Q&A: A Forum for Green Building Experts and Beginners

[Click map to enlarge]

Please register for a free account or sign in to ask and answer green building questions.

The usual rules of courtesy apply:
1. Be nice.
2. If you can't be nice, be polite.
3. If you can't be nice or polite — well, please be brief.

To attach a photo or illustration:
Under the box labeled "More explanation," look for the words "File attachments."
Click that, and you should be able to attach a photo.

Thanks for joining the conversation!


5 Answers

Biggest bang for your buck?

We are about to begin construction of a new home near coastal Connecticut. We are trying to incorporate green approaches where feasible. Three main components are: Insulation; energy source (ie Geothermal); and energy distribution (ie in-floor radiant heat or forced air). Of these three green approaches, how would you rank them in terms of biggest bang for yurt buck, assuming you can't afford all three. Thanks!

Asked By Justin Murphy | Mar 1 15
9 Answers

Why is it so trendy to hate on radiant in-floor heat?

I recently built a 2000 square foot house in climate zone 7. The building is two stories on a slab heated by a Navien 240a combination boiler. There is no heat source on the second story, and the simple system has only one zone, which is all it needs because all the rooms in the house stay at the same temperature--maybe it's a few degrees cooler in the upstairs bedrooms if the doors are shut for 24 hours or more. I spent just over five grand on the heating system--installed--although I got a tankless water heater in the process, so the real cost was more like $3500. How is that overkill?

Asked By Josh Jipson | Mar 1 15
8 Answers

Do screws through exterior insulation reduce the wall R-value?

I was in a Net Zero Building class this weekend and there was mention that screws that are used to attached exterior insulation reduce the whole wall R-value by 39%.

The screws are attached from the outside thru the rainscreen, insulation, WRB, sheathing and into the framing.

This individual referred to an article from Energy Design Update (no issue was noted). I'd check but $600.00 for a subscription is too rich for my pockets.....

Any help here on the article or data at least, with other references?

Asked By brad hardie | Mar 1 15
17 Answers

Recommendation for minisplits vs. gas-fired HVAC for new Massachusetts building

I am building an energy efficient 15 unit apartment building in MA this spring. We can either go natural gas or electric. I am considering going all electric since the MA Energy Code is so stringent and the heat load will be relatively small even though there are very cold temps at times. We might even put on solar panels for the house meter.
The electric units would take up much less space and I would rather not have to put in gas at all. I am not thrilled about electric hot water heaters but understand that the newer tankless units are much better.
Any input would be appreciated.

Asked By Bill Perkins | Feb 25 15
15 Answers

Wood floor underlayment over radiant heated floor

Hi,

I am building a 2 story house wood frame house(with basement) that is heated with radiant hot water system installed in the floor.

The joists have been blown in with loose fill cellulose (for both sound and to keep the heat up) and a plywood floor is on top of the joists. R5 foam board is installed on top of the plywood and the PEX tubes are installed to the foam board. They will be pouring a self leveling concrete on top of the PEX and then gluing down engineered wood floors.

Asked By Howard Klein | Mar 5 14
8 Answers

Seasonal humidity and lack of outside airflow

Hello,

Asked By Geoff York | Mar 2 15
8 Answers

Adding wall R-value in a historic retrofit

What options are available for adding r-value to a wall if we can't remove the exterior siding? I see three options...
1) dense pack cellulose in the existing 4" wall cavities (~R 14-16)
2) Closed cell spray foam in existing 4" cavity (~R 26-28)
3) Add a double interior wall filled with 7.5" of dense pack cellulose (~R 26-28)

Asked By alok khuntia | Feb 28 15
6 Answers

What is the correct climate zone?

Can anyone point to a web site that will be zip code specific to determine which climate zone you are located? The Department of Energy web site leaves something to be desired. I cannot determine a clear explanation of climate zone 4 and 4 Marine. It seems there should be a site to enter zip code or address and get definitive information regarding climate zone.
Thanks,
William

Asked By william dempsey | Mar 1 15
3 Answers

Dana, others, DIY PV, mini split, superinsulate, costs

What would it cost today to roof install 5.6KW of PV DIY?

DIYers are eligible for what rebates in NY in 2015?

Anyone?

Martin a blog on DIY PV and DIY mini split installation?

5,6KW PV for $2/W? $11,200?

DIY 2 ton mini split two heads, $1800x2= $3,600?

Superinsulate a 1,800sqft home, DIY cellulose purchase, 12" walls, 30" lid, $5.000?

These items can be done by one timers, DIYers.

Be nice to have a Q&A with this information on costs all in one thread.
Thanks
aj

Asked By aj builder, Upstate NY Zone 6a | Mar 2 15
4 Answers

Double wall exterior sheathing

I am designing a near zero energy home in climate zone 5 and working out the details for a double wall system.

There is a lot of talk about what kind of sheathing to use or not use due to the fact that the sheathing will be very cold. As I understand what I have read so far, it is recommended NOT to use OSB or foam but OK to use DensShield Gold, structural fiber board or plywood in Zone 5.

Asked By Terry Herschberger | Mar 2 15
Register for a free account and join the conversation


Get a free account and join the conversation!
Become a GBA PRO!