Category Archives: hindsight is 20-20

Important but…

OK, so it’s been about 3 years since we moved OUT of our wonderful “almost passivhaus” house in Stow, MA… a few comments (now that I have a little distance) about things I would do differently.

1. Building a passivhaus in very cold climates is important but not *that* important. Our’s was REALLY close but even getting as close as we did was VERY expensive because it’s such an unusual thing but also because the climate is so extreme that the insulation needed (to do it right and not have condensation problems) is expensive. Condensation… see book: Builder’s Guide: Cold Climates

2. Building a cube is… not that important.

3. A custom design is… not that important.

4. Building the house so the roof points EXACTLY solar south (or whatever your designer tells you is absolute best for PV solar panels or passive-solar) is…. not that important

5. Small windows on the North is… not that important. It’s important, but not at the expense of views and connection to nature.

What to do instead:

1. Instead of passivhaus, do something more along the lines of the “pretty good house” with 10-20-40-60 insulation. Why? You can get 90% of the way there for $100k or more less money which would be more efficiently spent on saving the planet with solar panels. The house will be just as comfortable.
Read more:

Good example: Bick Corsa’s house

2. There are lots of energy efficient houses in recent years that are tall little cubes with footprints on the scale of 26×26, and sure that is a LITTLE more energy efficient and uses less concrete for the foundation or basement, but it also is less ideal for 1) entertaining since you have a small 1st floor 2) little kids … stairs to get to bedrooms and playrooms means more separation… they want to be closer to the action which is in the living room and kitchen. Sure there will be a time as they get old where being farther away is good too, but there are ways to do both.
So… instead?
They get knocked a lot, but the classic split-level ranch we have found to be the ideal compromise. Everything is a half-flight away and there are long views that are right out of A PATTERN LANGUAGE. It’s a popular design for a reason. And number 3) a wider foot print means more space on the roof for solar panels.

Book info: A Pattern Language

3. Since you are interested in this stuff, you will most likely be perfectly happy with a stock plan … just build it with slightly thicker walls for more insulation — either a double wall or with crosshatched studs. Your interior rooms will be at most 6″ smaller and the only details to have worked out is how to frame the doors and windows a little differently and just be careful to pick a plan with a simple roof line so that air-sealing is straightforward. This doesn’t have to be so difficult.

4. Getting close to solar south is good, but even a full 45-degrees off will work quite well. Solar panels are MUCH cheaper than they were just a few years ago so you will still get huge savings, especially if your electric company allows net-metering. But even without this, it’s still worth it — we didn’t have net metering in Stow at the time and it will worked out $$-wise. You’ll see by changing the orientation at PVWatts that it doesn’t matter that much.

5. Do some windows you want on the North. Not worth sweating it. It’s worth the extra $100 a year in energy costs (because this is literally how little we are probably talking) to have the view and house design you want. If you fell guilt get the *even fancier* windows with even more panes of glass and better insulation in the frames. If it’s the environmental damage that concerns you… buy some more carbon offsets or PV panels for your neighbors house, ride your bike more, or cut down on your meat eating. Lots of other things to do.

What does matter instead:

1. Location location location. Our solar panels in Stow generated as much energy as we used doing extra driving vs living closer to our work and schools in a less ideal house. And living in a walkable neighborhood close to friends, shops, nature, etc. Our Stow house was in a dream location in terms of nature… amazing quiet and nature and trails and water. But the driving was a bit much for us.

2. Connection with the site. Views. The yard you want. We had that in Stow, but just be careful to not let the tail wag the dog. Sometimes a certain house design will just not work with certain sloped lots. That’s OK, do something that makes sense for the location and site you love!

3. A garage. OK, build it separate or not (it can be designed to visually loot connected, but all the air-barriers can keep it separate). But build it! 2 reasons: 1) even more room for solar panels. 2) Could allow you to build a smaller house, but leave some unfinished space for bonus room for later, or for storage space (if you are not building a basement or attic) We are an active family and need room for 1) bicycles, scooters, skateboards, ramps, ski equipment, camping equipment, kayak, canoe, etc, etc. It’s very difficult to fit this amount of active gear into a small shed. That was our experience at least! Just build the garage. They also work very well as a mudroom. (Also a must have but a section of garage can do pretty well double duty as a mudroom. I’ve also seen a screen porch work very well as a mudroom….)

See also:
My further comments about A PATTERN LANGUAGE

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20 green “strange thing” gotchas when building a custom green house (or, how I learned why things end up costing so much)

Most of these can be avoided if one chills out and builds 90% of a green house, or perhaps by working with a very experienced green architect (or ideally I think?) a design-build company that gets both sides.

Some strange things include:
1- no-VOC products
2- TJIs used in walls
3- dealing with innie or outie windows in superinsulated walls
4- unusual windows with R-5 or R-6
5- HRV systems and proper balancing and inside placement of intake/exhaust vents
6- sizing and choosing placement of inside heads in a minisplit system
7- custom design & specs instead of stock plan
8- insulating properly behind a bathtub on an exterior wall
9- how to add interior light block shades to outie-windows (it’s problematic, take my word for it!)
10- foundation brine loops for pre-heating/tempering HRV air
11- exterior framing and sheating all flush (no overhangs) and taped. overhangs applied after air-sealing
12- hot roofs
13- worrying about orientation (solar south) (too much)
14- things that people are used to which might be missing in your design (a fireplace/mantel, a basement, a garage, a formal dining room, a master bathroom, a paved driveway)
15- composting toilets
16- cellphones and radios and TVs might not work well in a house with foil-faced PolyIso insulation
17- not having a furnace or boiler that can very quickly heat or cool the house if setback temps used (usually with minisplits, they are slow to catchup, so best to not use nighttime setbacks)
18- you maybe found land in a weird spot farther away from things
19- smaller than typical houseplan with things like:
open plan, limited wasted space like hallways, no loops for kids to run-around, big furniture
20- big windows in awkward spots (and none in others) if trying especially hard to do passivhaus
21- special parts that take a week to order to repair a strange thing
22- strange things that are difficult or expensive to repair or troubleshoot
23- strange things that are done (products used or designs) to save money (but don’t or else else cause other side effects that undo the savings)

Who is affected by your stange choices?
– the building inspector has to approve of strange things
– the builder might have difficulty in sourcing products and/or pricing labor effort for strange things
– beware a builder who is not used to or doesn’t like doing custom projects rather than spec houses
– the contactors who have probably not done strange things or used strange things
– you (the owner) not having lived with strange things
– difficulty in finding contractors nearby to repair or maintain strange things (for instance, a radon removal system for potable water) or redo work they did on strange things that weren’t done properly in the first place.
– the future buyer when you move — they won’t appreciate the strange things as being awesome, just different, and maybe even annoying.

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Book Review: A Pattern Language

Green building people… if you are designing/building or buying a house, I cannot emphasize enough the importance of this book — A Pattern Language (1977, Christopher Alexander et al.). I also recommend it to those thinking deeply about education, Sudbury Valley School/Democratic Free Schools.

I have skimmed and skipped around, and I am sure there is much hooey to ignore (I certainly can’t speak to the CONSTRUCTION section), but there is MUCH to consider deeply and carefully. Fail to consider the points made at your own risk!!! Lots of food for thought. Don’t worry about the perhaps seemingly haphazard organization of the sections. Just enjoy the sections for themselves.

And I am speaking from personal experience. When I ponder what makes one house or apartment I have lived in comfortable, I inevitably find a number of “patterns” which pretty clearly make sense of it. Here I list some of my favorite sections from the BUILDINGS major section, numbered as they are in the 1200 page book:

(76) House For A Small Family
(In this pattern I think he is wrong… the 2-part house is a typical ranch/rambler/split-level. It’s a question of age. When the kids are little, they love having their beds/room very near the parents.)

(109) Long Thin House (Popular in many green architects designs… I actually don’t like this very much!)
(110) Main Entrance, (130) Entrance Room
(111) Half-Hidden Garden (explains the success of some patios I have experienced)
(112) Entrance Transition, (113) Car Connection
(117) Sheltering Roof
(125) Stair Seats
(127) Intimacy Gradient
(128) Indoor Sunlight (duh but still some interesting comments)
(131) The Flow Through Rooms (Which contains one of my personal favorites — loops “Even better, is the case where these is a loop”. This one is almost NEVER followed in many new smaller houses I look at… but it is fundamental to why many older homes are comfortable. And kids love them! And you will too if you live in New England or somewhere cold!)
(132) Short Passages (as opposed to bowling-alley hallways like one house we looked at recently)
(133) Staircase as a Stage (both our current and last house made good use of this pattern)
(137) Children’s Realm
(142) Sequence of Sitting Spaces
(143) Bed Cluster (partly why the boys’ bedroom is so comfortable)
(154) Teenager’s Cottage (the basement!)
(159) Light on two sides of every room (Nice, but also better ignored in some cases I have found)
(167) Six-foot balcony (porch size rule-of-thumb)
(181) The Fire (“There is no substitute for fire.” Don’t let your dream of a superinsulated passive house let you forget this!)
(190) Ceiling Height Variety (In spades with our current house. love it!)
(192) Windows Overlooking Life (“Rooms without a view are prisons for the people who have to stay in them.”) (SVS related as well)
(196) Corner Doors (yes!)
(197) Thick Walls (Your superinsulated home will have that!)
(203) Child Caves
(242) Front Door Bench, (243) Sitting Wall


(Also, an aside. This book is also very interesting to me because of the way it links to different sections within each of the individual writeups. It is hypertext written before it’s time! It would work well as a PDF E-Book with links to the different sections.)


Also… Communities:
(9) Scattered Work (Discussing the problem of separation of work from homes)
(12) Community of 7000 (That democratic voices are lost when towns/cities get too big)
(14) Identifiable Neighborhood (We live in one now)
(18) Network of Learning (hmmm… sounds like a Sudbury Valley School (SVS) ad)
(26) Life cycle
(31-33) Promenade, Shopping Street, Nightlife, (58) Carnival
(40) Old people everywhere

And more SVS-related themes:
(57) Children in the City
(64) Pools and Streams
(68) Connected Play
(72) Local Sports
(73) Adventure Playground
(80) Self-governing workshops and offices
(84) Teen-age Society
(85) Shopfront Schools

Also… Transportation:
(11) Local Transport Areas (A diatribe on cars), (20) Mini-buses (half taxi, half bus), (22) Nine percent parking
(51) Green Streets (good for driveways)

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Do as I say, not as I do…

I have maybe written about this before, but if not… here goes. Some house-building advice:

1. Hire a builder, any builder. Just make sure they are obsessed with wanting to learn this stuff … passivhaus, superinsulation, etc.

2. Hire a very good architect (or do it yourself) but what you will need is:

2.1 A detailed all-in-one diagram showing where the air barrier is on your wall/roof

2.2 See #11 and #12

2.3 require a 3d walkthru view — if not the architect, hire someone to do with with SketchUp

2.4 Consider the site… your unique location — in designing the house, window locations, entrance etc.

3. If doing passivhaus, absolutely do the PHPP before your design is even finalized

4. Don’t give up views. If your N views are gorgeous, I don’t think it’s worth $50 or $100 in heat per year to give that up.

5. Build a gorgeous looking house. I don’t mean expensive, I mean the outside design. Make it look nice. Even if/when energy prices go up or people start caring about global warming, people will want a nice looking house. And this definition won’t change TOO much. Because I am telling you… people will build nice looking passivhaus-es in the Northern US even if you haven’t seen one to your liking yet. Human ingenuity.

6. Use cellulose. I’d build a 2×6 load bearing wall and pull wood I-joists on the outside and fill with cellulose. Voila, no foam and no thermal bridging at the studs.


7. Consider “innie” or “midway” windows. At least behind the kitchen sink. Our walls are 17″ thick with outie windows. In most places this is great. A built in cat bed, book shelf, plant location. But behind the sink is VERY difficult to reach, at least if you have the intention of using cellular blinds. For the same reason, even if you really like double hungs (leaky but nice in my opinion) consider casements in SOME spots.

8. Don’t make those windows too small. There are a few spots I wish we skipped a window and instead made another window twice the size.

9. Talk to your local building inspector and show him rough plans LONG before you finalize a design. Especially if you have a deed restriction of some sort.

10. When getting detailed bids from builders, I think it’s worth paying a little to have them do the numbers and have them categorize the numbers in the same ~20 categories that YOU give them. That way you can compare apples to apples. Otherwise it’s difficult to know if a given estimate truly includes the weird specs or products you are asking for. Also consider (mandate!) using the same ~20 categories the bank is going to want you to use (if you are getting a construction loan).

11. Architect should draw framing plan. Every stud. Framers won’t nec care.

12. Architect should draw HVAC plan. Every duct. HVAC contractor won’t nec. care.

13. Give detailed outside specs, even if mostly unfinished site. Depth of topsoil. Depth of gravel drive. Require some sort of edging separating the gravel drive/walk/round the house from the yard. It’s a HUGE pain to deal with afterwards.

14. Storm doors on every door without overhang.

15. I still think a partial basement is smart (especially if you might need water filtration which takes up a lot of room) but also consider a garage with an “attic” for storage, instead of a large basement. It can even be built to look connected, even if it’s really not. If you are an active family, even without car storage, you are going to need a $3000 shed to hold:

– bikes, scooters, bike trailers, skateboards, sleds, ice skates, skis, and on and on.

– lawnmower, shovels, rakes, and on and on.

16. Remember that you kids are going to grow. Remember also that they are going to leave shortly.

17. Don’t use any unusual product for interior finishes without seeing/trying it *in person*. And require that the installer/finisher be someone who has worked with the product before.

18. Give yourself a lot of roof space for PVs. A shed roof or (2 story house instead of 3) will have more room. I don’t personally think it’s worth having more passive solar window space at the expense of good roof space for PVs. Better to do a solar furnace in your yard or a thermally-isolated sunspace attached directly to the house rather than “living in the heat battery”.

19. Skip the solar hot water and pack in the PVs. Not worth it. Sunpower PVs if possible. Look into at least. Don’t dismiss it out of hand. Run the numbers.

20. have someone — an arborist probably — help you choose what trees to keep and which not and use this to inform house location.

21. Save money on something and spend it on a pool. Or so that you can afford ______ (insert thing that you might consider giving up). It’s not worth it. Really it’s not.

22. Consider moving closer to work, riding a bike, a prius, instead. Think holistically and big picture. If you are trying to save energy, you might get more bang for your buck with a prius, a bike, or a nearby home rather than a superinsulated house out of town. Do the simple math. For instance, our kid school carpool commute essentially uses as much energy as our solar panels make each year. Just as good to live close to school/work!

23. See above links about design… consider a design someone has already built and pay a little to have an architect adjust it with thicker walls. Better than settling for a poorly designed but VERY energy efficient house.

24. Read the PRETTY GOOD HOUSE posts at


So… detailed specs.

And I feel like there are exceptions to every rule.

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Things I would do differently…

Not to be a downer, as the house is really AMAZING, appears to be performing right in line with estimates we made for heat load and UA and the more detailed PHPP workup. But I can’t help it, there are definitely things I would do a little differently if I were to build a house again.

  1. Our property has a 2-bedroom deed restriction, which we knew going in, and it’s totally fine, but if I were to do it again, I would have been in communication with the town’s building inspector (who is also the zoning enforcement person) early on in deciding — show him our rough plans, what we were going to build — instead of waiting until submitting formal plans. Novice mistake. Luckily things turned out fine.
  2. Don’t be afraid of stock plans. I don’t think one necessarily needs custom home plans to build a superinsulated house. Certainly if you are trying to do passivhaus then you probably do since it will mean really messing with window sizes and placement, but otherwise, I would advise that, if you already have a plan that you really like, just go with it, and ask your builder to build 12″ or so double walls, rather than the 2×6 walls shown in the plans. Spend that money you save on something else!
  3. If I were to do it again, I might not be quite so enamored of strict strategies for reaching/approaching passivhaus in New England. A passivhaus would use 2.5x less energy than our house, approximately (assuming the same TFA) but we’re talking maybe $200 in heating PER YEAR vs $600 PER YEAR. I am not at the moment convinced it is worth the substantial extra effort/expense due to slightly unusual methods needed and products. It’s still tricky to do this stuff and so it means having a team — a builder and architect — who are obsessed I would say. Correct me if I’m wrong! So, do all of the items on the passivhaus checklist that are low-hanging fruit, but pass on items that are stretches. Might as well do 6″ of foam under the slab and edge, for instance. But have nice views on the North, East or West of your house? I would say not to feel bad about putting in nice windows there! That’s me. (I would aim for R40 walls including basement, R80 roof, R5 windows, R20 slab)
  4. On the other hand, I would also ENCOURAGE everyone to VERY EARLY in the project to seek out a Certified Passivhaus Consultant (such as ours in the Boston, Massachusetts area: DEAP GROUP) and have them model your house plans in PHPP. Even if you don’t follow all the Passive House advice, you will be very well informed!
  5. On Solar PV panels: I really like the Enphase microinverter approach we took, but I can’t help but think that the grass-is-greener — IOW, a central inverter. I like that a central inverter approach would have 1) been a little cheaper, and 2) allowed for a “hybrid” grid-tie AND small battery approach, and 3) w/ battery, allowed for some degree of “off-grid” use in case the grid goes down during storms and such. Ah well, I probably would be wishing we had microinverters had we gone with a central inverter approach! I am remembering that I think part of my decision for microinverters had to do with worrying about shade. I should have trusted the solar survey more! We are pretty much totally shade free except at the beginning and end of the day. Which microinverters don’t help much with I don’t believe.
  6. I would probably try to use as little foam as possible. Cellulose all the way! And generally, vapor-open envelope assemblies seem like a Good Idea. I now like this thinking better than the Lstiburek “perfect wall” approach which is closer to what we have. Ah well, grass is greener…
  7. I would use bigger windows in some spots and remove them in others. I guess trying to be a bit more site-aware. Where are neighboring houses… where are views, etc. We did this to some extent, but there are a few misses where I wish there was a double bank of windows. That sort of thing.
  8. I would have looked into unusual choices IN PERSON a bit more. I think it would have helped, for instance, to visit a house with had the Thermotech windows we were considered upgrading too. We were feeling stuck on using double hung (which we love) vs casement (which we do not). But maybe we would have been swayed seeing them in person?
  9. Sorta related to that… I would have in some cases gone with the experience of the subcontractors (on paint brand choice) but in other cases, considered using a different contractor who had specific experience using an uncommon but greener product (OSMO Poly-X floor finish). So there are 2 alternate sides to the same issue of trying too hard to use a product that is maybe greener, but if it also gets installed wrong might mean expensive undoing or redoing. And “wasting” green ($) is not green! 🙂
  10. I said not to worry about custom house plans, but on the other hand, I will admit that it is a Very Good Idea to have it worked out ahead of time exactly where the HVAC ductwork will go. I think it is wrong to leave it to the contractors. Better to have it worked out ahead of time.
  11. I might have considered more seriously a “backwards saltbox” approach (we face south, so the long roof would be in front) since it would give more room for panels.
  12. I think everyone who builds a house feels this way, but there are definitely a few spots where I wish a light-switch or outlet was in a different spot. Our electrician did a great job helping us with this, but maybe there is a way to get this even MORE right. Not sure how without living in it first.
  13. OK, that’s a pretty short list actually. More as I think of it…

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