Digital Fabrication of a Passive House - Extreme Green Prefab

Last week we completed fabrication of a panelized passive house in Portland. Trucks continue to be loaded and assembly will begin next week.  We are really excited about this project and how it will demonstrate advanced digital fabrication and high-performance.

We have great partners on this project and are very excited to be working with Guido Wimmers PhD, our passive house trainer, staff member of the Canadian Passive House Institute, advisor to the City of Vancouver on the passive house design toolkits, and owner of building evolution.

We are working with an incredible client, Shirra, who is great to work with and who is very interested in demonstrating the benefits of passive house on her own residence.  We are also excited to be working with our builder friends at the Econ Group, Marcel Studer and Michael Dutson.  Last year we collaborated with the econ group on another panelized project in Vancouver (photos here) and we expect to be partners on many more projects in the future.  Check their website and tweets for updates. 

Stefan has been working with this group for months to finalize the Cadwork cad/cam model and manage the fabrication in Portland.  The full photo collection is available on flickr, and some selected images are below.

After all the modeling Stefan generated renderings, three examples below,

Deliveries of lots of wood to the factory.

and a lot of cutting on our Hundegger lines

and some larger "sticks"

and some lots of angle cuts, here are some LVL rim boards

some LSL edge boards for floor panels

some dormer components

it has been very helpful to use the high speed printer heads to mark each piece

the shop has been very busy, with a few very large assemblies being produced by Tony and team.

and assembling all of these components into panels has kept Nate's team very busy

and optimizing the loading of the trucks has taken a lot of work and planning

and now to delivery and assembly at the site.  Check back for more images and videos.

CutMyTimber joins Passive House Northwest Group - Looking forward to the PHNW Spring Conference in Portland

We finally joined the PHNW group and are already listed on the PHNW Passive Pages. It is great to finally formalize our relationship with the passive house community in Washington and Oregon.  We look forward to attending the upcoming PHNW Spring Conference in Portland, Oregon on March 2nd.  The list of speakers is impressive and it will be a great opportunity to catch up with other professionals passionate about promoting passive house. Given that we just finished fabricating our first passive house project in Portland, Oregon we had to make time to finally join the local organization.  You can find photos of the project on flickr.  Watch for more videos and updates about the project on this blog over the next few weeks.  We plan on releasing videos of time-lapse images of the assembly to demonstrate the benefits of panelization.  We also hope to make another video showing the cadwork model with Stefan describing the project much as he did for a Tahoe residence we did a few years ago (see the video below, it has almost 4,000 views already). 




We are already very well-connected to the Passive House community in British Columbia, represented by the Canadian Passive House Institute (CanPHI), and received our passive house training from Guido Wimmers of Building Evolution of  (we made an earlier blog post about our training here).  

We were previously members of Passive House California and need to renew membership. Next week Greg is flying to New York for a conference on Digital Fabrication of buildings and will also be meeting with the passive house team at 475, a high-performance building supply company and active members of the New York Passive House group.  We are too busy building to stay up-to-date with all of these passive house groups but are enthused that the NY, CA, and PNW groups collaborated to form the American Passive House Network (we wish it was named the North American Passive House Network so people understand collaboration with Canadian groups).

CutMyTimber trained in Passive House

I think we all agree that homes need to be more energy efficient. There is a lot of talk about different systems and standards. I was trained and involved in many Minergie projects in the past.

Dr. Wolfgang Feist,German Professor and founder of the Passive House Institute went a step further and developed one of the highest green building standards in the world.
CutMyTimber spent a lot of time researching and testing various standards, products and software tools. We came to the conclusion that at this point the Passive House standard is probably the most advanced and thought-out green building standard at this point.

Therefore it’s no surprise that there is a strong move in Passive House all over North America. We are fortunate to have many local PH experts in Vancouver.  This was probably also the reason why the very first Passive House Designer/Consultant course took place in Vancouver.

I was one of the 25 professionals that took this very interesting course. We had a really good crowd mixed with engineers, architects, builders, building inspectors, green building consultants and building scientists.

What is a Passive House?

Basically a Passive House is a high performance building that uses solar (south windows) and interior heat gains (people, electronics, etc.)  Please see Passipedia for more details.

Passive Houses require less than 15 kWh/(m²yr) for heating or cooling (relating to the living space).

(Graphic: PH Institute)

In a nutshell following points are essential for Passive House design:
1.   Building shape, Compactness (Area/Volume ratio)
2.   Building orientation and window position/Solar exposure
3.   Building shell: High performance walls, roofs and foundation.
4.   Windows: Triple pane, double low e glazing windows with U-values of <0.8W/m2K
5.   Airtightness: Extreme tight building envelope (0.6 ach@50Pa)
6.   Thermal bridge free construction
7.   Heat recovery ventilation system

 
Following a few slides from our course.

First morning: Malcolm Isaacs and Dr. Guido Wimmers start the course and introduce the other instructors Dr. Andrea Frisque and Stefan Lotz. I felt very fortunate to have such a knowledgeable and passionate Passive House training team. Our instructors didn’t just talk about Passive House. All of them are very actively involved with the PH Institute in Germany, they are involved in current Passive House projects and clearly they knew their stuff and truly believe in Passive Buildings. Thanks again for such a great course.

Compactness and orientation of a building has a huge impact of heat and cooling energy consumption. The more compact a building is the better. Ideal building orientation is North-South.

The Building shell is one of the most important elements of a Passive Building. We require highly insulated and airtight walls. Ideally free of thermal bridges or penetrations. A Passive House should have R40 or better walls and R45 or better roof  (depending on location and many other factors). Malcolm explains a Passive House compatible floor to wall connection detail.

Thermal bridges that can’t be avoided need to be calculated. The calculation results have to be entered in the Passive House Software (PHPP). PHPP will consider these in the overall energy calculation.

Penetrations in the building envelope should be avoided in order to achieve an airtight building.  We learned about innovative products that can be used if there is no way to avoid a penetration. Unfortunately these grummets are not available in North America yet.

We learned a lot about the newest generation of windows. High quality windows triple pane, double low e glazing windows with U-values of <0.8W/m2K are essential for a Passive Building. Innovative window manufacturers came up with insulated window frames.

Unfortunately it’s hard to get windows with PH proprieties in North America. Many companies are working on it and it looks like we will see a new generation of window on the market soon.  

Because of the tight building shell a controlled air exchange is really important in a Passive House. A heat recovery ventilation system (HRV) is part of every passive house and requires proper planning.

Today’s Heat recovery units achieve efficiencies of 90% or more. Malcolm presents a few of the most efficient units currently available.

We also got exposed to a few of the currently available Passive House building Materials. Without pushing certain brands or products we had a chance to see new wind and vapor barriers, sealing tapes, ventilation ducts and nozzles.

Guido Wimmers opens the champagne at the end of the first Passive House Course in Canada. Many Thanks again to Guido, Malcolm, Andrea and Stephan for such a great course!! To my classmates: It was nice to meet you all and I hope we can pursue the Passive House move and be part of the local PH community.  

I can’t wait to design or manufacture our first Passive House.

Stefan Schneider, CutMyTimber INC.

USEFUL PASSIVE HOUSE LINKS:

Canadian Passive House Institute

Passive House Institute Darmstadt, Germany

Passive House Institute U.S

Passipedia

City of Vancover Passive Design Toolkits