The Fruits of Labor: Gut-Rehabbing the Structure and the Lot

Portland, OR

May 31 2010 By Peter Yost | 4 comments

General Specs and Team

Location: Portland, OR
Bedrooms: 3
Bathrooms: 2.5
Living Space : 2000 sqf
Cost (USD/sq. ft.): $65/sqf

Completed: March 2010
NOTE: Square foot cost would likely double to reflect true labor costs.

Remodeler: Dan Cote, Planted Earth Sustainable Consulting

Construction

Foundation: Basement; new, sistered, strongback foundation section (to handle the lack of footer); medium-density spray-foam insulation (Froth Pak)
Walls: 2x4 studs at 16 inches on-center; exterior 1.5-inch XPS plus closed-cell foam cavity insulation (R-27)
Roof: 4x4 (plywood gusset sandwich) rafters at 16 inches on-center; 30-year shingles; unvented; closed-cell foam insulation (R-25, SWD Urethane)
Windows: low-e wood-clad (SHGC=0.24; U-factor=0.38)
Garage: none

Water Efficiency

  • Toilets: 1.6 gpf with tank retrofit
  • Faucets: 1.5 gpm (original faucets with aerators)
  • Showerheads: 1.0 gpm

Indoor Air Quality

  • Spray foam insulation (formaldehyde- and VOC-free)
  • Fresh air ventilation system: ERV (basement and first floor; timed high-efficiency exhaust second floor)
  • Low-VOC caulks and adhesives
  • Low-VOC paints
  • Re-purposed, original finish cabinetry stock

Green Materials and Resource Efficiency

  • Rigid XPS insulation: reused/salvaged, purchased online
  • Durable, low-maintenance floors throughout: tile, slate, refinished Douglas fir
  • Retained most of original framing
  • 75% of construction waste recycled

A building consultant practices what he preaches by retrofitting his home for healthy and productive living

When Dan Cote bought this run-down property on Woodstock Avenue in Portland, he wanted to take everything he had learned about high-performance building and building science from his day job as a technician and consultant for Conservation Services Group and pack it into the structure and the lot. He pretty much lived in the middle of his work for the next several years.

Beauty and building science
Perhaps the most striking aspect of Dan's project is how well he has combined all the technical details with a truly beautiful home, inside and out. From color schemes to flashing details, from plant selection to thermal bypasses, Dan's home and lot show both right and left brain prowess.

On the outside, Dan dreamed up the eave-overhang green roof. "I spent a lot of time looking at my beautiful secondhand Doug fir doors out back, wondering how I could protect them without an overhang so low that it becomes all that you see," Dan relates. "In the end, I decided, why fight it; do something attractive on the overhang." The result is planter boxes full of hardy sedums, minimally attached and flashed in such a way that it does not affect the water management capacity of the roof. "The overhang is a stepped-down add-on to the roof, completely separate. I used a self-healing membrane on the overhang, gooped [sealed] each of the six fasteners securing the planters, and then left the soffit open to dry readily."

On the inside, Dan's big thing is durable, low-maintenance floor surfaces. "I really liked the pre-finished bamboo because it is a rugged, low-maintenance material, but I thought the kitchen needed something a bit more interesting as well," says Dan. With a box full of tile odds and ends, Dan began planning a mosaic right in the center of the kitchen floor. Dan chuckles: "It was like doing a puzzle without the picture on the box."

Dealing with a "hammock" roof
It is not uncommon for the rafters in old bungalows like Dan's to be grossly undersized. His rafters were rough-cut 2x4s that sagged nearly two inches in the center. Dan got all but about 3/8 of an inch back in two ways: having each rafter bear directly on the new knee-wall studs (reducing the length of the rafter runs) and sistering both sides of each rafter with plywood gussets.

A tough flashing detail at the bathroom corner window
Dan's downstairs bathroom has a nifty two-window corner off the back side of the house. The problem is that the back window on the corner is less than a foot from where the back addition roof intersects the main part of the house. This meant that getting the water-resistive barrier and window flashing details and interconnection right was critical for water management. Dan said, "With the housewrap interior to the exterior rigid foam insulation, it was pretty easy to tie the window flashing and WRB together. Then tucking the kick-out flashing behind the step flashing, which were tucked under the WRB, sealed the deal." Dan mocked all this up ahead of time, including a change in exterior cladding just above this window, to make sure he had it right when the window and housewrap were installed.

"Habitat for Hu-Dan-ity"
So Dan really did all this work in his spare time? Not entirely; Dan is a creative guy and conjured up his "Habitat for Hu-Dan-ity" work crew. You invite your best and most loyal friends over for beer, barbecue, and building. It's sort of a dude ranch for building science; Dan gets a bunch of free labor and they all get some on-the-job training they can use on their own projects. This explains quite a bit about how low Dan's cost per square foot is for this gut rehab. Dan scratches his chin and adds, "I suspect that my total project cost might double if we factor in the real labor costs."

Urban agriculture
Dan's lot is as high performance as his home: about 1,000 square feet of his 7,500-square-foot lot is raised beds of vegetables and fruits:

The raised beds are elevated by at least six inches of local compost and top soil so that Dan essentially is growing above (not in) the untested urban soil below.

Lessons Learned

The main lesson learned for Dan was about the insulation package for the exterior wall assembly. "I used closed-cell spray foam in the wall cavities, and THEN learned the advantages of warming the cavity with rigid exterior insulation," quips Dan. "If I could do it over again, I would definitely use a loose insulation such as cellulose for the cavity fill, and go with the taped rigid as my exterior air barrier."


Peter Yost

Tags: , , , , , ,

Image Credits:

  1. Dan Cote

1.
Thu, 06/03/2010 - 10:19

Your foam board should go all
by Anonymous

Your foam board should go all the way down and then a 1x furred over it at the roof line and a z flashing over the the 1x which has been felted and step flashed already.


2.
Wed, 06/23/2010 - 08:09

foam board detail
by Peter Yost

Thanks for your comment, but could you try again?

Just not sure what you are saying:

1. the foam board should go all the way down to where? In the photos, the foam board goes down to the basement level, where the insulation and air sealing switches to the interior of the basement.
2. 1-by furred over at roof line with z-flashing and step flashing? does this comment refer to the gable end photo where it meets the adjoining roof? Please take another crack at your recommendation.


3.
Sun, 09/19/2010 - 17:34

Materials
by Robalee

What materials did you use to build the front porch? Thanks, Robalee


4.
Mon, 09/20/2010 - 07:30

Materials porch products - rebuild
by Dan

Thanks for your question. For the structural support, I used locally treated PT for all the framing and posts. I had to completely rebuild the structure as it was rotten to the core. Based on our local code I had to use PT and re-pour all the footings. The deck joists are 2x8 and run left to right @12”o.c. The joists are supported by flush mounted double 2x8 on the ends of the porch and dropped double 2x8 in the middle. The dropped beams are tied into the two posts spaced equally apart in the middle. Dropping the middle two beams kept me from having to use additional hangers and saved a few bucks. I used scrap 2x8 to block the joists over the beams. The flooring is probably one of the questionably "green" products in that it is South American sourced "Mahogany". I have issues with the other options though; PT decking in my opinion does not hold up, local cedar can be found as FSC, but I just don't find it durable enough for the traffic a porch gets. The composite options in my opinion have their own pros and cons as well. The mahogany material is very hard, and durable. I have had it down for 3 years now and it is still in great shape. It takes the weather very well and has a silvery grey tone as it ages. In Portland I get wetting from wind blown rain a good 2 feet into my porch and this product just endures. So yes it is imported but my compromise is that it will be durable and thus last many more years than other options. I'm sure all this can be debated but this is how I justify it so I can sleep at night... Thanks for your question. Dan


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