Tue, 19 Dec 2023 05:22:36 +0000 http://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=8842 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=8842 Wed, 21 Mar 2012 22:18:23 +0000 tony http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=8828 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=8828 Mon, 19 Mar 2012 08:34:17 +0000 tony
Heating degree days need to be used in the calculations, how are these applied to historical data, is there a standard year or is everything comparative etc?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=8572 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=8572 Tue, 07 Feb 2012 13:21:07 +0000 Shevek
What about any 3D modelling thermal design analysis software for Mac?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=6883 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=6883 Thu, 27 Jan 2011 17:07:43 +0000 Sprocket Uncoarsed stone rubble walls, Newlath membrane, then breathable VCL, then battened out.
Roof insulation is in. All sealed at top of wall + wall plate etc and down to floor
Cabling and pipes are in and VCM penetrations hopefully sealed.
Everything is well taped and/or glued. It *ought* to be pretty air tight.
But wall insulation + board + plaster not in yet.

We are wondering if it would be a good idea to check air tightness as soon as doors and windows are in. That way if something is leaking we can do something about it without having to remove wall boards etc.

What do folks think? Is it a waste of time before final interior finish?
And what sort of person/company should we go to for this sort of thing?
I don't really need a certificate. I just want to know how air tight it is and if it leaks then where does it leak.
And I am wondering how expensive testing is likley to be?

TIA]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=8540 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=8540 Thu, 02 Feb 2012 23:10:03 +0000 tony
I heard about one the other week that was very pleased with itself and its energy saving measures as the bills were so much lower this year than in each of the previous two.....]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=8356 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=8356 Wed, 04 Jan 2012 13:43:42 +0000 tony
I think that we should base these calculations on the assumption that they are replacing CFL's, comparing to tungsten is also possible but that will give a very rose tinted result.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=8391 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=8391 Wed, 11 Jan 2012 14:17:19 +0000 wookey
My existing spreadsheet uses Room_Vol * Temp_Diff * Air_changes * Specific_heat_capacity_air, which I think came from SAP.

Do we just do the same, but add a factor of 1-MVHR unit efficiency?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=8376 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=8376 Sun, 08 Jan 2012 16:49:36 +0000 RobinB
See http://www.bre.co.uk/sap2012/page.jsp?id=2759

Comments are invited not later than 28 March 2012

RobinB]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=8344 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=8344 Fri, 30 Dec 2011 16:09:09 +0000 Mike George
So as not to hyjack that discussion, thought I'd copy the relevant bit here. It would be good to see what others have concluded]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=8339 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=8339 Thu, 29 Dec 2011 14:56:33 +0000 tony
Assume that electricity cost is 12p per kWh and the bulb cost three quid. (heating effects can be ignored)]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=8233 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=8233 Mon, 05 Dec 2011 09:33:16 +0000 Triassic
Levelized cost is often cited as a convenient summary measure of the overall competiveness of different generating technologies. Levelized cost represents the present value of the total cost of building and operating a generating plant over an assumed financial life and duty cycle, converted to equal annual payments and expressed in terms of real dollars to remove the impact of inflation. Levelized cost reflects overnight capital cost, fuel cost, fixed and variable O&M cost, financing costs, and an assumed utilization rate for each plant type.3 For technologies such as solar and wind generation that have no fuel costs and relatively small O&M costs, levelized cost changes in rough proportion to the estimated overnight capital cost of generation capacity. For technologies with significant fuel cost, both fuel cost and overnight cost estimates significantly affect levelized cost. The availability of various incentives including state or federal tax credits can also impact the calculation of levelized cost. The values shown in the tables below do not incorporate any such incentives. As with any projections, there is uncertainty about all of these factors and their values can vary regionally and across time as technologies evolve.

http://www.eia.gov/oiaf/aeo/electricity_generation.html

Thought the above paper may be of interest to some of you. Makes Solar and wind look very expensive!!]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=8209 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=8209 Thu, 01 Dec 2011 21:01:55 +0000 suegreenbuilding
However using this has dramatically changed by U value calcs for an uninsulated block/brick wall (down to .78 from 1.81). Can anyone help please?

Thanks.

Sue]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7985 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7985 Thu, 20 Oct 2011 17:26:30 +0100 tony
Again it is a difficult question for which I would like to see a simple one size fits all answer

The water used to freeze by my bedside when I was a lad, explains a lot:wink:]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7837 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7837 Tue, 20 Sep 2011 18:48:07 +0100 tony
Solar panels should produce a nice turn of profit due to FITs, but miss sold can be and sometimes are disastrous.

Why didn't they ask us we could have given them the low down]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7766 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7766 Thu, 01 Sep 2011 14:46:21 +0100 sinnerboy
just spotted this -

Annual heat demand relaxed to 25kWhr/m2/a
n50 achr relaxed to 1

Probably a good pragmatic move . The standard relaxes so hopefully an incentive for refurbishment projects to go for it.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7715 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7715 Sun, 21 Aug 2011 20:41:41 +0100 ahpotty
I have lists of Green materials available but don't know what thickness to go for.
annie]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7677 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7677 Wed, 10 Aug 2011 10:22:30 +0100 ted
The house has won an award for its environmental credentials, the county council's best eco-friendly new build in 2005.

The agents details show that it scores 79 on the Energy Efficiency Rating. http://bit.ly/qj8F6Z]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7656 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7656 Wed, 03 Aug 2011 17:01:21 +0100 delboy
The assessor is certainly needed to be accredited designer, and ideally can also issue certification.

Ta]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7131 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7131 Fri, 18 Mar 2011 10:54:56 +0000 tony
Ideally I would like some for typical Victorian terrace, 1960's semi and a new three bed house built to satisfy current building regs

thanks -- answers in W/m2/y please]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7610 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7610 Fri, 22 Jul 2011 09:02:40 +0100 arnyj
will it tell me where the air is leaving the house with the aid of some form of dye so that I can go around and seal up holes.

Am currently installing internal insulation "sheeps wool /cotton waste" covering with blue sheets and pro-clima tape.

after having test intend to install MVHR system I'm also hope-ing they will tell me the house is tight enough for it to work properly.

Will they make that type of statement?

Am I right to think BSRIA will send someone who lives near me to do job.

can't think of anything else.

thanks Arnyj in chester]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7595 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7595 Mon, 18 Jul 2011 23:30:22 +0100 tony http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=6317 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=6317 Tue, 21 Sep 2010 17:36:23 +0100 JTGreen
imeasure only records direct use in your home (no transport or indirect use). Carbon account has flights and vehicles. I have played with both and they seem pretty user friendly. imeasure has a "Carbon Club" facility that would allow GBF members to sign up to it. On carbon account you have to choose your friends, so we could all befriend each other (facebook stylee). I guess it's unlikely to allow us to reach any firm conclusions, but might provide a competitive spur to reduce energy use - which in itself would be a good thing.

http://www.imeasure.org.uk/

http://www.thecarbonaccount.com/

What do you all think?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=6881 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=6881 Thu, 27 Jan 2011 11:12:48 +0000 mybarnconversion
Can anyone recommend someone with a bit less of a double-glazing salesman approach in Carmarthenshire?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7541 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7541 Mon, 27 Jun 2011 17:18:07 +0100 delboy
My accrediting body (who I should keep nameless!) told me on the phone that Stroma are "unethical" because amongst other things, they steal their assessors' clients for future work.

This is quite an allegation. Does anyone have anything to say on the subject?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7338 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7338 Mon, 02 May 2011 20:07:32 +0100 tony
The hare on the other hand was using fossil fuels and wood to supply most of his energy and as these didn’t carry the same multiplier his energy use looked pretty good too. This was despite the fact that his house was using just about two and a half times more energy than his neighbour the tortoise.

Until that was that oil, gas and wood all ran out or became prohibitively expensive. Now the hare had no choice but to convert his home to electricity as it was the only transmittable form of energy but he found that he now needed two and a half times as much as the tortoise who was still enjoying his low energy warm and cosy environment at a much lesser cost the his poorer, colder and sadder neighbour the hare.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7301 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7301 Fri, 22 Apr 2011 12:53:18 +0100 Jonti
Any help gratefully received

Jonti]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7262 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7262 Mon, 11 Apr 2011 15:54:34 +0100 Louis Any help would be most appreciated.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7229 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7229 Mon, 04 Apr 2011 16:49:40 +0100 James Norton
Couple of calcs ok but latest project doesn't seem to want to 'report'. Despite all the data entered in (little green ticks all over the place) it still says I can't get a report as "Dwelling incomplete, reports are unavailable!"

Have a look.

Thanks

(for those interested yes its my new house)

J]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7179 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7179 Thu, 24 Mar 2011 18:00:40 +0000 Louis
I'm doing a life-cycle analysis on the Modcell structurally insulated straw-bale panel as part of one of my final year modules at university. I'm wondering, because the straw used in the panel is a by-product of the agricultural industry does this mean i should take into account the carbon used/sequestered for the growing and harvesting of it..or just from when it is ready to be gathered, baled and collected..?if that makes sense.

Thanks]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7156 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7156 Mon, 21 Mar 2011 18:56:04 +0000 tony In a heated building at a particular point in time the amount of energy required to keep a room at its design temperature is fixed. For the sake of argument let us say that the room in question needs 500W to keep it warm. This energy is supplied by a radiator that emits 400W and a 100W light bulb. Now someone fits a low energy light bulb which only needs to use 20W to light the room to the same level as the old incandescent one did. The problem now is that the room has only got 420W of energy going into it but its heat loss is 500W so it will be colder. In order for us to maintain the temperature at the same level as before we must now supply 480W through the radiator. Thus no energy has been saved.

400W + 100W = 480W + 20W

The uptake and increase in the use of low energy light bulbs is being used by central government as way of meeting our carbon reduction targets YET NO ENERGY IS BEING SAVED!
Many reports on energy use in buildings are assuming quite incorrectly that energy and costs are being saved in the winter, whereas, no energy is being saved although some costs might be depending on the relative costs of the different energy sources used. In the summer there will be a cost saving but lighting is used less as it is lighter for later into the evening and light early in the mornings. In this way 80% of the savings being claimed are not being made in the real world.

I call this over-accounting.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7145 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7145 Sun, 20 Mar 2011 08:57:16 +0000 tony
Why arent we using absolute numbers like kWh/m2/y?

These can then be tabulated for different types of homes, all homes different years etc

but at least we would be able to what was going on.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=5389 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=5389 Mon, 22 Feb 2010 19:28:01 +0000 CarneyC
So far it's motivated me to replace some 50W GU10's with Megaman CFL replacements, although annoyingly the kitchen ceiling fire hoods prevent their use in that application (bulb too tall) - any alternative recommendations ?

Interestingly though, I still have a nightime base draw of around 250W & I want to minimise this further. Wherever convenient I turn off at the socket / switch, but sometimes it's difficult to do so. The only practical thing I can come up with is to use some timer switches where getting to the switch / plug is a pain.

The question is - How much electricity does a timer switch use? Anyone know? No point in using them if I lose overall :wink:]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7117 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7117 Tue, 15 Mar 2011 16:02:51 +0000 Luke.Smith
I've trawled through lots of posts on the forum regarding SAP assessment procedures and thermal dynamic modelling packages but there seems to be no mention of the BREDEM methodology.

I'm looking at ways to model baseline performance of exisiting housing stock beyond the capabilities of rdSAP. I'm not convinced that complex modelling packages are necessary but recognise that elements such as location, exposure, orientation, occupancy, heating patterns, lighting and appliance use etc assumed by rdSAP are critical variables.

The BRE Domestic Energy Model (BREDEM-12) seems to be the logical methodology to use. Do BRE share this? Has anyone had a go at putting the calculation in to spreadsheet?

Luke]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=6990 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=6990 Fri, 18 Feb 2011 13:48:17 +0000 tony
I visited a large secondary school today and was horrified by the numbers of doors left open to heated areas

The doors were nice commercial quality aluminium ones with two rows of brush draught strips unfortunately the doors had hold open as well as self closers but were held open all the time.

1500 people looking at doors left open but no one seeing this as a problem -- what hope is there for Eco Schools?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=6917 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=6917 Thu, 03 Feb 2011 23:42:28 +0000 tony
My surface temperatures in the late evening are:-

Frame indoors 16.6 all round; sash 18.5; glass 17; reveal at coldest point 18.5

Frame and sash outside 4.8 ; glass 7.9 varying to 5.6; reveal 4.8]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=6928 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=6928 Sun, 06 Feb 2011 09:15:25 +0000 Joiner http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=6887 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=6887 Thu, 27 Jan 2011 21:59:56 +0000 delboy
We have entered identical inputs, but we are getting different results.

This seems insane as they are both meant to be identical software.

Has this happened to anyone else?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=6843 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=6843 Thu, 20 Jan 2011 11:19:03 +0000 piersadler
I'm having a go now using BuildDesk, but I'd be interested to compare results/method). I will post my results.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=6814 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=6814 Fri, 14 Jan 2011 16:00:54 +0000 tony http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=6750 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=6750 Wed, 29 Dec 2010 16:54:02 +0000 petecooper I hope you're all enjoying the festive shenanigans. I've been replacing halogen bulbs with lower power consumption alternatives. I've written it up here, if you're at all interested in my solution:

http://emmaandpete.com/cooper-acres/how-not-to-throw-money-down-the-sink-with-halogen-lights

It's a bit nerdy and wordy (~1250 words, hence me not posting it verbatim here), but hopefully someone will benefit from it.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=6697 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=6697 Thu, 16 Dec 2010 14:48:42 +0000 StuartB
Any evidence to support this?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=6687 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=6687 Wed, 15 Dec 2010 12:49:27 +0000 tony http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=6678 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=6678 Mon, 13 Dec 2010 16:31:03 +0000 jamesbl SAP worksheets ask for width and depth, I think - How are these measured ? Does a soffit count as an overhang for instance, and how close to the window does it have to be ?

thanks
James]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4280 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4280 Wed, 15 Jul 2009 17:54:02 +0100 RobinB many thanks
RobinB]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=6507 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=6507 Wed, 03 Nov 2010 13:16:37 +0000 twolittlepiggies This is my first contribution to the forum having just joined.:confused:]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1903 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1903 Wed, 11 Jun 2008 14:16:54 +0100 ludite
Just nearly fell through the floor over our last quarterly 'leccy bill - £650.

We are due to have our ground floor rewired in the next few weeks, and it got me thinking.

Is there anything we can do to reduce our bills? Our wood fired stove heats our water and one room in the winter and we have the oil fired boiler on for an hour a day to do our DHW in the summer. (so I'm kind of discounting a retrofit of solar water panels)

Would solar pv panels on our small area of south facing roof help run fridges and a washing machine or are they only good for lights?

Which is better, compact flourescents, or dimmer switches? I was wondering, with the new kinds of lights - led etc, if there could be a separate lower voltage system installed to run the lights. Sparky says no, but I wondered what you all thought.

Should I scrap (freecycle) our old fridge and get a more up to date one?

The rewiring is going to cost us over £7,500 as it is (we have outbuildings, and the old stuff needs to be stripped out - some is still round pin sockets). I've been following the solar pv discussions and I'm still not sure if the payback is worth it until the installation prices come down a little.

I guess what I mean is, is there a way of doing the rewiring which will save us money, and then we can buy new appliances later (lower voltage ones?) , when we need them.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=6379 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=6379 Tue, 05 Oct 2010 18:45:57 +0100 tony
I told her probably not but that it would make more difference how much too much water was boiled than any difference in efficiency

who was nearer?

I only drink cold water.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=6340 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=6340 Mon, 27 Sep 2010 08:19:01 +0100 JTGreen
I have just done so, and realised that 'heating on' (yesterday for a couple of hours) makes a MASSIVE difference. I expect my CO2 weight to rocket this winter. But I have at least been prompted to contact my builder about the loft access and insulation.

Of course, the Carbon Club is using data from the week ending 12 Sept, where I scored a more healthy-looking 7kg CO2 per person. The full horror is yet to come.

A few people have registered, but are not entering the data - our little club of six or so is puny compared with Money Saving Expert Forum (they have over 180 members). It's never too late to join, either.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=6324 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=6324 Thu, 23 Sep 2010 14:48:29 +0100 tony
Is very confusing!!!

Energy saving is the goal and economics enter into this but carbon savings confuse the issues alarmingly

It is a great report but like wading through treacle to understand.

Some good conclusions but will they be lost in the melee of saps, csh, passivehaus, bream etc etc

anyone understood it?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4136 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4136 Wed, 10 Jun 2009 13:31:09 +0100 RobinB
It's at http://www.handymandy.co.uk/house/sappish.xls

I wanted to be able to play around and quickly look at the impact (financial and carbon) of different choices for our new house, 2G v. 3G, insulation values, window sizes etc. etc. Feel free to download and enter your own data.

I'd be REALLY grateful for your comments, and if a similar spreadsheet already exists I'd love to know about that. I've looked at the Kingspan website one but I want to be able to play around a lot more and see the results immediately.

thanks
RobinB]]>