Home addition, Need energy efficient design suggestions

[comish]

So the Comish family is expanding a bit more rapidly than planned as some may have seen in the car thread. With this in mind we are doing an addition and I'm in the design phase, but am planning things like windows, lighting, electrical, heat, etc.

Looking for tips, suggestions, etc from the collective on design ideas for a more energy efficient home. If I had to overarching goals it would be to cut the electric bill and water use, and design a cooler structure as the current house gets rather warm.

A few details about the current abode. In SoCal about 11 blocks from the beach so only use heat for maybe 4 to 6 months a year and even then its for an hour or 2 in the morning and maybe it blips on a bit at night. Our gas bill is a whopping $8 / mo in the summer and maybe it hits $80 in the coldest month of the winter, but I installed a timer thermostat late in the winter which helped a bunch. No AC and should in theory only need it 2 weeks a year, but current place gets quite warm even when cool outside.

I know about most of the low hanging fruit ala insulation, we are replacing all the windows with double glazed, low-e, likely argon filled. Trying for cross ventilation and to shade the windows a bit on the S and W aspects where possible.

Where I'm curious is in things like:
-Lighting: What kind of fixtures would you put in today and why? We have a predisposition for recessed cans, what is the most energy efficient solution that is still cost effective? ie LED's are still too much $$$ from what I have seen.

-Heating: Does underfloor heat make any sense in SoCal? Is it expensive? Do I keep current gas blown heater for current house and get something different or the same for the addition?

-Water: Given I'm fairly sure I have a gas hot water heater and my gas bill last month was a whopping $8, I'm thinking tankless really wouldn't pay off for me. Combine that with the wasted water of waiting for the thing to heat up and that water is debatably a more scarce resource in these parts, I'm leaning toward staying traditional, but possibly with some sort of recirculation pump so I don't waste water waiting for it to get hot?

-Windows: Leaning toward fiberglass or fiberglass clad (Marvin Integrity?). We have pretty large temperature and humidity changes here and I'm shit at maintenance. I also want something that will last. Any thoughts? I'm nixing wood b/c of the maintenance factor, not too impressed with look of vinyl and figure they will yellow in the sun here, like the fact that fiberglass is relatively unaffected by the elements relative to other materials. Any thoughts on which coatings or level of Low-e make the most sense from a cost/benefit perspective?

-Attic/Ceiling ventilation with a vaulted ceiling. We are doing an A-Frame gabled roof on the 2nd floor and will stay with the vaulted ceiling. One of the reasons my current abode gets stinkin hot is there is no attic ventilation... How would one ventilate a gabled roof where there really is no attic? How does one get the hot air out of the top of the vaulted ceiling?

I have read 2 theories, 1 you just seal the "attic" and insulate it, or 2 you leave a few inches of air space between the roof and the insulation and then ventilate it at the roof and eaves like a normal house. Any thoughts on what is best given that I'm in SoCal and want it to be cooler...

Anything else? This all has to be cost effective as I don't even have the money to do what I'm doing, but would like to be smart about it. Thanks for any and all suggestions. Any good websites where I can go edumacate myself?

[BigDaddy]

You want a lot, but why not?

Check out Fine Homebuilding, great reference: http://www.finehomebuilding.com/

For venting vault, you can install an exhaust fan on one gable and put a window on the other. Then you draw the cool air in and pull the hot air out.

Marvin windows are a great choice and I agree, don't go wood. My only concern is fiberglass may get brittle over time and exposure to the sun. (But maybe less so than vinyl.) They will help you determine which are best for your climate as a free service.

Insulation is the best way to keep the attic from getting so hot. If you can spray in polyurethane foam, you'll get the most r value for the inch. That is "closed cell", so you don't need to vent it (with air spaces like convention roofs.) Also one thing to consider is roof color. Clearly you want as light a color to reflect the heat.

Is it possible to plant any trees on the southern side? Shade is king.

Can you post some pictures?

[iceman]

How much water use will there be in the new section? A small tankless heater close to the point of use is probably the most energy- and water-efficient set up if it's just for a bathroom.

Passive solar using overhangs that block summer sun but let the lower winter sun in are easy and work well. In-floor heating is a slow process not generally suitable for taking the edge off in the morning, solar to battery to resistance heating would be optimal, otherwise heatpumps, but geothermal probably won't pay there. Propane or NG industrial spaceheaters are way cool-looking and pump a shitton of heat quickly.

Fast-growing deciduous trees on the south side are great if they'll grow there. an evergreen windbreak on the North or NW side can be functional and attractive.

LED lighting is the future, fuck a bunch of flourescent. Install incandescent on dimmers and remember the best savings come from turning lights off when you don't need them.

You need to look into what are called "whole-house" fans. Best bang for your cooling buck by far.

Like BD said, you want "Fine Homebuilding". You can buy every single issue they've printed on DVD for like $300, it will be worth it. Plus subscribe.

What else?

[lemmycaution]

these are complex questions:

yes a tight envelope is the number one thing. reflective roof, good windows and doors, well insulated. a thoughtful design that uses passive ventilation / cross breezes and ceiling fans might work for you, you could always add a mini-split ac system (with high-seer rating- 16 or more) for supplemental ac just where/ when you need it.

flourescent lighting is way way better than in the past, with colors just like incandescents. use them in all the places except dining room. dimming them is often a PITA so consider that. their wattage is very low and saves a lot- and little heat load. LED's are getting cheaper, check them out also.

radiant makes a lot of sense in a warm climate. the water does not get super hot, just to like 120 or so which makes the boiler work very little. it is a different boiler and some additional equipment but very common.

a well insulated traditional water heater (gas) would work but tankless is always more efficient.

marvin windows are good, not the greatest but good. aluminum clad is better than the fiberglass. definitely get low-e in a southern climate, it will reflect a lot of energy (heat) out of the house.

definitely vent the roof. there are all sorts of roof vents for gables. you can do it out the eave or i think better- also add a little stovepipe thing on top.

sounds like you already got your stuff together but i would really recommend getting an architect involved. that is the way to get these questions really answered in the way you want them answered. they are going to give your project the thought and time it deserves and will save you money over working with a builder directly (unless you are a builder yourself). why? they will bid to multiple builders and you will get to choose rather than getting a take it or leave it price. if you are interested, i am an architect and have done LEED rated (certified "green") projects and take this stuff very seriously. i would talk with you about it or recommend someone out there (i lived in LA for a few years). let me know if you would like, sorry about the spam, best of luck.

of course i would be glad to help you out in any capacity if you want to shoot me more questions also, it takes time to get into the nuts and bolts of it and there are specifics as to the site orientation etcetera that have huge bearing on all these issues.

[back bowl]

I don't have much to offer in terms of actual advice because you're in a totally different climate than I've ever worked in, but if you are looking to take on the design/planning yourself and want good resources, skip Fine Homebuilding and go right to the Journal of Light Construction. It's like Fine Homebuilding for pros. You can buy all their back issues on a CD or get access to an online database... Well worth the $$$ if you will be making expensive decisions...

[Jethro]

All good information in the above posts. As far as lighting goes, the new LEDs will be the future. I saw a demonstration of some new LEDs at work (I am an electrician) and was very impressed. The lights we saw were designed to replace high pressure sodium lights for high output needs. They are almost to flourescent as flourescent is to incandescent lighting. Cost might be the sticking point right now.

[RootSkier]

SIPs for the vaulted roof. No venting required.

[iceman]

I don't have much to offer in terms of actual advice because you're in a totally different climate than I've ever worked in, but if you are looking to take on the design/planning yourself and want good resources, skip Fine Homebuilding and go right to the Journal of Light Construction. It's like Fine Homebuilding for pros. You can buy all their back issues on a CD or get access to an online database... Well worth the $$$ if you will be making expensive decisions...

He's not a pro, that's why Fine Homebuilding is better. It has a ton more general stuff like "why geothermal?", he can always look up details later after he's figured out what he wants. They're both published by Taunton press, maybe he could get a deal on both.

[back bowl]

He's not a pro, that's why Fine Homebuilding is better. It has a ton more general stuff like "why geothermal?", he can always look up details later after he's figured out what he wants. They're both published by Taunton press, maybe he could get a deal on both.

Sure. I suppose either is fine... I find JLC to have a lot of good insight while still being pretty accessible... Fine Homebuilding is good for the "why geothermal" or "explanation of SIPs" articles, JLC is more "theories of moisture transfer" and the like. If you have enough knowledge to understand what they're talking about, you'll get a lot more out of JLC than Fine Homebuilding. But if it's beyond where you are, it'll be worthless.

Plus, there's some pictures of me in one of the late 90s issues...

[comish]

Good info here, thanks.

Nope, not a pro, just very involved in the process...

LC, Why are aluminum clad windows better? They are a fair bit more expensive (likely out of budget) and I'm not sure I see why they are all that much better. If they do fade or crack or whatever supposedly I have been told that you can't just repaint them like you could a fiberglass clad. What windows would you buy/recommend if Marvin Integrity are just "ok".

Same w/ LED's. I have been told they are still too expensive, while yes, the wave of the future and efficient, just not to my price point.

New section is master bath, and a 2nd full bath that will mostly function as guest bath so not much showering going on...

I have good overhangs on the W side where I have traditionally gotten a lot of heat gain out of my crappy 1940's era windows, but on the 2nd floor not so much. My side setbacks are only 4.5 feet and I need a chunk of that for a walkway on the W side, but I have been working on Mrs. Comish on the planting of something over there to shield both the sun and our neighbors heinous roof.

Great tip on the Fine Homebuilding. Wasted most of my morning there thus far...

[boarddad]

Lose the vaulted ceiling! It's just a place for hot air to get trapped in the summer and heated air to get lost to in the winter. Do yourself a favor and go visit the Gamble house in Pasadena. It's AMAZING for starters, but also amazingly efficient, especially considering it was built 100 years ago. If you want energy efficiency, you'll want to maximize the natural airflow of the structure as a whole. I.e. Open up a window on either side of the house and vent the whole house. I HIGHLY recommend max insulation, door seals, double paned windows and attic fans in that order.

fWIW, we made the leap and doubled the size of our house about 5 years ago. Our gas and electric bills went DOWN! I've talked to a couple of solar installers and just can't make the numbers work because our AC bill is so low. I should note; we live in Long Beach about a mile from the beach.

[iceman]

LEDs should work fine in incandescent fixtures, I just meant don't go out of your way to accomodate flourescent (i.e. DO go ahead and install dimmers) when LEDs will be taking their place fairly soon.

[lemmycaution]

aluminum clad windows have a baked-on factory finish that is typically waranteed and very durable- the aluminum is pretty decent guage also. i would certainly check the warantee before buying but they should not fade. my concern of fiberglass would be cracking and then water infiltration- i have not heard of this specifically with windows, but fiberglass can crack.

i recently used alu clad pellas that i thought were pretty nice. they are the main competition to marvin.

i also used led recessed lights in a bathroom recently that were the same price as incandescents and easier to dim than flourescents. i think they were lightoliers.

vaulted ceiling with a ceiling fan can be a good idea to be comfortable without ac- even better with a venting clerestory window- and it will let light wash the ceiling for indirect lighting.

[Skipig25]

fwiw, I agree with what lemmy said.

if led's are out of the price range, new fluorescents are much better than before, and electronic ballast doesn't make that humming noise. (my parents were surprised when I told them to switch, and they didn't like old fluoro because of the noise)

[mitch_cumstein]

I am a landscape architect (unlicensed) and have worked on several LEED projects. I realize the site and landscape may be of little concern to you now, but I think more attention could be paid to building siting for energy efficiency ie, quick items like cross ventilation, solar gain, and planting deciduous trees along southerly windows to encourage shading and cooling in the summer and heating in the winter when trees drop leaves.

There's a movement toward 'gadgety' sustainability that I don't think is necessary if true sustainability and efficiency is your goal. It seems ludicrous to me that people often consider the type of light bulb before they think about how their home sits on the land, then again many people dont have that luxury to choose.

If you are interested in an seriously considering less-gadgety solutions for a more efficient home I might recommend checking out this book:

http://www.treehugger.com/files/2010...inal-green.php (The Original Green by Steve Mouzon)

I speak with Steve via another website and he has a lot of smart, constructible ideas particularly pertaining to urban planning.

The most sustainable design isn't necessarily 'green' design, but simply 'good' design.

my two cents..

[EarlyWood]

SIPs for the vaulted roof. No venting required.

Are you suggesting lack of a "cold roof"? If so, and if you have done so, twelves years later you will most likely be getting a call.

In my early days of SIP and timber framing world I relied on a recommendation like that from the manufacturer. When going back to add an addition ten or twelve years later I discovered the top OSB layer was a disintegrated flaky mess, the shingles literally had nothing to hold to. No wonder many of them had curled up making nice bat caves.

"Fortunately" it was my own house but it caused a world of frustration.

[lemmycaution]

and i agree with mitch above concerning "gadgetry". doing something sustainable is about synthesizing and thinking holistically about the project, not about adding technology on. that being said, efficient mechanical systems are typically "high performance" ones.

[Garrett]

"Fortunately" it was my own house but it caused a world of frustration.

What climate and how thick/what foam was in the SIP? Curious, as I've never built anything with them, and I'm wary of the details of vapor pressure gradient across them.

-Water: Given I'm fairly sure I have a gas hot water heater and my gas bill last month was a whopping $8, I'm thinking tankless really wouldn't pay off for me. Combine that with the wasted water of waiting for the thing to heat up and that water is debatably a more scarce resource in these parts, I'm leaning toward staying traditional, but possibly with some sort of recirculation pump so I don't waste water waiting for it to get hot?

Sounds like the right conclusion to me, but your concept of tankless heaters may be twisted. Water waste waiting for hot water at the tap is a function of the source of hot water being physically removed from the tap. The only two ways to completely remove the wait are to recirculate hot water (inefficient energy-wise) or to move the heating to the tap (inefficient capital/maintenance cost-wise).

Central tankless water heaters are "more efficient" in a ridiculous way where they cost more upfront than you could reasonably recoup during their expected life unless your fuel gets much more expensive.

If you want to take advantage of some low hanging fruit, you could plumb the addition with insulating materials (PEX instead of copper, ferinstance) and use a modern point to point topology so as to allow smaller diameter hot water feeds that store/waste much less water. Costs little to implement, few/no downsides, no expensive gadgets. The little details take competent people with good planning skills to implement, but they pay off much bigger than ever more expensive and complex mechanicals.

I know nothing about your climate, but I'd echo icemans suggestion that you strongly consider passive solar detailing where feasible, and I'd also suggest you look into whether or not thermally massive elements will be useful during summer in your climate. If so, good design of their placement wrt windows and aspect can really make a difference...I've spent a lot of time in southwestern houses built with traditional materials and single glazed ancient windows that are comfortable all summer long.

[Tippster]

Dimmable CFLs are waaay nicer light than dimmable LEDs.

[iceman]

hm, I'm not sure about that, I mean I'll take your word for it, but the LED installations down at the building museum were really nice light and completely tunable as to what spectrum you wanted, while I've never seen a fluorescent of any kind that made me think "nice light". On the other hand I'm sure there's plenty I've never seen.

edit: the LEDs were like $30+ a "bulb" though.

[Tippster]

If we're talking dimmable ceiling cans you don't really want the LED spots anyway. you'd want something that fills the whole can with light like an incandescent bulb would, thus softening the light as much as possible.

Tunable - you can buy daylight or tungsten balanced CFLs now - just look at the Kelvin numbers - the higher the bluer the light. The 2750K bulbs are really nice for a warm toned environment (we use them in our living room) and the 5000K for daylight oriented spaces like kitchens and sunrooms.

They also cost about $10 vs $40.

[splat]

If you want to save money on lighting costs, look at retrofitting your existing fluorescent T12 bulbs w/magnetic ballasts to T8s w/electronic ballasts and your incandescent bulbs to cfls. Then you won't feel so guilty about incandescents on dimmers, though I hear you can dim cfls these days. You can also get cans for cfls, which you might want to do, as incandescents could get outlawed in the next few years.

[Garrett]

splat, I just did a project exactly as you describe replacing ballasts and bulbs. Worthwhile tax credit, works great, best unexpected benefit is that now all the bulbs are simultaneously new and of the same brightness/color temp which makes a difference in itself.

[OSECS]

Are you suggesting lack of a "cold roof"? If so, and if you have done so, twelves years later you will most likely be getting a call.

In my early days of SIP and timber framing world I relied on a recommendation like that from the manufacturer. When going back to add an addition ten or twelve years later I discovered the top OSB layer was a disintegrated flaky mess, the shingles literally had nothing to hold to. No wonder many of them had curled up making nice bat caves.

"Fortunately" it was my own house but it caused a world of frustration.

I think they've dealt with that problem. Newer technology of heat radiant materials, different glue systems have made the SIPS roof viable again I believe. It's really the same technology as a conditioned attic (similar to a conditioned crawl) insulating the actual roof deck and introducing a heat radiant barrier in the construction. A really good way to reduce thermal loads on HVAC ductwork and air handlers in your attic.

[lemmycaution]

fwiw, yes an led bulb costs like 30$ but their life is 25-30 years so you obviously literally never replace it.

you can dim most types of flourescent fixture but you need to coordinate the switch, the wiring and the fixture- depending on the people and delivery method involved this can obviously prove difficult.