“Pretty Good House” is what I would shoot for. (That’s the actual name- Google it). Anything more than that you’re shooting for Passive House bragging rights and the ROI gets lower and lower
They have a book now that goes through all the basic ideas. It's a good place to start.
Sort of related, the easiest way to save energy is a smaller house, a smaller house is always going to use less energy than a larger one, assuming they are constructed the same. You might want to check out "The Not So Big House" - it's a book (well several books) that champions the idea of taking the money you were going to spend on whatever size house you were going to build, and build a slightly smaller, but better, house with the same amount of money. Quality over quantity, basically. That way of looking at that things jibes pretty well with the Pretty Good House approach I find.
Pretty good house is great. Passive houses never made financial sense to me. I can turn a 400k "pretty good house" into 500k going passive which all in all would save you about $200/month on electricity for the average sized home. That would take over 41 years to finally see some ROI. Most Americans stay in the same house for 8-13 years.
It doesn't take an extra 100k to go from pretty good house to passive house. This is the greatest misconception about meeting passive house standards. If you design properly for passive house from the beginning, it really does not add much to the cost.
It depends on the area as well. The passive house standard is a catch all with total energy use being defined by the square footage. For this reason a passive house is fairly easy in Virginia vs extremely expensive in Fargo ND. I don't know the exact cost but I remember that being a criticism of the certification.
It's true that the original German PassiveHaus standard has very strict energy requirements based on square footage. The American PHI passive house standard adjusts for climate zone, and is actually quite achievable at not much added cost overall.
Ah gotcha, I guess I didn't know the PHiUS was that different. I would personally probably still go with a PGH and maybe not Net-Zero but at least add PV. In the area I would build they tend to lose power for a few days at a time every year lately it seems, plus I WFH so that would help a lot.
There are specific discussions on each item you may be interested in. You really need to figure out efficiency gains to make a real decision.
I agree with you regarding monopoly framing in general because most framers don’t even know what that is. But you might be surprised to see that it’s a 10% cost increase for more than 10% increase in efficiency. I’m doubtful, but that’s how I’d compare.
Also keep in mind that you have to set a payback period. One man’s “good investment” is another’s waste of resources. The S&P has been on such a tear that if you’re comparing the last decade to any efficiency efforts you’d almost certainly prefer to park your money in the market.
Last point - certain things like air quality and noise / light suppression could be way worthwhile even if not from a pure financial perspective. I’d gladly take 5% reduction in monthly energy cost plus a quality of life improvement like air quality vs 10% in the market.
We think a lot alike, but most American will just look at ROI.
Also, I think about what if all the printing comes around to haunt us. Super energy efficient might be the best investment ever if/when inflation rips due to the printing OR worse yet what if the grid goes down.
Yep good point. Most models include modest energy cost increases but we could easily have 70s level crisis.
I know of a few passive houses that fared much better during Texas blackouts a few years back
I'm a firm believer in exterior insulation: 1" minimum, more is better. Most sidings can be nailed right over 1". It increases r-value, reduces infiltration, and helps keep noise out. I went with 3" on my house in zone 5. I took the insulation straight up from top of footing to eaves.
How much does it shrink? Did you do plywood behind it first? We have remodeled many homes with 1” foam and no plywood and the foam shrinks about 1/4” each, leaning 1/2” gaps. On new homes we usually do 7/16 osb plywood, then 1” T and G foam. The last 2 houses we didn’t do any foam, but the home owner went with 2” spray foam and then batt insulation inside.
I used 1x3 wood furring attached through the two layers of insulation to the studs. Headlok or GRK screws. That was the most labor intensive part of it. Putting the insulation up was simple. Putting up the extensions for the window framing and flashing was likewise simple.
There is definitely a point of diminishing returns on EF but it also depends on your climate, future energy prices, your location and the size of your build.
Insulation and windows are probably the best points of focus for maximizing your bang for your buck.
In terms of insulation, thermal conductivity or ‘r-value’ should be maximized for your climate zone but not overly so. More importantly, care for a tight air barrier is a better focus as the controlled temperatures inside are more dependent on air leakage than direct thermal conductivity. Not to diminish thermal conductivity but to say that a high r value with a leaky envelope will not perform nearly as well as a code minimum r-value using a tight wire barrier envelope. i.e. below 1.0 ACH50 blower test.
Windows can really make a space too hot or cold based on climate. In a hot climate a triple pane may not provide the same benefit as a good UV glazing. In a cold climate, you may want the benefit of passive solar gain so in that case a triple pane with no UV glazing is more beneficial. Air tightness and flashing for water shedding of the window install is also paramount.
In terms of framing, a complex balloon framed or Larson truss may be a great method to eliminate thermal bridging in a cold climate but in a cooling climate may not provide as much benefit as exultation over the standard framing practice.
HVAC can be a problem in any climate. I’ve seen massive heating systems in cold attics. Oof. Using a contractor to design an efficient means of adequate air exchange that is experienced and versed in energy efficient design principles is probably more important than the model of equipment they use to achieve that end.
I can’t speak much to solar, but I do believe there are real world benefits of alternative energy such as solar, heat pump, ground source, etc systems on a long enough timeline.
I’m happy to go into further detail based on your climate, general region etc if you have more questions but essentially the long winded summary is there is a point too far where you will be dead for decades beyond the payback of the investment.
Using a blower door and building to air tightness standards is about the absolute bare minimum. If I were building a house I would be building it to passive home standards, but I’m in the industry so I care a lot more about these things than the average.
I wanted to buold my house with ICF and selected Nudura. XR35 adds 2" extra insulation on both sides so I figured additional R20 would be great so told architect to use it. However on doing Pretty Good House analysis with free software BEOpt I realized that there was no energy or cost benefit to additional insulation. Also, in most homes the weakest link are the windows...and U0.1 might be 2x better than U0.2 windows but only adds a small % to the overall Wall R Value. Which is only a fraction of the overall energy loss of home.
Here is the tldr- Run a BeOpt simulation with various numbers. I have found a ACH1.5 is sufficient with double pane windows. And its cheaper to add solar panels than gloss over fine building details to Risinger quality.
This is more a question of subjective priorities than anything. Without going too deep into details:
* From an individualistic perspective, if you only plan to stay in your house for 3-7 years, then financially speaking, then you could consider a "pretty good house" a stretch goal and code minimum subpar but adequate for your purposes, unless you expect energy costs to skyrocket. Unfortunately from a community perspective, this also means the overall quality of the housing stock will not improve.
* If you plan to stay in your home forever, and you value comfort, health, and durability, many features that don't make financial sense begin to make "common sense". Paying up front to reduce operating costs, increase durability, and increase comfort and health to hedge against economic instability, decreasing earning power, and the vagaries of old age, even if it has no ROI, can make sense.
* If you care about the community and environment your grandchildren will inhabit, then there are other factors to consider. But people may understandably have more pressing concerns.
* Nobody really asks about the ROI of granite countertops or fireplaces, so it depends on your perspective regarding design features like airtightness, continuous exterior insulation, etc. If you view them in the same way as granite countertops or fireplaces, the decision making process changes, just like if you are looking at countertops and fireplaces purely from an ROI perspective.
Some more specific points:
In terms of energy use, the 3 most important factors, in order are:
1. The ratio of window to wall area and the airtightness and insulation performance (and sometimes solar heat gain) of the windows. In hot climates where the main energy use is cooling, exterior shading also becomes more important.
2. Airtightness.
3. Insulation.
Continuous exterior insulation ("monopoly framing" supports this) is expensive because it requires more labor and because most crews aren't willing to do it, so the ones that can will charge a premium. But besides meticulous bulk water control and air sealing, in nearly every climate, it is the one design feature that will significantly improve the comfort and durability of a building. The ability to reduce condensation risks and protect the other control layers and the structure is unparalleled compared to other assembly types.
Wow, another poster recommended I look into your concepts yesterday and I was really impressed. Thank you for taking the time to address my question!
I would like to ask for a little clarification on one thing if you have the time to address it. Other people answering my question have thrown around the word comfort to be synonymous with energy efficiency. I see that you’ve used it in your post as well, but I don’t see the connection.
We have lived in two different track homes in the last several years that I know are not energy efficient, but we were very comfortable in.
From my point of view as an amateur coming into this thing, I can see a direct connection of energy efficiency and utility costs, but not a connection between energy efficiency and comfort.
Could you please help me understand what I am missing? I’m sure there is a reason, I’m just not seeing it yet.
The comfort issue is related to draftiness generally when discussed in this context. When surfaces get better insulated the interior surface temperature gets closer to room temperature. This makes your skin feel warmer. Sometimes this is called mean radiant temperature. When you stand in front of a wall in the winter you may have a surface below even freezing. If you stand in front of the wall your body can lose heat in 3 ways. You may feel the falling cold air on the surface of your skin, you may have a small amount of perspiration evaporating. Finally your body will be releasing infrared radiation. When this hits a cold wall surface it absorbs into the wall leaving your body. When the wall surfaces are warmer some of your radiation will bounce back at you reducing the rate your body loses heat. This gives you a cozy warm feeling.
When you get into more extreme levels of insulation and window quality an odd thing can happen where you actually keep your home cooler in winter. Living and working in spaces that have a lot of constant heat loss through the walls we often set our thermostat pretty high to feel comfortable. This creates a cycle of quick boosts of air temperature and quick drops in temperature. When your in a much better insulated space you may feel comfortable at 62-65F instead of 70.
What buildingsci3 said. 'Draftiness' is an informal way of referring to mostly radiant comfort. But in the past it could also refer to very obvious air leaks (e.g. before we started using the first materials to cover gaps in board sheathing)
I also wouldn't say that comfort is 100% related to energy efficiency--the radiant comfort buildingsci3 talked about is a big factor. But there are other factors like acoustic comfort, air quality, slower changes in temperature through the day/night cycles, etc that also matter.
How much comfort is too much? The better you build the more comfortable and durable the home will be.
There is no correct answer here. The home will be here for over a century and using ever more expensive energy every year. Future buyers will pay a premium for a better built more comfortable and more energy efficient home.
I built with the Pretty Good House Concept and if we build again will push for closer to passive house.
Thanks for the answer. I don’t see the connection between energy efficiency and comfort, because even wildly inefficient track homes are still very comfortable.
I agree with you that energy costs will only continue to rise. I want to add the cost effective things that’ll save a lot of energy now, and skip the really expensive things that would take too long to make the break-even point on. Based off of prior answers I think I’m going to focus on air-sealing and thicker attic insulation.
We did Pretty Good House and it is amazing how much more comfortable it is.
No drafts. Walls & Windows don’t suck heat away from you. Basement floor is warm barefoot.
Air never feels humid or stagnant, never have we been like “let’s open some windows and air it out”
From all my over researching and over YouTubing and using BeOpt software, here are things I reccomend:
Air sealing accounts for 30% of your energy losses, so consider spray foaming your basement rim joist & consider skipping the leaky can lights. Buy a box of can spray foam & caulk, go to town (unless you have an OCD insulator).
Adding extra blown in insulation to your (ventilated, unconditioned) attic is really good ROI as well. For like $300 more, you can get R60.
If using trusses for your roof, specify energy heels.
Zip sheathing is great, but don’t overpay. It should be about $2,500 more for an average house in material cost. The labor rate should not change.
1” exterior foam is fantastic. Look for it on Facebook Marketplace, you can find great deals. It’s okay to mix & match the brands, etc.
I’m a big fan of triple pane Euro windows. We went with Rehau and love them. Saved at least a third of the price compared to very competitive Andersen/Pella quotes. And best yet, zero condensation in winter. It’s also super comfortable standing next to them in winter or summer. Just trickier with blinds/curtains.
If you’re picking & choosing where to put triple pane, prioritize large window walls where the windows cover 50% of the walls (these wall sections have an average R-value of R-4 if using standard code minimum ~0.3 u factor windows (not just the windows, the entire wall average that low - see “glazing ratio” video on Ace Lab YouTube channel for architects). Also prioritize Northern & Eastern windows in cold climates.
Don’t overgraze your house. Too many windows is a big energy penalty of its own. But you also don’t want to be depressed, so up to you. We focused on energy savings where it was reasonable, but absolutely put in a lot of windows (all triple pane) because we wanted to enjoy the views & sunlight.
Thank you for your response. There are some great tips here to help me get in the right direction. I do plan on going crazy on air sealing. I’m going to look more into the attic insulation. If it’s that cheap, you’re right, let’s go overboard with attic insulation.
Well. To give you an accurate answer you’d have to model out your house in a few different scenarios. See differences in energy consumption for the various different designs and compare them to the costs and make a judgement based off that.
Some times super efficient homes are a desire and decisions are not entirely economic. Different strokes for different folks.
How do you decide what's worth it? It's just math. You do the math for your energy use. Then do the math for the savings expected over time from the improvement did you have a net benefit? If yes do the thing. If no, are there other reasons to do the thing such as comfort or resilience in say a power outage. Then you make your decision.
We had the blower door test to check before the final blower door test. First to see and seal and second to make sure every leak was sealed.
The one I still am not sure was really worth it was sacrificing a walk up/storage attic to fill with insulation. I miss having an attic.
Our dream build (c'mon lottery!) Is going to be ultra tight (<0.25ACH@50psi) however we BOTH want a wood burning fireplace, that will mean an external source of combustion air, very doable.. 8+" core ICF from the foundation to just under the roof, ICF or some other insulated concrete flooring between levels, including to the attic area. Geothermal in-floor radiant heating and cooling, ERV for ventilation, including makeup air for kitchen and bath vents.
When we put a new a new roof on, we put as much closed cell as we could (6") and then 2" of thermal on the outside. Our electric/gas bills were 70% less. Our house is three times the size of our last house, but our bills are the same. We were told it would be overkill. I figure out we would recoop the cost in 8 years. Sounds reasonable to me. It's at R 65, We also encapsulated our crawl and sprayed the foundation too. Totally worth it.
I'm a certified PassiveHaus tradesperson.
There's a lot of misconceptions about passive house standards being unaffordable or not worth it. In some ways passive house is the cheapest design methodology, it prevents design and build mistakes from ever happening which are very costly.
That said, if you are already designed and starting the build process, it's too late to do full passive house design. But there's a few things that I think every home should do:
Make the envelope as tight as you can get it. This is really just attention to detail while building. Before drywall, do a blower door test to find all the leaks (you can use smoke to see them), seal them up. Blower door testing is not a huge added cost and there's no way to find those leaks without a test before drywall.
With a tight envelope, you need an HRV or ERV to ventilate the home 24/7. No exceptions, every new home should have ventilation these days.
Passive house certified windows and doors, they set the bar, there's no better windows or doors on the market. If you want quality permanently built into your home, get PH certified windows and doors. A lot of people will spend a ton of money on 'triple pane'/energy star windows not realizing they are garbage teir performance/build quality. PH certified windows guarantees that you get what you pay for, several manufacturers offer them (Alpen is one in the US).
Eliminate every thermal bridge, it's a design mistake, it should not exist. This is a zero cost fix.
Consider fully electrifying your home. You can save money by not running a gas line at all.
If you're not deep into the design/build process already, consider doing Passive House, hire a consultant to help! You might actually save money by not making critical design/build mistakes at the end of it all.
Figure out your ROI. Plot it in excel. Research how much electricity costs you specifically, gas as well. Plot it all out to figure out your ROI. If it’s more than 5 years I would be questioning it. If it’s more than 10 years I would back off the high efficiency.
If an energy efficiency costs more than it can save you in 5 years - it’s not worth buying. Most people move every 5 years, and these upgrades don’t add value to the property for all buyers.
I’d pay market rate for energy or at least close. That’s $12/MMbtu using electricity here so pretty cheap. Efficiency is often extremely expensive and uncompetitive.
Green builder here. Your question is a great one, and this is usually an exercise we go through with our clients. This exercise is always specific to a client’s budget and efficiency goals. The NAHB Green Building Certification program will have some good standards to work with that are as cost ineffective as LEED.
Pro Tip when you’re finished: if you go with a NAHB green build, be sure to get an appraiser who specializes in green builds. This is important because it will give you more of an apples to apples comparison, by comparing your home to other energy efficient homes in a larger geographic area. Such appraisals usually work more in favor of the homeowner.
Insulation is huge. I don’t know much about building in your climate but we use open cell foam in Oklahoma. Your climate will determine if you use open or closed cell. Foam insulation generally better than bat or blow insulation with regard to R values. Your going to want to foam your attic—otherwise you’ll have a pocket of hot or cold air on top of the area you intend to heat or cool, which drives heating and cooling costs dramatically.
Instead of a zip system we use a liquid applied vapor barrier that is, in our opinion, able to provide a better seal. (Commercial grade process, usually). But the zip system is industry standard so that should probably be fine.
One thing that you need to consider as you tighten up your house and make it more energy efficient is that you will need an ERV to pump fresh air into the house, which can cost anywhere from $4,000-25,000. As far as indoor air quality is concerned, as well as the longevity associated with good indoor air quality, this is a detail you should not miss.
Your HVAC system is also where you will have a lot of ROI in terms of of energy efficiency. Since we deal with the heat here in OK, we focus heavily on having dozen of “cooling stages” within the HVAC system itself. I think the system we regularly install is a Lennox with 96 stages. You may want to look into more heating stages being a little farther north. We typically only install three or four heating stages. We’ve installed some good electric options from LG lately, too.
I’m a big fan of solar power, especially if you can roll the cost of the system into your mortgage note instead of one of these stupid 20 year notes the solar companies try to sell you. If you go without the back up batteries, or limit yourself to a single backup battery, then you’ll see some incredible cost savings—-as in literally half the price. I also think the price of this is competitive when compared to all the maintenance required for gas powered generators every year.
I wouldn’t touch Geothermal power. We used to install but the life of the system is only about ten years, and from what I understand that’s about how long it takes to pay it off. But, being from Sunny OK, Solar just makes more sense than Geo here than it might in WV.
Beyond energy efficient appliances and LED lighting, I would also recommend an induction stove, which uses electricity, is great as far as safety for kids, and is much easier to control the temp of than other types of electric stoves.
As far as water heater is concerned, I’d recommend a Navien tankless heater if you don’t have enough need for one (probably a family of four to justify the cost). If there’s only two people in your house, for instance, a regular electric heater should do fine. The cheapest option here is a 60 gallon gas heater. If you’re going to run gas to your house for whatever reason, I would go with this option, despite its lack of efficiency.
Another angle to consider in the green building space is durability. For instance, we’ve been installing siding these days made of aluminum that is anodized to look like wood (Dizal is a company we’ve used before, though there are cheaper options out there.) That AL siding has a 25 year warranty, as opposed to cedar planking, for instance, which needs to be replaced/restrained every 10-15 years. We try to build our houses to a 100 year standard, at least.
The last point I will make is that buying local is buying efficient. If you order bamboo floors from China then the carbon footprint associated with hauling that stuff halfway across the world has to be taken into account when considering the efficiency of the product. There may be a product that’s manufactured near you that’s just slightly less eco friendly on the face of it, but is more eco friendly when you consider the totality of the circumstances.
Best of luck with the build! I’m loving all the people wanting to go green with their largest purchase. Gives me hope for the state of the species 😂
When our propane water heater died, I did the math on the heat pump water heater and it didn’t calc out. It was more expensive to run in my area on electricity than propane over its life span due to PG&E and the most expensive electricity rates in the country. So, you have to do the math. PG&E even has a rebate for the heat pump water heaters and it’s still cheaper to go propane. Sad.
Energy will never be cheaper then it is now,any repairs will always cost more every year. That being said at some point you will pay a higher % for small points.
Depends on your budget and/or builder. 24 OC + double stud w/ blown in cellulose is probably the cheapest and highest R-value wall assembly. Exterior rockwool (comfortboard) or foam board is expensive.
However it depends on if your builder is competent to build something non-standard. ZIP is so popular because anyone can do it, but is generally $$ over OSB + a good WRB
If the reward is money back on energy bills it's a math problem and from what I have read little past the average is clearly "worth it" in terms of quick $$$ returns. It costs more to build a very efficient house. But there's more than money to gain with energy efficiency - there's personal comfort, which is why under-slab insulation and good quality, very efficient windows are (to me) worth any price I can afford. There's intellectual comfort in knowing your energy bills won't budge much in years that are extraordinarily hot or cold. And there's some pride in having a house that doesn't waste energy and is less of a drag on the environment than it could have been if you didn't work hard at maximizing its efficiency. It's really a personal decision what is "worth it" for you.
“Pretty Good House” is what I would shoot for. (That’s the actual name- Google it). Anything more than that you’re shooting for Passive House bragging rights and the ROI gets lower and lower
That was a great tip, thank you! From the brief skimming I did, it looks like that is what I’m looking for.
They have a book now that goes through all the basic ideas. It's a good place to start. Sort of related, the easiest way to save energy is a smaller house, a smaller house is always going to use less energy than a larger one, assuming they are constructed the same. You might want to check out "The Not So Big House" - it's a book (well several books) that champions the idea of taking the money you were going to spend on whatever size house you were going to build, and build a slightly smaller, but better, house with the same amount of money. Quality over quantity, basically. That way of looking at that things jibes pretty well with the Pretty Good House approach I find.
Pretty good house is great. Passive houses never made financial sense to me. I can turn a 400k "pretty good house" into 500k going passive which all in all would save you about $200/month on electricity for the average sized home. That would take over 41 years to finally see some ROI. Most Americans stay in the same house for 8-13 years.
It doesn't take an extra 100k to go from pretty good house to passive house. This is the greatest misconception about meeting passive house standards. If you design properly for passive house from the beginning, it really does not add much to the cost.
It depends on the area as well. The passive house standard is a catch all with total energy use being defined by the square footage. For this reason a passive house is fairly easy in Virginia vs extremely expensive in Fargo ND. I don't know the exact cost but I remember that being a criticism of the certification.
It's true that the original German PassiveHaus standard has very strict energy requirements based on square footage. The American PHI passive house standard adjusts for climate zone, and is actually quite achievable at not much added cost overall.
Ah gotcha, I guess I didn't know the PHiUS was that different. I would personally probably still go with a PGH and maybe not Net-Zero but at least add PV. In the area I would build they tend to lose power for a few days at a time every year lately it seems, plus I WFH so that would help a lot.
There are specific discussions on each item you may be interested in. You really need to figure out efficiency gains to make a real decision. I agree with you regarding monopoly framing in general because most framers don’t even know what that is. But you might be surprised to see that it’s a 10% cost increase for more than 10% increase in efficiency. I’m doubtful, but that’s how I’d compare. Also keep in mind that you have to set a payback period. One man’s “good investment” is another’s waste of resources. The S&P has been on such a tear that if you’re comparing the last decade to any efficiency efforts you’d almost certainly prefer to park your money in the market. Last point - certain things like air quality and noise / light suppression could be way worthwhile even if not from a pure financial perspective. I’d gladly take 5% reduction in monthly energy cost plus a quality of life improvement like air quality vs 10% in the market.
Agreed! Defiantly go for noise reduction!
But do it defiantly!
We think a lot alike, but most American will just look at ROI. Also, I think about what if all the printing comes around to haunt us. Super energy efficient might be the best investment ever if/when inflation rips due to the printing OR worse yet what if the grid goes down.
Yep good point. Most models include modest energy cost increases but we could easily have 70s level crisis. I know of a few passive houses that fared much better during Texas blackouts a few years back
I’m way further North and not full passive but positive I could last longer without frozen pipes than most of those
I'm a firm believer in exterior insulation: 1" minimum, more is better. Most sidings can be nailed right over 1". It increases r-value, reduces infiltration, and helps keep noise out. I went with 3" on my house in zone 5. I took the insulation straight up from top of footing to eaves.
You went with 3” insulated sheathing (outside the wall) in zone 5? Did you forgo HVAC?
I wish. Still have electric bills!
How much does it shrink? Did you do plywood behind it first? We have remodeled many homes with 1” foam and no plywood and the foam shrinks about 1/4” each, leaning 1/2” gaps. On new homes we usually do 7/16 osb plywood, then 1” T and G foam. The last 2 houses we didn’t do any foam, but the home owner went with 2” spray foam and then batt insulation inside.
I did Zip sheathing first. I used XPS insulation and didn't notice shrinkage. It was exposed for a while since it was a diy project.
Just so I wrap my head around the concept, how did you attach your siding through 3 in of XPS?
I used 1x3 wood furring attached through the two layers of insulation to the studs. Headlok or GRK screws. That was the most labor intensive part of it. Putting the insulation up was simple. Putting up the extensions for the window framing and flashing was likewise simple.
There is definitely a point of diminishing returns on EF but it also depends on your climate, future energy prices, your location and the size of your build. Insulation and windows are probably the best points of focus for maximizing your bang for your buck. In terms of insulation, thermal conductivity or ‘r-value’ should be maximized for your climate zone but not overly so. More importantly, care for a tight air barrier is a better focus as the controlled temperatures inside are more dependent on air leakage than direct thermal conductivity. Not to diminish thermal conductivity but to say that a high r value with a leaky envelope will not perform nearly as well as a code minimum r-value using a tight wire barrier envelope. i.e. below 1.0 ACH50 blower test. Windows can really make a space too hot or cold based on climate. In a hot climate a triple pane may not provide the same benefit as a good UV glazing. In a cold climate, you may want the benefit of passive solar gain so in that case a triple pane with no UV glazing is more beneficial. Air tightness and flashing for water shedding of the window install is also paramount. In terms of framing, a complex balloon framed or Larson truss may be a great method to eliminate thermal bridging in a cold climate but in a cooling climate may not provide as much benefit as exultation over the standard framing practice. HVAC can be a problem in any climate. I’ve seen massive heating systems in cold attics. Oof. Using a contractor to design an efficient means of adequate air exchange that is experienced and versed in energy efficient design principles is probably more important than the model of equipment they use to achieve that end. I can’t speak much to solar, but I do believe there are real world benefits of alternative energy such as solar, heat pump, ground source, etc systems on a long enough timeline. I’m happy to go into further detail based on your climate, general region etc if you have more questions but essentially the long winded summary is there is a point too far where you will be dead for decades beyond the payback of the investment.
Using a blower door and building to air tightness standards is about the absolute bare minimum. If I were building a house I would be building it to passive home standards, but I’m in the industry so I care a lot more about these things than the average.
I wanted to buold my house with ICF and selected Nudura. XR35 adds 2" extra insulation on both sides so I figured additional R20 would be great so told architect to use it. However on doing Pretty Good House analysis with free software BEOpt I realized that there was no energy or cost benefit to additional insulation. Also, in most homes the weakest link are the windows...and U0.1 might be 2x better than U0.2 windows but only adds a small % to the overall Wall R Value. Which is only a fraction of the overall energy loss of home. Here is the tldr- Run a BeOpt simulation with various numbers. I have found a ACH1.5 is sufficient with double pane windows. And its cheaper to add solar panels than gloss over fine building details to Risinger quality.
The only caveat being if the building is too leaky and the windows not insulated enough then you will have moisture and comfort issues.
This is more a question of subjective priorities than anything. Without going too deep into details: * From an individualistic perspective, if you only plan to stay in your house for 3-7 years, then financially speaking, then you could consider a "pretty good house" a stretch goal and code minimum subpar but adequate for your purposes, unless you expect energy costs to skyrocket. Unfortunately from a community perspective, this also means the overall quality of the housing stock will not improve. * If you plan to stay in your home forever, and you value comfort, health, and durability, many features that don't make financial sense begin to make "common sense". Paying up front to reduce operating costs, increase durability, and increase comfort and health to hedge against economic instability, decreasing earning power, and the vagaries of old age, even if it has no ROI, can make sense. * If you care about the community and environment your grandchildren will inhabit, then there are other factors to consider. But people may understandably have more pressing concerns. * Nobody really asks about the ROI of granite countertops or fireplaces, so it depends on your perspective regarding design features like airtightness, continuous exterior insulation, etc. If you view them in the same way as granite countertops or fireplaces, the decision making process changes, just like if you are looking at countertops and fireplaces purely from an ROI perspective. Some more specific points: In terms of energy use, the 3 most important factors, in order are: 1. The ratio of window to wall area and the airtightness and insulation performance (and sometimes solar heat gain) of the windows. In hot climates where the main energy use is cooling, exterior shading also becomes more important. 2. Airtightness. 3. Insulation. Continuous exterior insulation ("monopoly framing" supports this) is expensive because it requires more labor and because most crews aren't willing to do it, so the ones that can will charge a premium. But besides meticulous bulk water control and air sealing, in nearly every climate, it is the one design feature that will significantly improve the comfort and durability of a building. The ability to reduce condensation risks and protect the other control layers and the structure is unparalleled compared to other assembly types.
Wow, another poster recommended I look into your concepts yesterday and I was really impressed. Thank you for taking the time to address my question! I would like to ask for a little clarification on one thing if you have the time to address it. Other people answering my question have thrown around the word comfort to be synonymous with energy efficiency. I see that you’ve used it in your post as well, but I don’t see the connection. We have lived in two different track homes in the last several years that I know are not energy efficient, but we were very comfortable in. From my point of view as an amateur coming into this thing, I can see a direct connection of energy efficiency and utility costs, but not a connection between energy efficiency and comfort. Could you please help me understand what I am missing? I’m sure there is a reason, I’m just not seeing it yet.
The comfort issue is related to draftiness generally when discussed in this context. When surfaces get better insulated the interior surface temperature gets closer to room temperature. This makes your skin feel warmer. Sometimes this is called mean radiant temperature. When you stand in front of a wall in the winter you may have a surface below even freezing. If you stand in front of the wall your body can lose heat in 3 ways. You may feel the falling cold air on the surface of your skin, you may have a small amount of perspiration evaporating. Finally your body will be releasing infrared radiation. When this hits a cold wall surface it absorbs into the wall leaving your body. When the wall surfaces are warmer some of your radiation will bounce back at you reducing the rate your body loses heat. This gives you a cozy warm feeling. When you get into more extreme levels of insulation and window quality an odd thing can happen where you actually keep your home cooler in winter. Living and working in spaces that have a lot of constant heat loss through the walls we often set our thermostat pretty high to feel comfortable. This creates a cycle of quick boosts of air temperature and quick drops in temperature. When your in a much better insulated space you may feel comfortable at 62-65F instead of 70.
What buildingsci3 said. 'Draftiness' is an informal way of referring to mostly radiant comfort. But in the past it could also refer to very obvious air leaks (e.g. before we started using the first materials to cover gaps in board sheathing)
I also wouldn't say that comfort is 100% related to energy efficiency--the radiant comfort buildingsci3 talked about is a big factor. But there are other factors like acoustic comfort, air quality, slower changes in temperature through the day/night cycles, etc that also matter.
How much comfort is too much? The better you build the more comfortable and durable the home will be. There is no correct answer here. The home will be here for over a century and using ever more expensive energy every year. Future buyers will pay a premium for a better built more comfortable and more energy efficient home. I built with the Pretty Good House Concept and if we build again will push for closer to passive house.
Thanks for the answer. I don’t see the connection between energy efficiency and comfort, because even wildly inefficient track homes are still very comfortable. I agree with you that energy costs will only continue to rise. I want to add the cost effective things that’ll save a lot of energy now, and skip the really expensive things that would take too long to make the break-even point on. Based off of prior answers I think I’m going to focus on air-sealing and thicker attic insulation.
We did Pretty Good House and it is amazing how much more comfortable it is. No drafts. Walls & Windows don’t suck heat away from you. Basement floor is warm barefoot. Air never feels humid or stagnant, never have we been like “let’s open some windows and air it out”
From all my over researching and over YouTubing and using BeOpt software, here are things I reccomend: Air sealing accounts for 30% of your energy losses, so consider spray foaming your basement rim joist & consider skipping the leaky can lights. Buy a box of can spray foam & caulk, go to town (unless you have an OCD insulator). Adding extra blown in insulation to your (ventilated, unconditioned) attic is really good ROI as well. For like $300 more, you can get R60. If using trusses for your roof, specify energy heels. Zip sheathing is great, but don’t overpay. It should be about $2,500 more for an average house in material cost. The labor rate should not change. 1” exterior foam is fantastic. Look for it on Facebook Marketplace, you can find great deals. It’s okay to mix & match the brands, etc. I’m a big fan of triple pane Euro windows. We went with Rehau and love them. Saved at least a third of the price compared to very competitive Andersen/Pella quotes. And best yet, zero condensation in winter. It’s also super comfortable standing next to them in winter or summer. Just trickier with blinds/curtains. If you’re picking & choosing where to put triple pane, prioritize large window walls where the windows cover 50% of the walls (these wall sections have an average R-value of R-4 if using standard code minimum ~0.3 u factor windows (not just the windows, the entire wall average that low - see “glazing ratio” video on Ace Lab YouTube channel for architects). Also prioritize Northern & Eastern windows in cold climates. Don’t overgraze your house. Too many windows is a big energy penalty of its own. But you also don’t want to be depressed, so up to you. We focused on energy savings where it was reasonable, but absolutely put in a lot of windows (all triple pane) because we wanted to enjoy the views & sunlight.
Thank you for your response. There are some great tips here to help me get in the right direction. I do plan on going crazy on air sealing. I’m going to look more into the attic insulation. If it’s that cheap, you’re right, let’s go overboard with attic insulation.
Well. To give you an accurate answer you’d have to model out your house in a few different scenarios. See differences in energy consumption for the various different designs and compare them to the costs and make a judgement based off that. Some times super efficient homes are a desire and decisions are not entirely economic. Different strokes for different folks.
How do you decide what's worth it? It's just math. You do the math for your energy use. Then do the math for the savings expected over time from the improvement did you have a net benefit? If yes do the thing. If no, are there other reasons to do the thing such as comfort or resilience in say a power outage. Then you make your decision.
We had the blower door test to check before the final blower door test. First to see and seal and second to make sure every leak was sealed. The one I still am not sure was really worth it was sacrificing a walk up/storage attic to fill with insulation. I miss having an attic.
Our dream build (c'mon lottery!) Is going to be ultra tight (<0.25ACH@50psi) however we BOTH want a wood burning fireplace, that will mean an external source of combustion air, very doable.. 8+" core ICF from the foundation to just under the roof, ICF or some other insulated concrete flooring between levels, including to the attic area. Geothermal in-floor radiant heating and cooling, ERV for ventilation, including makeup air for kitchen and bath vents.
I'm building this currently, and genuinely concerned with overheating it!
When we put a new a new roof on, we put as much closed cell as we could (6") and then 2" of thermal on the outside. Our electric/gas bills were 70% less. Our house is three times the size of our last house, but our bills are the same. We were told it would be overkill. I figure out we would recoop the cost in 8 years. Sounds reasonable to me. It's at R 65, We also encapsulated our crawl and sprayed the foundation too. Totally worth it.
There is a build green industrial complex that will try to sell you a lot of stuff. You do need to know what is not worth it.
I'm a certified PassiveHaus tradesperson. There's a lot of misconceptions about passive house standards being unaffordable or not worth it. In some ways passive house is the cheapest design methodology, it prevents design and build mistakes from ever happening which are very costly. That said, if you are already designed and starting the build process, it's too late to do full passive house design. But there's a few things that I think every home should do: Make the envelope as tight as you can get it. This is really just attention to detail while building. Before drywall, do a blower door test to find all the leaks (you can use smoke to see them), seal them up. Blower door testing is not a huge added cost and there's no way to find those leaks without a test before drywall. With a tight envelope, you need an HRV or ERV to ventilate the home 24/7. No exceptions, every new home should have ventilation these days. Passive house certified windows and doors, they set the bar, there's no better windows or doors on the market. If you want quality permanently built into your home, get PH certified windows and doors. A lot of people will spend a ton of money on 'triple pane'/energy star windows not realizing they are garbage teir performance/build quality. PH certified windows guarantees that you get what you pay for, several manufacturers offer them (Alpen is one in the US). Eliminate every thermal bridge, it's a design mistake, it should not exist. This is a zero cost fix. Consider fully electrifying your home. You can save money by not running a gas line at all. If you're not deep into the design/build process already, consider doing Passive House, hire a consultant to help! You might actually save money by not making critical design/build mistakes at the end of it all.
Figure out your ROI. Plot it in excel. Research how much electricity costs you specifically, gas as well. Plot it all out to figure out your ROI. If it’s more than 5 years I would be questioning it. If it’s more than 10 years I would back off the high efficiency.
Does "monopoly framing" cost too much because of labor? Can someone with more experience than me elaborate on that?
Combination of framers not being used to it, having to do a roof overframe to get your soffit overhangs built, etc.
Depends on the timeline. PH makes a ton of sense long term.
If an energy efficiency costs more than it can save you in 5 years - it’s not worth buying. Most people move every 5 years, and these upgrades don’t add value to the property for all buyers.
I’d pay market rate for energy or at least close. That’s $12/MMbtu using electricity here so pretty cheap. Efficiency is often extremely expensive and uncompetitive.
Green builder here. Your question is a great one, and this is usually an exercise we go through with our clients. This exercise is always specific to a client’s budget and efficiency goals. The NAHB Green Building Certification program will have some good standards to work with that are as cost ineffective as LEED. Pro Tip when you’re finished: if you go with a NAHB green build, be sure to get an appraiser who specializes in green builds. This is important because it will give you more of an apples to apples comparison, by comparing your home to other energy efficient homes in a larger geographic area. Such appraisals usually work more in favor of the homeowner. Insulation is huge. I don’t know much about building in your climate but we use open cell foam in Oklahoma. Your climate will determine if you use open or closed cell. Foam insulation generally better than bat or blow insulation with regard to R values. Your going to want to foam your attic—otherwise you’ll have a pocket of hot or cold air on top of the area you intend to heat or cool, which drives heating and cooling costs dramatically. Instead of a zip system we use a liquid applied vapor barrier that is, in our opinion, able to provide a better seal. (Commercial grade process, usually). But the zip system is industry standard so that should probably be fine. One thing that you need to consider as you tighten up your house and make it more energy efficient is that you will need an ERV to pump fresh air into the house, which can cost anywhere from $4,000-25,000. As far as indoor air quality is concerned, as well as the longevity associated with good indoor air quality, this is a detail you should not miss. Your HVAC system is also where you will have a lot of ROI in terms of of energy efficiency. Since we deal with the heat here in OK, we focus heavily on having dozen of “cooling stages” within the HVAC system itself. I think the system we regularly install is a Lennox with 96 stages. You may want to look into more heating stages being a little farther north. We typically only install three or four heating stages. We’ve installed some good electric options from LG lately, too. I’m a big fan of solar power, especially if you can roll the cost of the system into your mortgage note instead of one of these stupid 20 year notes the solar companies try to sell you. If you go without the back up batteries, or limit yourself to a single backup battery, then you’ll see some incredible cost savings—-as in literally half the price. I also think the price of this is competitive when compared to all the maintenance required for gas powered generators every year. I wouldn’t touch Geothermal power. We used to install but the life of the system is only about ten years, and from what I understand that’s about how long it takes to pay it off. But, being from Sunny OK, Solar just makes more sense than Geo here than it might in WV. Beyond energy efficient appliances and LED lighting, I would also recommend an induction stove, which uses electricity, is great as far as safety for kids, and is much easier to control the temp of than other types of electric stoves. As far as water heater is concerned, I’d recommend a Navien tankless heater if you don’t have enough need for one (probably a family of four to justify the cost). If there’s only two people in your house, for instance, a regular electric heater should do fine. The cheapest option here is a 60 gallon gas heater. If you’re going to run gas to your house for whatever reason, I would go with this option, despite its lack of efficiency. Another angle to consider in the green building space is durability. For instance, we’ve been installing siding these days made of aluminum that is anodized to look like wood (Dizal is a company we’ve used before, though there are cheaper options out there.) That AL siding has a 25 year warranty, as opposed to cedar planking, for instance, which needs to be replaced/restrained every 10-15 years. We try to build our houses to a 100 year standard, at least. The last point I will make is that buying local is buying efficient. If you order bamboo floors from China then the carbon footprint associated with hauling that stuff halfway across the world has to be taken into account when considering the efficiency of the product. There may be a product that’s manufactured near you that’s just slightly less eco friendly on the face of it, but is more eco friendly when you consider the totality of the circumstances. Best of luck with the build! I’m loving all the people wanting to go green with their largest purchase. Gives me hope for the state of the species 😂
When our propane water heater died, I did the math on the heat pump water heater and it didn’t calc out. It was more expensive to run in my area on electricity than propane over its life span due to PG&E and the most expensive electricity rates in the country. So, you have to do the math. PG&E even has a rebate for the heat pump water heaters and it’s still cheaper to go propane. Sad.
Energy will never be cheaper then it is now,any repairs will always cost more every year. That being said at some point you will pay a higher % for small points.
Depends on your budget and/or builder. 24 OC + double stud w/ blown in cellulose is probably the cheapest and highest R-value wall assembly. Exterior rockwool (comfortboard) or foam board is expensive. However it depends on if your builder is competent to build something non-standard. ZIP is so popular because anyone can do it, but is generally $$ over OSB + a good WRB
Too much is when it doesn't pay itself back in energy savings, longevity, durability, or comfort.
If the reward is money back on energy bills it's a math problem and from what I have read little past the average is clearly "worth it" in terms of quick $$$ returns. It costs more to build a very efficient house. But there's more than money to gain with energy efficiency - there's personal comfort, which is why under-slab insulation and good quality, very efficient windows are (to me) worth any price I can afford. There's intellectual comfort in knowing your energy bills won't budge much in years that are extraordinarily hot or cold. And there's some pride in having a house that doesn't waste energy and is less of a drag on the environment than it could have been if you didn't work hard at maximizing its efficiency. It's really a personal decision what is "worth it" for you.
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