Ecological and green building methods and materials

[Ecoman]

Are there real and effective ways in the building industry to help the environment ...in terms of methods and green products for building?

[jadnashua]

Simple answer, yes. But, it can get quite complex. One of the best is factory panel construction...minimal waste, controlled conditions, optimized construction methods. Site location and orientation can help immensely, too. Landscaping can make a big difference in shading and cooling effects, or blocking prevailing winds. Too many things to discuss in this type of forum, but there is lots of info out there.

[DonL]

Hello all,

I say Yes also.

The Drawback it they all take a lot of the Green out of your wallet.

Have a great Day.


DonL

[Dana]

Not so DonL. It just plain depends.

For instance, advanced framing techiques use less material and less labor to achieve a higher thermal performance than traditional methods, with the same structural performance as traditional methods. That's stuffing green INTO your wallet.

Money spent on air-sealing a building as you go enhances thermal & moisture performance IMMENSELY at a very low cost. Retrofit air sealing is still very cost effective, but it's difficult to achieve the same tightness a when the primary air barrier is defined in the plan and implmented during construction.

Then there's the matter of spending it wisely: Rigid foam outside the sheathing is more effective (and cheaper) than spray foam in a stud cavity fill, since it provided a thermal break over the relatively low-R bridging of the studs, and provides a thermal break over the band joists as well. It's easy to build a low-cost studwall with an R20 whole-wall R value (thermal bridging included) with 2x6 24" o.c. advanced framing with spray cellulose in the cavity and an inch of exterior foam, which has the same or lower costs of a 2x4 16" o.c. with open cell foam cavity fill that only comes in at ~R10 for a whole-wall R.

[DonL]

I Agree with what you are saying Dana,

But I am a firm believer that "You can not get something for nothing"

If You invest more than you will save big time over the long run. Doing it correct the first time, Saves Money.


But it takes Money to make Money, it takes Money to save Money...


DonL

[hj]

There are many ways we can do it, BUT only if the consumers are willing to pay for them. The consensus seems to be that people will only pay for "green" if it saves them money immediately.

[Dana]

I Agree with what you are saying Dana,

But I am a firm believer that "You can not get something for nothing"

If You invest more than you will save big time over the long run. Doing it correct the first time, Saves Money.


But it takes Money to make Money, it takes Money to save Money...


DonL

In the advanced framing case (no exterior foam) you SAVE money while saving money. A 2x6 AF wall with R19 batts has a whole-wall R of ~R14 and costs slightly less to build & insulate than a 2x4" 16" o.c. code-min type wall with R13 batts that comes in at ~R10.

Wet spray cellulose at low density is usually cost-competitive with low-density batts for installed price, but outperforms the batts by all measures that count. (And it buys you greenie-points for being a recycled & renewable resource.)

Using smaller windows for less total glazed area, and push-out awning/casements or fixed-windows rather is cheaper, more air-tight, and higher performance than double-hungs, single-hungs or sliders. (And you get more egress area per square foot of glazing out of a casement than a doulble-hung or slider too, for meeting code for sleeping areas.) Thinking of every window as an R2-R3 hole in your R14 AF wall is the right way to think about it, most of the time. (The exception being when specifically designing in the balance of solar gain for the thermal mass of the building in heating dominated climates.) It doesn't take much window area to provide daylighting, an properly sized/scaled, even planning for scenic views can usually be done with 30% less glazed area. All it takes is planning.

Right-sizing the HVAC is usually an up-front cost savings (smaller compressors, burners, air-handlers & ducts) with double-digit percentage operating cost savings compared to typical 2-4x oversizing. (And it's more comfortable too.)

More than money, it takes thinking and planning to save money, but it's pretty straightforward stuff if you take the time to figure it out. Even if most people building a custom new home are more interested in picking out the granite for the countertops or how many side-sprays the shower really needs, that doesn't mean that you have to spend more money to build 25-30% better thermal performance into the building envelope than an old-school code-min affair. It's only a matter of planning, which means somebody has to focus on it at least a little bit at the beginning. Again, less money up front, for higher thermal performance.

The payback on air-sealing during construction is less than one year of heating & cooling, but I s'pose even tiny money is still money... But if the performance boost from air sealing is correctly factored into the HVAC equipment sizing, it's usually net positive cash-wise from day zero. Again, saving money up front while saving money (and energy) long term. All it takes is planning.

There's no cost premium for using CRCC rated cool roof shingles, but it means your exterior color scheme has to deal with lighter hues on the roof (not just white.) In TX it'll show up on the cooling bill, if you measure it carefully.

Designing the shell to accomodate all ducts and mechanical systems inside of the conditioned space rather than above the insulation in the attic is both cash and performance positive. It means adding 12-18" to the framed height of the upper story to accomodate the ducts, but is very low cost- usually cheaper than insulating all of those ducts to code-R for placement outside of conditioned space. When ducts are inside of conditioned space leakage doesn't induce oudoor air infiltration to NEARLY the level it does if leaking into ventilated attics, and conducted losses are to/from the conditioned space as well. Even when it's at a slight up front cost (it's usually "in the noise"), it's well worth it. Cost neutral, higher performance.

Using blown cellulose vs. low density blown fiberglass or low density batts in the attic is also usually higher performance at identical rated-Rs, and cost neutral to cost-negative. (High density f.g. will match it at any given R, but for a cost premium.)

Designing the attic insulation support such that you get at least 3" of insulation over the tops of the joists or truss chords is also cost-neutral, higher performance, providing a thermal break over that framing element.

But I dunno, is the green Taiwanese marble a bit too dark to use on the floor in the bathroom, or should we go with the rose granite instead?

[jadnashua]

It takes planning up front and a builder that is familiar with the newest techniques so he doesn't have to learn on the job, and raise his costs accordingly for the extra time. Someone who knows the tricks can get it done. I'm still a fan of factory build systems, erected on site in short order once delivered. The whole thing is closed in quickly, and many subsystems are already installed.

[Dana]

Factory building of components has it's advantages, but of the two homes I've seen built that way both required EXTENSIVE site remediation of defects one had dimensional errors between sections requiring a re-engineering of interior load-bearing walls.

The other was totally deficient in air-sealing, which the home-buyer ended up remediating himself as the thing went up, burning through an entire 600 board foot foam kit in the process. The pace of closing it in was also not up to snuff, and a nice oak staircase needed a lot of touch-up including some tread replacements, other components developed mold issues that needed fixing due to the bulk-moisture it acquired prior to closing it in.