Colorado PassivHaus? almost...

This morning brings us a great New York Times article about where we are headed in green building design.  Bravo, people!

Here is a shot of Green Line Architects' recently completed Off-grid PassivHaus!  (Passive House to us Americans)  

The Living Room trusses are made of reclaimed timber and steel, and you can see a section of the 12" thick, R-60 SIP's (structural insulated panels) being installed above for the roof.  High insulation values, coupled with a very airtight "envelope" and proper ventilation make for an extremely energy-efficient home.  This one is estimated to be 94% more energy efficient than a standard home.  That's very near Net-Zero Energy!

Stay tuned for more news about this terribly exciting new home...

UPDATE

5-13-2001

Turns out this house is 105% more energy-efficient than the standard home, which means that it is a Net-Zero Energy or NZE Home!!

Technically, it falls just short of being a true PassivHaus.  See notes from our energy consultant, Megan Gilman, of Active Energies, Inc. below:

Performance Characteristics

PassiveHaus Standard 1 • Airtight building shell ≤ 0.6 ACH @ 50 pascal pressure, measured by blower-door test.

This home had 0.1 natural air changes per hour and an ACH@50Pa of 2.14.  LEED and other programs have started using ACH@50Pa (LEED has three tiers of infiltration for this climate – required 5.0 ACH@50, 2 points for 3.5 ACH@50, and 3 points for 2.0 ACH@50.  These figures make sense… we were very close to LEED’s most stringent level.  

PassivHaus Standard 2     • Annual heat requirement ≤ 15 kWh/m2/year

(4.75 kBtu/sf/yr)

            Our annual heat requirement (according to HERS) is 12,000 kBtu/year, so this would be 5.96 kBtu/sf/year.  This might be a hangup, if it doesn’t meet their requirement.  However, they specifically say that it has to get this energy use in their software, which has specific weather and conditions, which could be a bit different

PassivHaus Standard 3 • Primary Energy ≤ 120 kWh/m2/year (38.1 kBtu/sf/yr)

Our total is 7,200 kBtu/year.  Yeah, I know that it’s weird that this is lower than the heating requirement, but this is because the PV production knocks down the total energy requirement.  I suppose the specific heating requirement is to ensure that you don’t just have a home with bad insulation and windows and slap a bunch of PV on.  Anyway, this total energy use would be 3.58 kBtu/sf/year.

In addition, the following are recommendations, varying with climate:

PassivHaus Recommendation 1  • Window u-value ≤ 0.8 W/m2/K  Window U-value is 0.213 in English units (Btu/hr-sf-degree F).  To convert to SI units, the conversion factor is 5.678, resulting in a value of 1.21 W/m2K.  They say this varies by climate, but I’d bet we’d be in one of the more aggressive climate zones.

PassivHaus Recommendation 2   • Ventilation system with heat recovery with ≥ 75%  

   efficiency with low electric consumption @  0.45 Wh/m3  I believe the HRV has an efficiency right around or above 75%.  My records show there is a 500 cfm unit (really two 250 cfm units) that runs 2.5 hours per day at 300 watts total, which is a total of 31.25 watts-hours per day, divided by 907.16 cubic meters is 0.034 W-h/m3.  This seems really low, but they wrote cubic meters, so that’s what makes it so low.  I don’t believe this item would be a problem.

PassivHaus Recommendation 3 • Thermal Bridge Free Construction ≤ 0.01 W/mK

I believe that with a SIPS shell, that this house is on par.

Villages in France

Check out the amazing masonry work on these buildings in France.  From L'Internaute.com.


Bargème, Var

Châteauneuf, Côte-d'Or

Noyers, Yonne

Pérouges, Ain

Lavaudieu, Haute-Loire

Modern Treehouse

We outfitted the treehouse with some modern furniture...

What do you think?

(thanks to Robyn Scott, Kim Umemoto and of course Dave Rasmussen!)

Mallet Design Study

That oughtta do it.


-rollin' post

Greener and Weirder

Are we thinking about this in the right way?  Check out Alex Steffen's article:

ArchCalc Construction Calculator

This is a great piece of FREEware for your computer.  We've been using handheld versions of these calculators in our office for a long time.   They are simply a "must" for doing quick dimension string checking, and for estimating materials.
This one from Stefan Hampden gives you all of the main functions of a construction calculator. It works in feet and inches, converts to metric, converts between fractions and decimal, solves trig functions and has a tape display.

It is available for:
Windows Me, Windows NT, Windows XP, Windows 2000, Windows 98
and
Windows XP / Vista and MAC!

Its free, but if you like it and use it, please pay Stefan $20 for his hard work on this...  I did!

Why Use an Architect?

Architects save money. An architect's services are a wise investment because a well-conceived and designed project can be built more efficiently and economically. As ideas evolve, changes can be made on a computer screen or paper much less expensively than when construction is under way. Other ways architect-designed projects save money include:
• Designs that take full advantage of solar heat and natural lighting to save on energy needs.
• Space-efficient plans use less floor area, which can result in 5% to 15% cost savings on a home.
• Flexible design solutions accommodate future growth and usage needs.
• Accurate construction costs based on detailed drawings and specifications that result in quality materials and workmanship at a fair market price.
• Materials, finishes, and design solutions that reduce maintenance and replacement costs.
• Architect-designed homes sell faster and hold higher resale values.

Architects solve problems. The architect is the one professional who has the education, training, experience, and vision to guide the design and construction process. This broad knowledge helps architects focus individual home owners' needs to maximize their investment in livable square footage on time and within budget. Architects stay abreast of advances in roofing, brickwork, floor tile, paint finishes, and other building materials to ensure a smooth and cost-effective building process
Architects see the big picture. Few people realize how complicated it is to build until they find themselves lost in a maze of design options, building codes, zoning laws, and contractors. Architects don't just design four walls and a roof; they create total environments, interiors and exteriors that satisfy specific needs and functions. If a project requires engineering or other construction services, an architect can coordinate the team of experts. An architect sorts out complex building codes and zoning laws and can locate qualified contractors, visiting the construction site to ensure that the project is built according to plans and specifications.
Architects know aesthetics.  Your architect will design a home for your personal tastes that works within the context of the local vernacular style and the community.  Architects design homes to be timeless, with long-lasting appeal.
Architects give you peace of mind.  Architects hold the health and life safety of building occupants as their highest calling.

For more information:  AIA, How Design Works