The Greenest Building is the One Already Built
"Preservation saves energy by taking advantage of the nonrecoverable energy embodied in an existing building and extending the use of it"
- ASSESSING the ENERGY CONSERVATION BENEFITS of HISTORIC PRESERVATION: Methods and Examples, Advisory Council on Historic Preservation.
EMBODIED ENERGY CALCULATOR: Survey Model
More advanced than the concept model, this requires a rough survey of nine building materials.
To use the calculator, begin by choosing your property type from the box on the left.
In the box labeled gross floor area enter your building's total square footage.
Next enter the quantity of each material. Click calculate to get the amount of total energy embodied.
ABOUT THIS PAGE
In the survey model, the sum of all 9 (the report shows seven, combining brick and concrete as well as glass) material
categories is multiplied by a factor of 1.4. As the ACHP report explains,
"The surveyed materials account for about 50% of the total embodied energy of building construction. The surveyed materials
do not include 'misc. plastics; paving; non-ferrous wire; mechanical, plumbing, and electrical equipment and fixtures;
sheet metal work; metal doors and plate work; misc. and architectural metalwork.' and many other items which do not,
individually, contribute significantly to the total embodied energy." In the survey model, materials account for 70%
of the total embodied energy. The energy used in construction--floor area multiplied by the invested construction energy--is
added to the energy invested in materials in the final calculation. The values for each building type are presented
to the right, with the values for materials below, as published in the ACHP report.
|Energy Embodiment of Primary Materials|
|Material Category||Embodied Energy per |
|Wood Products||9000 BTU/BDFT|
|Paint Products (450sf/gal.)||1000 BTU/sq. ft.|
|Asphalt Products||2000 BTU/sq. ft.|
|Glass Products: Windows||15000 BTU/sq. ft.|
|Glass Products: Plate||40000 BTU/sq. ft.|
|Stone & Clay Products: Concrete ||96000 BTU/cf|
|Stone & Clay Products: Brick||400000 BTU/cf|
|Primary Iron & Steel Products||25000 BTU/lb|
|Primary Non-Ferrous Products||95000 BTU/lb||
|Energy Embodiment of Construction|
|Building Construction Type|| MBTU/sq.ft.|
|Residential – Single Family||90|
|Residential – 2-4 Family||100|
|Residential – Garden Apartment ||120|
|Residential – High Rise||150|
|Other Nonfarm Buildings||310|
|a. Amusement, Social & Rec.||300|
|b. Misc Nonresidential Bldg.||240|
|d. Libraries, Museums, etc.||380|
If you'd like to learn more, click here to download
ASSESSING the ENERGY CONSERVATION BENEFITS of HISTORIC PRESERVATION: Methods and Examples.
This report, published in 1979, forwarded the concept of embodied energy.
The calculations published are based on new buildings constructed in 1967.
Energy embodiment of primary materials comes from "Energy Use for Buildings," December 1976. These figures
are being used here because they are the only identified database of embodied energy information.
As we're told, there is no contemporary equivalent, but people are working on it (why not you?!).
What we gain from using the '79 report is a raw figure that helps us find what's been called the
"avoided embodied energy" that would be needed to construct a new building
(and if we're talking preservation, we're largely talking about buildings before 1967).
* ASSESSING the ENERGY CONSERVATION BENEFITS of HISTORIC PRESERVATION: Methods and Examples, Advisory Council on Historic Preservation.
We got our copy of this report by joining the National Trust Forum.
The National Trust's Sustainability Initiative is the best source on the web for green preservation.
We recommend their Green Home Tips. Learn more with sustainability
news, research and case studies. And read
the article that started it all, Carl Elefante's "The Greenest Building Is...One that is Already Built," from the Summer 2007
More links? Visit our blog: The Greenest Building is the One Already Built
Read more about embodied energy in Australia's "Your Home Technical Manual"
May T. Watts
AT gmail DOT com