[Mark Siddall]

I know this thread has got a little aged by now but I thought that this little review of books on energy/building science may be of interest. A number of the books are listed under the 'books' heading: –

INTRODUCTION TO ARCHITECTURAL SCIENCE: THE BASIS OF SUSTAINABLE DESIGN BY STEVEN SZOKOLAY.
Though it is not UK specific (whereas Little/Thomas is) in terms of currency and accessibility this is the best all rounder I have come across so far. The book does venture into the discussing ASHRAE standards as well as those of the UK/Europe thus giving a convincing overview of building science as it currently stands. Offering insight over a range of topic areas including comfort, thermal performance (U-values, thermal mass and thermal bridging), acoustics and lighting. For those inclined the book also has some handy worksheets at the back.

ENVIRONMENTAL DESIGN (PAPERBACK) BY RANDALL THOMAS
Competing for best building science book is Thomas’s regularly updated book. Useful and informative though it caters for a broader audience than Design with Energy i.e. it examines commercial buildings also. The book has an impressive array of case studies, the main criticism being that they all belong to the practice that Thomas works for. NOTE: The third edition of the book is now available whereas my criticism relates to the second.

THERMAL ANALYSIS AND DESIGN OF PASSIVE SOLAR BUILDINGS BY A.K. ATHIENITIS AND M. SANTAMOURIS
This is a detailed examination that goes into the building physics of passive solar design. This is not a coffee table book, quite the opposite. It made me realize just how much calculation is involved in the design of a truly successful passive solar building. Most of the algorithms discussed went straight over my head. This book is not for the faint hearted rather it is for the serious building scientist.
From reading this book I also concluded that some serious software is needed to assist with the design of a true passive solar house.

PASSIVE SOLAR ENERGY BOOK BY MAZRIA, EDWARD
Having tracked a copy of this book down as a consequence of David O’s suggestion above I have to agree that this book is a classic. Structured in a manner similar to ‘A Pattern Language’ I have not come across a book that tackles passive solar design in such a thorough or pragmatic way. My only concern is that as time has moved on more detailed modeling techniques have developed and new technologies have been developed, particularly with regard to glazing. This may impact upon a number of the books propositions.

THE NEW AUTONOMOUS HOUSE: DESIGN AND PLANNING FOR SUSTAINABILITY, B AND R VALE
I have read a number of books on the subject of environmental science/passive solar design (the best I’ve read so far being covered in this review) but this is the only book offers detailed insight into the full range of selecting and specifying for a domestic setting. It offers insight into the specification of cooking appliances through to a useful concept for assisting with the preliminary stages of a design; what could be termed the “Vales Room.” The book also has some astonishing, and frankly amusing, heat load calculations regarding the thermal performance of cats. A quirky lovable classic.

Mark

[Mark Siddall]

Jim,
I think the original intention was that the two elements block wall and timber frame would be structurally independent; the driving force for this decision was to mitigate thermal bridging.

However this approach raises the issue of the slenderness ratio of the blockwork wall. If it isn't considered appropriately then the wall will be prone to collapse. Three ways of addressing the slenderness ratio have been considered:
1) concrete ring beams. Though this does not address the slenderness ratio in the true sense of the term is does tie the blockwork together in such a manner as to increasing the stiffness of the masonry.
2) increased width of block i.e. 150mm rather than 100mm
3) Tying the timber frame and the blockwork together, be it studs or I beams. (It is recognised that this compromises the structural independence, however with appropriate detailing the thermal bridging issues could be addressed to reflect details built on mainland Europe.) NOTE: This is the closest to traditional timber frame and will probably require the least input from a struct eng.

All the above are subject to input from a struct eng.

Hope this clarifies my interpretation and thus my comments above.

Mark

[Mark Siddall]

In search of resources: –

Is anyone aware of software to calculate thermal bridging in accordance with BRE IP01/06, or BS EN ISO 10211-1 Thermal bridges in building construction – Heat flows and surface temperatures – Parts 1and 2?

The reason for asking it that the THERM software does not extend to this. (I've contacted LBL about THERM and they said they will add this request for features to the list of future upgrades…..though they also noted it may take a few years.)

Mark

[Mark Siddall]

Nick,
Another option: –
If the web team elect to go down the editing route it would be great if members could mark certain subjects as his/her favorites (Over time certain subjects may be less discussed but still remain a useful reference).
This system would ensure that a useful subject can always be found rather than one having to hunt for it. (As with other facilities this would be activated by log-in.)

Mark

[Mark Siddall]

I have had a few more thoughts about this idealised window. Perhaps it can do more than offer and insulated frame and optional double or triple glazing.
I have heard of uPVC window manufacturer that supplies a window in two sections, a sub-frame and a preglazed window unit. The advantage for the spec. housebuilding market is that it saves time during construction and at it is a two part assembly the preglazed windows can be kept out of harms way until a suitable stage. A modification of this system could be adopted with the new eco-window. Such a window would allow the same advantages as the above and have the following features:
1) DPC and airtightness membranes would be pre-installed with the sub-frame
2) I have seen PH details that show and extended frame that apparently helps to resolve thermal bridging details. see http://www.baudetails.info/ for details. Consequently the sub-frame could be made available in two sizes PH/Gold and Silver. Obviously the window/sub-frame interface would need gaskets etc for airtightness.
3) If the sub-frame can also be used as pre-insulated cavity closer then the construction tolerances can be reduced thus helping to avoid the 10mm potential thermal bridge that occurs at the interface between the wall and the window. (On reflection this could be why the PH window on the Baudetails site has the extended frame i.e. In this example I have merely thought of a slightly different approach to the solution noted in item 2.)

[Mark Siddall]

I'm in danger of repeating myself….but here goes: –
The hope was to do a thermal performance/cost slight-of-hand in such a way as to achieve the same overall U-value for the same cost but in an alternative and innovative manner(as far as the UK market is concerned).

As for my comments on expensive glazing; I meant that triple glazing costs more than double (increased materials, energy, labor etc)….but there is no reason why an insulated frame could not be used to improve, or achieve, the performance of both. In essence by making a one-frame-suits-all the supply demand profile is changed and the extra over costs of the frame are minimised as a consequence.

Mark

[Mark Siddall]

A question for Chris:

It would seem that one of the stumbling blocks in developing advanced window systems in the UK is that they represent a significantly over specification compared to the UK norm. So the question is how can the market be stimulated to move incrementally towards improved windows systems? I've had an idea that I would like to think could work, but I have no about whether it is truly a realistic proposal. This is where you kick in.

The following explains me thought process to date:
The difference between any new UK energy standards and those of mainland Europe it that we have the luxury of knowing exactly how the standards will need to develop and which technologies will help to achieve those goals.
Let me explain my thought process: –
On mainland Europe aka Germany low energy standards have developed incrementally through successive years of research and development. They have learned the hard way. We don;t have to.
Due to the hard work of the Passive House Institute we know in order to achieve windows with a U-Value of 0.8 that the technology required is achieved by insulating the frames and triple glazing the windows. My question is can the technology be dissected in some form in order to broaden its appeal?

In my fanciful theory what could be done is, rather than relying upon argon filled units to satisfy B.Regs or the Silver standard, insulated frames could be used instead.
If the frame is suitably engineered then in could be designed to accept both double and triple glazed units (e.g. a suitable packer would be used on the warm side). The framing system can then be used to satisfy a range of standards. Having appeal to a much broader range of specification standards it has vastly increased economic viability, and a vast amount of future proofing to boot. All in all this manufacturer would be so far ahead of the game that they could stand to make a pretty penny.
In effect we now have the beginnings of a Gold standard window, all we need now is the expensive glazed units.

The areas that my theory needs more detailed input:
1) Can this frame be manufactured in such a manner as to be competitive, or cheaper than, argon filled windows? I don't have a clue.
2) Can this frame really be used as a substitution for argon or even low E? Again not my area of expertise. (It may that its suited to windows of a certain size but not others.)

Anyway, its just a thought.

Mark

[Mark Siddall]

As I think most people are aware one of the things that is probably hindering the implimentation of more construction at Silver and Gold standard is access to suitable construction information and details. Has anyone come across the first edition of this book? If so is in any good for use in the UK? The most resent edition of this book (mixed suggestions as to whether its been published yet) has been updated to incorporate the Passive House standard.

Details for Passive Houses – A Catalogue of Ecologically Rated Constructions
available from Springer or Amazon.com and Amazon.fr (but not Amazon.co.uk I note…..typical!)
http://www.springer.com/uk/home?SGWID=3-102-22-90285285-0&changeHeader=true

(Assuming that the book fits the bill in a generic sense the airtightness and thermal bridging principles could concievably be applied to both Silver and Gold standards. Thus allowing designers to gain confidence in the practicality and workabilty of the details whilst also and allowing them, if they work with the same constructors regularly, to approach those most exacting construction standards set out by the Gold standard.)

Mark

[Mark Siddall]

David,
1) Has the house been completed yet? If so what was the final airtightness and how much work did the constructor have to undertake in order to achieve this (i.e. did the building pass first time or were remedial works required…much or little…any hot tips?).
2) Was the mass concrete insitu or precast? If insitu what technique was employed tunnel form or traditional shuttering? (I am trying to get a handle on which solution you found to be cost effective.)

I look forward to the responses.

Mark

[Mark Siddall]

Chris,
Do you think that in terms of promoting the Gold and Silver standards moves to get the larger high street banks involved could be benefitial?

David,
Is the Austrian construction industry similar to that of Germany with regard to its focus on masonry construction?

Mark

[Mark Siddall]

David,
In your postings your use “AFAIK” quite regularly its obviously an abbreviated term…..what does it stand for?

Cheers,
Mark

[Mark Siddall]

David,
Thanks for picking up on the incongruities within the posting (i.e. CEPHEUS being pan-European and being at an experimental stage). Now that Passive House has had the chance to bed in somewhat it’s reasonable to expect that this has given rise to a better understanding of means by which value engineering can be undertaken. As a consequence payback times will have had the opportunity to fall; in some cases I would guess quite considerably.
So, I guess we have to opportunity to learn from those experiences and avoid the pit falls. Would you agree that this would require new construction techniques for the UK (Are there any books that would be a useful reference?), or do you think that UK techniques will suffice?

Touching on other reasons for the spread of the Passive House, from other information that I have read it would seem that the banks in Germany (and some other European countries) help to promote Passive House projects by offering lower mortgage rates. It would be nice to think that this could happen over here with the AECB standards. Has the AECB approached any moneylenders been approached on this matter?
(The reason for asking is that I read one survey that noted the Financial Services sector, through its various CSR charters, has a desire to be “seen to be green”. If the survey holds true (can’t find the stats) then offering, for want of a term, Eco-mortgages would a sure fire way for them to make ground on this. Also if banks consider the trend for rising fuel prices Eco-mortgages makes sense i.e. the banks have greater fiscal security knowing that these houses are less likely to be reposed due to fuel bills.)

To pick on your note about peak electrical loads, I see the logic now and I agree that this should be avoided as this would lead to an oversized electrical supply that, left to government initiatives, would no doubt require nuclear power stations and other no no’s that will have long term impacts. Given that the energy demand is so low for the AECB Gold tying the heating system to both the MVHR and the Solar water makes a whole lot of sense.

On this basis I’m interested in idea of LPG-fired mini-CHP – Is there a manufacturer/supplier in the UK, or is this another market that needs to develop i.e. who would you need to import from?

Finally the questions raised above RE: AECB Silver/Gold cost data, payback period, upturn cost…though I will add…. if subjected to well managed value engineered design.

regards,
Mark

[Mark Siddall]

When trying to promote the standards to the less environmentally aware layman reference points on construction costs and payback periods would be rather handy.
I know its a subject fraught with complexity due to concerns about predicting fuel costs, whether or not you use steady state analysis heat loss analysis, occupancy patterns etc.

From this line of enquiry a few questions arise: –
1) Has the AECB collated the £/sqm for the Silver and Gold projects and compared this to the national average construction cost for the various typologies? If so, what is the range in the up turn cost (i.e. between x% and y%)?
2) Is there any data on the payback periods for building to these standards?

(The CEPHEUS Report by the Passive House Institute suggests that you can achieve Payback within 30 years if you build to their standards. This data however relates to another country with different building procedures, abilities and costs.)

3) I guess an underlying question is, does the AECB have a framework for Payback Periods that can be applied to its standards?

If there is an underlying agruement to this line of questioning it is; if the AECB is to expand the appeal of the Silver and Gold standards such data is worth developing.

Regards,
Mark

[Mark Siddall]

Chis,
Agreed some more technical comentary on the building science front is required. There are a whole range of system combinations available with various U-values and SHGCs (some of the SHGC's look reasonable i.e. over 50%).

If such windows can work for Passive House designs isn't is possible (or at least conseavable) to get a UK, or even some form of pan-European, license (excluding Belgium or something) from Southwall Technologies? (it would seem from their blurb that they own the patent)

If things look reasonably favourable perhaps the thing to do would be to agree a license provisionally the Southwall pending reciept of Passive House approval. If the system passes you have deal, if not no harm done.

If a UK owned company could start to develop cheap high performance windows using this technology we could even begin to think about exporting them back to Germany. Given all the talk about Zero Carbon houses recently these windows should be selling like hot cakes within a couple of years.

I almost wish I was in manufuacturing……do I smell the wiff of Natural Capitalism? ;- )

[Mark Siddall]

Andy,
The Refus wall tie (or similar) was used at the Elizibeth Fry Building. I recall reading (in either the Architects Journal or Building Services Mag) that the the Clerk of the Works felt that the cutting of insulation resulted in such damage to the insulation that, in his view, it compromised the specification of the Refus type wall tie i.e. you create more weak spots in the insulation than are offset by the Refus ties. It was his belief that a stainless steel tie would have been better and would have actually minimised cold bridging by comparison. So with this in mind structural calcs for steel ties is perhaps the most promising route.
RE: Refus ties, in essence I agree, based upon the nugget from the journals, if this type of tie is to be used careful cutting of the insulation is certainly required.

Nick
Regarding your comments that got this thread going, there is a German company called Schoek (www.schoek.co.uk) that has rescently set up in the UK. They produce thermally broken structural elements (generally used in larger commercial and blocks of flats) for use on balconies/solar shading etc.
With some innovative thinking these kinds of fixing may offer a potential solution to the dilema…..if you are seeking to tie two largely independant structures together that is.

Regards,
Mark

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