Power density of a home?

[reverbbb]

It has been a couple of weeks since I have posted any 'green' comments.

I was just thinking about the power consumption of a home. What if we could establish an energy rating for a home's "Power Density"? You may be wondering, 'why would that matter?'

For one thing, it is a serious waste of precious heating and cooling in a home that has 15~25 foot vaulted ceilings. The cubic foot of air that must be processed should be a huge consideration. I was once told by a realtor, that "The builder designs homes that are inspired by women's wish list. Most women prefer high ceilings and lots of windows.". I don't argue these points. But that discussion was 9 years ago when electricity was $0.05/kW in Texas. Now, the price is surpassing $0.18/kW.

It is wrong when folks stereotype women as all thinking the same way. The new reality is, that I know a higher ratio of women who are more concerned about energy costs than the aesthetics of their ceilings. The are now millions of women who wish that their utility bills could be lowered. But they made (or the builder marketing made) the choices of having huge ceilings in their homes. For the next 125 years, all these homes are going to experience high utility bill due to their piss-poor design. What were they THINKING?!

I suggest that a method is established for determining the Power Density of a home. This would include the amount of insulation, the cubic feet of heating/cooling and the number of poorly insulated windows. You ratio this up with the size of heating/cooling equipment, kW ratings of appliances and any other measurables of energy consuming devices.

Here is how it would be used. Let's say that you had a home [A] built in 1968 that had 8 foot ceilings throughout the house. The floor plan was 1500 sq ft. Based on the calculations, this home would have a Power Density Factor (PDF) of 135 (ficticious number for affect). On the other hand, home [b] built in 2005 had vaulted ceilings and a floor plan of 1800 sq ft. Its PDF is 278 (also ficticious number). If you knew that home [A] was going to cost $145/month in utilities whereas home [b] would cost $395/month, don't you think that the buyer would be better informed on their major purchase?

An energy rating is already applied to appliances and automobiles. You can easily estimate what that purchase is going to cost you in the future. But here we have homes that use FAR more energy, and are the largest investment in a person's life, yet they have no information about how much that home is going to cost them beyond the purchase price and interest rates.

I can tell you one thing, the energy ratings on appliances and cars have caused a concious effort by manufacturers to improve their products. Home builders on the other hand, continue to produce products that are worse every year. Yet, the consumers are blindly buying these crappy homes. Homes in America are total junk. They cannot withstand severe weather, insect attacks or sky-rocketing energy prices. Why are we accepting this junk?

I have been involved with homes from the inside out for the past 35 years. I don't call homes "junk" lightly. I know of way too many problems with the current home designs and the builders techniques to 'save money' (a.k.a. more profit).

I will step off my soapbox for now and review the responses.

[Big John]

Hmmmmm, interesting post !
This is the view up into our loft .......



The house is largely 15th Cent and you are looking at a lot of the original wall beams and the original infill which we call 'wattle and daub' (basically cow pooh and sticks).
The back of the roof (to the right) has a 18thCent tiled roof as the front does but you can see to the left a lot of thatch still remains.

It may look like a bomb has gone off up there but this house is always warm in winter and wonderfully cool in summer, i'm sure we wouldn't pass any modern 'eco' standards but we wouldn't change it for the world (as a 'listed' building there isn't much we can do but you know what i mean).

We heat with a small(ish) wood burner and i tells ya, we are a pair of very cosy bunnies in there -- haunted ?, don't get me started.


Truth is though, if every one saved just a little on things like insulation it would make a difference.

[reverbbb]

That is an awesome picture. I have never seen the inside of a UK loft - yet alone a 15th century home.

I am sure that older homes will have difficult time of making the desirable grade in some cases.

What is happening in the US is driven by builder profits. The home cosntruction is getting worse. The designs are attempting to appeal to the senses with clean sharp lines and large open spaces. But in the attics (lofts) you will find some really horrid duct applications.

Even the historiclly 'tile showers' in $400,000 homes has been replaced with fiberglass and glass walls. Real wood or wood veneer is nearly none existant in new homes these days. Yet these are simply the cosmetic issues.

On the energy front, the builders will specifically ask for the LEAST expensive heating/cooling equipment for a new home. The consumers don't know any better. They tend to see the granite counter tops and don't realize that the $8000 upcharge for the counter top could have been better spent on better HVAC equipment and insulation. That pretty granite countertop is going to cost them an additional $800/year because the builder selected the lowest quality HVAC equipment. 15 year life of HVAC x $800/year = a whopping additional $12,000 in utility costs. Sad, but true.

Again I ask, why are we accepting this non-sense?

[tiktok]

I lived in Texas for many years, and much of my family now lives in Arizona, and whenever I visit either of those places I look around and think "Y'all are in trouble when the cheap gas, cheap electricity and water imports run out--this place is pretty unlivable without all three of those things..." Tall ceilings, big single-pane glass, everything all spread out in the city, AC nine months out of the year, etc.

I've also wished that there were some good figures on the average kW/h usage of a home has changed over the last 20 years. My impression is that despite the Energy Star type stuff that's become common, the overall power usage is still going up per person.

[neocaster]

Originally Posted by Big John

The house is largely 15th Cent and you are looking at a lot of the original wall beams and the original infill which we call 'wattle and daub' (basically cow pooh and sticks).

So THAT'S where "poohsticks" comes from! All this time I thought it was a game you played on a bridge with sticks...

[Tim Armstrong]

I spent several years in the new home building business as an interior trim subcontractor, and I can absolutely testify to the incredible cheapness of the materials and design shortcuts on homes built in the last thirty years...

One day, if I can manage it, I'll be building my own house, and it sure won't be like any of the ones I worked on!

Cheers, Tim

[tiktok]

Originally Posted by Tim Armstrong

I spent several years in the new home building business as an interior trim subcontractor, and I can absolutely testify to the incredible cheapness of the materials and design shortcuts on homes built in the last thirty years...

Thing is, people have $X they can afford for a home, say a 3 beds, two baths, sort of typical family home. You could build it with quality trim, insulation, etc., and it's going to by most people's standards tiny and plain...for that price point. Or, you could build cheap and big with crappy fittings and most people are happy. They're not thinking they're going to be in it for 20 or 30 years, or long enough for things to start failing.

And these days, there's just not a market for a high-quality 2 bedroom house with 600 square feet in most cities.

[Guitar_Ninja]

Tighten building codes. Anything else is just increased bureaucracy for the sake of doing a run around on the tightening of building codes.

[reverbbb]

Building codes ARE a form of bureaucracy. What I am talking about is a rating system that increases the awareness of the consumer. The builders would be less willing to show their crummy ratings on their crummy houses. The informed consumer would steer the quality demand - not the government.

Energy Star is a good start, but it fails to provide any quantative measurement system for the consumer. For instance, if I buy a washing machine with an "EnergyGuide" rating of 113 kW/year, the label also tells me that it will cost me $13/year to operate. If I am walking down the appliance isle, I can easily make a decision based on the features plus the EnergyGuide. I am simply proposing that new homes offer this automatically, and older home buyers can contract someone to obtain that information.

[woodman]

blowing money on bells and whistles is the modern way, but they'll eventually grow boring or go out of style. but investing in insulation is the gift that keeps on giving -- that would raise your rating considerably, no?

[fakeocaster]

there is a an energy rating being introduced here for new homes and future youll need certification before you sell

The average peak demand ppeak demand for a house in Ireland and the UK is about 12kVA. however houses are usually smaller than the US and dont need Air Conditioning

Id guess that most US homes that Ive seen that are about twice that for the above reasons

[evol04gt]

i spend a lot of time watching HGTV and other programs that always advertise GREEN GREEN GREEN on everything... all they are doing is plugging commercials for companies that make crap like bamboo floors and diff paints...

this is REAL seat of the pants thinking that americans have gotten out of. we have a decent home (2000 sq feet plus basement and finishable attic) built in 1914. two story... i know how in efficient it is when i go from one level to another... one of these days i swear i am going to reinsulate my attic and some how find away to insulate my walls better (mostly for guitar playing!) structurally, this house is a tank... however im sure out duct work is very inefficient.
would wrapping our ducts from the furnace/ac to where they start entering the basement cieling with thermal wrap really help a lot? in winter i can put my hand in the crevaces of our tuck away doors (doors that slide into wall pockets) and feel cold air.... the main ones from our living room to the dining room we are ripping out at some point and i plan on insulating the walls a lot and then doing an opening french door motif.


my friend just had a 2500-3000 sq foot home built... its REALLY nice in many aspects, but i did learn how "code" really doesnt mean much at all..

i know one thing- ill take my house in a bad storm.

ceiling fans are GREAT (we have 2 downstairs and one in 3 of our 4 bedrooms..

can really help an older 2 level home balance out the temps!

[Guitar_Ninja]

Upon further investigation it seems the program you're talking about already exists in the US under the Energy Star program:

http://en.wikipedia.org/wiki/Green_b..._United_States

Though it seems it's being implemented in some places through building legislation. Ahem.

[cowboytwang]

WOW
What a coincidence on this thread. I'm scribbling down notes, and surfing the web to get ideas for our new home. We are meeting with an architect on Saturday to start drawing up floor plans and all that fun stuff.

We are building an off grid straw-bale construction house and recordings studio, just outside of Tucson AZ.

It will have a wrap around porch to keep the summer sun out, but still let the winter sun shine in. With 18+ inch thick straw bale walls that have an R60 rating. Solar panels and roof top garden up top to capture energy and block heat.
It's an U shape design with a covered courtyard down the middle. This is the rough sketch I have so far.


This is the property. Kind of the view look south out of where the courtyard will be.

[tiktok]

Originally Posted by reverbbb

Energy Star is a good start, but it fails to provide any quantative measurement system for the consumer. For instance, if I buy a washing machine with an "EnergyGuide" rating of 113 kW/year, the label also tells me that it will cost me $13/year to operate. If I am walking down the appliance isle, I can easily make a decision based on the features plus the EnergyGuide. I am simply proposing that new homes offer this automatically, and older home buyers can contract someone to obtain that information.

That's tough to do, since the price of electricity isn't uniform.

Plus, they'd figure it based on keeping the house at some arbitrary temperature, say 68F in the winter and 76F in the summer. Which would probably not be the thermostat settings chosen by...your wife.

[Joe-Bob]

Our house was built in '54, and three weeks ago, we added 18 inches of new insulation in the attic.

This spring we put in a new more efficient water heater.

We're trying. We drive small cars, and my wife only drives about 4 miles to work. We've spent alot of $$$ keeping up our trees to shade the house, and we have blinds in several windows to help keep out the hot sun.

[Buckocaster51]

You've hit upon a topic that really grates my nerves.

We know how to build "good" houses. There are all sorts of designs and technologies available that allow us to minimize our footprints.

It's not like it is rocket science.

"We" have just chosen not to implement them.

There is much inertia in the housing industry.

There is also the human factor.

Houses are like guitar collections. We like them bigger, bigger, and bigger.

[Buckocaster51]

Originally Posted by cowboytwang

...

We are building an off grid straw-bale construction house and recordings studio, just outside of Tucson AZ.

It will have a wrap around porch to keep the summer sun out, but still let the winter sun shine in. With 18+ inch thick straw bale walls that have an R60 rating. Solar panels and roof top garden up top to capture energy and block heat...]

Hope you can keep us up-to-date on how this project goes for you.

It sounds exciting!

[cowboytwang]

Originally Posted by Buckocaster51

Hope you can keep us up-to-date on how this project goes for you.

It sounds exciting!

We've been toying with the idea of getting funding and sponsorship to do the build as a how-to/documentary TV show, for HGTV or the likes.
Just to show people how easy it is to build an extremely energy efficient, low cost home out of renewable resources.

[reverbbb]

Excellent discussion folks.

Alvin:

I applaud you for taking such significant steps. I think a straw house is a great idea. There are those that feel that is too extreme. Certainly, city building restrictions would not allow those type of structures.

On the other hand, there are very conventional ways to improve the construction of a house. I say conventional only in the aspect of 'commercially' available materials. Yet, the application and design of a better house just does not exist in the typical city development. 30 years ago, I learned how effective an 'envelop home' is at reducing energy consumption. The materials cost more. But the pay off of 30 years would have more than offset the cost of the materials y several times. Yet, almost nobody has built any envelop homes on a commercial scale in that same 30 years. How many homes were built in the US in the past 30 years? 20, 30, 50 million homes? Just think of all the energy that was consumed by those homes that could have been avoided if they were built better?

Will we let another 30 years go by and continue to pay for junk houses that consume our paychecks in utilities? The housing market has almost come to a halt. Perhaps when it restarts, we should demand homes that are fit for the new century.

[cowboytwang]

I applaud you for taking such significant steps. I think a straw house is a great idea. There are those that feel that is too extreme. Certainly, city building restrictions would not allow those type of structures.

Yup it ain't for everyone, but I don't see the energy problem ever changing for the better and living in the desert where at least half of the year the daytime temperature is over 100f, this is my solution.

There are many other renewable building resources that can help with saving energy, and many small things that people can do to start saving right now.

[tiktok]

Originally Posted by Buckocaster51

We know how to build "good" houses. There are all sorts of designs and technologies available that allow us to minimize our footprints.

It's not like it is rocket science.

"We" have just chosen not to implement them.

There is much inertia in the housing industry.

There is also the human factor.

Energy efficient houses have a lot in common with energy efficient cars--the payback seems too far in the future for most folks versus the immeidiate gratification of large floor plan, etc. Particularly when most folks already own a car or have somewhere to live.

I have electric heating in my house (built in 84), and I looked into adding gas, and it'd take more than a decade to pencil out. I don't plan on living in the house more than another seven years, and for the significant outlay to add gas (most of which comes in a lump sum), I could do a lot of other things to the house which would both improve my daily living experience and also add some value when I resale. It's not like I don't already have a perfectly workable heating system in place.

[tiktok]

Originally Posted by cowboytwang

WOW
What a coincidence on this thread. I'm scribbling down notes, and surfing the web to get ideas for our new home. We are meeting with an architect on Saturday to start drawing up floor plans and all that fun stuff.

We are building an off grid straw-bale construction house and recordings studio, just outside of Tucson AZ.

My next door neighbor just finished helping a friend of his build a straw-bale house, and he said you want to be careful when you're planning your footprint to take into account the MUCH thicker walls. His friend ended up with smaller interior space than he was hoping for since he was already locked into an existing slab.

[Westerly Sunn]

My house (Duplex) was built by my grandfather in the early 50's. Basically cinder block foundation, 2x6 floor joists, 1" solid pine sub-flooring 2x4 stud walls, no insulation and brick facade. Big kerosene heaters flued into chimneys. Those are long gone and so is the functionality of the cheap Central HVAC heat pumps that were installed well over 20 years ago before I moved back in as an adult. (My parents stayed in one side when I was born) I own it and stay in both sides now. I really need new HVAC! I cool with window units and get by with the heat on those old heat pumps... I can see the energy and money I'm wasting wafting up into the atmosphere. And Still...; I wish I had me some 12' ceilings!

[jhegel]

Here in Montana we have adopted the International Energy Code.

At this point the code is only enforced on commercial buildings. We do hand out information to new home builders providing information on the code for residential buildings.

Unfortunatly our state legislature has refused to make these standards manditory for single family dwellings. It's an attitude that comes from the deregulation people. They are unable to see the benefits from these types of programs. Fewer electrical generation plants, lower costs of power.

When I built my house 15 years ago I went with an insulation factor of R-50 in the ceilings and R-30 in the walls. It's and all electric house. I pump my water from a well 450 ft deep, heat 2800 square ft of living space, all electric appliances and in wall heating units with blowers. We have modest cathedral ceilings max height of 11 ft in the main room and master bedroom. I used earth burming on the lower floor that covers the walls from 8 ft down to grade on the lower level. You could call it a daylight basement if you like, real estate people will downgrade the building because of it.

The house is built with conventional framing and construction practices. When I built, it cost me $38 per square foot. I did my own electrical, plumbing, painting, and tile flooring so I could afford to build.

In the past 15 years my highest electric bill came one winter when is was between -10 f and -20 f for the whole month. That month the power bill was $150.00.

That little extra we invested in insulation has paid back 10 fold.

What you will not find is this type of thing in a home built for speculation, or your tract homes. These are built with maximum of what I call ginger bread. This is driven by the real estate market and appraisal system that put more emphasis on what shows, rather than true quality.

The real estate market and appriasal system have more control on the type of housing built than any energy code out there.

Until the people demand a higher standard for housing it will not get done. Most houses are built with resale in mind and no attention is given to energy consumption. Joe average home owner has little chance of getting an energy efficient house.

[e-merlin]

Originally Posted by reverbbb

That is an awesome picture. I have never seen the inside of a UK loft - yet alone a 15th century home.

I am sure that older homes will have difficult time of making the desirable grade in some cases.

What is happening in the US is driven by builder profits. The home cosntruction is getting worse. The designs are attempting to appeal to the senses with clean sharp lines and large open spaces. But in the attics (lofts) you will find some really horrid duct applications.

Even the historiclly 'tile showers' in $400,000 homes has been replaced with fiberglass and glass walls. Real wood or wood veneer is nearly none existant in new homes these days. Yet these are simply the cosmetic issues.

On the energy front, the builders will specifically ask for the LEAST expensive heating/cooling equipment for a new home. The consumers don't know any better. They tend to see the granite counter tops and don't realize that the $8000 upcharge for the counter top could have been better spent on better HVAC equipment and insulation. That pretty granite countertop is going to cost them an additional $800/year because the builder selected the lowest quality HVAC equipment. 15 year life of HVAC x $800/year = a whopping additional $12,000 in utility costs. Sad, but true.

Again I ask, why are we accepting this non-sense?

And that, boys and girls, is why I want to spec, and maybe GC, my next house.

I have been interested in energy efficiency long before the "green" movement came along. I would never categorize myself as a tree hugger, but I have always wanted to build a house that used energy from the sun and wind. Taking advantage of geothermal has also interested me for quite a while.

Growing up in a house that was built in 1903, I wondered why someone didn't come up with a way of heating the floor. Now, that's a reality, and it will be incorporated in my build.

Heating is pretty much a given, but what do you do about air conditioning? I think maybe a basement under the basement may be part of the answer, circulating cool air from the lower levels to the upper. Also, a roof that captures the sun's heat in winter and reflects it in the summer would be a tremendous energy saver, if it didn't use more energy than it saved in the process. I wonder if a permanently "reflective" roof woud save more in the summer than it would cost in the winter? Also, how much would it contribute to climate shift if implemented on a widespread scale?

I agree with your premise, Reverbbbb. I just wonder what we're going to do with all those energy wasters.

[voodoostation]

don't you think that the buyer would be better informed on their major purchase?

Unfortunately, you can't fix stupid. We have home inspections, walk throughs, bill of materials lists, architects, designers, builders and homeowners. If the prospective buyer doesn't have the common sense to realize that a lack of enough insulation, cheap windows and doors, heating and air conditioning systems riddled with holes are gonna cost them more in the long run, then they should pay it. How people want to spend their money should be completely up to them. A little research can go a long way, if they choose to. If common sense was gold, there'd be pockets full of plastic.

Check out HERS, house energy rating system (energystar.gov). Done been thunk of. It's a completely valid idea, I'll grant you, but, so are warning labels on everything. You can't fix stupid, unless maybe you remove the warning labels...

[Robbie W]

Originally Posted by reverbbb

I suggest that a method is established for determining the Power Density of a home. This would include the amount of insulation, the cubic feet of heating/cooling and the number of poorly insulated windows. You ratio this up with the size of heating/cooling equipment, kW ratings of appliances and any other measurables of energy consuming devices.

Here in Texas building contractors are required to comply with the 2000 International Energy Code (not sure if they have formally adopted the 2003 or 2006 ICC Energy Codes at this point) . Lots of other states are under this code as well.

This code places certain parameters on residential dwellings depending on the geographic location. For instance some areas in the southern regions of the United States might require a window glazing U factor or insulation R rating that is different from areas in the northern part of the US. The whole purpose is to make homes more energy efficient while taking into account the annual climate factors. It even has guidelines for things such as provisions for minimum air leakage within the building envelope.

This a fairly new code that originated in 2000 when all the International series of codes were issued by ICC (International Code Council).

This is a DEEP subject in reference to the exact intent of the energy codes, who is required to follow them, how states have amended them, etc. but to give a broad response to your original post...there are codes/standards in place to achieve an energy efficient home.

http://www.internationalcodes.net/20...-6533-06.shtml

http://www.seco.cpa.state.tx.us/sa_codes.html

take care,
Robbie