Green Building FAQ
Top Ten Frequently Asked Questions About Green Building
1. Does building green cost more?
Yes and no. Initial capital costs for a new green house can be anywhere from the same as conventional construction to twenty per cent higher. It depends on where you start. If you start your calculation with the cheapest possible code-minimum construction and finishing, and go whole hog adding in high-quality green approaches, well yes, you’ll end up with a 20% premium. Over the long run, if you make smart choices, you will come out ahead even if you confine your analysis to purely financial returns. In fact, investing in the energy intelligence of your home is far and away the best investment out there.
The premium depends on the project. Let’s talk about new houses first. In some cases, green building is actually less expensive. We can save you 25 per cent on the cost of wood in your project by using stack framing. Since wood has doubled in cost in the last couple years, that can be a significant savings. You also save money on labor with stack framing, because there are fewer pieces of wood in the structure. You could spend some of that savings on additional insulation and better windows that will result in lower heating costs for the life of the home–and energy costs are not showing any signs of going down, are they? Or you might put some of that savings into a more sophisticated ventilation/filtration system that will keep the house fresh and clean, or help reduce allergies.
Going further: If you decrease the energy consumption of the house beyond a certain point, you can dispense with a conventional furnace. This is done by rigorously reducing heat loss through the three paths of envelope (walls, floors and ceilings), windows, and air leaks to 10% of what it would have been. At that point all the space heating that is needed can be supplied with inexpensive electric resistance heating. We like to supply that heat with electric mats in a tile floor in bathrooms, or with heated towel bars. You shift what you would have spent on a furnace into the additional insulation and better windows. Again, the house is more comfortable, less drafty, and quieter—but you haven’t necessarily spent more than you would on conventional construction of equivalent quality.
So you could spend the same amount on a green house as you would on conventional construction, yet enjoy a more comfortable, healthier house that costs you less to operate.
For smaller projects, such as kitchens, going green is not significantly more than high quality custom work, but it will undoubtedly cost more than going the cheapest route possible. Formaldehyde-free substrates for cabinets only cost $200 or so more in materials for a typical kitchen, but because not a lot of mass market cabinetmakers offer a formaldehyde-free option, you’ll have to go with a custom shop, and thus pay up to 30% more. Of course with that custom shop, along with breathing fewer toxic fumes, you also get better fit, nicer and more durable hardware, exactly the configuration and dimensions of cabinets you need, and exactly the door design, wood and finish you want.
Features like utility inter-tie photovoltaic electrical systems and rainwater collection systems will always cost more than hooking up to an existing local utility grid or municipal water system, but they will add both long-term value and resilience.
Let’s say you go ahead and add some of these extra “gee whiz” features to your house, and it does end up costing more than a conventionally built home. Most people don’t question why a Lexus costs more than a Toyota. A house with green features costs more because it’s more comfortable, more durable, costs less to operate, and overall is just higher quality than most conventionally built houses. Sure, you can build a house for less. But remember, if you build a cheap house, you live in a cheap house.
There are also special mortages for energy-efficient homes, rebates for water wise appliances, and permit incentives for building green in King County. For more about the financial rewards and economic aspects of building green, read Investing in Efficiency.
2. Green building–oh, I get it–you do underground houses and geodesic domes? The next question is usually the corollary–what do I have to give up to go green?
My first job out of school was working for Buckminster Fuller. (And Isamu Noguchi.) Bucky was a brilliant engineer and lateral thinker. When I designed my dream home in art class as a junior in high school in 1972, it was a geodesic dome with photovoltaic panels. (This project, by the way, was what lead me to consider architecture as a career. Thanks Mr. Lillback!) Geodesic domes are by far the most efficient means of enclosing space, in terms of material use. But making a home isn’t entirely about efficiency. That’s why here we call it lyrical sustainable design. It’s more than the technology.
Underground houses can be interesting, and we’ve done some earth-berming ourselves here and there, as well as several green roofs. But the popular image of an “underground house” has little to do with our version of green design. Have a look at a few of our projects to see what we mean. We hope you’ll agree that our clients have not given up anything to be green.
We prefer to think of architects like, well, bugs or plants. We all occupy certain ecological niches if you will, with some of us best adapted to providing services of a particular nature. If someone is interested in building a straw bale house or underground earth ship or geodesic dome home, we know people who do that really well, and are happy to refer our prospective clients to them. We’d love to do a rammed earth house some day, but the right client and site hasn’t come along yet.
3. Why don’t I see any straw bale houses/photovoltaic panels/insulating concrete forms/structural insulated panels/rainwater collection systems on your website? Are you sure you do green architecture?
My friend and colleague Mark Frankel once called these kinds of green approaches “gee whiz” features. The kinds of things you see and go “Gee whiz, that’s neat!” We’ve seen more and more of this kind of thing as green architecture has moved into the mainstream, a good bit of it from architects who have little experience with green building.
Photovoltaic panels on the roof signals green. It’s a bit like the billboards Robert Venturi talks about in Learning from Las Vegas. Once you see the photovoltaic panels, you know it’s supposed to be a green project. But as attractive as it is as a strategy for that reason, you have to ask:
- Have the owners done all they could to reduce the house’s demand for energy first?
- Are they using LED lighting throughout?
- Is the home super-insulated?
- Do the windows have a U-value of 0.24 or better?
- Are heating and ventilation systems as efficient as they can be?
- Do the ecological and financial benefits outweigh the costs?
If the answers to all of those questions is yes, then fine, hook ’em up! Every time, so far, we have analyzed the costs and benefits of photovoltaics, we have determined that right now our clients would be better off putting the money into reducing the energy demands of the house. We think they will make sense in a few years, so we design places for the panels, and pre-wire for them so that they can be easily installed later. A 2.5 kW system that would supply about half the power needed for a typical house currently would run $15,000 to $18,000 from our friends at Puget Sound Solar. Don’t get us wrong, the “sending the message” aspect is great if you have that kind of extra cash. And we do wish more of our clients would put a few PV panels on their roofs so people would know they’re green projects…. But if you haven’t done everything possible to reduce the energy consumption of your house (like get to the Passive House standard), then putting solar panels on the roof is putting lipstick on a pig. Sorry, but that’s the truth.
There are many things to like about straw bale construction. It uses a waste product, and often building with straw is a community effort, which we think is fabulous. However, we don’t think it makes complete sense in western Washington, especially if you’re going to hire a contractor to build the house for you. One thing you want to do as a green architect is look around for indigenous building materials, because they are most likely to be well-suited to the local climate. I don’t see a lot of straw on the west side of the mountain passes in Cascadia. I believe straw bale is well suited to places that are hot and dry in the summer, and cold and dry in the winter, such as, say, the Palouse in Eastern Washington. Where there is a lot of straw…. Coincidence? I think not. If I had a project in the Palouse straw bale would be the very first material I’d investigate. The insulating properties of straw bale, while good, are not as good as first thought. Recent tests place an 18-inch bale at about R-28, rather than the R-50 put forth when the technique was revived in this area in the early ’90’s.
Insulating concrete forms have some of the same issues as straw bale. The actual performance sometimes doesn’t live up to the hype. Some of them don’t insulate as well, don’t save concrete, and aren’t less expensive. However, there are several systems and manufacturers of ICFs that we do think work well, and we have used them with great success.
Using rainwater collection for potable water in Washington (other than in Island County, where it is encouraged) is difficult and expensive only because of current law. It requires a permit process that can take, at best, several years. (In fact the state is currently eight years behind processing these water rights applications partly because there are only two people in the whole state reviewing the applications…but you can jump to the head of the line by paying several thousand dollars to, essentially, pay the reviewer yourself.) As with our approach to photovoltaics, we design to allow rainwater collection to be installed later, when it does make sense. We believe it is an important strategy, and ought to be implemented on every house, but we suggest to our clients that they wait until there aren’t so many beaurocratic hoops to jump through. On the other hand, it makes complete sense, right now, to use rainwater to flush toilets and do laundry. A complete system runs about $7,000 installed, and will pay for itself in five to seven years. That’s return on investment of 10.3%.
4. Does active solar space heating make sense in Western Washington? (On the scale of a house, active solar often includes techniques like large expanses of south-facing glass, Trombe walls, sun spaces, water-filled tubes, etc.)
No. It’s quite simple really: In this area the sun doesn’t shine when we need heat. Again, this knowledge is courtesy of our friends at Ecotope, who have modeled and documented the energy performance of thousands of homes in Washington. Unless you have night shades you draw every night you’ll lose more heat out of your big south-facing windows than you will ever gain. And you’ll gain too much heat when you don’t want it–in the summer, when the sun is shining, and the house will overheat.
On the other hand being aware of when and where the sun will appear and using that knowledge to reduce the energy use and increase the comfort of a building, does make sense, and is a great green strategy. We have the tools to analyze and tweak the design of a house so that it will take advantage of the available solar resources.
With the incredible efficiency of the new heat pump water heaters, solar water heating no longer makes a lot of sense. Vacuum tube solar collectors extract heat from the sun even when its cloudy.
5. I don’t want my house to be too tight! Aren’t leaky houses healthier?
This notion is left over from bad press on (or actual experience with) energy efficient homes built in the late seventies and early eighties, where air tightness and poor ventilation led to mold and mildew problems. That was a serious issue with those houses. Now we know better.
Historically, Craftsman houses worked well, for their time. A wall assembly of lap siding, skip sheathing, 2×4 wood studs, no insulation, and interior plaster with lime-based paint allowed the structure to dry to both the interior and exterior. However, if you’ve ever lived in an old Craftsman house (as I have) you know that it’s also drafty, uncomfortable and expensive to heat in the winter, and hot in the summer. We have higher expectations for the comfort and operating costs of our houses today, so this approach no longer serves our needs.
The average house has the equivalent of a three foot diameter hole in it, just from leaks in the envelope. That’s your expensive heated air escaping through that big hole! And here’s what happens: Let’s say its 40 degrees out, on a Seattle winter day. Moisture-laden 70 degree air from the interior, in a bathroom, for example, heads toward the outdoors through whatever channels it can find. Along the way, as it gets closer to the outside wall, it cools…and reaches the dew point, and condenses. All of the sudden you have moisture in your wall. Which leads to mold, which leads to allergies, etc etc. Not good. If you make a house tight you have to ventilate it really well.
So our approach is to 1) create a consistent air barrier and eliminate thermal bridges with special construction details; 2) seal the leaks; 3) do a blower door test that objectively documents the air-tightness (twice in the construction process); and 3) install a balanced, heat recovery ventilation system to ensure fresh air. With this approach you get the energy efficiency and the fresh air. That’s good!
6. What about pre-fab houses? I’ve some some really cool ones in Dwell Magazine that only cost $70,000.
As much as we like the folks at Dwell for their championing of modern homes, sometimes we are perturbed at their slightly optimistic notions of what things cost…or slightly inaccurate journalism perhaps. I dated a New York Times reporter back in the day, and she did what they call “fact checking.” On the cover, you’ll see “Build a Modern Home for $70,000” and when you read the article, you learn that first you have to marry someone who’s father is a builder and will not charge you for the labor or half of the materials. Or upon investigation of the manufacturer mentioned, you learn that the pre-fab house you can buy for $70,000 does not include the sitework, foundation, electrical, plumbing, heating, windows, interior finishes or cabinets! And by the time you add all those other things in, it ends up costing just as much as a comparable site-built house. Especially once you factor in the shipping from California.
As a concept, pre-fab holds a lot of promise. The most interesting possibilities on the table in our office now is pre-fabbing cross-laminated timber panels for walls and floors, which can then be assembled quickly on site. We have the supplier who’s been doing it for 20+ years in Europe lined up, and we are looking for a project to try this on.
8. OK, so maybe it doesn’t cost more in the long run, but surely the toxic products are better…aren’t they?
An outdated notion. Formulations have improved dramatically since the first water-based coatings came out.
From what you’ll read on the internet, hydronic in-floor radiant heating is the Cadillac of heating systems. But, here’s the deal: It will cost at least twice what a modern, HEPA-filtered 94% efficient integrated heat and hot water system will cost. (That is, currently, $35,000 vs $18,000.) It doesn’t work well in combination with passive solar applications; it’s not as efficient if you are not at home all day to enjoy it; and it doesn’t work well where you need to heat up the house quickly, say in a weekend cabin. It’s finicky about the kinds of floors you use with it. It’s best with concrete or ceramic tile, not so great with wood or cork, and unusable with linoleum. We would prefer to design a house that does not need a conventional “heating system” at all. (See our description of a Passive House.)
Geothermal heat pumps are pretty cool, but again, much more expensive than other systems (starting at $70,000), and it depends on the situation whether geothermal makes sense or not. The more efficient your home, the less difference the kind of heating system you choose makes.
10. Anyone have any other questions?
If so, please feel free to drop us a line, and we will do our best to answer them.