Sustainable Remodeling for Houses

By Alan Ness, Principal, Ten Directions Design

This is an overview of Sustainable Remodeling, based on over 25 years of experience. This is a broad area with many subjects worthy of their own lengthy and detailed talks. Luckily for you, I will be summarizing everything into 3 major points.


Why Sustainable Remodeling? You may have your own reason: weather disruption; deforestation, and loss of habitat; air and water pollution, etc. Providing for our needs and the needs of future generations. Energy costs may continue to rise, so this is a way of saving money over the long run. There are implications for oil addiction and national security.

From the Intergovernmental Panel on Climate Change 2018 Report: “…if greenhouse gas emissions continue at the current rate, the atmosphere will warm up by as much as 1.5 degrees Celsius above preindustrial levels by 2040, inundating coastlines and intensifying droughts and poverty. To prevent 1.5 degrees Celsius of warming, the report said, greenhouse pollution must be reduced by 45 percent from 2010 levels by 2030.”

Here are the three key points:

  1. Energy Efficiency;

  2. Sustainable Materials and

  3. Indoor Air Quality.

At the end I will summarize an approach to How To Get It Done.

Point One: Energy Efficiency.

Existing buildings make up one of the largest users of electricity and energy in our country. We need to cover the basics of making our existing homes and buildings energy efficient.

  1. Insulation levels - Can use cellulose/borate insulation or non-urea chopped fiberglass batt blown into walls. Code minimum levels: Roof R-49 (R-38 for sloped), Walls R-21, Floor R-30 above crawl space.

  2. Tightening the envelope: seal holes and cracks.

  3. Efficient heating: heat pumps: air or ground source: split-mini heat pumps; or high efficiency furnaces: 95% +

  4. Cool roofs (lighter colors) lower your cooling needs.

  5. Green roofs - add plants for reduce air temperature, storm water capacity, pollution and dust control.

  6. Highly insulated windows - A typical house loses 25% of heat through windows. But windows can get close to the insulation value of a solid wall - R-10 to R-20 (using triple-panes and/or 1 - 3 sheets of suspended film [see Alpen window brand]). Savings; comfort; reduce UV fading; noise reduction.

  7. Efficient lighting and appliances. LED = Light Emitting Diode. LED is 10% of CFL. Appliances like washing machines and refrigerators are now rated for you with the yellow tags in the store.

  8. Not-So-Big design (Example: new bungalows with smaller footprints <1000 SF). Just right sizing of living spaces.

  9. Our first Image of Green might be solar panels and wind turbines. But before we start with high-tech solutions, we need to accomplish these basics.

Point Two: Sustainable Materials.

We can start to specify materials that have high-recycle content, locally sourced, well-managed and renewable sources. Examples:

  1. Bamboo - example of fast-growing (up to 48 inches in 24 hours - can you see it grow?)

  2. FSC Wood - example of well-managed resources. Buildings use 25% of all wood. FSC wood is the highest level of sustainable certification with a "COC" Chain of Custody number for each stage of wood processing.

  3. Cork is harvested every 9 years without harm during the 200 year life of the tree.

  4. Locally produced (Seattle & Washington) 500 mile radius.

  5. Countertops: Paperstone is an example of countertops made from recycled paper plus a water-based petroleum-free resin. Novustone has a low-carbon concrete formulation. Squak Mountain has high-recycled content of glass and paper in the low-carbon substrate.

  6. Tiles: Local company Bedrock has glass tiles that are 100% recycled content.

  7. PET Carpet- example of recycled content. PET Carpet made from soft drink bottles (melted to the consistency of honey).

  8. Linoleum - example of low carbon foot print: based on LCA [Life Cycle Analysis]

  9. Salvage - example of reuse and recycled components. Construction related debris accounts for over 30% of all waste disposal in Seattle (more than our household garbage).

Point Three: Indoor Air Quality
(integral part of being green)

  1. New materials: no or low VOC, like paints and wood finishes. [VOC = volatile organic compounds]. Indoor pollution can make people sick - sometimes very seriously. In Washington DC, the EPA Headquarters had to remove all its carpeting due to sickening off-gases!

  2. Sources and their pathways: mold from moisture; dust and microbes and chemicals from air. We need to seal up the pathways that lead into our houses.

  3. Ventilation - properly done. (Dilution). Every exhaust needs of source of fresh clean air (kitchen, bath or whole house). Question: why seal up my house just to bring in outside air? We say: Insulate Tight & Ventilate Right. Use Heat Recovery System that saves heat before it is exhausted out.

  4. Air Cleaning- good filtration on your furnace. In my own house I have a pre-filter ($15) and a "basket" style HEPA filter ($187) - only needs changing every 5 years (no pets). And get your ducts cleaned as well.

How To Get It Done

Like a 3-legged tripod: you need all 3 members of your team to be on-board:

  1. Designer: should have training, familiarity with processes and materials, and knows where to find answers.

  2. Contractor: should be familiar and /or experienced with built-green programs, the energy star program; Passive House.

  3. Owner: should look at up-front cost versus life-cycle costs. You may want to pick a few areas where you initially spend a little more to get greater savings over time.


  1. Focus on energy efficiency

  2. Use sustainable materials when possible

  3. Don't neglect ventilation and indoor air quality

  4. Create a great team for a great project.