All the Framing is Backwards!

We've had people go by our site and wonder why we were doing things backwards.  Normally, one builds the concrete walls and places a wood floor system on top of it.  We didn't.

The wooden house frame rests on the footings - not on the concrete walls.  Why?  One thing we're discovering about radically energy efficient buildings is the structure!

When the structure is not designed for insulation, it gets very hard to achieve thermal-bridge-free construction.  Placing the first wood (or steel, or whatever) floor frames on top of the concrete walls means there is a strong connection to the concrete (a heat conductor, not an insulator).  Unless the concrete is on the warm side of insulation, this is a significant thermal issue.  In our design, the structural concrete is all on the cold side of insulation.  (This means the outside shell of the building is hard.  When one thinks about a building lasting 25 years, having rigid foam on the outside might seem OK.  But what if we want  it to last 150 years or more?  Well, I don't know if that will happen with this house, but in case it does, it seems a good idea to have the outside shell be hard and durable.  One loses some potential to have thermal mass inside, but that can be achieved in other ways).  Getting back to the wood frame, we therefore have thermal separation between the inner frame of the house (which is the structural frame) all the way from the footings, up to the roof.  Therefore, framing starts in the basement, not on top of the concrete walls.  This might seem like a radical departure from conventional practice. But so far, in our project, we've found no real problem, and we are framing the 2nd floor walls now.

There are some considerations to handle, however.  First, we start with wooden walls, not floors.  The reason for this is that if we started with floors, the insulations inside them would get all wet.  So we wait for the roof to be on and the building closed up before building the basement floors.  This also reduces the natural settling of the building - pretty much all of the shrinkage of framing lumber happens in the floor frames.  Although we built the wide footings very level, we also shimmed the walls so they are not in contact with the concrete and any water can drain from under the walls, into the space between the footings, and finally to the sump pit.  

The walls against the concrete are not sheathed.  Again, this is so we can insulate the space behind the frames after the building is closed in.  We borrow shear strength from the concrete walls to stabilize these open frames.  The photo below shows a wide 3/4" plywood top plate (placed over the upper top plate) which reaches to the concrete and laterally anchors the walls to the concrete with steel brackets.  The 1/2" female Zamac anchors ($1 ea) were placed in the forms during the wall pour, but could probably be drilled in afterwards.  The concrete crew didn't really pay attention to the location of these anchors so you'll see that some of the steel brackets connect to the underside of the plywood, and some to the upper side.

Smallest Wood Stove and Smallest Wood Boiler

Help!
I have been getting more and more interested in the possibilities of wood stoves and wood boilers - BUT cannot find that very small, high-efficiency, sealed-combustion, direct-vent wood boiler!  This would be ideal for the occasional back-up hot water heating, and possibly snow-melting.  However, I have located a number of smallest wood stoves, some of which are beautiful!

Here are some:
http://www.salamanderstoves.com/docs/64/the_hobbit/  4kW output (14,000BTUh), $800 including delivery to NA.

http://www.morsona.com/index.php/morso-1440.html  

30,000 BTUh, 17x14x28"h including legs

http://www.marinestove.com/herringinfo.htm  This site lists three or four tiny wood stoves for sailboats.  Lovely.

http://www.jotul.com/en-US/wwwjotulus/  The F602 is listed at 28,000 BTU output - about 8kW - 19x11x25"h cast iron, non-catalytic clean burn 75% efficiency

http://www.waldeneffect.org/blog/Smallest_wood_stoves/

http://www.youtube.com/watch?v=xDUrSsILmNA&feature=related

http://www.fatscostoves.com/

http://www.theboilerwerks.com/

http://www.refleks-olieovne.dk/

http://www.blakes-lavac-taylors.co.uk/prod01.htm - Kerosene, Diesel, and Parafin heaters

A very small, 55,000 BTUh on-demand propane water heater:
http://www.globaltowne.com/product_info.php/products_id/54

An Excellent resource on heating with wood, its history and all the different types of wood burning appliances.
http://autonopedia.org/crafts_and_technology/Woodburners/Wood_Stoves_Part1.html

Ah!  Found a water heater for a jacuzzi - the CHOFU!
http://www.islandhottub.com/woodhtr.html - about $1200 from Amazon.com right now.

To convert any woodstove into a water heater:
http://www.hilkoil.com/  By the way, as far as I can tell, there are wood boiler makers using these coils such as this one:  http://nationalstoveworks.com/hotwaterstoves.html

An engineer who's built his own wood-fired cookstove/space heater/water heater.
http://www.gulland.ca/homenergy/stove.htm

Construction Has Begun

So much to report!

We started construction.  There's been about 2.5 months in prep, but just three weeks with crews on site -
Starting Tuesday Jan 10th:

Prep:
Moving out, finalizing drawings (ongoing!), disconnecting electricity, gas, water, phone, etc. Salvaging all we could form the old bungalow, sourcing specialty materials, building window and door bucks for the forming, and getting the detached garage ready to act as an onsite workshop and office.  The house was standing until Jan 10, 2012, when the following took place:

1. Week 1:  demolition and excavation - Details:  removal of soil:  $600 per load, 35 truck-loads to remove - building foot print was increased only about 500 SF, but we also went about 12" deeper into the earth.  Garbage - everything other than masonry/concrete.  The excavator crushes the building into the basement until everything is in small pieces - then scoops it out into the garbage bins.  The 40-Yd bins are $125 delivery/p/u plus $75/ton dumping.  Concrete/masonry recycling is $275 flat fee for 14-yd bins.  Excavator on site for 3 days.
   This phase was pretty standard.  Expensive to remove soil!
   Terraprobe performed a soil verification just an hour after the final excavation with the entire pit open (3-page report - $450 plus tax).  They found our soil strong enough to hold 200kPa at SLS and 300 kPa at ULS.  It is Glacial Till.
   Straw was spread in the pit Thursday evening. - It is lovely and easy to work with at this point.
   Surveyors came on Friday to drive in these 3/8" pins marking the corners of the building.  They used standard practice, marking the exact corner of the building, without any offset.  Normally, the pins end up inside the footings, and the footing forms are placed outside these pin locations.  In our case, this caused a problem because our footings were to be exactly in line with the outside edge of the building - so the pins were in the way.  Note also the surveyors don;t really provide any height reference - they expect the footings to be placed on the bottom of the excavation, and levelled using bubble levels.  As we would be making very precise footings, we didn't like this idea.  We used a laser site-level instead.

1. Week 2:  Footings - Form and Pour - Cold weather this week - we worked in minus 5C to minus 10C weather - one day it was minus 17 C wind-chill.  The 30 bales of straw kept the earth in the pit from freezing.  We added another 8 bales later.  Footing forms took extra time - we did it ourselves due to the careful design of the wall-to-footing intersection.  As the basement walls would be in-line with the edge of the footings, the forms had to be executed precisely along their outer edges.  The forms for the outside edges of the footing would stay in place after the footing pour.  They were anchored to the footing using the Zamac T-35 female anchors at 8' OC.   Wall forms could then rest on the footing form, which was 2x12 material, so only 1.5" wide.  These had to be precisely in the right place, and also very firm.  We felt this was necessary because we wanted to form a key at the outer edge in the footing to hold the walls against earth pressures, and also to improve water sealing (dowels would have been enough to hold the wall, I think).  There is no concrete floor slab to hold them, as in most regular basement foundation structures.  
   The floor slab was to be placed between the footings rather than on top of them.  This, and the thick footings (11.25") will allow us to place insulation under the basement sub floor, while the basement floor joists rest upon the footings.  We seemed to have done a good job forming the footings, because there were absolutely no issues in placing the 10' wall forms later on.  This seems an ideal way also to form lot-line footings.  We used higher-strength (25MPa) concrete all around to improve water-tightness.  I also feel drainage of water down along the basement wall is improved by having the footing and wall edges in line.  The seem between wall and footing is easily bypassed and the water can flow right down to the weeping tile.   Weeping tile will be placed on both sides of the exterior footings, draining to a deep sump pit in the bottom of the elevator shaft.  Drainage of the basement is of utmost importance since the airtightness requirements will mean a permanent subfloor will be needed in the basement, as far as we can figure out for now.   - And we don't want any water under this floor.

Footing Forms made using 2x12's.  Ext footings are 26" wide to accommodate the double basement wall system.  Ext surface of basement walls will be inline with the outside edge of the footings.

Female concrete anchors to hold outer footing forms after the pour.  Note also the continuous 2x4 key at footing edge.  2x12 forms.

Exterior Edge of completed footing.  15M Rebar Dowels at 2' OC placed against the 'key'.  The 2x4's that formed the key have been removed.

Week 3:  Concrete Basement Walls - Form, Pour, Strip, Spray, and Apply Weeping tile, membrane, etc.  It took a crew of 8 the full day to place all the 10' forms, place the ties, the rebar and window bucks, and straighten and brace the forms, and place the scaffold.  Next morning they oil-sprayed, did some final straightening and bracing and poured all the concrete (4.5 trucks - 36 Cubic meters) in 3 hours.  We cast electrical outlets into the walls - I looked long for plastic boxes designed for casting in place.  I did find them (Kwik-on is one), but they needed ordering, and weren't cheap.  The normal stuff to use is what contractors call 'slab-boxes', which are just metal boxes without holes - all knock-outs instead.  Cheap, but not good, IMO.  I came up with my own instead.

A Rather Massive Roof

Well the hip was 'Piddley', and some said it was like a chunk cut out from the roof.  I personally liked it, and the reduction in mass it offered but we were also encouraged to make a simple, single gable.  Here is the result.  Still don't see any connection to the neighbours, as per the recent comment in the last post, but that is a tougher issue, perhaps, and will be worked on soon.

The taller, and more massive gable struck me as elegantly simple, though it gives the building a more serious air, compared to the cuter three-part roof.  One major excitement is the improved solar angle and the now much larger surface for solar PV modules, which are way down in price right now at about $1.73 per watt, with the required Canadian content.  I'd love to have the entire roof covered with panels, but the sizing is not working out quie yet.  The west facade is rather plain and needs work too.

Last minute change?

We are about to demolish, excavate, and start concrete work.  Wife and Hubby disagree on the roof line!
A:  features the Hip Roof on the West side.  B: Features a gable instead.

A:

B:

What do you think?
Thanks
LT

Disconnection of Services

We've moved out of the house and have started deconstruction.

We are disconnecting services, including gas, electricity, water, etc.

Re. Electrical:
Toronto Hydro wants min. 2 to 3 weeks to perform the meter recovery, as they call it.
Our neighbours are OK with us using some of their electricity, so no temoporary service will be installed.
Re. New connection:  Underground service will require a $1000 fee for 'design' by Toronto Hydro, and up to $7000 to install.  Lead time is 14 to 16 weeks, so it could miss our foundation backfill, which means they'll dig a new trench.   Meter location is not too important now since they are using smart meters, but if the service is an overhead line, they will probably install the meter at the front of the house anyway (right near where the overhead line connects to the house).  Then we underground conduit to the back of the house, where our Utility Room is.  Conduit will be 18" below grade right beside the foundation....so this means a trench inspection, and we'll probably leave the backfilling operation short at the trench areas.
Trying to figure out where they want the damn meter.....
LT

Toronto Zoning Bylaw Repealed

On May 18th, 2011 the city of Toronto repealed its zoning bylaw 1156-2010 (and all subsequent amendments to it), which was passed into law last Aug. 27th.  This means all the little parts of Toronto are back to their old zoning systems until the new bylaw is once again prepared to be enacted - apparently in Jan 2012.  In the meantime, the Planning and Growth Management Committee will continue to consult with residents.
There was a couple of amendments to the repeal motion - They provided that 500m setbacks from concrete production and distribution facilities and propane facilities be considered separately from the bylaw's repeal - in other words, these measures, brought into force with the initial passing of 1156-2010, may remain in force...it is still unclear to me for now.
I was impressed by Adam Vaughn in the Council meeting.  He was well informed, and calmly noted that the reason to repeal was not that it was a bad piece of legislation.  Implementation of the bylaw was the real cause of the problems.  The strange thing here is - the whole emphasis on the interim period is to meet with residents and concerned parties on the content - but the PGM Committee seem poised to follow the same implementation track when it is enacted a second time - that of enforcing two zoning bylaws simultaneously.  I don't see how implementation will be any easier at that time - except that there is now a period of about 8 months when everyone can rush their projects through.  Does the PGMC really expect that everyone will hold off on their projects for a year or so while the appeals (which will hopefully be fewer than 700) are dealt with?

I wonder what all those people who paid for zoning adjustments under the new bylaw have to say about the repeal?  I doubt there is any easy way for them to get a refund on the $1700 application fee.  The cost of the lost time, redesign work, and disruption to work crews would be significantly higher, I think.

I am amazed at the absence of this issue in the popular media.
LT

Lyndon Than and Phi Than Toronto Star Article

Cynthia Vukets, a Toronto Star Reporter wrote an article about our 'passive solar house' in the Toronto Star.  Note how she does not call our house a 'Passive House'.  I find there is a funny response from some people about the word 'passive'.  Our plans examiner at the City of North York thought the name 'Passive House' was a bad name - he thinks one should be 'assertive'.
Anyway, the article appeared in the Thursday April 14th edition of the Toronto Star, Living Section, Page L7.  About a 1/2 page, discussing our project and Passive House in general.  I liked the article - but sorry, no link - I haven't found the online version. Here is the scan, click on it to enlarge.
LT

Passive House Design in Canada Series of Articles Coming Up

Hi All,
I plan to begin a series of articles discussing Passive House design and general house design together.  I will be using our own project its specific design challenges and ideas to highlight concepts.  Here is the latest rendering of our design to date.  More to come on this.
LT

Preparing the Garden for Construction

Although this long winter seems never-ending, we know spring is just around the corner! To remind us of the greenery that is surely on its way, here are some photos of the garden in preparation for the eventual demolition of our house, and with it, much of the yard.  We spent a sweaty afternoon last June moving our beloved tree peony to a corner where we hope it will be out of harm's way during construction.  In a few weeks, we'll know if the many transplants survived the winter...
-PT

Before

After