NewenHouse was completed in 2011 in downtown Viroqua, Wisconsin and was designed and developed by Sonya Newenhouse as a 3 bedroom 2 bath kit home offering an affordable, zero-energy, sustainable dwelling that is easy to build and connected to the sun and climate. COULSON provided Passive House Certification (the pioneering building was the 2nd to earn certification in Wisconsin), Energy Modeling, Hygrothermal Modeling, Construction Design and Details, and Mechanical and Electrical Design. The project is LEED for Homes and Energy Star certified and is a postive-energy building with integrated photovoltaic and solar hot water systems. The innovation of the project is that it meets these most stringent targets in a very cold climate for a cost of less than $225,000. How this integrated design puzzle was resolved using common materials, simple details, and low-tech passive strategies is the important lesson and COULSON was honored to lead that effort.
Traveling to Viroqua, Wisconsin, one experiences the pastoral landscape that architect Frank Lloyd Wright called home. The dramatic rolling hills and exposed rock of the Ocooch Mountains are dotted with small, hardworking farms. The culture is unpretentious and deeply connected to the land and the seasons. Locals celebrate the mild summer and are thankful for the abundant sunshine in the extreme winters. It is no surprise this community is home to the first prototype of NewenHouse, a single-family detached residence developed by Sonya Newenhouse. Like Wright’s Usonian Homes, NewenHouse addresses the challenge to provide affordable, low-energy, and sustainable housing that is easy to build and connected to the sun and climate.
“Let us be less luxurious, and more magnificent.” -Okakura Kakuzo
The first NewenHouse prototype was completed in 2011 on a south-facing downtown lot where it engages the community and offers regular educational tours and building science presentations.
The project is Passive House, Energy Star, and LEED for Homes certified. The innovation of the design is that it meets these most stringent criteria in a very cold climate for a construction cost of less than $225,000. How this integrated design puzzle was resolved using common materials, simple details, and low-tech passive strategies is the important lesson and COULSON was honored to lead that effort.
One hairdryer can heat NewenHouse on a cold January night.
The space heating demand was reduced by 90% and the peak heating load of 1400 watts is satisfied with three simple $100 radiant electric panels. The cost saved by eliminating the traditional heating system is swapped for the added cost of super-insulation, triple-pane windows, and airtight construction.
COULSON provided this energy design and modeling, construction detailing, mechanical systems design, and passive house certification.
The total annual site energy demand before renewable energy is 3300 kWh.
This is a 79% reduction in energy consumption compared to the same home built to code. The energy demand is easily supplied by the small photovoltaic system integrated on the roof, and included in the construction cost, to achieve Net Zero Energy.
A solar hot water system, with roof mounted panels is also included in the construction cost and reduces the domestic hot water energy by 58%.
A tiny HRV (heat recovery ventilator) is located in an upstairs closet and operates continuously with a heat recovery efficiency of 92%.
Meeting energy and cost goals begins at the schematic design stage when the functional layout and form is finalized.
The Usonian Homes were innovative for their open floor plan, borrowed-space strategies, and clever built-ins. Wright knew he must control the house size to achieve economy, so he pushed the efficiency of the plan.
Ms. Newenhouse took inspiration from this and the small home movement as she designed her 3 bedroom 2 bath floor plan. The main house is only 1240 sqft (115 sqm) gross over two levels, but functions like a home twice the size.
The insulated enclosure is a compact cube without a basement or heated attic. Heat loss is greatly reduced because the exterior surface area is minimized. The simple form is very cost effective to build.
A concrete slab-on-grade foundation, exposed as the floor finish, is surrounded by 12 inches of EPS foam. The additional insulation is cost neutral as the thick foam is also utilized as the concrete formwork.
Trusses installed on the top of the cube create a traditional-looking roof and a pitched surface for solar panels.
The adjacent screen porch and root cellar expand the summer living space outside and offer unheated storage and tornado shelter.
NewenHouse is cost effective because the framing sequence is simple and the materials common.
In the first phase the cube is constructed like a standard platform-framed house with flat roof using 2x4 wood structural walls with osb sheathing and 2x10 roof joists with plywood roof deck. The osb and plywood create the airtight layer and all seams are taped. Roof trusses with energy heel are installed. This basic structural enclosure is made very quickly, with minimal instruction required and with components from the local lumberyard. All mechanical and electrical are installed in the 2x4 walls and do not penetrate the airtight sheathing.
The next phase is the installation of the 12 inch larsen truss using scrap 2x4 and plywood material.
NewenHouse utilizes an improved design of the larsen truss that further reduces thermal-bridges and the amount of lumber to maximize insulation value and reduce heat loss. It consists of 2x4 verticals at 24 inches on center, fastened back to the structural wall using minimal plywood gusset plates and 2x4 blocking. The exterior is sheathed with fiberboard.
All wall and roof cavities are filled with dense-packed cellulose. The exterior cedar siding has a vented air space behind it and the attic is vented. These are diffuse-open details where the moisture dries to the outside. COULSON completed advanced hygrothermal modeling to verify the moisture performance.
The design has a low carbon footprint as cellulose is made from local recycled paper and the FSC lumber was milled locally. When the home has reached the end of its useful life these components can be deconstructed and recycled.
NewenHouse is a kit home. Like the popular Sears, Roebuck and Co. homes, it further reduces building costs by taking advantage of quantity discounts to provide a package of high-performance components for the best value. The kit includes construction documents, custom climate and site analysis, triple-pane windows and doors, airtight tapes, foundation foam raft, heat recovery ventilator, photovoltaic system, solar hot water system, and guidance to purchase local items like lumber and cellulose insulation. NewenHouse includes other high quality and sustainable features such as FSC certified wood, low-VOC materials, recycled and salvaged interior components, energy efficient appliances/lighting, vegetative roof at porch, rain collection system for irrigation, and edible landscape design.
1775 total sq. feet
33 kBtu(sqft.yr) 104 kWh(sqm.yr) pEUI source before PV
12.6 kBtu(sqft.yr) 40 kWh(sqm.yr) pEUI site before PV
3.8 kBtu(sqft.yr) 12 kWh(sqm.yr) space heat demand
0.51 ACH50 pressurization test
R-60 0.094 W(sqm.k) wall
R-94 0.060 W(sqm.k) roof
R-57 0.100 W(sqm.k) slab foundation
R-4 1.31 W(sqm.k) window frame
R-8 0.75 W(sqm.k) window glass
92% heat recovery efficiency
Certified Passive House (PHI-Germany)
LEED for Homes
Int’l Passive House Conference Lecture - 2012
© 2011 COULSON