Costs and energy savings for new construction
Hatherly
| Posted in GBA Pro Help on
I’m meeting with the some people from our state’s CID next week to talk about the costs of energy efficiency upgrades for new construction for when you go above and beyond code. Does anyone know of a good current source that gives average cost to energy savings / payback analyses for different EE upgrades?
Thanks.
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Replies
Amanda,
These lists have been prepared often, and every list differs from the other lists. It's important to note that such lists are very climate-dependent. The best measures in Minnesota differ from the best measures in Florida. They are also dependent on the specifics of the house for which they are intended: a house with many windows will need different strategies than a house with few windows. Needless to say, energy savings depend on fuel type and energy costs, which change all the time.
Here is a list of measures considered in 2006 for a hypothetical new 2,592-square-foot home in Sacramento, California. This is a list of ALL measures cheaper than a photovoltaic array (in terms of energy savings per dollar invested). If all of these measures are implemented, the homeowners will see their energy use drop by 44%. The cost of implementing the measures is given in parentheses. (The list comes from an NREL study conducted by Ren Anderson, Craig Christensen, and Scott Horowitz.)
1. Upgrade walls from 2x4 studs filled with R-13 batts to 2x6 studs filled with R-19 batts plus 2-inch foam sheathing ($1,748)
2. Upgrade ceiling insulation from R-38 to R-60 fiberglass ($480)
3, Air sealing improvements ($1,408)
4. R-10 slab perimeter insulation ($1,371)
5. Energy Star refrigerator ($178)
6. Energy Star dishwasher ($89)
7. Energy Star clothes washer ($563)
8. Upgrade interior lighting to 100% CFL ($110)
9. Upgrade air conditioner from 13 SEER to 15 SEER ($450)
10. Credit from downsizing air conditioner to 2-ton unit (-$681)
11. Upgrade gas furnace from 80% to 92.5% AFUE ($435)
12. Credit from downsizing furnace to 50,000 Btuh (-$108)
13. Upgrade gas water heater from 60% EF tank-style to instantaneous ($203)
14. Relocate ducts to within the thermal envelope ($829)
15. Solar hot water system (integrated collector and storage) ($2,654)
Thanks so much Martin - that is the type of thing I am looking for. Do you know if there is anything current for IECC Zone 5?
Amanda,
The list I provided was developed with software called BEopt. BEopt was developed by researchers at NREL; it is not yet available for distribution, but should be available within a year.
There are a great many energy modeling programs that can help you answer your question. Because I don't use these programs daily, I hesitate to recommend one. I appeal to our readers: what's the best software to use to answer Amanda's question?
Amanda, There is an informative Return on Investment table which is available to you. Check out http://www.greenandsave.com/master_roi_table.html
Though a far amount of information is dealing with remodels, it is still a good source of info. Hope this helps.
Most of our verifiers on our green homes can give good advice from their RESNET software although may not give you exact dollar amounts of savings will be more of a percentage inprovement. Any BPI certified contractor will be capable of calculating estimated dollar savings from a standard wall with R-13 to an upgraded wall with R-19 for example. They will take into consideration the number of heating days in your climate as well as the cost of power in your area. Go to http://www.bpi.org/ to find a certified contractor in your area