Skip to main content

Introducing: The Flatrock Passive House

So...after 8 1/2 years in our home, we have decided to move on.  Well, not right away! We have quite a bit of planning ahead of us.  With the likely onset of a 233% hike in the cost of electricity from Muskrat Falls (when compared to todays rate of $0.0972/kWh) we decided it was time to take energy consumption seriously before its too late to do anything about it.  The land has been acquired, the planning has started!  I am planning on nipping my energy bill in the bud before it becomes a major sinkhole in my pocket book.

Upon investigating current building standards, I realized that the Canadian Building Code is below the standards necessary to really make a difference in energy consumption.  There are some standards like R2000 which can make a difference to total energy usage.  A R-2000 home can use up to 50% less heating energy compared to a code built home; if built properly!  A blower door test will reveal the truth about that.

Now....Imagine living in a home where you have employed 5 guiding principles during design:

1.  Super efficient envelope:  Super-insulated, thermal bridge free walls that are air tight.
2.  Efficient layout of mechanicals:  energy efficient wiring, efficient plumbing layouts
3.  Controlled Ventilation:  Use of a HRV/ERV to control the amount of ventilation and recapture energy
4.  Integrating passive elements: Using large south facing triple glazed windows to capture solar energy
5.  Use of renewable energy:  This could be anything from PV to solar thermal to a wood stove.



If I told you that this home will use between 80%-90% less heating energy than a code built home you would think I was off my rocker!!!  If I told you that my hot water costs are now going to be the largest part of my electrical bill you would say that's not possible!!  Well, it is possible!!  I didn't fall of the rocker!!  I stood up and started looking...and realized that there is a whole lot of science that has gone into creating buildings with energy efficiencies you wouldn't think were possible in a cold climate.   Such a crazy standard does exist!  Its called Passivhaus and although the origins were in Canada, it was researched and refined in Germany.

To put the power usage for a house like this in perspective,  most homes around the size of our house are using up to 30000 kWh per year.  It's an early estimate but we are expecting that our annual energy usage for the new home to be 8000 kWh!  A whopping 75% reduction in energy usage!  How is this possible....science....and a lot of it!

Here are some links that may be of interest:

Passivhaus Institute http://passiv.de/en/

Passive House Institute - US  http://www.phius.org/home-page

More to come about this amazing standard...stay tuned!!!!

Comments

  1. Good to see this blog......following your comment on Uncle Gnarley blog today
    Winston Adams, Logy Bay

    ReplyDelete
    Replies
    1. Winston,

      I hope you follow along. I've been generating some traffic but few comments. I am hoping that this will be the first house in NL designed to the PHIUS standard. I am pretty sure that there are no others. There are a couple of NetZero ready homes in flatrock.

      Delete
  2. Hi David,
    Just decided to see if you had progressed on decisions on your plans over the past few weeks.
    I have been testing and monitoring minisplits as to actual performance for heating in our severe climate. Severe as to high winds, blowing snow, sleet and freezing rain. Rather impressive in handling all of this.......the recent blizzard was no problem. Actually our outdoor temperatures are better than much of ova Scotia and most of NB and Maine.
    I am seeing a COP of about 2.5 that is rather constant even at low temperature. But ideally, instead of mounting these units outdoors they should be in the attic.........and as to your layout for the garage, wonder if you have space there for that. I can go into details of the many advantages later.
    As to envelope construction.....have you considered urethane foam prefab panels,,,,,like they use for commercial refrigeration systems. It solves the bridging problem of wood studs and is available in 4.5, 6.5 and 8 inch thick. You might check the site ECO Panels.They say they meet passive design, are quick to install, and easy to seal so very low air charge.
    I have read on other foam panels and they are very inferior to these.
    I have used 4 inch thick urethane commercial panels for a retrofit, actually a add on to my cottage. I used them for the floors, supported underneath with 2 x 6 pressure treated joists at 24 in spacing. This has really worked out great, solid and warm, They were actually originally used in one of the large supermarkets refrigeration rooms and I bought them from the refrigeration contractor who salvaged them as they were like new. They have painted galvanized skins., So I put half inch plywood on top of this, as they have ridges in their construction. Very pleased with he outcome. And with solar gain the room heats up very easy compared to if this was a insulated concrete slab.
    In my cottage I did install a minisplit in the attic. For a full year my heat only, on all the time at 22 or 23 C was 260.00 for energy total for 12 months.
    I just recently learned that fiberglass insulation losses half its R value at low temperature , due to convection currents......so the R20 is R 9.2 at -18C. I thought there might be some loss, but man, this is terrible, that few realise. And other foam insulation lose some 25 percent with aging and some with lower temperature as well.
    Winston

    ReplyDelete
  3. Hi Winston,

    the plans are coming along. We are currently in the construction drawing phase and I have been updating the page with some information as I get a chance. I am hoping to present an overview of the energy usage according to different energy sources this weekend. I'll do a comparison from purely electric to ductless mini splits, to wood, to hot water heat pumps.

    As for the construction, we have decided to do an interesting wall that meets code and is very different!!! its a 2x6 load bearing stud wall which has 10" TJIs on the outside (nonstructural) and is filled with dense pack cellulose! R-value is around 53! This wall system is extremely cheap compared to foams and has great longevity as long as it's built properly. The advantages are mainly that they can be built onsite as the building is erected and all materials are local. The air sealing method is also quite different but beautifully simple and does not depend on application of an interior vapour barrier. The best thing is that all of this has been modelled using WUFI to verify the hydrothermal integrity of the wall system and it further illustrates that the use of vapour barriers is highly misunderstood and often leads to more problems then they try to solve. There will be minimal thermal bridging in the wall which will minimize energy usage immensely and we are hoping for a blower door test that's less than 0.6 ACH50!

    As for fibreglass, the effect you describe is pretty common in most homes, mainly because the outside of the house is not sealed properly. People think that walls need to breath. In fact, they do not. it leads to many issues including the movement of moist air from the outside in during times of extreme vapour drive and drafts lead to a wind washing effect on the insulation in the wall. It is detrimental to the performance. A wall can have as many air barriers as you want as long as there is only one vapour control layers. people think this air barrier has to be on the inside when in fact it can be in as many places in the wall as you want as long as the materials used for the air barrier are vapour permeable.

    Some foams are good, others are bad. Poly iso is a waste of money in our climate since the R value decrease with decreasing temperature. EPS is exactly the opposite. BUT with the right wall system dense pack cellulose gives a great long lasting wall where the R value don't decrease in time or with temperature and prevents drafts immensely due to dens packing.

    I will be updating the site in the next couple of days with energy data for a variety of modelled energy sources....stay tuned!

    DJG

    ReplyDelete
  4. My recent research on insulation left me convinced that cellulose was the best, except that I had concern that if it got wet it would not easily dry.
    Then last night one site on cellulose said if it gets wet it loses Rvalue, but moreso it can create mould situations. ........my biggest fear for that. An attic can dry out easie that a wall with cellulose.
    With windows , door and siding and the high winds we get here, it appears it is almost impossible to assure no leakage to prevent at times part of a wall getting some water penetration. And cellulose is like a sponge, once wet, not easily dried. And cauklking shrinks over times or breaks down.........and on reading on the ECO panels I though this was not a worry for that. The panels have achieved a air change of o,28, but generally 0.5.
    Panels I understand are some 20,000.oo US for a average house plus shipping. You are probably too foar advanced to re-think on that , but what is your view on the wet wall problem! I have a gable end not finished inside, and under high winds a couple of times a year I am getting some leakage.......and may have to take off the siding and try to seal it. High wind can drive water vertically up a couple of inches. I just hate leaks, and some are difficult to stop.
    Winston

    ReplyDelete
  5. very informative blog. I'm thinking about starting a new build project soon. great read

    ReplyDelete
  6. Hi MarkJ,

    I hope to keep the information coming. So far its been fairly easy but who knows as things become more demanding onsite!

    later,

    DJG

    ReplyDelete
  7. Hi from Central!
    Doing my own take this spring on a passive solar greenhouse. It’s a low budget build : )
    Not expecting to harvest year round but I’ll be happy with March-October! Which we all know is a FAR cry from our usual growing season.
    Enjoying your blog, love to see people pursuing sustainability and food security on “The Rock”!

    I’m doing a small 8’x12’ wood frame - 3’ knee wall, 6’ back wall - all on a gabion wall, sunk 2.5’ in the ground. 1’ layer of stone for drainage underneath. Going to cover in 2 layers of poly, compost bin in the center for extra warmth, adding a 55 gal black barrel filled with water to retain heat in the fall. Will probably insulate the north facing wall, with removable reflective panels between the framing, from around September-April.
    Im thinking I may also add tunnels over the beds in the spring/fall, not decided on that yet. Should work? I’m not super confident but I’ve been doing a lot of research... Any tips?

    ReplyDelete
    Replies
    1. Hi Jess, sorry for the late response. It is likely your greenhouse is done by now! If you wish you can reach out to me again!

      Delete

Post a Comment

Popular posts from this blog

Building the Air Tight Barrier: Door Flashing Details.

It took us a while to wrap our heads around the door details on my plans.  The main exterior wall is composed of 2x8s.  The rough stud opening was substantially larger than the door.  Because the walls are much deeper than a standard door frame for a 2x6 wall, the interior of the 2x8 opening was studded with double 2x4s.   Outside of these 2x4s, there is 1.5" of foam and another 2x4 on face which brings the door frame opening flush to the exterior 3" of EPS foam.  The brick mould of the door will sit against the exterior of the wall.  The ganged 2x4s which define the opening will allow the door to open a little further than that of a 2x8 wall.    With the door details finalized, I had to flash the opening as per the plan.  I specified the size/shape for aluminum sill pans and CBS Eavestroughing made them for me.  The sill pans have a kind of end dam to prevent water from entering under the under the stud opening should the door ever leak. (Photo 1-1).   After verifying t

Choosing an HRV...My Thoughts....

So, which HRV do you want for your home?  This is a question not often asked by the homeowner.  When the house is built, somebody installed an HRV and that was it.  The home owner is rarely involved in anything other than turning a knob on the HRV wall control if they dare fool with it at all.  An HRV is probably one of the most important appliances in your house;  it expels moisture, eliminates odours, evacuates stale air from bathrooms, provides clean air to keep you healthy and it recovers a lot of heat that would have otherwise been blown out through the vent on the house.  It serves three main functions: 1.  Supplies the home with fresh dry air. 2.  Removes stale air and removes excess moisture. 3.  Recovers heat or heat/moisture For a low energy home we need an HRV that is as efficient as possible.  With the ventilation unit taking care of exchanging most of the air in the building, having an efficient one will pay for itself in the energy saved over it's lifetime.  Zeh