The Ranch – EnerPHit Renovation Step 1

  • EnerPHit   •   July 9, 2019

Recap of the first step of our step-by-step Passive House renovation project.

Comfort, or rather lack thereof in large parts of the house during winter time was the main driver to start with these first renovation measures. Here is a quick rundown on the previous comfort situation, and relevant building assemblies and systems.

Building Assemblies and Systems  – before –

Very leaky

During Blowerdoor testing I could not even pressurize house to 50 PA. House has a vented gas dryer, 2 fireplaces (one without damper), many cracks and openings around  incoming pipes. After all things considered I calculated an air change per hour of 18! Passive House requirement for retrofits is 1.0 ACH. We have a VERY long way to go but also many opportunities to get there over time.

No wall insulation

Wall was original 1948 construction with 8″ hollow concrete blocks with rebar inside and a few layers of paint on the in- and outside. Insulation value: NONE

With the exception of the addition, which was build with 91/2″ monolithic hempcrete walls. Insulation value: R21

Various levels of roof insulation

In some areas insulation has never been replaced; in some areas it was replaced or added on but installed improperly (gaps between rigid insulation, missing pieces and different thicknesses). Again with the exception of the addition. A 9″ denim batt insulation was installed (properly) in the cathedral ceiling below the roof.

Slab on grade concrete floor

The concrete floor does not have any insulation at the outside edge or underneath. The slab also extends to the outside veranda, breezeway and other concrete extensions 3/4 around the whole house. Huge thermal bridges!

Cast-iron bathtubs on 2 outside bathroom walls

Each of the original bathtubs was installed on the outside wall with no wall insulation and no insulation beneath. They literally sit on the dirt. Huge thermal bridges!

No high performance windows

Standard double glazed windows provide different grades of performance due to different levels of code requirements at time of installation. Windows are not airtight enough and U-Value is too high to be considered high performance.

Veranda and overhangs

Besides the sliding doors in the addition all windows are equipped with deep enough overhang to avoid the sun reaching the glazing in summer. Half the house is enclosed with an 8′ veranda and the rest with 3′ overhangs. The sliding doors have 2′ overhangs and face south/west.

South/west facing sliders

The findoes and sliders in the south/west facing addition are only equipped with 2′ overhangs and only partially protected from the lower afternoon sun in the West.

If our architect for the additon would have had a  better understanding of building science and would have created a sun study in Revit or SketchUp, the solar heat gain in the addition could have easily been avoided.  Unfortunately back then I didn’t not know either. We could have avoided this issue by asking better questions before we hired our architect. 

Very cool and comfortable during summer

Cooling was practically not needed. If we would spend time in our addition in the afternoon we might turn on the air-conditioning on for a couple of hours when the sun hits the sliding doors that time of the day on a very hot summer day (>90°F).

What makes our house so comfortable during summer?

  • Besides the sliding doors in the addition all windows are equipped with deep enough overhang to avoid the sun reaching the glazing in summer. Half the house is enclosed with an 8′ veranda and the rest with 3′ overhangs. The sliding doors have 2′ overhangs and face south/west.
  • Slab on grade concrete floors throughout the house stay cool no matter what temperature outside. The slab floor does not have any insulation at the outside edge or underneath. The slab also extends to the outside veranda, breezeway and other extensions 3/4 around the whole house.

 he would have designed the overhang a foot deeper. That way   reason to start with he most important initial in goals for this first step was to  for House is uncomfortably cold in the winter time without enough heating available. The back of the house is especially cold during these colder months. This area includes bed- and bathrooms as well as Bern’s office.
Bern works mostly from home and needs to run an electric heater when it gets too cold in his office. We also run electric heaters in the bathrooms. Without heating, bath towels won’t dry during cold days and nights. I often take towels after we showered and let them dry in the warmer living room, of course I forget to put them back before I take my next shower…
I let our mini split run all day during cold periods in the front of the house where I work. Due to the open floorplan of our house the heat spread unevenly and creates hot and cold spots, especially in the evening.
We have slab on grade, concrete floors throughout the house, which are uncomfortably cold during the wintertime

  • Live in a comfortable, healthy home with minimal mechanical systems to cool, heat and ventilate our home.
  • Reduce our need for power to run our home, cars and activities to a minimum, without changing our lifestyle, rather improve it.
  • Power our home, cars and activities without burning fossil fuel.
  • Have the option to be independent of the utility provided grid voluntarily or in case of a grid-power outage.
  • Be more aware of our impact on the environment – eliminate the negative and increase the positive.
  • Multiply the outcome by educating others. 

Since we do not tear down our existing house and build a new one, but rather modernize, we are already off to a good start minimizing waste, CO2 output and disturbance of native wildlife and plants around our home. On the other hand this means we have to find solutions for existing performance flaws of our 70 year old house to reach our goal.

Educating myself in building science, green building standards, as well as talking with many experienced industry professionals I concluded that only a whole-building approach will enable us to accomplish our goals of energy efficiency, comfort and will support a more positive impact on our environment.

Recap of the first step of our step-by-step Passive House renovation project.

Comfort, or rather lack thereof in large parts of the house during winter time was the main driver to start with these first renovation measures. Here is a quick rundown on the previous comfort situation, and relevant building assemblies and systems.

Building Assemblies and Systems  – before –

Very leaky

During Blowerdoor testing I could not even pressurize house to 50 PA. House has a vented gas dryer, 2 fireplaces (one without damper), many cracks and openings around  incoming pipes. After all things considered I calculated an air change per hour of 18! Passive House requirement for retrofits is 1.0 ACH. We have a VERY long way to go but also many opportunities to get there over time.

No wall insulation

Wall was original 1948 construction with 8″ hollow concrete blocks with rebar inside and a few layers of paint on the in- and outside. Insulation value: NONE

With the exception of the addition, which was build with 91/2″ monolithic hempcrete walls. Insulation value: R21

Various levels of roof insulation

In some areas insulation has never been replaced; in some areas it was replaced or added on but installed improperly (gaps between rigid insulation, missing pieces and different thicknesses). Again with the exception of the addition. A 9″ denim batt insulation was installed (properly) in the cathedral ceiling below the roof.

Slab on grade concrete floor

The concrete floor does not have any insulation at the outside edge or underneath. The slab also extends to the outside veranda, breezeway and other concrete extensions 3/4 around the whole house. Huge thermal bridges!

Cast-iron bathtubs on 2 outside bathroom walls

Each of the original bathtubs was installed on the outside wall with no wall insulation and no insulation beneath. They literally sit on the dirt. Huge thermal bridges!

No high performance windows

Standard double glazed windows provide different grades of performance due to different levels of code requirements at time of installation. Windows are not airtight enough and U-Value is too high to be considered high performance.

Veranda and overhangs

Besides the sliding doors in the addition all windows are equipped with deep enough overhang to avoid the sun reaching the glazing in summer. Half the house is enclosed with an 8′ veranda and the rest with 3′ overhangs. The sliding doors have 2′ overhangs and face south/west.

South/west facing sliders

The findoes and sliders in the south/west facing addition are only equipped with 2′ overhangs and only partially protected from the lower afternoon sun in the West.

If our architect for the additon would have had a  better understanding of building science and would have created a sun study in Revit or SketchUp, the solar heat gain in the addition could have easily been avoided.  Unfortunately back then I didn’t not know either. We could have avoided this issue by asking better questions before we hired our architect. 

Very cool and comfortable during summer

Cooling was practically not needed. If we would spend time in our addition in the afternoon we might turn on the air-conditioning on for a couple of hours when the sun hits the sliding doors that time of the day on a very hot summer day (>90°F).

What makes our house so comfortable during summer?

  • Besides the sliding doors in the addition all windows are equipped with deep enough overhang to avoid the sun reaching the glazing in summer. Half the house is enclosed with an 8′ veranda and the rest with 3′ overhangs. The sliding doors have 2′ overhangs and face south/west.
  • Slab on grade concrete floors throughout the house stay cool no matter what temperature outside. The slab floor does not have any insulation at the outside edge or underneath. The slab also extends to the outside veranda, breezeway and other extensions 3/4 around the whole house.

 he would have designed the overhang a foot deeper. That way   reason to start with he most important initial in goals for this first step was to  for House is uncomfortably cold in the winter time without enough heating available. The back of the house is especially cold during these colder months. This area includes bed- and bathrooms as well as Bern’s office.
Bern works mostly from home and needs to run an electric heater when it gets too cold in his office. We also run electric heaters in the bathrooms. Without heating, bath towels won’t dry during cold days and nights. I often take towels after we showered and let them dry in the warmer living room, of course I forget to put them back before I take my next shower…
I let our mini split run all day during cold periods in the front of the house where I work. Due to the open floorplan of our house the heat spread unevenly and creates hot and cold spots, especially in the evening.
We have slab on grade, concrete floors throughout the house, which are uncomfortably cold during the wintertime

  • Live in a comfortable, healthy home with minimal mechanical systems to cool, heat and ventilate our home.
  • Reduce our need for power to run our home, cars and activities to a minimum, without changing our lifestyle, rather improve it.
  • Power our home, cars and activities without burning fossil fuel.
  • Have the option to be independent of the utility provided grid voluntarily or in case of a grid-power outage.
  • Be more aware of our impact on the environment – eliminate the negative and increase the positive.
  • Multiply the outcome by educating others. 

Since we do not tear down our existing house and build a new one, but rather modernize, we are already off to a good start minimizing waste, CO2 output and disturbance of native wildlife and plants around our home. On the other hand this means we have to find solutions for existing performance flaws of our 70 year old house to reach our goal.

Educating myself in building science, green building standards, as well as talking with many experienced industry professionals I concluded that only a whole-building approach will enable us to accomplish our goals of energy efficiency, comfort and will support a more positive impact on our environment.

By whole-building approach I mean to look at all building assemblies and systems and their interdependences. Conventional modernization focuses on isolated systems and assemblies without any regard to the impact that singular renovation might have on other assemblies and systems and the performance of a building as a whole.

I also concluded that the Passive House Standard is the best guidance for a whole-building appraoch and ergo our retrofit project. Following the Passive House Standard will facilitate that designed solutions and construction practices will transfer into the intended improvements and goals as stated above. In addition we are using other green building Standards as guidelines.

The Passive House Institute has developed the Passive House Standard through extensive research in building physics and monitoring of thousands of Passive House projects and has withstood testing of performance for over 25 years.

Passive House is a whole-building design and construction concept that can be applied by anyone in any climate around the world.  The Passive House Standard is the world leading standard in energy efficient construction; and it is way more than just a concept to build low-energy buildings. Passive House is a building standard that achieves ultra energy efficient, comfortable, affordable, durable and ecological buildings, regardless of the regional climate.

The Passive House Institute has assumed a leading position with regard to research and development of construction concepts, building components, planning tools and quality assurance for especially energy efficient buildings since it started in 1990.

Based on the Passive House Standard for new buildings, the Passive House Institute has developed a step-by-step methodology called EnerPHit to modernize existing buildings to become ultra-energy efficient and more comfortable in a cost effective way.

EnerPHit by Passive House Institute is going to be our compass, road map and guide to achieve our goals. You can read more about the concept here –> EnerPHit

In the next journal entry I will provide a short overview of the first step of our step-by-step Passive House renovation project.

Here are a few images of the first step of our Passive House renovation project. More details will follow about our path to fossil free living.

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