thermal bridge free exterior

next up on skidmore passivhaus is installing the outsulation on the walls along with the rainscreen furring. DSC_0849

the plywood sheathing was first covered by a weather resistive barrier with metal head flashings at the windows and doors.

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most walls get a layer of 3" poly-iso, while the south wall will get 4" to match the recessed pocket for the exterior shades.

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2 screws (with plastic washer) per 4x8 sheet hold it in place until the furring strips are installed.

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all seams and fasteners are taped.  the face of the insulation is treated as a second weather resistive barrier.

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additional flashings at all doors and windows will be taped to the insulation as the wood trim is installed.

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1/2" x 2" pt plywood furring strips run vertically to create the drainage plane.  they are held in place by just a few fasteners until the next layer is installed.

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since we are using vertical siding, a second layer of furring runs horizontally.  we used pt 1x4 as a solid nailing base for the siding.

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long fasteners secure the second layer of furring strips running horizontally through the foam to the studs.  the straightforward framing layout makes the studs much easier to locate.

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keep in mind that long fasteners get expensive.  we settled on grabber #10 x 6" square drive coated screws (from nw staple).

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next up on the exterior is trimming windows and installing siding.

stop by again soon.

small project update

we recently shared some drawings and photos of a small bathroom remodel inspired by the japanese bath house.   the work is complete and it turned out quite nicely (thanks to right arm construction).  here are some photos of the completed project:

a quick reminder of what it once was.

www.insituarchitecture.net

passivhaus progression

as we inch closer to getting started on our project, we continue to scrutinize our current plans in an effort to create a house that is fine tuned for our needs.  as an architect, i want a house that is inspiring and beautiful, and embodies what is important to us.  as the owner with a very limited budget, we want to make sure that our cost expectations are realistic.  since i'll be playing general contractor, i want an easy to construct and problem free building. we've taken another pass at redesigning the house with an eye toward efficiency and simplicity - both in terms of square footage and energy.  we felt there were a few redundancies, tricky details, and program pieces that we are better off without.  here's a quick snapshot of the progression of the plans.

as always, there are a few ideas though that we refuse to give up.

requirement #1: warm, comfortable, and extremely energy efficient

we want to live simply and in a beautiful inspiring place that is warm and comfortable regardless of the time of year.  we also want to minimize our footprint and our energy costs.  although we will most likely pursue passivhaus certification, the path we take isn't really as important as the end result.  for us, passivhaus is just a means to a better end.  our generous friends at brute force collaborative have been providing the expertise to help us get there.

meeting passivhaus requirements means the house will use no more than 4.75 kBTU / ft2 annually for space heating.  for the main house, this translates to about 5.27 mBTU or 1544 kWh annually for space heating (we are planning to use electricity to heat the house).  at our current rate of around $.09 / kWh, our annual heating bill would be no more than $139.

although we know that the studios will see far less use than the main house, using the same formula yields an annual heating bill for the studios of no more than $51.

requirement #2: wood windows and doors

since we want wood windows and doors, and they need to be extremely high performing to achieve requirement #1, we have been looking at manufacturers based in germany and austria.  this is our largest single expense and perhaps an easy target for criticism, as these beauties will need to be shipped overseas.  we would love to use a locally produced product, but unfortunately no wood windows made in the US come even close in terms of performance.  it's a bit of a quandary, but brute force collaborative has performed an interesting analysis (based on our previous design) that has us feeling more comfortable with our decision: Can European windows actually save carbon?

requirement #3: separate work from home

an important part of our program is space to do work and make things.  we know we could make a more cost effective and thermally efficient house if we combined our work space with our home, but we like the idea of some separation.  we think we can make this simple idea a huge asset.

requirement #4: create positive outdoor space

our intention has always been to use the form of the house to shape outdoor space.  again, this may contradict requirement #1 but we don't just want a box sitting in the landscape.  we want two boxes sitting in the landscape creating positive space between!

requirement #5: keep it modest and make it beautiful

many people may not agree, but we think these two wood clad boxes with concrete floors, white sheetrock walls, natural wood doors and windows, and flooded with light will be quite beautiful.

on the boards: BUG

Beech Urban Gardens is a new mixed-use building designed to meet passivhaus standards and substantially raise the bar on energy efficiency.  Located at the heart of the burgeoning N Williams corridor, BUG sits on an empty south facing 50' x 120' corner lot.  Seven residential units occupy the top two floors, while six creative offices are situated above three ground floor retail spaces.

BUG features a fully glazed south facade utilizing a high-performance window system to maximize direct solar gain, minimize heat loss, and provide exceptional views and daylight.  A system of sliding wood shutters is incorporated into the facade to provide complete external shading in the summer and eliminate overheating, while still allowing views and daylight.

The roof features a community garden with raised beds and a potting shed, a huge terrace with views to the neighborhood and the city, and photovoltaic panels making the roof's south guardrail and providing the building's minimal electrical needs.  A greywater recycling storage tank provides gravity fed water for the rooftop gardens and the building below.

interior of typical residential unit

southwest view with wooden shutters in closed position

www.insituarchitecture.net

rainscreen installation

open joint cedar rainscreen siding aligns with existing lap siding

building paper for color only installed over air infiltration barrier

battens run behind belly band to maintain continuous airspace

view of battens and siding at corner in preparation for butt joint

pre-primed rough sawn cedar siding with open joints

closed cell spray foam against underside of roof deck

previous entries on this project:

construction progress

under construction