Archive for the ‘Passive House’ Category

Quality Approved Passive House

October 14th, 2010 by Tim Delhey Eian

Passive House in the Woods, Quality Approved Passive House

We received the certificate from PHIUS today. The Passive House in the Woods is now officially a Quality Approved Passive House.

Here is a quick list of it’s key performance data in reference to Passive House limits:

  • Heating Load: 10.6 kWh per m2 living area and year [3.36 kBTU/ft2yr]
    (limit: 15 kWh or 4.75 kBTU); about 30% less than allowed
  • Air Tightness: 0.25 ACH50 in reference to the building’s volume
    (limit: 0.6 ACH50); almost 60% better than allowed
  • Source Energy Consumption: 106 kWh per m2 living area and year [33.6 kBTU/ft2yr]
    (limit: 120 kWh or 38.05 kBTU)*
  • CO2 Emissions: 16.5 kg per m2 living area and year;
    CO2 Emissions avoided with solar PV system: 16.9 kg per m2 living area and year.
    Therefore the building becomes CO2 neutral for operation.

*) The design was made for a 2 person household, which lowers this number to 65 kWh, or 20.6 kBTU

Calculations are based on the Passive House Planning Package 2007 model.


PHitW listed on “Built Passive Houses” website

September 14th, 2010 by Tim Delhey Eian

Passivhausprojekte Screenshot

The Passive House in the Woods project is now listed on the “Built Passive Houses” website. This page holds a lot of specs about the building and is a great resource for built Passive House projects around the world.


Final Blower Door Test

September 4th, 2010 by Tim Delhey Eian

Gary Nelson from the Energy Conservatory was gracious enough to perform the final blower door test today. We used the Minneapolis blower door with a duct-blaster and Tectite Software—following the PHIUS protocol and the DIN EN 13829 norm. The house performed better than during the rough-in test, which was to be expected since added finishes and completed window assemblies add to the tightness of the home.

The averaged result: 68 CFM50 leakage, or 0.25 ACH50.

Gary Nelson and the Minneapolis Blower Door

Gary Nelson and the Minneapolis Blower Door

Gary Nelson explaining the Tactite software

Gary Nelson explaining the Tectite software

Both blower door tests have been a fun learning experience for the team and a big success, since the house performed remarkably better than the Passive House limit of 0.6 ACH50.

Passive House in the Woods blower door test

The team is watching the numbers projected on the wall

For those who think in CFM leakage numbers, the house averaged 70CFM—75 depressurized (0.28 ACH50), and 60 pressurized (0.22 ACH50). For those who could care less 😉 this is a really, really tight house.


Come see one of the most energy-efficient buildings in the country at Living Green this weekend

May 1st, 2010 by Tim Delhey Eian

TE Studio booth at LGE 2010

We are in booth U21E and S7E on the upper floor of the Living Green Expo this weekend. We’ve had lots of enjoyable conversations about Passive House and energy-efficient building design. Come join us—it’s free!

Grandstand, MN State Fairgrounds

Tomorrow, Sunday, we’ll be there from 10 until 5pm.


This is the Passive House in the Woods

December 2nd, 2009 by Tim Delhey Eian

This is the Passive House in the Woods

The Passive House in the Woods is a 1,900 square foot two-story single family home with walk-out basement level, and a rooftop terrace. It was commissioned by a private client and designed by TE Studio. It sits on just over one acre in the Town of Hudson, WI—minutes from interstate 94. Located on the outer edge of a residential development, the home overlooks the St. Croix river valley. The building lot provides stunning views and prime passive solar exposure. The property’s north boundary is heavily wooded and borders undeveloped land. The design of the house works with the natural landscape, and minimizes impact on the wooded character of the lot.

Passive House in the Woods rendering

High Performance Building Envelope

Exterior walls, windows, doors, slab, and roof designed according to Passive House principles can radically reduce the amount of energy used to condition a building. The exterior wall assembly of the Passive House in the Woods consists of 11” Insulated Concrete Forms (ICF) for structure, and an 11” Exterior Insulation and Finish System (EIFS) facade with an overall R-value of 70. Windows and doors are Passive House certified, come with triple pane low-E coated glazings and insulated frames for installed R-values of 8, and solar heat gains of over 60%. The slab sits on 12” of extruded polystyrene insulation with an R-value of 60. The flat roof utilizes an average of 14” of polyisocyanurate insulation with an R-value of 95.

High-Efficiency Mechanical System

The mechanical system in a Passive House is typically centered around a heat-recovery ventilation machine. In milder climates, this system provides all the necessary heating energy, as well as outside air needed for balanced hygienic ventilation. The heat-recovery ventilation system in the Passive House in the Woods consists of a high efficiency heat-recovery ventilator, combined with a 600 foot PEX-tubing loop field—buried on the property—to pre-heat and pre-cool the incoming air stream. This also dehumidifies moist summer air.

In extremely cold climates, the paradigm of heating with ventilation air changes slightly. The overall annual energy goals for Passive House can be met but the extreme cold winter temperatures require a small additional heat source. Electric in-floor heating mats with local room-air thermostats are used to provide about 3kW or 10.5kBtu*. That compares to the energy draw of two hair-dryers.

Renewable Energy Systems, Net Energy Positive Energy Balance, and Carbon Neutral Operation

Renewable energy systems are optional and not required by the Passive House standard. Our client chose to achieve a net energy positive energy balance and carbon neutral operation. A 4.5kW photovoltaic system generates a surplus over the energy consumed on site, avoiding 2.78 tons of CO2 annually*, and therefore providing carbon neutral operation for a household of two people*.

The domestic hot water system utilizes a 40 square foot hot water solar collector on the roof to pre-warm water in a 50 gallon storage tank. It is capable of providing over 85% of the hot water used in the home*. Backup heating is provided by a small electric on-demand water heater.

Minnesota GreenStar pending certification

Minnesota Green Star Certification

The Passive House in the Woods is registered with Minnesota Green Star and designed to achieve a gold rating.

The Team

Meet the design and construction team by clicking on The Team link at the top of this page.

The Scoop

Currently, there are only about a dozen certified Passive House(TM) buildings in the U.S. The Passive House in the Woods is slated to become the first certified Passive House(TM) in Wisconsin, and one of only a few net energy positive and carbon-neutral buildings in the country.

It blends economy, ecology, health and durability in ways only Passive House can. The project sets out to demonstrate that this level of performance and quality can be achieved with today’s technology—even in an extremely cold climate. The Passive House in the Woods is a unique show-case. Ground braking happened on December 3, 2009.

The Passive House Standard is the most rigorous building energy standard in the world. Consultants, projects or building components that have obtained the right to carry the logo have committed themselves to design excellence and the Passive House energy performance criteria.

*Performance figures are based on Passive House Planning Package 2007 calculations.