I could not have designed and built this house without our good friend Google. I created all of the 3-D drawings in the free version of SketchUp, and I researched literally every component of this house using Google's indispensable search engine.
Unfortunately Google is nearly useless for researching items that are aggressively marketed online, particularly LED lights. The problem is that discount LED vendors use every trick in the book to rank among the top Google search results, so it's nearly impossible to find helpful online advice about how to buy LED strip lights.
Until recently I had only a dim (ha!) idea of what components we'd need for LED strip lighting. But now that we've figured it all out and completed our lighting schedule, I'd like to share what I've learned about illuminating a room primarily with LEDs.
Not all LED lights are created equal
I do not usually use all-caps (the Internet equivalent of screaming), but this is hugely important. It is tempting to order LEDs online from discount vendors, and you might know people who like the lights they purchased that way. Ted and I have some friends in Austin who purchased a lot of accent lighting from Eco Light LED, and the lights look really cool. Installed inside bookcases and behind valances, they have RGB controllers and can be adjusted to display a huge range of fun colors. Ted and I assumed we'd light our house with something similar, only on a larger scale.
We subsequently learned, however, that you can only get away with cheap LEDs if you aren't using them as a primary lighting source. When you look at a person, you're seeing the light that's bouncing off of them; the surface of their clothing, skin, etc., absorbs certain parts of the spectrum and reflects the rest back out. So if your light source is missing crucial colors, that person will look downright creepy.
Any decent LED manufacturer will publish the product's Color Rendering Index (CRI). This is an adequate (though incomplete) measure of the light's color fidelity. CRI is measured on a scale from 1-100, with ordinary incandescent lights at 100 and everything else somewhere below that. For your primary indoor lighting source, you shouldn't go below a CRI of 80.
Color temperature is also important, and it is easily misunderstood. "Warm" light actually has a lower temperature — incandescent bulbs are 2,700K and those blue-white LED xmas lights are around 6,000K (compact fluorescent bulbs usually range from 2,700 to 3,500K). All of our LED lights will have a color temperature around 3,000K and a CRI in the mid-80s.
Once you know a little about CRI and color temperature, the discount LED vendors no longer look so good. Eco Light sells Warm White LED Strip Lights for about one-quarter the price of the strip lights we're buying, but a closer look at their downloadable spec sheet reveals that the color temp is a not-so-warm 3,500K, and they don't mention CRI at all. I found CRI info on a few other discount sites, but the numbers were unacceptably low (70-75).
Most of our LED strips will be installed behind a valance, with the light shining upwards across the ceiling (the sole exception is the under-cabinet lights in the kitchen). The LEDs we selected have a good overall CRI (85) but are a little weak in the red part of the spectrum, which means we need to choose ceiling paint with a hint of red pigment so it won't absorb all the red coming from the LEDs. Our lighting consultant told us a cautionary tale about how indirect non-incandescent light bouncing off cream-colored walls can turn everything yellow, and we don't want that to happen to us. In fact, we had planned on using pigmented plaster for our walls, rather than the usual paint over drywall, but the lack of fine-grained color control pushed us back to the standard approach.
LED strip lighting basics
The first thing to know about LED strip lights is that they run at a much lower voltage than most other electric devices in your house. In North America, we use 120 volts AC (alternating current), and most LED strip lights run at either 12 or 24 volts DC (direct current). You will therefore need a transformer to convert from line voltage (120V) to the voltage of your LED system.
In case you're rusty on how electricity works, I should point out that the voltage has nothing to do with how much energy the lights draw. Voltage is analogous to water pressure (not the total amount of energy used), so the important number is how many watts a fixture requires.
Each circuit of strip lighting will require its own transformer (by "circuit" I mean a strip that's controlled by its own switch), and the total wattage of the strip lights cannot exceed the maximum output of the transformer. Our strip lighting draws 3W per foot and our longest stretch on a single circuit is 14'-4" (the upstairs hallway), which means our heaviest circuit will only draw 43W. The smaller WAC Lighting transformer is rated up to 60W, so we'll be well within the limit.
In case you're curious, here's what you'd need to run 14'-4" of strip lighting:
Two 2-inch LED strip lights
Four 1-foot LED strip lights
Two 5-foot LED strip lights
One 12-foot lead wire (connects the light strips to the remote transformer)
One end cap
One remote transformer (driver). Converts from 120V (line voltage) to the 24V required by the lights.
Each segment of strip lights connects to the next, and the end cap terminates the string.
Incidentally, the reason we're fiddling with the 2-inch segments instead of just trimming a 1-foot segment (the lights are trimmable every three inches) is that it's marginally less expensive. This will give us the exact length we need.
Why bother with LEDs?
I confess that writing this post has made me wonder why we're installing LED strips when CFLs use roughly the same amount of power. People criticize fluorescent bulbs (compact and otherwise) for containing mercury, but it's just a tiny amount and can be recovered if the bulb is properly recycled. LEDs don't contain mercury, but various toxic chemicals are used during production, and their heat sinks are made from valuable metals like aluminum.
So why are we using LEDs? I suppose it's partly the eco-bling factor. But we're installing plenty of conventional fixtures too, and in the short run we'll probably fit most of them with CFLs. LED replacement bulbs tend to shine in a single direction; this makes them a good choice for recessed downlights, but not so good for wall sconces and multidirectional fixtures.
We considered using a series of T5 fluorescent tubes for all the indirect lighting, but then we'd run into "socket gap" — dark spots where two bulbs meet. We would also have to build a larger valance to hide the bulbs, and there are a few places where we need to keep the valance quite small.
We therefore succumbed to the blingy lure of LEDs, and I sincerely hope they'll earn their keep during their projected 50,000-hour lifespan. That's 17 years, assuming we run them eight hours a day, which I doubt we'll do. Again, this is why it's important to choose the manufacturer carefully, since we're likely to be stuck with these things for a long long time.
I keep thinking I can cover lighting in a single post, but each time I try I wind up having too much to say. In a future post I'll share diagrams and photos of our indirect lighting setups. I'd also like to talk a little about switches (whee!), and now that my eyes have been opened to the subtle art of lighting design you can expect a rant or two about bad lighting.
One of the many things I like about the internet is how it enables a green-building wannabe like me to eavesdrop on the hotshots at the popular table. And unlike the popular crowd at my junior high school, these people are generally quite friendly if I pipe in with my opinion.
One big culprit in the second house is air conditioning. Passive houses in New England are optimized for cold weather, since that's the bigger requirement out here. But big south-facing windows with a high solar heat-gain coefficient can cause problems when the weather warms up, since they let in too much solar heat. Ted and I expect to have this problem, but we plan to address it by hanging exterior louvers from the south-facing windows in late spring (and then removing them in October or so). We might not get around to building them this year, but it's our long-term low-tech workaround to the problem.
The second culprit is plug loads (lights, appliances, TVs, computers, etc.). The Monday-morning quarterbacks in the green building community are rolling their eyes at the owners of the Shrewsbury passive house, who have two televisions (including an energy-gobbling plasma TV), a DVR, multiple computers, an old freezer and a dehumidifier in the basement, along with oodles of lights. The house still uses less overall energy than a conventional house, since the heating costs are so low, but it's nonetheless a bit embarrassing.
I shouldn't laugh, though, because Ted and I might find ourselves in a similar spot. We don't have a plasma TV or DVR, and we cleverly eliminated the need for a basement freezer and dehumidifier by not building a basement, but we are major computer geeks and have more than our share of blinking-light devices. We also have a deep attachment to automatic dishwashing, and I joke that we'll be able to use Ted's espresso machine to heat the entire house.
I got into a little Twitter exchange about it the other day with Passivhaus BMOC Mike Eliason and British architect and sustainability pro Elrond Burrell (both of whom have way more Twitter followers than I do). Here it is, minus some helpful details from rising star Floris Keverling Buisman, who gets bonus cool points for (A) being a co-founder of Four Seven Five, importers of geektastic high-performance construction products like this mini-HRV Ted covets even though we have no use for it, (B) living in Brooklyn, the Passivhaus epicenter of the western hemisphere, and (C) being from the Netherlands, which automatically boosts one's eco street-cred (hello bicycles!).
(My avatar is the extremely out-of-date rendering of our house, on the right.)
The point I couldn't make in 140 characters is that energy-efficient living needn't be austere. Both of my interlocutors (intertwittulators?) point out that constraints can inspire brilliance — perhaps the biggest "constraint" in promoting green building is that people don't want to sacrifice their own comfort. Yes, our definition of comfort has grown out of proportion in the last 50 years, but I suspect that most people living in 4,000-sf houses secretly yearn for the relatively zen-like feel of a well-arranged 2,000-sf home.
The key phrase here is "well-arranged." If a smaller house lacks the rooms they need, they won't want it. Likewise, if an energy-efficient house doesn''t satisfy their longing for comfort and entertainment, they're not going to build one. I read a depressing blog post last year that described how to save energy by heating only the space your body occupies and only using task lighting right in front of you. Yeah... good luck getting that to catch on. Unless energy prices skyrocket (a distinct possibility but not a certainty), nobody is going to willingly embrace that lifestyle.
This is why Ted and I are so aggressively pursuing a third alternative: the low-energy-use house that doesn't sacrifice comfort. I hope we can tame our plug load, because I'd hate to be next year's poster child for Passivhaus overconsumption. We strategically chose our appliances and lighting to make conservation automatic and painless, plus we use smart power strips to curb our power-sucking ways. I really hope we can pull it off, and that everyone who visits us will get a peek at what I hope will become the new normal.
In 1939, General Electric wowed visitors at the NYC World's Fair with "the World of Tomorrow." They showed off modern kitchen appliances and other work-saving devices which wouldn't hit the mainstream for another decade or so. It all came at a cost, of course, and the climate is now a lot screwier than it was in 1939, but new problems inspire new solutions, and maybe Ted and I can help show people what that third alternative — a comfortable and ridiculously-efficient house — will look like.
Honestly, I can't believe my luck that they're based right here in Brattleboro and seem to need someone with my precise skill set. And I'm not referring to my Passivhaus-building experience — my relevant skills in this case are marketing and web design. Happily, they seem to like my writing style, and they even let me use the word "chump" on a promotional page. It's a real treat to work with genuine leaders in the field and to help promote their mission. Plus their office is in Brattleboro's old pipe-organ factory, which is about as excellent as it gets!
After struggling for months to complete our lighting plan, I now understand why most builders just give up and install recessed cans everywhere. You put a decorative fixture over the dining room table and in the bedrooms, maybe combined with a ceiling fan, plus some attractive pendants in the master bathroom, and voilà — a lighting plan!
Ted and I stubbornly resisted this approach, and after wrestling for ages with our own lighting design I can absolutely see why most people succumb and go the easy route. Our not-so-fun experiences included:
Getting a terrifyingly-high initial quote from a top-tier lighting consultant (more on this later).
Being led down the garden path by a vendor who said we simply had to see their terrific showroom, and then driving a long way to discover they had a tiny showroom with exactly nothing we liked.
Asking for specific advice from said vendor, waiting a week for that advice, but then being sent nothing but a quote for hugely expensive fixtures we never even asked about.
Choosing a bunch of attractive and reasonably-priced pendant fixtures, only to find out that someone near and dear to us suffers petit mal episodes around gently-swaying pendulums.
Yup, putting together this lighting plan has been a non-stop party! But now that the plan is done, I'm glad we toughed it out — I think our lighting will look great and function well, and I want to share what we've learned.
Our first step back in October was to contact a highly-recommended lighting designer from out of state. We got off on the wrong foot, though, when he sent us a quote based on a palatial Vermont ski house he had consulted on, and we had to explain that we were the lesser-known kind of of Vermonter who only has one home. (The overwhelming majority of Vermonters fall into this category, but if you're a renowned lighting designer in the greater NYC area you tend to meet only the other type.)
Once we conveyed to him what cheapskates we are, he assured us that he's happy to work on an hourly basis for people who just want a few pointers. Our first meeting with him was very productive and we planned to keep consulting him, but then Ted broke his collarbone and I freaked out about costs and decided we should just figure out the lighting all by ourselves. Ted devised an elaborate plan, rife with LED strips and T5 fluorescent tubes hiding behind valences, but it was really way too complicated and when I presented it our electrician in late January he soberly told us it was going to cost a friggin fortune to install.
We weren't really sure how to proceed, so we decided to meet with the lighting consultant again. He took a red pen to our plan, and two hours later we were all set. Here are the key items:
Indirect LED strips
We're probably going to get WAC Lighting InvisiLED Pro strip lights. They have a pretty decent color-rendering index (CRI), though a little short on red, which means we need to be careful when we choose our wall paint color. The light will bounce off the paint, so we'll go with a faintly rosy shade of white.
More recessed cans than I expected
Our lighting bible has been Martin Holladay's 10 Rules of Lighting, and he really hates recessed downlights. He points out that in nature the sky is bright and the earth is dark, and yet downlights mostly just light the floor. Furthermore, they cast unflattering shadows (as my bathroom mirror reminds me every morning), and on a high ceiling they don't really provide much useful light at all.
Ted and I were prepared to forgo recessed cans almost entirely, using them only above the shower and bathtub, and also as tasks light over the kitchen sink. But it turns out they work well if placed the right distance from the wall (24-27" for a high ceiling), and so we're going to use a wee smattering of them. They'll all be Juno IC-20 5" housings, with LED PAR30 replacement lamps.
Lighting alongside the bathroom mirrors
The most flattering lights for a bathroom mirror are the old Hollywood-style lightbulb surround. Light hits the subject from all directions, which means no creepy shadows. But many bathrooms only have downlights (this kind of fixture is all too common) — they look nice on the wall, but not so nice on the face.
The Hollywood lights are a bit over the top (and screamingly inefficient), so we're going with sconces on either side of the mirror. Not fancy, but flattering, and it'll bounce some light off the ceiling as well.
(We found an awesomely goth lighted mirror that we wanted for the master bath, but sadly it is discontinued and we'll have to content ourselves with something far more pedestrian.)
Incandescent decorative fixtures
Wait, huh? I thought incandescent bulbs were a big waste of electricity!?
They are, but the fixtures have nice standard sockets which take plain old Edison bulbs, and that's the biggest segment of the LED replacement market. So as long as we choose decorative fixtures that don't take too weird of bulbs, we can easily make them more efficient.
Choosing fixtures was often quite a challenge. Ted and I don't always have the same taste, and we're both quite opinionated. And once we agreed on a fixture that was the right price (another huge challenge), we'd discover it uses some crazy little non-standard halogen bulb which will almost certainly never get an LED replacement.
No dark shades!
This also comes from Martin Holladay's lighting rules: Don't block that light with silly dark shades. And don't obstruct light from bouncing back toward the ceiling. We're being careful to prevent glare from exposed bulbs, but otherwise we're letting it all hang out, lightwise.
I could say much more on the topic of lighting but will instead treat you to photos of some of the fixtures we've picked out.
Wall sconces along the stairwell:
On either side of the master bathroom mirror:
Two rigid-stem (non-swaying) pendants over the dining room table, hanging off a monorail:
A big friendly pendant in the middle of the kitchen ceiling:
Wall sconces in one of the guest bedrooms:
A cheerful little ceiling light at the back door:
There are several others, but I will wait until I can display them in their new home!
One of the special challenges of building a Passive House is heating it during construction. The standard solution for temporary heat is a portable forced-air propane heater, but there are two reasons why we can't use one of them:
They put out a tremendous amount of moisture, which would take ages to dry out in a tight house.
It would release a lot of nasty combustion chemicals into our building envelope.
But it's winter in Vermont, and our various crews and subs are oddly cranky about working in a frigid building. So we had to come up with something.
Once again, it was Eli to the rescue. He somehow found a weird exterior heating device, and we're pumping the heat into the house through a temporary hole in the floor. This puts the combustion outside but fills the house with delicious heat. (Note that we have to open a window first, or else there's nowhere for the warm air to go.)
It's cantankerous little devil — Eli spent the better part of a week getting it to work, seeking advice from a wizened engine guru of his vast acquaintance. Ted and I live in vague fear that it will either (A) stop working or (B) explode, but we are also grateful that it has shown up to lend us a hand.
In other news, the garage is nearly complete. Mark and Luke (from Eli's team) will start the roof edge trim later this week, and the roofing will soon follow. Windows and doors will arrive by the end of the month, and we look forward to being able to store stuff inside. I'll upload more garage photos soon, since it's truly a cool and wonky little building, deserving of its own post.
Here's a photo from this morning. Can you spot what's funny about it?
Update: We didn't get the upgraded panel. Thanks for everyone's advice!
Ted and I need some advice in a hurry: The electrician is about to install our electrical panel, and we need to decide whether to pay an extra $2,350 for a panel that's compatible with a backup generator.
We have no immediate plans to install a backup generator, and we hope the grid stays reliable enough that we wouldn't need one. But if we do want a generator one day, it would be a lot cheaper if our panel is ready for it.
Note that our house is run entirely on electricity. No wood stove, no gas range. Our water comes from a well, which requires a pump, and our sewer hookup requires a pump as well.
The idea of burning propane to power our house gives me the willies, but if there's an extended power failure I'd rather burn propane than abandon ship altogether.
[I should add that the solar panels won't work in the event of a power failure. There's an automatic shutoff if the grid supply goes down, in order to protect line-workers.]
One of the many things I like about building websites is how easy it is to change things later on. Want to change some wording or add a new photo? Piece of cake! Need to change something complicated like the page layout? That's a bit more work but 100% doable — change a few settings and template files, and you've got a new layout.
Changing a building? Not so easy. You can't just edit the source files and hit "Reload." Nope, changing a building involves crowbars, debris, dumpsters, and a whole lot of work and expense. My sole consolation about building a house from scratch is that it's apparently less painful than trying to remodel, so we're making every effort to do things right the first time around.
This has meant paying constant attention to detail and making sure we're designing for longevity. The idea of doing things right is so deeply ingrained that we don't even ponder the alternative, and so we often forget how unusual it is.
For example, Ted recently shared some photos of our garage on Google+ and received unexpected praise for the generous overhangs:
I designed the garage myself, and when it came to sizing the overhangs I simply asked Eli what he recommended and went with that. It didn't occur to me not to have overhangs, or that sizing them properly was unusual enough to attract praise.
And yet it is. When people with building experience come visit our house, they're astonished by how well-built it is and how little we've compromised. The most recent was Russ, our new rep from the building supply yard. He said he's worked with lots of customers who initially intend to build a super-insulated, passive solar, [insert eco-adjective here] house. But then they see the price for all those green-building features, and they scale it back until they wind up with a house that's only marginally more "green" than a conventional house.
Russ told us what a thrill it is to see a house where this hasn't happened. Quite the opposite — our original target was an almost-passive house, and yet here we are building what is now likely to be a certified passivhaus with solar hot water and a 3.96 kW photovoltaic array. I honestly can't think of a single corner we've cut with regard to the building's performance.
We've certainly trimmed some other corners. Heck, we lopped about 500 square feet from the original floor plan. The bathrooms are small and simple, the bedrooms have ordinary (not walk-in) closets, the kitchen cabinets are stock rather than custom. But we can't bring ourselves to install anything we'll want to rip out and upgrade in a few years. Hence no formica counters, vinyl floors, or any of the other money-saving standbys.
Alas, there is a reason so few people build this way. It's really expensive! I know I've posted about this before, but it's such a big part of our building experience that I can't help repeating myself. Nearly every estimate we receive is like getting the wind knocked out of me — it seems impossible that construction could be this expensive, and yet apparently it is.
One of the hardest parts is how often I feel ashamed or that I've somehow failed. When I started this blog, I really wanted it to describe how we built an almost-passive house for some cute number like $100 or $125 a square foot. But we've sailed past $200 a square foot, and I don't yet know what the final number will be. I'm not looking forward to taking out that mortgage, nor do I relish the possible eventuality of selling the house for less than we put in.
Ted suspects that a lot of our costs are because this is a custom home. Yes, all the eco-bling is adding a lot, but not as much as the general costs of building a distinctive home on a challenging site.
Perhaps this blog will help illustrate the need for production-scale passivhaus construction. Such construction is common in Europe, and it's beginning to take off in North America. Builders of modular homes are getting in on the game as well, and perhaps very soon it will be possible to get a house like ours much more easily and cheaply than we are. I certainly hope so, because I wouldn't wish this process on anyone, and yet I definitely want more people to have this kind of house.
Basement rim joist areas; holes cut for plumbing traps under tubs and showers; cracks between finish flooring and baseboards; utility chases that hide pipes or ducts; plumbing vent pipe penetrations; kitchen soffits above wall cabinets; fireplace surrounds; recessed can light penetrations; poorly weatherstripped attic access hatches; and cracks between partition top plates and drywall.