Hello friends....
It seems to be a pretty good forum to discuss and clarify various concerns and doubts on Green building issues. Well, I have a qstn regarding the energy efficiency of Green buildings. Do you guys really believe that the Green rated buildings are really energy efficient...???
From the history of various Green buildings constructed so far and the way by which they all intended to meet the required credits imply that energy effeiciency was not given the prime importance. Although Energy & Atmosphere sections bags the maximum number of total credits, it doesn't hold the same when it comes to the targeted credits for most of the Green buildings. The usual tendency is to bypass energy efficiency section[agree that the capital cost will be high in case of targeting this part] and concentrate on other less expensive and easily attainbale areas. The end result is Green buildings enjoying the economical and political benefits without actually reducing the enrgy consumption to a respectable level.
The recent decision of USGBC to make 14% energy savings as mandatory for the LEED NC 2.2 Rated buildings is really a welcome move.
Does sustainability do not call for maximum energy efficiency...??
Isnt't ironic that a Gold rated building with only 14% energy savings enjoy better status than a Silver rated building with possibly 25% energy savings....??
Thanks & regards
Anoop.
Books 
Comments
You have raised an interesting debate. Green Building is no just about energy efficiency although it is an important factor. We also need to consider materials and their embodied energy as well as numerous other issues such as having a healthy house, ventilation, transportation, natural lighting.
It would be far too simplistic to measure a buildings greeness purely on its energy rating.
The BREEAM rating is an attempt at weighting the various elements of an environmental building.
Lots of glass is always a problem as this leads to big heat losses. The desire for a heating system ( all the talk about ufh for example) -- green buildings should not need heating systems in the UK.
Yes sustainability does call for maximum energy efficiency -------- but what is maximum? eg if they generate it themselves can they waste it?
In Iceland they build from uninsulated solid concrete and have single glazing!
There are many methods for rating the "greeness" of buildings, each weighting energy efficiency differently.
I have more knowledge of EcoHomes and the Code for Sustainable Homes than I do of other rating systems. The latter of the two requires a very energy efficient building for its top level (level 6) as the building's heat loss parameter must be less than 0.8watts/m^2/K. This is irrespective of heat source.
However the majority of energy credits for both assessment methods are more concerned with carbon emissions than energy usage. The code for sustainable homes sets carbon emission limits per square metre for each of its 6 levels. This is of course subtly different to energy efficiency as you can effectively get away with building yourself a biomass heated shed. Whether or not you consider that to be green is another matter.
OTOH, a code that is too complex won't be taken up by the industry and there is little other choice: We perhaps must accept thet we will end up with buildings that are designed to beat the code rather than designed to meet the intent.
Olly, I think the whole load of stuff about carbon saving is not the way to go, sustainability and gross levels of insulation and air tightness is where it is at and this leads to relavent savings of gross energy use.
I think part of the problem is that what is green/sustainable changes with regard to your perspectice and, it seems. the direction of the wind in a political sense. Do you build for now, for a potential climate scenario (which may be wrong) or for a post apocolyptic (peak oil/energy shortage) scenario which may also be wrong. The 'green' answer could be significantly different in each case (houses wrapped in great slabs of airtight insulation at one end of the scale to thin walled adobe/cob at the other) who knows for sure?
The problem is we are asking business (which is about money), politics (which is about being re elected & winning boo hoo arguments with another suited fruit cake you went to Oxford with) and the general public (who have myriad distractions) to synthesise a load of different information and come up with a single answer to which we can apply 'green' both now and throughout its design life (which in this part of the world could include mini ice ages and/or desertification if we enter a mad Bond cycle combined with runaway warming).
It is hard enough for those of us who are really trying to get to the 'best' answer for our existing property/new build with the wealth of epertise/opinion on this forum event when informed by research and 'quality' publications.
Whilst it can be and is said that building to gold/passivehaus standards has to be a top option It ain't neccesarily so, as has been pointed out. So you are left with a confusing array of options based on local conditions and resource availability. Ok some of these are extreme, like iceland or those shoebox things people occupy in Japan but there is a continuum of options for what might be regarded as energy efficient.
I feel personally that all 'green' buildings should be energy efficient and healthy and aesthetic/invoke a passionate response & all the rest of it as a minimum all at the same time. Any thing esle is just energy efficient OR healthy OR nicely desinged OR uses sustainable materials etc. I also know that the existing housing stock (that which is built or will be built in the next 25yrs) is never going to get close to performing to part L standards for it's lifetime let alone anything else.
I suppose, in a typically roundabout way, I am less concerned with gold standards etc as, by their very nature, they only apply to a very small percentage of new builds in any case which will make a very small difference to the overall carbon footprint of housing. I believe we should be focusing on lifting the bar at the bottom end by properly monitoring the performance of houses supposedly build to part L standards and addressing the gross inadequacies of the existing stock - this is where major savings can be made now.
Stands back, puts on blindfold, waits for the sound of safety catches!
Posted By: skywalker
to synthesise a load of different information and come up with a single answer to which we can apply 'green' both now and throughout its design life
It is hard enough for those of us who are really trying to get to the 'best' answer for our existing property/new build with the wealth of epertise/opinion on this forum event when informed by research and 'quality' publications.
While I agree with your tartly sceptical comment on the unlikely leadership to be given by Business and Parliament in this complicated desire to Green our lives, I think part of the problem may be your belief that we are seeking "the best" solution in each case. There ain't no such simple thing in life!. It depends on what aspect you are emphasising in your calculation, and within that troublesome framework, just where you stop including the myriad elements of the project build in the accounting. For example, we all try to account for eco-costs of delivery to site, but does anyone then compute effects on existing industries when everyone disbars any deliveries over 'n' miles: whatever 'n' is!
We are all digging in the covering layers of a potentially deep mine of green engineering, social and technical. Nobody knows just what precious seam or isolated nuggets such activity is going to yield, but I think we all want to go on digging, willing to freely discuss our findings without rancour. As number of miners grows, and media, business and Yea! even Parliament begins to identify themselves with the cause, a small number of crucially important targets will appear, and our diverse diggings will be given focus.
I bet roof mounted domestic wind turbines won't be among them, and I'm not so sure about heat pumps
Niggle
ps
perhaps a mining metaphor is inappropriate?
Nice post Sky, I am with you all the way and I will stand next to you and wait for that click too.
Don't green technologies need to be efficient in overall terms not just their running costs?
I prefer nuclear power, there is a nice reliable one 93 million miles away, wonder who built that?
1. All new build homes must have Solar PV & Solar Hot water to suit designed occupancy levels.
2. All new roofs must incorperate Solar PV & Solar Hot water to suit designed occupancy levels.
3. Low noise wind turbines should be installed were ever practicable on all new builds and re fubishment projects.
4. Energy companies must give "Free on grid connection" and pay a minimum set rate for power export.
5. Homes should use LED lighting interlocked only to illuminate occupied rooms (exept or dedicated night lights)
6. Install a very high level of insulation.
7. Ban the use of fossil fuels for heating in all new builds and referbishment projects.
The result would be most house holds would reduce thier energy bills and carbon footptint by aproximatly 75%
Dare I say why the above would not be acceptable ? It might affect the profit margins of the Energy companies. But Hey it would be GREEN !!!!!!!!
:bigsmile:
Nowadays thanks to various building regulations and other busybodies we can no longer do our own thing (with the odd exception) we are dependant on the 'grid' for everything! So even if we don't want to this grid comes into our lives and consumes our lives! Get rid of the national grid! If yoy want a local grid by all means! A local grid will supply what you need, where you need it with less wastage! Now that I believe is looking after OUR environment, maybe not your environment, if you see what I mean!
Just a thought...................bound to be lots of experts telling me why we can't do that..........justifying their own use no doubt...................but why not???
I think someone pointed out before the problem with electricity is it is invisible. We plug something in and it works, the source is miles away and so we don't appreciate the environment cost of its production.
I can't help think this is why so many people make such a fuss about wind turbines because they are a "novelty" and considered aesthically unpleasing to the same people. To me I think they are a thing of beauty creating power from nature. If every village / town had one or an array would it make people appreciate where there electricity comes from and the enviromental impact? Maybe my view is different because I was brought up a few miles from Didcot power station so it was never really out of sight even 20 miles away in some cases.
Paul in Montreal.
Is that the very definition of synergy?
Paul
Mostly I agree with your sentiments
How will planes fly when all the fossil fuel is gone?
Oil is far better used as a chemical feed stock than as a fuel too.
ie I abhor waste, which surley makes me " green"
ie we have never flown anywhere, well except twice to spain in the last 30 years to visit relitives.
I also drive a 11 year old diesel car, bought new, and mostly heat our home with waste wood
and do not drink Starbuck coffee
On the other hand my preception would be that there is a "twittering cless" of greenies who drive electric or dont own a car at all, cos hey they live in a conurbation. Try living in the country on public transport.
but f----g fly off on hols, several times a year, , but hey they "offset" the carbon
Drink starbucks, throw out leftovers immediately, etc etc
So who is greenest?
Ps
stuff electric cars
where does the electric come from
Stuff renewable electric generation , do the sums first please folks
the only hope is NUCLEAR FUSION, then all electric everything
Fine by me
cheers
M
Hypothesis was that essentially we are all fubar-ed without fusion...(and to be honest its seemed quite compelling argument as well), but several promising projects were looked at in the show...
J