Missed Deadline - again!

Well as you can see by the web-cams, we are no where near ready to start the big dig.  So today's' deadline will come and go like many previous.

The deconstruction is now going pretty much to schedule, but we just did not start soon enough due to all the lost time re-engineering the structure to meet the new District policies. May was meant to be tear down month but both April and May were generally spent on re-engineering and drawing and getting the house fully empty.  This is one downside to doing ALL the work myself -  There is no overlap.  In general, I did not start this project prepared.  I had intended to purge and empty the house over the winter, but was generally fully occupied with drawing, redesign, and variance approvals.

I have pretty much given up on a schedule at this point and am just working as hard as I can each day to move forward. The actual deconstruction did not start until May 12 with the removal of the Kitchen followed shortly after by the laundry room.  We then had to prepare for the asbestos remediation. Since the remediation of the asbestos laden drywall completed June 4, I have been able to lift up aprox 650 sq. ft. of beech hardwood flooring (including grinding off nails), removed wood panelling from hallways,  removed all of the wood planking that was installed behind the panelling, and as of yesterday remove all of the non-bearing internal walls.

Front entrance at back left.   White wall used to be bathroom and back right was spare bedroom.  Wall in foreground is the central bearing wall holding up the ceiling joists.

Foreground was dinning room and stack of salvage 2x4.  Room behind brick chimney was laundry utilities and room to right was kitchen.  The few renaming posts are holding up some splicing in the ceiling joists near a roof valley above. Just visible behind chimney is a remaining bearing wall holding up ceiling joists at the south half of the house.

 Over the next week I hope to stack the salvaged wood outside (need to figure out where as really tight on space!), take a garbage and green waste run to the transfer station, pull up the sub-floors (this is plywood screwed to ship-lap, nailed to 2x4 sleepers. When we had the hardwood put in, I installed about 18 pounds of screws in the sub-floor to reduce the creaking that was present.  There is no way I will have the time to remove all of these screws to salvage any of the sub-flooring, so I will just be cutting it into 4ft x 4ft panels and taking to dump unfortunately), and then start taking off the exterior siding.  This should be much easier using the offset for the reciprocating saw I talked about on an earlier posting.

Lets see how well I do meeting this goal.

Thanks for stopping by!

Batt Insulation - Not all are poor!

Gregory La Vardera posted this excellent primer over at Green Building Adviser on the differences between fibreglass and mineral wool batts.

As Gregory points out, ROXUL Mineral Wool batts are not associated with the typical failings of a fibreglass batt installation. This is due to the density of the product and the ease of cutting and trimming. The product also sheds water and is fireproof.

My only critique of his article is is statement "I don't need my insulation to make an air seal, because I used that good ol' housewrap on the outside. Nope, nothing wrong with housewrap — but it provides no help with the air sealing you need at your vapor retarder. The air seal in this case wants to be on the warm side of the wall, to prevent interior moisture from entering the wall cavity and condensing during the winter heating season."

This is actually incorrect, an air barrier ANYWHERE in the assembly will block air flow through the assembly.  I will talk more about this in an upcoming blog entry.  For now, I did not want to detract away from the rest of the posters review of ROXUL mineral wool insulation.

Durisol ICF lowers the embodied energy of a dwelling.

Stuart Staniford at the Early Warning blogspot discusses the reduction in Embodied Energy a Durisol Foundaiton represents in a low embodied energy dwelling.  In his case study, the use of a Durisol ICF foundation over a conventional concrete foundation improved the "net carbon emissions" by 100%.

His analysis showed the the original carbon emissions associated with the foundation in the dwelling he modeled dropped from aprox 7.5 tons with no opportunity for sequestered carbon to just under 7 tons but now with the ability to also sequester close to 1.75 Tons.

Baseline with standard concrete foundations (http://earlywarn.blogspot.ca)

Utilizing Durisol ICF Block (http://earlywarn.blogspot.ca)

How It's Made - Roxul Stone Wool Insulation

The popular 'How It's Made' TV series visits the ROXUL factory in this 5 minute video http://youtu.be/clN-wB8Vl_k

You may also be interested in this video of ROXUL's "Test The Best" demo presented at building stores across the country. http://youtu.be/7rbRYs0XEAM

SENWiEco adds a weather station.

As part of the instrument package for the new build, I have installed a Vantage Pro2 Plus weather station.  I have had this recording weather since September of 2013, but only setup the web based access today.

My blog will show the current conditions, but clicking on the icon will take you to the station on the Weather Underground website where you will be able to look at historical data.

The station is currently uploading saved data and should be 'live' by tomorrow.

Enjoy!

Popsicle Stick House!

If only it was this easy!  A student builds a wonderful design from nothing but Popsicle sticks.

Building Popsicle Mansion Time Lapse HD

The interesting part is that he took the same amount of time to build the 1/24 scale model as I am budgeting for my build - 18 months

Should I be nervous?

Thank-you Readers!

You are all awesome!

I am now over 650 hits per month on this blog and I cannot thank you enough.

First, it shows a strong interest in the subject matter. Second, it keeps me very motivated to continue posting, and obviously I need to actually keep making progress on the project if I am to have something to post, so you are helping keep the project moving along.

Finally, it shows potential sponsors of the project, that there really will be great exposure for any products that I showcase in the blog and official building site (to be launched early spring).  And any sponsorship received, will ensure an even better and educational website and building lab.

Click to enlarge

AutoCad 2D model of a 3 level single family home.

Ever wonder what a completed model of a 2D three level home prepared in AutoCAD 2002 with all 43 layers turned on at once looked like?

Thought so!

Finished 2D model ready to send to the engineer.  Kind of frightening knowing each line had to be created manually.

Designing walls that are not vapour permeable - A good idea?

I have been having a discussion on a LinkedIn Passive House forum regarding the choices one can make in regards to insulation and the effects of these choices.

http://goo.gl/1vGTyI


The poster was asking for experiences within the building community with Wood Fiber vs. Cellulose insulation and I suggested that neither may be desirable depending on your climate conditions and instead suggested continuous exterior mineral wool fibre insulation.  This then morphed the conversation towards what constitutes a durable high performance wall.

I posted my thoughts on the perfect wall (which just happens to match my walls in my upcoming build) and other who are builders of PassivHaus (PH) structures posted their perfect wall details.  This led to a discusion about the merrits of designing a wall that is vapour open to the low pressure side, where one of the posters stated:

"I've been indoctrinated with the Bau-biology "Breathable Wall" idea with nearly 10 years now and spent many years preaching that gospel. But then I found the Spokane and Tsong studies where they opened the walls of 250 houses, that were built wrong in terms of 5:1 breathability but no decay was found.  The walls had no membranes, no decay was found, its the same for SIPs houses, ICF houses and most other construction methods, the walls don't breathe as per the 5:1 rule and the houses aren't falling down."

The two studies can be found here:
1) http://www.viking-house.ie/downloads/Tsong79.pdf
2) http://www.viking-house.ie/downloads/Spokane.pdf

I read the two studies the poster provided and was somewhat shocked at the jump in logic that is represented by the statement that we do not need to make walls permeable and that impermeable walls will not rot. This is such an important subject, I though I would reproduce my comments here to a larger readership.

The Tsong study is discussing the lack of VB, and not a wall that is vapour tight. A wall that does not have a VB is by definition VERY vapour open and in fact most of the assemblies studied were quite vapour open (poorly insulated wood frames).  It is also important to note that the study occurs in 1979 and the levels of insulation discussed are far below what we are talking about in today's high performance homes (the study does not state the R value but we are talking about poorly filled 2x4 walls, so probably an effective average of below R7). Therefore these walls all had a lot more drying potential due to thermal bridging than high performance homes of today and certainly a lot less drying potential compared to a PH. It is also important to note that these houses had an average ACH50 of 16.2, which is more than enough to also help dry the assembly when it was experiencing very high RH levels. I have been unable to locate the permeability of Urea Formaldehyde insulation so do not know how permeable those walls were if detailed perfectly – but per the study, these foam walls had a lot of air leakage due to foam shrinking and cracking. The average foam shrinkage was 8% and the report states that as a result of the shrinkage of this foam, there was a 70% increase in heat loss (heat loss dries walls, so even these walls could dry easily).

It should also be noted that areas of high moisture content were found at many locations on these homes where bulk water entry was occurring (in other words control layers regularly fail and you should design your assemblies for such to the extent possible).

What I do love about this study is their remark at how the mineral wool insulation had an ‘extremely low average moisture content’ when compared to the other insulation (in no case was the moisture content of the mineral wool above 2%). The study went on to say this is “probably attributable to the fact that mineral wool is not hygroscopic, whereas the cellulose and U-F foam both tend to retain moisture”. Go ROXUL!

I then went on to say that relying on this dated research to state that a wall should not be vapour permeable to the low pressure side is grossly flawed in my view, does not come close to lining up with the current recommendations of the building science community and their experience in repairing failed structures, and in my view also miss-interprets the studies results and compares conditions that are grossly miss-aligned with the high performance structures we are building today.

All this study can really claim is that there was no significant moisture damage associated with diffusion observed on any of the homes that generally had no or minimal insulation and high levels of thermal bridging. And as we know today, this results in assemblies with built in drying safety factors. The study was also was clear to specify that these results could not be related to colder climates.


The second study was by the same author but took place in a colder climate.  The same arguments above apply.  It should also be noted that colder climates generally have less problems with moisture damage to wall assemblies than milder climates.  In climates with cold winters and hot summers, the moisture typically exists as frost all winter and then quickly dries out in the late spring as the temps rise. In a location like the Pacific North West (3000 DD), moisture will stay in liquid form for months at a time as is able to cause a LOT more damage as the moulds take hold and flourish.

Can you build vapour tight assemblies that work in the Pacific North West?  Yes, but you then need to sweat the details.

An ICF IS a wall that works.  It is often quite vapour tight but because there is no air movement through it at any point in the structure, there is generally no opportunity for condensation to occur (I have heard of isolated events where condensation has occurred between the foam ICF and concrete core leading to mould build-up).  The typical foam materials of the ICF are also highly resistant to vapour diffusion, all but eliminating that risk as well. From a building science standpoint a typical foam ICF structure makes a lot of sense, but where it fails in my view is the very high embodied energy that it represents both in terms of the volume of concrete used in these homes and the foam used in the typical ICF blocks.

As far as SIP construction (structural insulated panels), which are typically fabricated with OSB sandwiched on each side of a foam block, I personally feel that the jury is still out.  There is a multitude of reports of SIPs failures across North America and once again, this style of construction represents a high embodied energy.

For me, I will stay true to my stick frame, plywood sheathed structure wrapped in a nice continuous warm blanket of highly vapour permeable and fire/rodent/bug proof Roxul mineral wool insulation thank you very much.

Durisol, FastFoot, EPS vs. XPS, PHPP, and Enginners - Oh My!

Sorry for the absence, been pretty busy of late.  I thought I would provide a brief update as to where we are.

1) Our testing of the Durisol ICF continues: after 8 months of continuously drenching the outer panel with water, we still do not have significant inward capillary action.  We will now fill the bays with concrete and see what difference this will make.  (8 month Status Video).

2) We are also progressing our testing of the fabric footing from Fab-Form called FastFoot. This product is used to replace the typical framing of footings and then provide a lasting protection from rising damp.  After 6 months of testing, there has been no noticeable moisture penetrating through the fabric.  However, we have realized that if the capillary flow was small enough, it would evaporate out the top as fast as it penetrated through the fabric.  So we will modify this experiment by creating a sealed envelope of the product around a paper towel and submerging it in water.  We will then open it in a few months time to determine if the paper towel has seen any observable wetting. (6 month status video)

3) The next experiment we will start is to compare the water uptake and thermal performance of EPS vs. XPS.  It is generally accepted knowledge within the building science community, that XPS is more water resistant than EPS. But there recently has been some discussion on LinkedIn that disputes this claim (LinkedIn Posting).  The post points to a 15 year case study performed by a EPS foam company that  may call into question the standard test (ASTM C 272) may not be accurate when taking into account long term moisture take-up. In a discussion I had with a local engineer, they advised that XPS is more moisture resistant, but EPS dries faster.  So I speculate that if the foam is only periodically getting wet and then is able to dry between wetting (granular layer below slab), then EPS may perform better than XPS depending in the cycles of wetting.

In order to try and come to some conclusion on this, I will run the following experiment:

- 12"x12"x2" samples of both 30# XPS and 30# EPS will be buried in my back yard in an area they will get wet often or just stay wet (near a fish pond).  They will be down around 4-5ft.
- Equal number of samples of each will be submerged below water in a sealed Tupperware container
- Equal number of pieces will be sealed inside a large zip lock back and put on a dark shelf in a conditioned space (no UV).
- Finally, an equal number of pieces will be just left loose on the dark shelf.

I hope to bury these samples within the next week (I am just waiting for some FoamGlass samples from Pittsburgh Corning to also include in the test).  All samples will be then tested for thermal resistance at the end of approx 6 months time to determine any changes to the control (samples sealed in zip lock bag).

4) I would like to accurately model the planed dwelling for heating and cooling loads.  I am a certified Residential Hydronic Designer, but have never been satisfied with the rather gross estimation calculations provided in the TECA manual.  The best software I have come across to date, is the PHPP produced by the Passive House Institute. Unfortunately, it has been a couple of years since I took the week long training course in PHPP and now do not remember enough of the nuances to correctly navigate my way through it.  A posting on a few of the LinkedIn groups netting over a dozen offers of help including several for free.  Once I solidify my design (see next topic), I will do the bulk of the entry into PHPP (entails entering in the volume of all of the surfaces like floors, walls, ceilings, windows, doors, etc.) and then choose the best of the respondents to work with.  One of the key needs will be to model many of the details in THERM to calculate the thermal bridge credits to enter into PHPP (it for instance presumes a fairly poorly detailed exterior corner and if you build with continuous insulation, you actually get a credit).

5) It appears that once again, I am in the need of a structural engineer.  I have had the worst luck I have ever had finding a vendor for this task.  I initially chose someone last spring who came recommended by two different people.  Initial communications had gone well, but on the first day of actual design, the project went south really quickly.  In hindsight, I believe the engineer was unfamiliar with ICF foundations (concrete poured inside permanent forming).  My first clue was when he insisted in designing a standard 8" foundation INSIDE the ICF.  This would have bumped me up to the 12" Durisol block instead of the planned 10" (costing substantially more for the block, freight to Vancouver, and the extra concrete). As a comparison, the BC Building Code allows for a 5.5" concrete core in an ICF.  The next issues was an insistence that I must use 2x6 studs for structure. When I tried to point out that only 2x4 Studs were required for structure and that the bump up to 2x6 construction was actually to meet the insulation needs of the 2006 code, and that as I had continuous EXTERNAL insulation, this was not applicable to me, they just stated that they only designed in 2x6 studs.  At this point the engineer suggested he step aside and I was in full agreement.

This was a very low point for me, because of this and a topic I will talk about in an upcoming post, my goals to start building in 2013 was not going to be met.  My wife and I came to a realization in March that it was not going to happen and that putting off for one more year made a lot more sense.  Of course this meant that I sloughed off from designing for a while and got out of the habit of working on it.  I picked it back up in earnest in June.  I decided to look for ways yet again to shrink the structure.  The District of North Vancouver building bylaw for my neighbourhood is VERY restrictive.  There is a rule that the upper floor cannot be larger than 75% of the lower floor.  Of course this goes against sound building envelope principles that dictate a cube as the 'perfect' structure, as it represents the smallest building envelope.  Anyway, I was able to shrink the upper floor enough so that I could meet the 75% rule if I added all my left over FSR to the bottom floor.  I will then go for a variance asking them to waive the 75% rule and not make me make the dwelling bigger than I need or want.

In June I received a list of engineers, who all reportedly work in ICF, from my friend Murray Frank.  I started to go through the list contacting each one and asking if they were interested.  Out of the seven names provided, 1 was out of business, 1 did not do residential, 1 was no longer doing ICF (and was actually an expert witness in a law suite against a prominent Foam ICF supplier), 1 was just not interested, 1 was never reached after lots of telephone tag, 1 was too busy, and I just did not get the right vibe from the last one (was too much like the one I parted ways with in March).  SO, so far I was batting 0 for 8.  The people on the list of five, provided three additional names.  Out of those three, 1 was too busy, 1 never returned my initial call, and 1 was not interested in ICF because of water ingress concerns (remember this one, I will come back to them).  This list of three recommended  2 more names and out of those two names, one was too busy (was a person I contacted back in March who was too busy then as well), and 1 sounded again like the fellow I had hired last March and I could see would not be a good match.  Scouring colleagues turned up another  4 names, 1 of which is not interested in ICF, 1 of which was not really recommended unless I had a basic design and did not need to ask questions, 1 which is in Ontario but licensed to practice in BC, and 1 of which looked like they basically only did large commercial work when I went to their website.  If you are keeping score, I am 0 for 16 plus 1 possible who works from Ontario.

I decided to go back to the person who did not like ICF due to water ingress concerns. I talked to him on the phone and assured him, my design with a full torch on membrane and several drainage planes would not have the same liability.  I was able to get his trust back when I explained that the ICF I was using was Dursiol and that yes I could do a full torch on without melting the ICF (something you cannot do with a foam ICF).  He agreed to meet with me and after a productive meeting, I felt comfortable proceeding with him and told him I would like to proceed on July 2.  That has been the last time I have heard from him.  After several follow up emails and phone calls, there has been no action.  I suspect the hold-up is based on some project requirements I have designed to.  I want to chose environmentally and IAQ friendly floor trusses, and for me, this means I want to eliminate the OSB I-Joists. I found a company in Quebec (TriForce) that uses the tops of Black Spruce trees to fabricate industry leading spans of 22ft with only a 11-7/8" deep truss.  This was great, as I have a height restriction in my neighbourhood (so need to keep my floor cavities as shallow as possible) and also want a fairly open floor plan.  This product fit the bill and I designed my floor plan around it.  The engineer had not heard of the product and seems to be reluctant to check it out and approve it.  I suspect he is just too busy to mess with something he is not familiar with.  But meeting my project requirements is important, I would need to redesign the whole floor plan if the 22ft spans was not approved by him,  as my wife and I do not want a bunch of drop down beams cutting off a nice 9ft ceiling space.

SO, it appears that I am back to square one yet again and that the fellow from Ontario may be my last chance at a touch down unless some of the people who were busy in June and July are now available.  I really was not expecting this task to be at all difficult, but it appears that as soon as there is a slightly abnormal quality to your project, a lot of vendors just are not equipped to deal with the extra effort required.  Out of the list of 17, I will re-approach 4 of them.

Lets hope threes a charm.

Thanks for reading - Cheers.

China or Paper - What should you eat off of?

GreenBuildingAdvisor.com looks at the energy and carbon comparison between disposable plates and china plates. http://goo.gl/OYn5C

As usual, the results are not black and white and highly depended on how the china is washed.

Australian Climate Commission states the obvious: fossil fuels must remain in the ground

Will Australia end up too hot for the crocs?

Do energy targets of Passivhaus make sense and will they pay back during the lifespan of the dwelling?

I have been discussing the payback periods of Über high levels of insulation and high R value windows on LinkedIn and thought I would share my thoughts with you and possibly promote a discussion.  My comments on LinkedIn started after one participant wrote “PS: BTW, why are we talking about this in the PH forum? Aren't we all allergic to any heating other than auxiliary heaters?”.  This was a topic asking for advice on whether it made more sense to install an Air Source Heat Pump or a High Efficiency Furnace on a home that currently had an oil furnace at the end of its service life.  The dwelling of concern was not a Passivhaus, but the poster felt that the expertise of the Canadian Passive House Institute forum may be beneficial to his decision.

I commented that I felt the jury was still out on the need for a heating system in a Passivhaus design for our climate, and that in most examples I have reviewed the only way it has ‘worked’ to not have a ‘real’ heating system (many designs incorporate a hydronic or electrical resistive heating coil in the dwellings ventilation air ducts to provide ‘auxiliary’ heat), is when the occupants were willing to accept significantly lower temperatures (<+ 65°F) during cold days and nights, which is just not going to be acceptable for most occupants in North America.  But the PH Program uses the claim that a normal heating plant is not needed as a way to justify spending the extra money on extreme amounts of insulation, which in many regions will never have a reasonable chance of payback throughout the life span of the dwelling.

If you accept that some form of heating plant will be required, but through increased insulation and better windows, that plant can be substantially downside, logic would say that the smaller plant will save you money and allow for the extra expense on the insulation and windows needed to reduce your heat load and downsize your equipment.  See the circle hear.  Well logic unfortunately has nothing to do with the pricing of consumer goods.  Pricing has nothing to do with the actual cost to make an item and everything to do with how badly does the consumer want it and what are they willing to pay.  Because the average North American consumer lives in a McMansion and has a bajillion gigawatt heating plant, there is very little demand for small 10-15K BTU units that are needed in a very energy efficient home.  The result is that they cost a lot MORE than the much larger units installed in the ‘average’ homes.  So not only are you spending a lot more money on windows and insulation, you now have to triple your HVAC budget even though you are getting less.

Another poster then suggested reducing the heating load by first “renovating to Passive House-Retrofit standard with R60 Wall, R90 Roof and R50 under-slab insulation, replacing your windows with R19 Ecoglass and PH doors”.

How long of a payback is and will be acceptable to most homeowners/buyers? Does R50/60/90 (slab/wall/roof) EVER make sense in the vast majority of climates around the globe? Are windows really able to reach a R20 thermal efficiency for the total assembly?

This then lead to a new discussion topic about windows, the claims by window manufacturers (in this case EcoGlass claiming a R20 window), and the general payback metrics of the Passivhaus program and what makes sense. 

In my travels I have generally been exposed to three trains of thought when discussing the Passivhaus program; those that have drank the full pitcher of Cool-Aid and take everything at face value and run with it, those that completely dismiss the program’s claims (these tend to be people who do not believe in Global Warming or the need to reduce energy use or our carbon footprint) and often call the practitioners of the program charlatans, and finally those that can see the value in a program like Passivhaus and see the building science wisdom in many of the program’s concepts but also feel the program may go too far down the energy reduction path.

I fall squarely into the last category.   I believe we are having a detrimental effect on the environment and need to make changes in how we build and live.  Yes I plan to build a ‘close to PH’ dwelling.  I believe that PH has the right focus when designing a dwelling, unlike LEED/Built Green/or other ‘green flavours’ of the year, that are more focused on the small to minor contributions that reduce the carbon footprint, and not ensuring the elephants in the room like heat load and thermal bridging are first looked after.  How many times have we seen a LEED Platinum building with 60-80% glazing and wondered how could that building possible be energy efficient and good for the environment? 

Building a dwelling that has reduced thermal load achieved by increased insulation, reduced thermal bridging, increased air tightness, reduced window glazing with the glazing present having higher insulating value or better solar gain harvesting, utilizing south solar gain when available, and of course correct ventilation (all the fundamental building stones of the Passivhaus system) just makes sense from a building science and energy reduction point of view. 

And concentrating on your insulation and air tightness as the first and highest priorities also makes common sense, because you will most likely never get another chance to address these components during the life of that dwelling due to their inaccessibility.   So it makes sense to concentrate more of the available funds to maximizing the efficiency of these soon to be inaccessible components and calculating the optimal insulation levels based on a full life of the building cycle (20, 30, 50, 100 years?).  Components like windows and heating plants are far less important to optimize during the initial construction, when working with a limited budget (a reality for all except a select few), because both will need to be, and most importantly can easily be, replaced or upgraded in 15-20 years at the end of their service life.

But I agree with many, that the PH program goes far too far up the pendulum in its goal to reduce the energy load on a dwelling, to a point of drastically diminishing returns that are not acceptable or practical for most in North America and in my view, may actually be increasing the building’s footprint on this planet (incorporating embodied energy in a dwelling that will never be offset with energy savings).

I also feel that so often the costs to build to PH standards are grossly misstated.  I often see figures of +10% to +20% as the premium to build to the standard.  In reality it is usually at LEAST 2 – 2.5 times the cost of a house built to building code minimums.  I have seen several examples of houses built in cities in my region for under $100/sqft over the last year or two (for a 3500 – 4000 sq ft dwelling).  These are house designs that do not utilize an architect or building envelope engineer on the team, and often have only minimal structural engineering input because they are generally optimized to meet the BC Building Code’s Part 9 prescriptive rules.  They still have fancy kitchens with gas stoves and granite countertops, a gas furnace or boiler, crown mouldings, and fancy paint schemes. They however usually incorporate PVC or vinyl windows of dubious quality (R2 max and air leaky like a sieve), code min insulation levels, and no air tightness to speak of.  The types of houses build by a majority of developers/builders in the majority of cities in my region (The only City’s that buck that trend in my area are the west side of Vancouver and North and West Vancouver).   A PH on the other hand requires the use of all the specialists (for one, because no Municipal inspector is going to take responsibility for the design and you have to have an engineer sign off on every aspect of the design).  Now you are looking at $200+ per sq ft to build minimum and that is if all the rest is par with a code min dwelling.  But clients who entertain a PH typically also still want all the bells and whistles including custom cabinets, media rooms, and home automation, and so on with the costs quickly escalating to $350/built sq ft or higher.  I am often directed to the stats for countries like Germany where a PH represents at least 25% or more of all new house builds.  There is a very good reason; a builder gets a huge government grant to build to the standard, the size of the grant reportedly offsets that bulk of the added expense to build to the program.

My final concern about the program is that it is not even possible in so many locations.  In order to meet the energy targets and not have a requirement for insane levels of insulation, a Passivhaus relies on solar heat gain (SHGC) to provide a large portion of your heat during the sunny winter days and shoulder month seasons.  This is obviously only possible if you have an unobstructed view of the sun (and of course have Sun) on your south elevation.  In an urban environment, this probably represents less than 10% of the available build opportunities which make the program quite elitist and limited in its ability to apply on mass.
 
I value the work that the Passivhaus community has done around the world and applaud there tenacity for building quality homes. I however personally would much rather see the energy use requirements lowered 20-30% and applied on mass to all new construction by means of building code requirements.  Only then will we truly make a difference in the carbon emissions and fossil fuel outputs of our society and substantially reduce our dependence on fossil fuels in North America.  Fortunately, I live in a Province that is leading Canada if not North America down this path with its new requirements for ever increasing insulation, ensuring for the first time that doors and skylights have to meet the same minimum air tightness requirements as windows, and hopefully really soon, will require an air tightness demonstration that meets a minimum level at the end of construction.

As always, thanks for reading and I look forward to your comments.

Determining the Lifespan of a Dwelling

In order to determine the payback of the various design decisions needed in a new build (or even a renovation), you need to first determine the most likely lifespan of the dwelling you are designing.  Many Europeans would say a home should be around for hundreds of years because many of theirs have been. 

How is this possible? 

Most are built with brick or stone and are in OLD cities.  How old?  Well the Romans were around when many of them were in their infancy. 

Why is the age (maturity) of a city important? 

To answer that we need to look, in contrast, to cities like Vancouver and its surrounding neighbours which are all very young in comparison and changing rapidly.  Single family dwellings on small parcels of land still represent the majority of the housing built and available (when looking at land use and not just total numbers of dwelling units).  As such there is a huge potential for redevelopment as the city matures and grows. 

I live in a large single family neighbourhood 10 minutes from downtown Vancouver.  North Vancouver has predominately been a single family neighbourhood since the early 1900’s.  But it is rapidly changing (many would say for the worse due to the traffic congestion that has developed and really does not have an easy cure due to the geographical challenges of the region).  The District and the City of North Vancouver are both looking to and have been dramatically increasing density in our region with the misguided goal that doing so will make accommodation in our cities affordable.  This has been attempted over and over again in Vancouver, and the facts are that these high density ‘villages’ become sought-after-hot-spots that have some of the highest rental and real estate values in the country if not all North America.  Cole Harbour comes to mind.

I digress, why is the age or maturity of a city important? 

Well, the fast growth of urban areas in my region dramatically shortens the life span of what I feel will be the soon defunct urban single family dwelling.  While my current house was built in 1954 and has had a good run until now, I highly doubt that the house I plan to build next year on this property will come even close to 60 years before it is torn down to make way for a low to mid-rise multi-family housing.  In fact, I would be surprised if it was still around in 25 years.  With its proximity to the Down Town core, Lions Gate Bridge, and Upper Levels highway, it is prime land for re-development; development that is already underway at several nearby locations.  A single family neighbourhood less than 5 minutes from me is slated to become the new Lower Capilano Village.  Another single family neighbourhood within 7 minutes drive has now been bulldozed and is slated to become part of the Lower Lynn Town Centre.

The point I am making, is that it is unreasonable to expect that a single family dwelling built today will still be around in 50, 30, or even 20 years in many neighbourhoods in growing urban centres.  Like the cities that have a much longer lineage than those in North America, there will be a forced march to densification and an abandonment of the single family home on a small distinct plot of land.  Does it therefore make sense to model a home that would have a 50, or worse, 100 year payback in energy savings or carbon reduction in these types of neighbourhoods?  Before coming anywhere close to cancelling out the costs to build or embodied energy of the dwelling, it would be torn down and end up in a land fill. 

So often logic is not part of our design decision making process.  We want something so badly that we will fabricate a way to make that decision sensible.  Designing a home that is SO energy efficiency that it would take 50 or more years to pay back may not actually be helping the planet if that dwelling is only around 20 years.  I hope that more discussions like these will encourage a greater uptake on what makes sense in the larger picture, and start allowing informed well thought out designs that are defensible.

For my part, I believe it will be sensible to apply a 25 year life span when calculating the break even point on the various design decisions I have ahead of me.  If the dwelling is torn down earlier, I will not have left too much on the table, and if it has a longer run, the payback will have already occurred and it will then be providing dividends in carbon reduction and utility bill savings.


As always, thanks for reading and please let me know your thoughts.

Peak Oil 'Solved' - But Climate WIll Fry

It is scary when even the oil producers admits we are in trouble and that burning all of that oil may not be in our best interests.

http://www.vancouverobserver.com/blogs/climatesnapshot/peak-oil-solved-climate-will-fry-bp-report

When will we as a society wake up and start forcing our politicians to make a difference?  When will we  start making a difference in our own lives?

SENWiEco considers the Durisol CBWF ICF Block for below grade foundations

Anyone who has read my previous blog entries knows by now that I like to verify and do things for myself.  SO it should come as no surprise that I will perform some testing on another ‘new’ product I am considering for my upcoming build.

As mentioned repeatedly on my blog, my focus on this build is a bullet proof and energy efficient building enclosure to lower my impact to this planet.  I am targeting R10/20/40/60 (Slab/Foundation/Walls/Roof) and these are effective values not nominal (so values after taking into consideration all thermal bridging). 

With these targets identified, it makes sense to optimize what ever insulation is installed by placing in locations less effected by thermal bridging.  This usually means putting most/all of the insulation on the interior of the structure or exterior of the wall or roof assemblies.  Now which side you put the insulation on is very important for preventing condensation.  In a Cold-heating-dominated-climate like Vancouver, you want to keep the sheathing above the dew-point potential so that if any interior air leaks into the wall assembly, it will not condense on the back side of the sheathing which can often cause rot and mould. 

Continuous exterior insulation is a great way to prevent thermal bridging (your insulation is firing on all cylinders) and keeps your sheathing, or in this case your foundation walls, warm and dry.  For this reason, an ICF form system makes a lot of sense.  In typical ICF formed walls, there is an interior panel of insulation attached to an exterior panel of insulation with plastic or metal ties.  The concrete is then placed to fill in the gap down the middle. 

From an insulation point of view, the continuous nature of the ICF panels is great and represents a thermal bridge free design.  Your nominal insulation is the same as your effective insulation R values.  However, you do end up with a thickness of insulation on the interior face of the foundation.  This prevents the concrete from acting as a thermal mass that would otherwise allow it to help moderate interior temperatures.  Insulation inboard of the concrete core can also represent a dew-point potential if the concrete pulls away from the foam as it cures and air leakage results.  Finally as the product is made from oil, it can represent strong off gassing potential and a real fire spread and toxic fumes risk if your drywall is not continuous or is damaged and a fire occurs.

But for me, the biggest demerit, against the foam based ICF’s, is that they are made from foam and therefore oil.  If your goal of creating a low energy house is to reduce your impact on the planet, it hardly makes sense to use a product that is the most responsible for human’s impact on the planet today.  We will be no further ahead if we create a demand for foam ICF on a mass scale, as this will just continue the dependence on a product we really need to start considering leaving in the ground.

Now many of you will say the benefits of foam ICF outweigh the use of an oil derived product.  You are at least locking away a lot of the carbon that would be created if the oil was otherwise used for combustion.  At least in a product like this, it will stay buried for probably 50-100 years (and there may even be a potential of recycling the product at the end).  And any increase in insulation decreases the amount of electricity and gas used in homes to provide heat and air conditioning. To an extent, I agree with this rational.  I do not believe you should abandon products just because they are made of oil.  In many categories, the alternative ‘green’ products are not suitable for use and have durability issues.  The regular replacement of an unsuitable component can represent just as large an embodied energy, as using a more suitable oil derived product.  However when you do have a suitable non-oil based alternative, you should do everything possible to incorporate it into your design. It was with this frame of mind, that I started looking at the Durisol ICF block for my upcoming build.

The benefits of a cement-bonded-wood-fibre (CBWF) block are:

• Made from recycled-wood and cement powder,
• Places all of its insulation outboard of the slab,
• Can be left as a final surface within the basement,
• Can be attached to anywhere in the field of wall (do not need to hunt for hidden plastic tabs to fasten drywall or framing to),
• Incorporates a drainage plane within the product,
• Is mold and rot resistant,
• Is bug and rodent proof, and
• Best of all – does not burn easily or give off noxious fumes if it does. 

Now for its negatives:

• Highly air permeable (a benefit of regular ICF is that the concrete core is an air barrier).  The material of these blocks is highly porous and the block has webs that connect the outer and inner panels together THROUGH the concrete core.
• These webs are not just an air path; they are also possible water and likely a vapour path.
• There is at least a passing concern that the block could rot in a below grade application.

In researching this product, I was unable to find any comments on-line that the product had ever broken down below grade from decay.  The manufacturer provided an Ontario MOT testimonial that stated they had never had to repair the product due to decay (the product is used extensively above ground, and partially submerged, as a road side noise abatement fences) after 30 years of use. 

The product has been manufactured since 1953, so certainly has been on the market a long time.  If there were significant failures, it would be readily visible on the web. 

So what’s the catch? 

Well the product has not had a huge uptake for below grade installations to date.  The manufactures claims they have a dozen or so projects a year on average in Ontario and I have found 2-3 blogs on the net describing the use of the product.

What’s the risk?

Well, unlike traditional ICF, the interconnecting webs of each block penetrate through the concrete core.  This provides a path for air, vapour, and possibly moisture travel. 

The air barrier is fairly easy to address with a fully adhered membrane outboard of the block (this still leaves some interesting details at the footing level and will probably require some thinking out of the box to seal on the interior face near the basement floor slab - more on this in the future). An airtight drywall approach (ADA) could also be implemented.

The vapour barrier again will be generally dealt with by the fully adhered exterior membrane. Besides, even regular formed concrete foundations have a considerable moisture movement through them from out to in, which is why you should never have a vapour barrier (just a retarder) beneath the drywall in the below grade basement (NO POLY! EVER!!!).

Now for the real issue: What is the danger of liquid water transport through the webs to the interior face of the block, either under hydraulic pressure or capillary action? 

Durisol partnered with the University of Toronto to study the drainage properties of the CBWF ICF block back in the mid to late 90’s.  This UOFT report confirmed the manufacturer’s claims that the product did not support horizontal capillary movement and that liquid moisture drained readily through the material.  In fact the free draining rate of the product was a whopping .5 gpm through a piece of material that was 3.5” Thick, 8” wide and 11.3’ (yes ft) tall.  In another test, where a sample was fully saturated and then allowed to air dry, the retained moisture after 60 minutes was only 38% and the sample had lost a majority of its moisture after just ten minutes.

So far, this all looks great!

Figure 1: Durisol 12” Thermal Block in the R21 configuration (5.5” Concrete Core)

Figure 2: (LEFT) Semi-rigid mineral wool insulation insert on the outboard side of the block. (RIGHT) Product is created with a mixture of recycled-clean-mineralized-wood-fibre and cement powder.

 

 

 

But unfortunately, I rarely accept others reported results at face value.  I wanted to put the product through a more rigorous testing protocol (in my opinion).  So enter the DBTTC or Durisol Block Torture Testing Chamber!

Figure 3: (Left) 28”l x 19”w x 15”t tub with a selection of Cactus Club takeout containers as standoffs in the bottom.  These support the block without being susceptible to rising damp.  They also isolate the outer and inner webs so that water flowing down the outer web does not flow along the support to the inner web. (Middle) A small water pump is rated for 70 GPH @ 0” head so probably around 40-50 GPH in my configuration. (Right) The containers are 2.5” tall and the water level was set at the halfway point so there is approximately ¾” gap from the top of the water to the bottom of the block (should allow for enough air movement around the bottom of the block so that the humidity does not build up too high and skew the results.

Figure 4: The inboard side of the block surface registered at 11.1% MC.  The block has been sitting in my living room for about a week (which by the way, translates to an indoor air relative humidly of 55% which is what I have the bathroom fan humidistat set to).

Figure 5: I also took the MC of the webs from within the inside journals that the concrete would be placed in.  This will be an easier location to monitor.  I had a reading of 10.4 and 9.3% MC (difference was probably due to a variation in density of the product at the tested location due to the random makeup of the wood fibre).

Figure 6: The Test

Over the next week or so, I will leave the pump on 24/7.  Water flows out of the plastic tube that has been drilled with holes at a regular interval.  The water is draining through the outer panel as fast as it is added at the top where it drips back into the tub and repeats the cycle.

Over time, I will measure the moisture content of the inboard panel exterior face (and the side faces of the internal webs).  The go/no go test will be to see if a piece of paper stapled to the inboard face of the block shows any signs of moisture over time.

I will of course post the results once they have been tabulated.  Here is a video showing the start of the test and another video showing 60 hours into the test.  At this point, there has been no horizontal travel of liquid towards the interior panel, which confirms the testing performed by the University of Toronto.