underperforming energetic retrofitting

[heinbloed]

The  Federation of German Consumer Organisations - vzbv ( http://en.vzbv.de/ ) published the results of a survey done recently.
1,000 homeowners who had energy saving work done on their properties (1-2 family homes) were interviewed about their own experience with energy saving renovation. The renovation jobs were done between 2007 and 2012.

http://www.vzbv.de/9550.htm (use google translate or similar)

The study here:

http://www.vzbv.de/cps/rde/xbcr/vzbv/Energetische-Gebaeudesanierung-Verbraucherbefragung-2012.pdf

A quarter of the  homeowners did see no energy saving at all or only minimalistic.
Another 28% will see an amortisation at the earliest in 25 years.
Only 3 % saved 50% or more.

With a quarter of energy saving jobs being a failure and another quarter with an ammortisation beyond the expected lifetime of the energetic renovation meassures there is no saving on any energy on a national or international base.

The facit of the vzb: Saving on energy consumption of 80% by homeowners until 2050 - as anticipated by the German government - can't be achieved. Impossible.

The advise by the vzbv (consumer organisation): get independant advise, make sure strict quality control is part of the job.

Those interviewed who got no independant advise saved an average of 16% on energy consumption.
Those who payed for independant advise saved an average of 27 % on energy consumption.



PS

Are there statistically relevant researches done in the UK on the issue -1,000 cases researched, or more ?
Thanks!




 

 

[J Ingram]

There's the UK gov stats I offered in the other thread on Fire risk of EWI.
more data here,  Energy consumption in the United Kingdom for various house type scenerios.
http://www.decc.gov.uk/en/content/cms/statistics/publications/ecuk/ecuk.aspx
These would be valid, even though as you mentioned other Uk gov stat show in some cases,  U value only achieved 1/2 that of designed spec
HB

The meassurement in homes (U-values meassured versus calculated) has revealed  that only half of the calculated U-value is actually achieved in the average home. So half of all insulation jobs are useless - in other words. Also a UK government job, about 5 years old .......

So i wouldn't use the word useless , just less effect than claimed at design level

Uk gov. stats. claim  
"17. The combined savings from insulation and heating efficiency improvements reduced
domestic space heating by an estimated 41.3 million tonnes of oil equivalent. Without
these improvements it is estimated that energy consumption would have been twice
as high as its current level."
http://www.decc.gov.uk/assets/decc/11/stats/publications/energy-consumption/2323-domestic-energy-consumption-factsheet.pdf

I agree, without quality control and post monitoring samples it's impossible to assertain whether these method are effective, though the above stats. do seem to show improvement/reduction which must be down to something, so presumably energy efficiency measures have had some effect.
cheers jim

[heinbloed]

Thanks, J Ingram.

The link
 
http://www.decc.gov.uk/assets/decc/11/stats/publications/energy-consumption/2323-domestic-energy-consumption-factsheet.pdf

shows on chart 2 an energy consumption (space heating and DHW) of 35 million t oil equivalent for 2007 and 48 million t oil equivalent for 1970.

Saved had been 13 million tonnes, not as claimed 41 million tonnes. Or did the population/number of households triple in 40 years?

A good deal of these 11 million tones were saved by demolishing old buildings and replacing them with new ones for which building regulations were made tighter after the oil shock in the 70s. Splitting up old large buildings into smaller units, apartments i.e. putting more households (people) into the same space has a similar effect.

The question remains if there is empirical research done on the effect of energy saving meassures in retrofit situations. Energy consumption before renovation and after.

The only empirical research done on this issue (as far as I rember) were some 50 or 70 cases of wall insulation were the U-value was meassured and compared to theoretical calculations.

For a statistic we need a thousand+ cases and compare the energy consumption before and after the energy saving meassurements done.
 

   


I read also chart 2, comparing the energy consumption of households for space heating 1990 with 2007. There is no change, despite billions going into insulation and more efficient heating systems.
(We have to keep the year 1990 in mind, the calculation base for climate change )

Looking further back in chart 2: From 1970-2007 the total space heating energy consumption of households went up by ca. 20%.
Did the number of households went up that much as well? Or further?



 

[J Ingram]

If what you say is true , what do you think the reasons would be for the quoted claims then ?
Uk gov. stats. claim  
"17. The combined savings from insulation and heating efficiency improvements reduced
domestic space heating by an estimated 41.3 million tonnes of oil equivalent. Without
these improvements it is estimated that energy consumption would have been twice
as high as its current level." (table 6 shows estimated saving of insulation and energy eff.)

I think one may be many homes in the UK prior to the mid 70s had no central heating systems. Heating demand has increased due to the desire of occupants to have higher levels of comfort in thier homes ( perhaps unnecessarly high ).
Population and households i believe have risen over the time span you mention , though i'm unsure of the percentage increase.
  edit : the summary offers some population/household increase info.
  "1. In 2010, energy consumption from the domestic sector was 48,871 thousand tonnes
      of oil equivalent. This was 31 per cent higher than in 1970, 19 per cent higher than in
      1990 and 13 per cent higher than in 2009. The increase in 2010 follows a general
      decline since 2004 and was largely driven by colder temperatures.
  2. Some of this increase has been driven by a 17 per cent increase in the number of UK
      household and a 9 per cent increase in the UK population since 1990, with a 1 per
      cent increase in both household and UK population since 2009."

despite the estimated increase in demand ,interesting though to see these levels of savings were achieved even though theoreticial U value weren't achieved (due to poor implementation?) imagine what could be achieved with greater quality control.

http://www.decc.gov.uk/en/content/cms/statistics/publications/ecuk/ecuk.aspx
this link may be more useful to study HB as it's a spreadsheet with a more detailed break down showing mean/medium for area/house type etc.
One thing that stood out was that houses built post 2000+ had a slightly higher mean gas use (main energy source used for space heating in the Uk ?) than those built in the previous period shown . ? Perhaps due to increase levels of occupancy per unit in new home ?

[J Ingram]

For a statistic we need a thousand+ cases and compare the energy consumption before and after the energy saving meassurements done.

with regard to monitoring i believe this database is trying to tackle that issue, though it currently only has 126 projects registered
http://retrofitforthefuture.org/projectbrowser.php

[heinbloed]

The calculation method in the UK government paper isn't clearly shown, but   

  2. Some of this increase has been driven by a 17 per cent increase in the number of UK
      household and a 9 per cent increase in the UK population since 1990, with a 1 per
      cent increase in both household and UK population since 2009."

gives a hint.
Since the last 5 years are missing in the UK report (for 2007 the last comparable data is published ) we don't know.

The lousy amortisation for insulation and energy efficient apliances is also part of a conference in Bressanone in Italy in October 2012

http://www.energy-forum.com/

http://www.energy-forum.com/finance.html   

Solar facades seem to have a better financial and ecological footprint than EWI and top-of-the-pops energy saving devices, they can be even financed since they prepare a tradeable good, energy.
Clearly the benefit, the energy production can be meassured around the clock, the installer being brought to the court room if the installation is underperforming.
Not like the insulation job here it is difficult for Harry homeowner to present a book of evidence.
The electric meter can be read by everyone.

The British Arup facade building company is taking part as well, presenting some research: architects and engineers are simply to far backwards orientated to calculate the benefit of a PV or ST facade compared to EWI.
Overestimating work and costs involved when confronted with the unknown.

Here some more on the issue energy saving versus generation of energy, refering to the conference in December (in German language only, Brixen=Bressanone):

http://www.solarserver.de/solar-magazin/solar-report/gebaeudeintegrierte-photovoltaik-neue-geschaeftsmodelle-koennten-solarfassaden-zum-durchbruch-verhelfen.html

Worth a try with google translate or similar. The conference language is English anyhow.

 

 

[Ebs]

We have worked on some of the TSB programmes and our view is that it has become more of an intellectual challenge for some architects and less of a meaningful practical approach to reducing the carbon emission of the existing housing stock.

One in particular springs to mind where by around £90K was spent on a two bed mid terrace house, chucking everything possible at it and the expected savings per year (at the current rates) according to the TSB were going to be around............................................... £500.00!

If everything stayed equal then that would take 180 years to pay back the initial investment, and that is without how much energy was also chucked at it as well.

Would have been better off just knocking it down and building a more efficient (cheaper) building.

Does anyone seriously think that we are going to meet our 2050 carbon reduction targets with superficial head line grabbing schemes such as the TSB programme.

Work with what you have in a efficient and meaningful way, you can not make a silk purse out from a sows ear.  Except that you have got a sows ear and make it more efficient with economical and suitable methods.  If you want a car with Ferrari performance then it is much cheaper to just go and buy one instead of trying to upgrade a Citroen Saxo to try and compete.

Personally we like this web site for its clear analytical approach to insulation although they do appear to be product bias, the product undoubtedly will do what they say it will and for the reasons that they go in to.  The catch is that it would work in off site pre fabrication units just fine but to retro fit, a complete different animal!!

http://blog.lamidesign.com/2012/01/what-you-don-know-about-mineral-wool.html