Thursday, September 29, 2011
Back Story
I owe a lot of you an explanation for the long delay in getting this post started. The design process was much more complicated than I ever imagined, and the flip-flops I made in the decision process would have driven you all mad. My respect for my Architect friends has risen dramatically. Tomorrow morning we begin excavating for the footings. This entry will detail some of the process we went through to get to this point.
The mission began when our last child graduated from college, and we began to look to downsize our living accommodations. We have lived in the city of Grand Rapids since the late 70's, and as nature lovers were looking for some land with a little elbow room. After about a year of searching we found a five acre parcel that suited our needs.
All of the New Urbanists are groaning now, but my office is in the home, and my wife's commute is about the same duration. We did ourselves no favors as far as the LEED site selection criterion are concerned, but the life style was of greater importance to us. We now have room for a garden, and will enjoy wildlife and wildflowers right outside our living room window.
Our goal is to build a LEED Platinum home, and at least on paper we are on track to build a home in the 110 point range which is well into the Platinum rating. I will share more on specific strategies in future blogs.
We were also interested in pursuing the German Passive House (PH) energy standard which is based on the Superinsulated homes built in the US in the 1970's. To that end we experienced a large learning curve in designing to meet the PH standards. We hired a consultant to help us through the calculations, and ended up with a design that did meet the requirements, but in the final analysis we chickened out. We had too many conflicting requirements that put PH out of reach for us.
The primary conflict was in our determination to design a barrier free home to meet our eventual needs in retirement. The obvious barrier free design solution is to construct a single story building, which is accompanied by wider corridors, doors, and more circulations space. That building geometry is not very efficient in the ratio of floor area to surface area. We compensated for these challenges by making the building envelope extremely efficient.
The cost to do this was not excessive overall with the common building components. We designed the walls with an R value of 68, the ceilings at R 90 via 30" raised heel trusses, underslab and basement wall insulation is at R30. Those design elements have a very low incremental cost over a code designed building on a square foot basis.
The significant energy loss in a well insulated home is in the window design. There was only one manufacturer in the world that made a window sufficiently well designed to make the PH energy model work. The cost of that window over the next best performing window was over $25,000, and provided a projected annual energy savings of only $145 per year. The energy efficiency of the alternate window is not sufficient to meet the PH standard.
A second conflict was our long term desire to have a marketable home should we need to sell. The life style of owning a PH home is something we would have willingly accommodated fifteen years ago. Now thermal comfort has a greater priority, and the market for the PH lifestyle is very limited in this area. We wanted to strike a balance between thermal comfort and passive survivability a hallmark of PH design. The less expensive window provided room in the budget for a ground source heat pump at the expense of Passive House Certification.
We also wanted to build a Net-Zero home. Our vision is to use no fossil fuels for the life of the building. I have been a fan of Uni-Solar thin film photovoltaic (PV) panels for a number of years for several reasons. The light weight means we don't require additional structural members, the amorphous silicon makes it impact resistant, operate in cloudy conditions, and provides the aesthetic we were looking for. We will be integrating the PV panel with a standing seam metal roof and will grid tie the panels with a net-metering plan.
Durability was also high on the list. Our last home had 100 year old cement stucco that looked great, and we are duplicating it on this home. We are installing the standing seam metal roof. We are using concrete floors to serve as the finish floor and to act as part of the passive solar system. They will contain a hydronic radiant floor heating and cooling system. The basement is covered with a precast concrete plank to provide a clear span and add to the thermal mass.
There is a whole lot of research to be done on materials for a project like this. I can't tell you how many hours I have burned on internet research. I get very helpful pop-ups months after I have made my material selections.
I hope you will enjoy tagging along on this journey as I log in what we are doing every week. I have a time lapse video camera set up on the site, and I will post progress periodically. Grand Valley State University, and the Alliance for Environmental Sustainability (AES) have teamed up to do a video documentary. We shot the first piece last week. I plan to put together a case study to put on the USGBC website when this is done, and I have already been asked to talk about it at a Chapter event soon.
Oh, yeah. The secret to warming a Passive House is to throw a wine and cheese party. We will be having a house warming party some time in April or May, so keep tuned.
The mission began when our last child graduated from college, and we began to look to downsize our living accommodations. We have lived in the city of Grand Rapids since the late 70's, and as nature lovers were looking for some land with a little elbow room. After about a year of searching we found a five acre parcel that suited our needs.
All of the New Urbanists are groaning now, but my office is in the home, and my wife's commute is about the same duration. We did ourselves no favors as far as the LEED site selection criterion are concerned, but the life style was of greater importance to us. We now have room for a garden, and will enjoy wildlife and wildflowers right outside our living room window.
Our goal is to build a LEED Platinum home, and at least on paper we are on track to build a home in the 110 point range which is well into the Platinum rating. I will share more on specific strategies in future blogs.
We were also interested in pursuing the German Passive House (PH) energy standard which is based on the Superinsulated homes built in the US in the 1970's. To that end we experienced a large learning curve in designing to meet the PH standards. We hired a consultant to help us through the calculations, and ended up with a design that did meet the requirements, but in the final analysis we chickened out. We had too many conflicting requirements that put PH out of reach for us.
The primary conflict was in our determination to design a barrier free home to meet our eventual needs in retirement. The obvious barrier free design solution is to construct a single story building, which is accompanied by wider corridors, doors, and more circulations space. That building geometry is not very efficient in the ratio of floor area to surface area. We compensated for these challenges by making the building envelope extremely efficient.
The cost to do this was not excessive overall with the common building components. We designed the walls with an R value of 68, the ceilings at R 90 via 30" raised heel trusses, underslab and basement wall insulation is at R30. Those design elements have a very low incremental cost over a code designed building on a square foot basis.
The significant energy loss in a well insulated home is in the window design. There was only one manufacturer in the world that made a window sufficiently well designed to make the PH energy model work. The cost of that window over the next best performing window was over $25,000, and provided a projected annual energy savings of only $145 per year. The energy efficiency of the alternate window is not sufficient to meet the PH standard.
A second conflict was our long term desire to have a marketable home should we need to sell. The life style of owning a PH home is something we would have willingly accommodated fifteen years ago. Now thermal comfort has a greater priority, and the market for the PH lifestyle is very limited in this area. We wanted to strike a balance between thermal comfort and passive survivability a hallmark of PH design. The less expensive window provided room in the budget for a ground source heat pump at the expense of Passive House Certification.
We also wanted to build a Net-Zero home. Our vision is to use no fossil fuels for the life of the building. I have been a fan of Uni-Solar thin film photovoltaic (PV) panels for a number of years for several reasons. The light weight means we don't require additional structural members, the amorphous silicon makes it impact resistant, operate in cloudy conditions, and provides the aesthetic we were looking for. We will be integrating the PV panel with a standing seam metal roof and will grid tie the panels with a net-metering plan.
Durability was also high on the list. Our last home had 100 year old cement stucco that looked great, and we are duplicating it on this home. We are installing the standing seam metal roof. We are using concrete floors to serve as the finish floor and to act as part of the passive solar system. They will contain a hydronic radiant floor heating and cooling system. The basement is covered with a precast concrete plank to provide a clear span and add to the thermal mass.
There is a whole lot of research to be done on materials for a project like this. I can't tell you how many hours I have burned on internet research. I get very helpful pop-ups months after I have made my material selections.
I hope you will enjoy tagging along on this journey as I log in what we are doing every week. I have a time lapse video camera set up on the site, and I will post progress periodically. Grand Valley State University, and the Alliance for Environmental Sustainability (AES) have teamed up to do a video documentary. We shot the first piece last week. I plan to put together a case study to put on the USGBC website when this is done, and I have already been asked to talk about it at a Chapter event soon.
Oh, yeah. The secret to warming a Passive House is to throw a wine and cheese party. We will be having a house warming party some time in April or May, so keep tuned.
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