Above: An old 19th c house with many additions burning $5,800 worth of fuel oil a year. What to do??
Green Retrofits Case Studies
The case studies listed below are downloadable PDF documents. Just click on the blue letters to access the document of interest. Many of us who own older homes are not in a position financially or otherwise to build our dream eco-house. In selecting our current home location we have optimized on a number of factors such as affordability; proximity to work, schools, family and friends; and neighborhood amenities. The challenge we face is living more lightly where we are -- making our current home more energy efficient, and modifying our behavior and purchasing choices to live more green.
In the following case studies, taken from analyses of our own home and those of our clients, we lay bare some principles, elements and findings you might consider in retrofitting your own home (and lives). We consider the following cases:
Case Study 1: Solar Retrofits. The newly-forming Ahimsa Village Community sought ways to "go solar". In this case study, we take you through the steps of conducting a site visit, preparing a site map, conducting a simple analysis of solar access, and share our observations on the feasibility of retrofitting their old farmhouse to make use of the available solar energy. The focus is primarily on solar hot water heating for either domestic hot water or some measure of space heating.
Case Study 2: Using Payback. It would be great if we could all have new, properly-constructed eco-homes, but the reality is that most of us are in older homes and can at best afford to consider retrofitting our homes. "What's worth doing?" is the most frequently asked question. For most of us, our biggest energy consumption arises from heating or cooling our homes. How can we lessen our dependence on the fossil fuel treadmill? Payback analysis can guide us in our decision-making and is valuable especially to most of us who do not have deep pockets....
Case Study 3: Old House Retrofit. Historic homes are wrought with additional retrofit challenges: one generally cannot alter either the stone or brick facade or the plaster-walled interiors without compromising the historic features. However, heating a largely uninsulated structure with oil when the price rose to ~$4/gallon provided great motivation to look into doing something! In this case study we share our analysis of one classic historic home and various options the owner might consider to pursue.
Case Study 4: R-Values and Wall Retrofits. While new construction boasts walls with R-values in excess of 25 and roof insulation on the order of 35, most homes that exist have very poor insulation, if at all! How does one determine the R-value of a wall? This case study provides an example of how we analyzed the R-value of a wall for different constructions that enabled us to determine how best to retrofit two different walls. You may use this as a guide to get you started on analyzing your own walls.
Case Study 5: Solar Hot Air Collectors. There are many advantages of solar hot air collectors over solar hot water collectors: they are more lightweight; there is no liquid that can freeze, burst or otherwise make a mess; there is no need for tanks or other complexities. The sun shines on your wall or roof and the hot air collector mounted there provides a dark, heat-absorbing surface that delivers warm air directly to your home or building. This case study summarizes our experience in investigating, and testing solar hot air collector designs, ultimately constructing one.
Case Study 6: Greenhouse Design. Attaching a greenhouse to a south-facing wall gives many advantages: protection from the elements, thermal storage in the house wall, attachment of greenhouse to a solid wall, easy and nearby access. In this analysis we helped a local resident think through the solar angles and floor layout of her greenhouse.
Case Study 7: Summary of Neo-Terra Home Retrofits (2012) In July 2012 we were on the League of Women Voters Green Homes and Gardens Tour. We created four large posters for visitors, and have posted these here as pdf documents. These posters summarize 12 years of retrofits, including insulation, active solar (hot water and hot air), geothermal heat pump, and high performance windows. Click on the pdfs below to open, you can enlarge/reduce using the + - signs in the tool bar:
Poster 1 - Retrofits Payback and Insulation
Poster 2 - East & South Walls
Poster 3 - Solar Insolation
Poster 4 - Geothermal
Watch here for additional case studies to be added!
In the following case studies, taken from analyses of our own home and those of our clients, we lay bare some principles, elements and findings you might consider in retrofitting your own home (and lives). We consider the following cases:
- An active solar retrofit (Feb. 2008)
- Using payback to order projects (Updated Feb. 2011)
- Retrofitting an historic house (July 2008)
- Calculating wall R values (Oct. 2008)
- Assessing the payback of a hot air collector (Nov. 2008)
- Summary of Neo-Terra Home Retrofits (2012)
Case Study 1: Solar Retrofits. The newly-forming Ahimsa Village Community sought ways to "go solar". In this case study, we take you through the steps of conducting a site visit, preparing a site map, conducting a simple analysis of solar access, and share our observations on the feasibility of retrofitting their old farmhouse to make use of the available solar energy. The focus is primarily on solar hot water heating for either domestic hot water or some measure of space heating.
Case Study 2: Using Payback. It would be great if we could all have new, properly-constructed eco-homes, but the reality is that most of us are in older homes and can at best afford to consider retrofitting our homes. "What's worth doing?" is the most frequently asked question. For most of us, our biggest energy consumption arises from heating or cooling our homes. How can we lessen our dependence on the fossil fuel treadmill? Payback analysis can guide us in our decision-making and is valuable especially to most of us who do not have deep pockets....
Case Study 3: Old House Retrofit. Historic homes are wrought with additional retrofit challenges: one generally cannot alter either the stone or brick facade or the plaster-walled interiors without compromising the historic features. However, heating a largely uninsulated structure with oil when the price rose to ~$4/gallon provided great motivation to look into doing something! In this case study we share our analysis of one classic historic home and various options the owner might consider to pursue.
Case Study 4: R-Values and Wall Retrofits. While new construction boasts walls with R-values in excess of 25 and roof insulation on the order of 35, most homes that exist have very poor insulation, if at all! How does one determine the R-value of a wall? This case study provides an example of how we analyzed the R-value of a wall for different constructions that enabled us to determine how best to retrofit two different walls. You may use this as a guide to get you started on analyzing your own walls.
Case Study 5: Solar Hot Air Collectors. There are many advantages of solar hot air collectors over solar hot water collectors: they are more lightweight; there is no liquid that can freeze, burst or otherwise make a mess; there is no need for tanks or other complexities. The sun shines on your wall or roof and the hot air collector mounted there provides a dark, heat-absorbing surface that delivers warm air directly to your home or building. This case study summarizes our experience in investigating, and testing solar hot air collector designs, ultimately constructing one.
Case Study 6: Greenhouse Design. Attaching a greenhouse to a south-facing wall gives many advantages: protection from the elements, thermal storage in the house wall, attachment of greenhouse to a solid wall, easy and nearby access. In this analysis we helped a local resident think through the solar angles and floor layout of her greenhouse.
Case Study 7: Summary of Neo-Terra Home Retrofits (2012) In July 2012 we were on the League of Women Voters Green Homes and Gardens Tour. We created four large posters for visitors, and have posted these here as pdf documents. These posters summarize 12 years of retrofits, including insulation, active solar (hot water and hot air), geothermal heat pump, and high performance windows. Click on the pdfs below to open, you can enlarge/reduce using the + - signs in the tool bar:
Poster 1 - Retrofits Payback and Insulation
Poster 2 - East & South Walls
Poster 3 - Solar Insolation
Poster 4 - Geothermal
Watch here for additional case studies to be added!
Below: Installing retrofitted solar hot water collectors on our roof with our team
