier than a conventional washer. Someday we'd like to get a genuine front loader, but in the mean time we're happy with what we have.
Since 2004, a lot of new very good washers have come on the market, and dishwashers have also gotten better.
For our water use, click here.
We've have done a lot with materials since moving in, although I've spent a lot more time researching salvage materials. At one point the Re-store stopped doing de-construction due to it being un-profitable, but they've now fixed their model and are doing it again. In the meantime, another non-profit, the California based The Reuse People ( www.thereusepeople.org), has pioneered a different deconstruction model that charge more for deconstruction and less for materials, giving them the ability to reuse lower value materials (like metal frame windows and hollow core doors).
One positive piece of news is that FSC lumber is now more readily available, with at least one supplier stocking some materials (see www.dunnlum.com). (Aside: I wrote to WA state lands commissioner Doug Sutherland that they should consider FSC certification, and the letter I got back was that they didn't think anyone wanted it or would pay the price premium for it. Obviously Doug never actually tried buying any of it. As of 2009, we have a new lands commissioner, so maybe this will change)
Salvage materials are becoming more popular, but as stated elsewhere, there is a learning curve.
Once you really get into reclaimed materials they become almost like pieces of art. This fact makes them both expensive and the most loved pieces in any house. For more information (and lots of pictures!) on how others have used salvage materials, see http://www.ci.seattle.wa.us/sustainablebuilding/greenhome.htm
There is still a large pile of leftover wood in the basement, although we've used some of it. Although its the wood that had the most "defects", most of it will be useable by cutting it into smaller pieces and gluing them together.
Our adaptable wiring system works, but leaves much to be desired. We're calling it a work in progress.
While the sound barrier between us and the ADU is very good, low frequency noise still travels thru the floor because we didn't isolate that. Its not a problem, but takes some getting used to when you've lived many years in a detached home.
The solution would have been to sit the floor joists on a sound absorbing membrane, or use a layer of green glue (which is like a caulking that isolates sound, there may be other products, but its the only one I've heard of) in one of the floor layers to help isolate the sound.
The whole project ended up more expensive than we hoped, but this is almost always the case for any custom construction, and we don't attribute much of that to the various green features. Our final construction cost was around $575k, which comes out to about $230/SF. This doesn't include cost of the land, the original house, landscaping, architects fee and all the various other permits and design fees we had. While this is very expensive, its not out of line with comparable non-green projects.
While we have only ballpark numbers on the cost of many of our green features (see Costs in the design section), we believe they're fairly accurate. Based on these, the majority of our "green" features added up to $22k, or less than 5% of our total cost. If you add in the PV, active solar and Cistern, it goes up to $58.5K or closer to 12% of our total cost.
While turf grass is cheap and easy to put in, a useful outdoor space filled with perennials is neither cheap nor easy. The good news is that you can put it in slowly, and as long as you keep up on the weeds, it probably could be lower maintenance than turf grass. However, in the process I became a bit of a plant nut, and now have over 300 different perennials. It would have been much easier for me to restrict myself to a much smaller number of only the tough ones, but like everyone who gets hooked on gardening, I wanted to have flowers or something of interest all over the yard all year long. In Jan 2006, we took over the partly shaded parking strip section, filling it mostly with tougher plants that are largely scavenged from neighbors or other parts of the yard. Some day I will add an entire gardening section.
Spring 2007 update: much of the garden has filled in, and we now have more than 250 different perennials. Documenting them has gotten to be a time consuming task since they die, they get moved, I loose the tag or get a plant as a gift and don't know what it is, so I'm no longer sure of the exact number.
As with many other gardeners, I'm now running into the problem of plants got bigger than expected and plants that spread more than desirable. In our initial installation, I planted about eight 4" pots of Sweet Woodruff (Galium odoratum) and am now ripping out many square feet of it. Its an attractive plant, but much too aggressive for good garden soil and regular water, so I've moved chunks of it to difficult spots and am ripping the rest out. All the old english ivy (Hedera helix) and St Johns wart (Hypericum) are also gone. I also had to move the Shasta daisy's as they were starting to take over.
Some day I will post a complete garden description, although generally I'm finding reasonable resources for northwest gardens on the web already. Here are a few I found useful:
We ran out of water in the tank last summer due to drought and new plants that needed water. In the two years of using drip, I've finally discovered its limitations. Everyone says to water deeply, but I've found at least two problems with this wisdom. The first is that in well drained soil, a drip system will produce a column of water that can easily be much narrower than the root system of your plant. The second is that many plants produce only shallow roots. To correct for this, I'm going to try installing more drippers on the bigger plants, and running the system for less time. My idea now is to try to get water into the top 4-6" of soil, rather than all the way down to 12".
Jan 2009 update: The problem plants are now gone--or at least moved to places with less desirable growing conditions. Although I still have small amounts of room, it seems unlikely I will buy many plants this year, so our "new plant" water should go down.
Jan 2010 update: the garden is much more stable now, but last year was very hard on it due to deep frosts followed by long hot drought.