Making Green Affordable, Part 1
A simple house is best: four corners, two roof slopes, and no boogie-woogie
Now that "green" design (usually defined as design that is energy-efficient and environmentally friendly) is arguably in the mainstream, our industry faces a challenge: to bring green design into the realm of affordability. "Affordable," like "green," is a subjective term, and so it makes it difficult to discuss without offending some people (specifically those who are struggling to afford basic shelter for themselves or others; where a donated sink, or 2x4, makes all the difference.) I don't think this article is necessarily for you/them. I should be clear, right up front, that we are mostly talking about very low-energy, high-quality houses. However, all the principles Phil and I discuss, can be applied to any home, of any size and scale.
So, join Phil and me as we knock back a cocktail, roll up our shirt sleeves, and discuss our respective approaches to affordable green design. I should also warn you that Phil and I are a bit chatty in the beginning, and if you are the type that likes to get right to the subject matter, and don't care about Phil's discovery of Campari, then you'll want to skip ahead to minute 06:00.
For the rest, well, here's to you!
What does affordable mean? To some, it means $45 / sq. ft. I honestly can't imagine hitting this number. To others, it means $175 / sq. ft., but that's for a house that's close to net zeroProducing as much energy on an annual basis as one consumes on site, usually with renewable energy sources such as photovoltaics or small-scale wind turbines. Calculating net-zero energy can be difficult, particularly in grid-tied renewable energy systems, because of transmission losses in power lines and other considerations..
The Three Cs: Client, Context and Creativity
Client. A client who understands the difference between needs and desires, between comfort and luxury, and who's value set is in the correct order, is essential for a successful approach to building an affordable low-energy home.
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Context. A site that cooperates (has utilities, easy access, good solar exposure, good soils and drainage) makes a huge difference. Steep slopes, poor soils, long driveways, difficult terrain -- all quickly add up to a substantial premium.
Creativity. Okay, Mr. Architect. It's time for you to turn simplicity into beauty.
- If the house is a box, make it a beautiful box.
- Watch your surface-to-volume ratio.
- Simplify the structure; minimize corners and dormers.
- Cost offsets: reduce energy demand with the goal of saving on a smaller, simpler mechanical system.
Don't forget to check back in later for Part 2, when Phil and I will get into more detail about the building components and how the simple design decisions can have a big impact on the budget.
Thanks for listening. Cheers.
Chris: Hey everybody, welcome to the Green Architects’ Lounge podcast. I’m your host, Chris Briley.
Phil: And I’m your host, Phil Kaplan. Hi Chris.
Chris: Hi Phil.
Phil: Welcome to the end of summer. It’s a very important phase that we go through as we change from a very different time in our lives. It happens every year – the shift happens right about now. I don’t know about you, but my kids go back on Tuesday, right after Labor Day.
Chris: Mine are already back; mine went back Wednesday. We say goodbye to our summer intern, Ben. Fare thee well, Ben.
Phil: Yeah, we had a summer intern, Maddy. She’s gone too.
Chris: Yeah, it happens.
Phil: Did you have a nice summer? Did you get plenty of solar gain?
Chris: I got lots of solar gain.
Phil: Excellent. I have to say, it’s been a little while since we’ve done one of these podcasts, and I’m excited to be back.
Chris: Yeah, it’s been a while. Sorry, everybody. We say that every episode. But this time, we really mean it. And hey, Jason Schafer (he dropped us a line on Facebook): this one’s for you, buddy. Your life is not ruined. We’re back. We’re gonna keep going.
Phil: Thanks for the push.
Chris: Thanks for the nice note.
Phil: We love doing this. It’s a passion of ours. Sometimes life gets in the way. So, what are we going to talk about today, Chris?
Chris: Today we are going to talk about making green affordable. And it’s a hot topic. It seems like – every forum you go to, every building energy conference, every Green Build – the sessions that are always full are the ones where everyone’s looking for the clever way to deliver this high-performance, energy-efficient stuff.
Phil: That’s right. And I’ll bet you – I don’t know this for a fact – if you were to look on Google and type “green building,” with the next, third, modifier… it would be “affordable.”
Chris: I bet you’re right.
[The guys jaw about Chris’s new partnership with Harry Hepburn, Phil’s company’s recent AIA New England award, this episode’s cocktail, and cocktail memories from their youth. They also drink a toast to adolescent stupidity.]
Phil: So, let’s talk about affordable green. One of the big questions we kick around all the time – and everyone does – is, “What does affordable mean?” What does it mean to you? Then I’ll tell you what it means to me.
Chris: Ooh. Well, it depends on who’s asking me, right? What’s affordable to HUD? Or Section 8 housing? (Which I probably shouldn’t call it anymore, since it’s changed.) It’s different. Am I in the Midwest? Or am I on the coast? Here in Maine, the last time I was trying to do an ultra-efficient, affordable house of substantial size, I was trying for $175 a square foot. And it was hard to do. It was doing a lot of what we’re going to talk about later, in trying to keep things tight.
Now, if I said to any of my friends in the Midwest, “affordable housing is $175 a square foot,” they’d say, “You’re high. You can’t tell me that’s affordable.” Although, in California they would say, “$175? That’s pretty good!” And we’re talking about something that’s ultra-efficient, very low-energy house. I wouldn’t go so far as to say Passivhaus or net-zero, but I’d say “near-net-zero.”
Phil: “Net-zero-ready,” at least.
Chris: “Net-zero-ready” – the type of houses we talk about all the time.
Phil: And I’d say you have to work to get to $175.
Chris: You do.
Phil: The problem in the press, when a lot of these buildings that we describe as “affordable green” get out there, then you see the people comment below, “$175 affordable? How dare you?”
Chris: Exactly! It’s almost offensive to some.
Phil: It is. And I completely understand that. Low-income housing. There are these modular buildings out of Pennsylvania I’ve found out that are kicking out these buildings for $45/square foot. It’s 2x3 walls. (The insulation… do they make it that small? I’m not sure.) But it’s affordable. And really, in the modular industry, $100/square foot is kind of where you want to hit. Or below. You should be able to get below that. So, when you talk about “affordable,” those people are really offended.
So, this is a different thing. This is a better building. This is a building where money… yes, it costs you a little bit more, but you pay less in utilities, and you get a high-quality, durable building. Those are the ones that we’re describing. We wouldn’t let ourselves be involved in anything that’s kind of junky.
Chris: Right. And, all these principles that we’re about to talk about, they can be applied to any of these houses. We’re going to talk about keeping the volume simple. That makes any house affordable, whether you’re doing a super-duper-insulated whatever or a modular whatever.
Phil: That’s right.
Chris: If you care to e-mail us your comments about “what is affordable or not,” send them to email@example.com. Or – I should put in our plug – go check out our lame Facebook page, and leave your comments there… where we will, every once in a while, look at them, and… ah, never mind.
So, do you want to get started? What’s most important to you, Phil? Let’s say you’ve got a client that says, “I want a lot of stuff and I want your help in reining things in and being affordable. Help me.” You say, “Here’s Number One, top of the list…”
Phil: I sometimes talk about the three C’s: Client, Context, and Creativity. Those things have to be in alignment. You’ve got to have a client who’s on board and helps you make decisions in the right direction; who’s willing to show restraint. And that’s harder than you think. Even people who say they want to have affordable homes sometimes will fight against that because it’s not really what they want.
Chris: Exactly. They want what they want, but they want it to magically be affordable and that’s a hard fight. That’s a long slog of a project.
Phil: Right. So there needs to be some clarity up front, in general. If you have buildings that have hit these numbers before, show them what they look like. If you haven’t, find others who have hit these marks.
Chris: Very good advice.
Phil: And then go from there. Another one that I’ll reference a couple of times – who I’m a fan of – is Carter Scott. He is of this caliber. He’s got a lot more under control, since he builds them himself. He’s really got it down. He’s a good example of what you may be able to hit if everything’s perfect. We can’t get to his level.
Chris: And a little experience goes a long way too. Naively saying, “Yeah, we can do that” – I mean, that’s…
Phil: So, the next piece after the Client is the Context. The site has to cooperate.
Chris: That’s a big deal.
Phil: It is. Everything really has to be in alignment.
Chris: Are the utilities there already? Do we need well? And septic? Is it a city site? Is there natural gas and utilities all right there? Water? Sewer?
Phil: Are you going to have to blast? How far are you going to have to blast?
Phil: Is there a slope?
Chris: We’re in the Northeast, everybody, where we blast every once in a while. You Midwestern folks with your sand…
Phil: That’s right. We like blowing things up here. We just don’t like paying for it, but we have to.
Chris: Right. It happens.
Phil: Is it a south-facing view? That’s a huge one. That’s one that is a little bit different. I mean, the other things we just mentioned are the same for any affordable house. But here, you want a lot of glass to the south for this to work properly. Our energy models tell us that’s absolutely what’s got to happen. So, if you have a view to the north, you’re going to have a challenge getting an affordable green home.
Chris: Absolutely. What’s next? Keeping the volume simple, I think, is the next thing that we do, right? Let’s say we’ve got a nice easy site. Easy access: that’s another thing. If the builder is going to have trouble accessing this thing – maybe it’s in the middle of nowhere and they have to start by driving an hour every day, or two, or three – then there goes your affordability.
Phil: Right. It’s not unusual to have $50,000 to $75,000 in site costs. Right off the bat, what does that do to a $300,000 project?
Chris: Yeah. Or a small house. You’d still have the same site development costs. Or maybe not the same, but they’re still there. So that kills your economy of scale. So, let’s keep the building simple.
Phil: Right. So, that’s the third C: Creativity. Okay? So it’s: how can we be creative to answer all of the problems with the clients’ program? And really, I mean – I want to go out of my way to say this – you’re kind of creating a box. It really is painful as an architect to think, “Boy, did we just say that out loud? Just make a box?”
Chris: Yeah, Just make a box, Phil.
Phil: Guess what? It’s not that simple… and it’s not that dumb.
Chris: Have you ever seen a beautiful box? Yes, you have.
Chris: It can be done. And a lot of what we as architects in the affordable housing realm… our creativity is in trying to make that box very pleasant. I mean, not to put too fine a point on it: we’re going to try and make every space functional – and with that creativity, maybe we can do two things with one space.
Phil: Alright, so, how about some rules about what “simple” means?
Phil: How about this one, Chris: four corners is ideal; eight is the max. No more than eight corners in your house.
Chris: I love it! When you first told me that: “When you’re doing affordable housing, eight corners is all you’re allowed.” If you tell the client that right in the beginning…
Phil: And they can get their heads around that pretty quickly.
Phil: “Alright, I can help you with that.” Which is great! Here’s another one: Having two roof planes is ideal; four is max. No more than four roof planes.
Chris: Right. The more “boogie-woogie,” the more complexity. Complexity equals dollars.
Phil: I like “boogie-woogie.” I’m going to put that in my specs.
Chris: Boogie-woogie. I say that all the time. I think I picked that up from my former boss. “You put some stuff up there, and it gets all funky, and you get the boogie-woogie, and that costs money.”
Phil: And also, it creates another place for air leakage to occur.
Chris: That’s right.
Phil: So, the more corners and joints…
Chris: The more labor.
Phil: That hurts us, not only cost-wise, but in trying to get a really nice, tight building.
Chris: Right. And that brings you to the volume, too. I mean: the more corners you have, the more surface area you end up with compared to the volume, especially if you’re biting in. If you have a re-entrant corner, then you’re using the exact same surface area to subtract volume from your building. And you’re doing yourself not a favor.
Phil: I’ve never used the word “re-entrant” corner. You must be an architect.
Chris: Yeah, I am! Actually, use that in front of your engineer, and he’ll sit up straight the next time you walk in the door.
Phil: He’ll shake your hand. I’d say he’d high-five you, but they don’t do that.
Chris: They don’t high-five. No.
Phil: But, talking about the volume-to-skin ratio… This is actually very interesting question, because we know that the ideal form, Chris, of maximum volume to minimal skin is… what?
Chris: A sphere.
Phil: A sphere. Right. And how much does building a sphere cost?
Chris: Yeah, that’s a little bit hard. So, the industrial equivalent to a sphere might be…
Phil: It’s a cube.
Chris: It’s a cube. Right. So, we’re all boards now. We’re all affordable boards.
Phil: That’s right. Holy box! But – here’s another thing that we talk about, and we’ve mentioned this in multiple podcasts – if you want to elongate your building so that it’s got southern exposure, it’s basically an east-west axis…
Chris: Exactly right.
Phil: That fights against the cube. So what’s the right answer here?
Chris: Well, personally, I think the two-story shoebox – which is what Passivhaus really forces you to do. Because there, you’re striving for efficiency, you’re not really striving for affordability. (Although, go ahead and try, but that’s what it’s forcing you to be: the two-story shoebox.) Personally, I think the proportion is 1 to 1.618, which is the Golden Section. That’s not proven scientifically… ah, that’s just me.
Phil: But you’ve got a beautiful vibe.
Chris: Right, but really, it is about 1 to 1.5. This is a good rule of thumb in the northern climate, zones 5 and 6. I think it’s going to start to change when you get lower and you want to shed more heat.
Phil: Well, I’m going to put a little hitch in your assumption there.
Chris: Awesome! Hit me. Challenge me, Phil.
Phil: So, if we go back to the cube, there are things that we can do. Granted, we do not get as much solar gain – because, with the orientation of the building, we have more challenges with our east-and-west exposure – but what we do get is: efficient spans. Say, the maximum span of a 2x10 is 16 feet. You can’t really have a 16-foot wide building…
Chris: You can, but you’re going to lose it on the surface area-to-volume ratios there.
Phil: Yeah, and I would also say that you’re not going to be able to have a very efficient floor plan, just out of experience. So, if you were to do a 32 by 32 foot building…
Chris: Yeah, you’re talking about the classic four-square there.
Phil: That’s right, the classic four-square. It’s extremely efficient. It does not have much siding, compared to your two-story shoebox, where it’s got less. I’m learning this – because in some of the projects we’re working on with Modular Builder, we’re trying to figure out what’s the most affordable and most efficient (and affordability is really Number One). The most affordable cost per square foot is the box. It’s that Great Diamond model, which is the cube. That’s it. We can hit $135/square foot, whereas our two-story shoebox with a dormer is about $175. This is dramatically different.
I mean, there is a variety of factors, but…
Chris: But, you attribute it mostly to the fact that you’re a cube and not a box.
Phil: Not a rectangle. I would attribute it at least 50% to that.
Chris: Well, alright. “Chapeau,” as the French would say.
Phil: So, kick it around as a possibility.
Chris: Right. Other things you can do, and you mentioned this as being rectangular in yours, is keeping things octagonal. We architects, we love to get funky: just skew that little angle! You know, just kick it!
Phil: Whoa! Why’d you do that again? Why is it angled? Well, the angle of the sun is off by 14%, so we want that angle to respond to the… ahhh.
Chris: It’s not going to happen.
Phil: It’s a cool idea. It’s architectural conceit. It makes it look a little cooler.
Chris: Well, and that’s fun. If our goal here is to be affordable… if the client said, “I need your help to make this thing hit this price,” and you go doing funky things, then you’re not helping.
Also, let’s think about – hey architects – both our structure and our mechanicals all at the same time. That’s what you’re trained to do. That makes you a cool guy. The word “transfer beam” really shouldn’t come up in an affordable house or you’re failing, sir.
Phil: That’s right. Eliminate steel. Somebody told me this once: imagine that you had to bring this building to an island and build it there. You’d have to get a bunch of small sticks to an island – you can’t say “I want a 22-foot member here and there.” You’ve got a pile of sticks and you’ve got to build this house yourself.
Chris: Also, with keeping things simple: your air sealing. Right? I mean – and you mentioned it before – the simpler your form, the simpler your air sealing.
Phil: Right. Less corners, less joints – the tighter this thing is going to be.
Chris: Right. So, you’re stacking up your structure. You’re stacking up your mechanicals. You’re keeping your runs short. That’s a no-brainer. And you’re able to air-seal this thing easily. Let’s keep those mechanical systems really simple, too. Right?
Phil: That’s right. Absolutely dead simple.
Chris: I don’t know how many times we’ve talked about cost offsets – Phil, you and I here on this podcast, but – that’s what it’s all about. If you can simplify your house, reduce that demand, now you’re able to even further simplify your mechanical system. And that is going to go a long way in saving money. If you can turn your $20,000 mechanical system into a $9,000 mechanical system…
Chris: Boom! Hero… right?
Phil: That’s right. Hero! Exactly! And what is that system? We talk about ductless minisplits.
Chris: Over and over. We say that. And that’s usually where we are, just because of their efficiency and the amount of demand we’ve gotten to. If we can get down to 25,000 or 23,000 Btuh…
Phil: Hang on, Chris. Can’t you buy a cheap little gas furnace?
Chris: Yes, you can! Let’s say, you’re right there on the street; you’ve got natural gas in the street. Maybe your condensing gas boiler is a great option that is cheap, and also wicked efficient. Sure, you’ll have way more BTU output, but if they modulate, then they’re still going to work for you.
Phil: Yeah. I mean, there’s fossil fuels there. That might be one of your goals.
Chris: That’s true.
Phil: Yeah. So, that’s a question, but… Yeah, that really is an affordable answer, and sometimes it’s a tricky one to argue against. You’ve got to believe in it.
Chris: And maybe at this point you start thinking about the exhaust-only approach to ventilation. I’m not a fan… I don’t like exhaust-only as much, but maybe if you put a couple of those little… what do you call them?
Phil: Trickle vents?
Chris: Trickle vents in there. Or maybe you use the Lunos system. But that’s not the most cost-effective in our opinion.
Phil: It’s not. So, the trickle vents are something that does work and it’s the most cost-effective, but you certainly lose control. So, if you get yourself a nice, cheap ERV(ERV). The part of a balanced ventilation system that captures water vapor and heat from one airstream to condition another. In cold climates, water vapor captured from the outgoing airstream by ERVs can humidify incoming air. In hot-humid climates, ERVs can help maintain (but not reduce) the interior relative humidity as outside air is conditioned by the ERV. or HRV(HRV). Balanced ventilation system in which most of the heat from outgoing exhaust air is transferred to incoming fresh air via an air-to-air heat exchanger; a similar device, an energy-recovery ventilator, also transfers water vapor. HRVs recover 50% to 80% of the heat in exhausted air. In hot climates, the function is reversed so that the cooler inside air reduces the temperature of the incoming hot air. – boy, wouldn’t that be a better option? It’s sort of a question of adopting – not of the unit itself – so, you’ve got to be smart about how you do that.
Chris: Right. And then, one more thing before we go to break. Let’s talk about the floor plan and the spaces and their functionality. We kind of alluded to it before. Phil, why would you have two entries, for example, in a modern household? You’re trying to be energy-efficient, right? Can you – challenge, architect! – can you create one entry that is functional and neat and clean and acts as the same entrance that your family uses and your friend uses and the same one that you use for the funeral or the – wait, I’m sorry – the wake, or the graduation, the parties that come over and that sort of thing. Can it all be done?
Phil: It’s a possibility. But Chris (I’m being the client right now), I really love the idea of French doors from my master bedroom and my dining room and my master bathroom. I’ve always had visions of those French doors.
Chris: Awesome Client, I know you do. And we all do. But you came in here saying you wanted my help in reining in that budget. Here’s an idea: maybe we can minimize those doors. Those French doors… man, they are costly! Maybe we can do it with one. Maybe one front door and one back door. Maybe you can do it without. Maybe we can do it all in one! I don’t know. Let’s… let’s… let’s… wait! Give me a shot! Give me a shot, Awesome Client. Let me show you how awesome it could be.
Phil: I love you, Sensible, Responsible, Sensitive Architect.
Chris: Well, we aim to please.
Phil: Alright. Hand me that invoice, I’ll pay it now.
Chris: Yeah! It’s already on the way. Let’s call that “Part One,” because I think those are the big ones.
Phil: That was good. We’ll come back and we’ll talk about a little bit more detail. We’ll talk about the wall section, the roof section, the building section. More specifics.
Chris: Right. The more technical things that we can do.
Phil: And, as architects, let’s come back and talk about how to keep these things from being ugly.
Chris: Awesome! I love it!
Phil: Battling the box.
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