Sun, 03 May 2026 09:58:03 +0100 https://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=6324 https://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?]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4136 https://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]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=3683 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=3683 Mon, 02 Mar 2009 15:18:49 +0000 Energy Saver
Am I right in saying that with a few days training using approved software I can do SAP and SBEM ratings but will need extensive training to produce and issue an EPC?]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=6223 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=6223 Wed, 01 Sep 2010 13:53:58 +0100 tony
How much should we each use?

At home I have used on average 16kWh per day for the past year.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=6158 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=6158 Sun, 15 Aug 2010 16:14:54 +0100 tony
We should be using a low energy standard.

A poorly insulated low carbon house could become a high energy user if the method of heating was changed from a low carbon one to something different

It is extremely likely that the heating method would change during the life of a house or housing estate with biomass boiler.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=5866 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=5866 Fri, 28 May 2010 09:23:23 +0100 DianeH
I’m doing an MSc at the Centre for Alternative Technology and am particularly interested in the problems of refurbishing traditional homes. My particular field of research is moisture and ventilation in stone built dwellings - as more of these dwellings are significantly improved we will need to be more aware of what the leakage level is in this type of building to ensure indoor air quality. There’s also a widely quoted rule of thumb of “twice the normal level of ventilation” which I’m trying to get to the bottom of.
For my practical research, I’ve had a group of dwellings tested, which have come out tighter than I had expected from anecdotal evidence.
Has anyone got an air tightness tests for un-improved homes? (irrespective of construction)
What views have people got about this area?]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=5727 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=5727 Tue, 27 Apr 2010 16:36:40 +0100 RobinB
Dwelling volume 532.58m2
Infiltration due to chimneys, fans and flues 0.04
Pressure test, result q50 3.00
Infiltration rate 0.19
Number of sides on which sheltered 2.00
Shelter factor 0.85
Adjusted infiltration rate 0.16
Ventilation : balanced whole house mechanical with heat recovery
air throughput (air changes per hour) 0.35
efficiency in % allowing for in-use factor 75.65
Effective air change rate 0.24]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=5665 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=5665 Thu, 15 Apr 2010 13:42:17 +0100 davidg234
http://www.historic scotland.gov.uk/energy_modelling_analysis_tenements.pdf

I would like to know if there is any more dcouments like the one from historic scotland (from link aobve), or does anyone know of academic journals where I would be likeley to find moreinfromation like this. I have had a quick look through journals such as cornerstone and conservation bulletin and not found any infromation on this topic that is useful.


thanks

david garland]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=5666 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=5666 Thu, 15 Apr 2010 14:07:27 +0100 PaulD You can download a copy here.
http://www.completepicture.co.uk/downloads/sap-support/downloads
thanks
Paul]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=5651 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=5651 Mon, 12 Apr 2010 13:22:53 +0100 gustyturbine All advice appreciated,
Gusty]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=5468 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=5468 Mon, 08 Mar 2010 16:59:44 +0000 Mike George https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=5426 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=5426 Mon, 01 Mar 2010 15:40:35 +0000 Luke.Smith
My understanding is that the purpose of the BRE Green Guide is to allow specifiers to compare various construction materials and build ups. In thinking this I thought it would be straight forward to compare fired clay blocks, hemp blocks, ICF, light gauge steel build up and ModCell. I don’t have the time or word count to do the comparison in any great depth but I thought by using the Green Guide I could compare the 13 category A-E ratings. However, this is proving near impossible to do!


I have found ICF build ups and Light gauge steel build ups on the green guide online but no data is given on embodied carbon or recycled content (as it is for all the listings in the printed green guide to specification)
I have found commissioned BRE environmental profiles for Kingspan TEK SIPs and Ziegel Thermoplan blocks but these don’t convert the numeric/graphical findings into green guide ratings.

I’m finding it very difficult to find a common grounding. Do most of us find the Green Guide a very incomplete, hard to navigate resource? Or am I missing something?]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4513 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4513 Mon, 07 Sep 2009 10:19:38 +0100 djh
Thanks, Dave]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4955 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4955 Thu, 03 Dec 2009 18:54:28 +0000 delboy
I've come across these products which extract the heat from your waste shower water, infuse the heat into incoming mains water and you then mix this heated up incoming mains water with your hot water while you're having a shower. Saves lots of energy apparently. It's approved in Appendix Q as well...

More info: http://www.shower-save.com

This seems great. Almost too good to be true.

Anyone got any experience?

Cheers]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1916 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1916 Fri, 13 Jun 2008 21:11:08 +0100 bigrightear single-storey building from the north-facing top road and a four-storey
one from the south-facing bottom road.

The walls are constructed from Polarwall ICF with a U-value of 0.14.

The windows are by Nor-Dan of Norway. They are double-glazed, argon-filled
and have a U-value of 1.4 for the whole window. Glazing represents
approximately 15% of the external surface area of the building. Around 90%
of the windows are south-facing.

The roof is constructed with Structural Insulated Panels which have a
U-value of 2.0. However, a further 150mm of Rockwool loft insulation has been placed in the attic floor.

The ground floor has 100mm of Kingspan insulation beneath a concrete screed.

The airtightness of other Polarwall houses is typically rated at 2m3/hr/m2@50pa.

The house is fitted with a whole-house ventilation system, with heat
recovery, supplied by Allergy Plus. The heat recovery unit includes a 1kW
heater to boost the temperature of the incoming air. No other heating
>system is currently provided. Will I need one?]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=5227 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=5227 Thu, 21 Jan 2010 19:49:20 +0000 CWatters
What difference does that make to Insurance premiums and why?]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=5016 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=5016 Sun, 13 Dec 2009 14:07:03 +0000 tony
The cavities weren't insulated the first year that the lived there but now are

Gas bill post condensing boiler = half of gas bill now with cavities insulated and solar ET system. this info is on their gas bill!

Gas bill with the old boiler would have been even higher so for the same house savings could even be as high as 75% but no info from previous owner.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4750 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4750 Tue, 27 Oct 2009 10:05:32 +0000 StuartB
Due to the length of time it took to sell, it has meant we have missed out on a couple of plots we quite fancied due to not being able to commit to buy. So to make sure we are in a good position to move quickly we have decided to rent until we find the right place to buy.

Through a mum's school gates conversation we have been fortunate to be offered an old farmhouse to rent on a short term basis just a mile from where we currently live. It is an old house at a very reasonable rent. However I have been told that the current tenants pay £500 a quarter for electricity! That must be on a par with Blackpool illuminations!

Granted it is a big house – 6 beds, 3 receptions, 5 bathrooms but the central heating and cooking is mains gas. The only electricity consumption should be lights and appliances.

Is this a reasonable consumption for the family of 6 that currently live there? Or would you suspect that there must be a dodgy appliance using a ridiculous amount of power?

Our current 4 bed home also uses gas for heating and cooking and we only pay £55 per month for electricity. We have energy efficient appliances and lights and don't leave anything on stand by.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=3475 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=3475 Tue, 03 Feb 2009 11:34:22 +0000 delboy
I find their software has quite a lot of bugs and it is generally pretty frustrating to use.

I find it hard to get through to their IT helpline and often when I leave a message it goes unanswered.

I find the people who are supposed to answer queries relating to the nitty-gritty of SAP are unable to provide answers because they don't really understand SAP.

In short, I am an unsatisfied punter, but having spent £700 on the software I am slightly stuck with Elmhurst as my accrediting body, and I need to be accredited to be the SAP assessor on Code schemes and to issue EPCs. I understand that all accreditors will require the purchase of their software in order to be accredited.

It seems to me that there is almost no accountability required by Elmhurst and they are allowed to continue pedalling this pretty fragile software. Frankly, it feels that they're out of their depth but the system allows them to be so.

I'm interested to know if I am alone in my frustration with this situation. If it turns out that there are lots of SAP assessors who are disillusioned with their accrediting body (not just Elmhurst), we might be able to put something together to send to the BRE. I spoke to the BRE's big SAP cheese not long ago and was pleasantly surprised to find that he is very interested to know of problems relating to SAP software. He also recognised the problem that at present in order to get SAP software approved by the BRE, the main criteria is that it performs the mathematical calculation correctly, and that little regard is given to the stability of a programme, let alone the quality of its support.

If anyone else has comments to make, post them here and if I amass a sufficient quantity of issues, I will send it to the BRE and see if they can introduce a bit more accountability for these accrediting bodies. Comments will be kept anonymous.

PS Yes I did recently post on something relating to this theme in someone else's question, but the subject title was different so may not have been read by many relevant to this.
PPS I'm also aware that there are those of you out there who resent SAP assessors and will be smirking at this post. Glad to provide you with some happiness! :jumping:]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4985 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4985 Tue, 08 Dec 2009 18:33:01 +0000 delboy
Does a very averagely sealed house really leak air at a rate of 105 air changes per hour? Or is 5.25ACH more likely?

105 ACH comes from my calculations thus:

The number entered into SAP for air tightness is usually 3-8. If you go for 5, you get the following answer:

SAP multiplies its air tightness figure by 20 to get Q50. Q50 is m3 of air change per m2 of building envelope area per hour. (So Q50 is divided by 20 for SAP entry).

Now then.

If you have a simple house with ground floor area of 5m x 8m which is 5m high, this means that you have a volume of 200m3 and an envelope area of 210m2. If you enter into SAP a pressure test of 5, this means that Q50 = 100 (multiply 5 by 20 = 100).

Therefore SAP pressure test of 5 is 100m3 of air change per m2 of envelope area, which in this example gives the sum 210(m2 of envelope area) x 100(m3 - q50) = 21,000m3/hour. Divide this by the house volume (200m3) and you have an ACH of 105.

I don't know much about this but 105 air changes an hour seems very high. If I don't multiply the SAP figure by 20, the result is 5.25ACH which feels more realistic.

Is this right or have I made this up?

The wisdom of the collective Brain would be much appreciated.

Ta]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4941 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4941 Mon, 30 Nov 2009 22:22:07 +0000 EdK
Looking to buy at least two (one upstairs and ones down).

I'm interesting in measuring temp in my currently un-plumbed (no rads) house and the effect that a wood burner (currently installed) has when I light it.

Or is there a cleverer way now with devices linking to laptops and the like ? Would make my life easier as I could set it to sample at hourly intervals throughout the day and night... any thoughts ?

Thanks,
Ed]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4905 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4905 Mon, 23 Nov 2009 22:04:17 +0000 welshboy NPower in conjunction with Build Centre are currently running a "£1 a roll" insulation offer.

Rolls in thicknesses of 100mm and 170mm so you can insulate to 270mm from scratch or top up an existing 100mm layer.

http://www.npower.com/web/diyloftinsulation/index.htm

Free delivery, gloves & masks as well.

I have ordered a load. You may have some difficulty with the links etc - it is best to copy and paste the link to your browser.
get a quote and there is a link to order but I had to persevere a few times to get it to work. eg back try again .back try again etc]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4824 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4824 Tue, 10 Nov 2009 13:13:51 +0000 MarkBennett
Later it could spread into other topics around PassivHaus or the higher levels of CSH.

Is there anyone on the forum who can offer this service, or can anyone recommend a consultant for me?

Edit - located just east of Bath.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4801 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4801 Fri, 06 Nov 2009 21:42:45 +0000 sinnerboy
http://news.bbc.co.uk/2/hi/uk_news/scotland/glasgow_and_west/8317134.stm

and not much better news from the Emerald Isle

http://constructireland.ie/Vol-4-Issue-2/Articles/Passive-Housing/Are-energy-ratings-letting-down-passive-houses.html

Maybe those who devised the EPC software reckon they know well what will happen - picture this -

Upon finding that her social housing unit ( PH ) has no boiler :shocked: - on her toes down to Argos to buy elec blow heaters . And leave the windows open . In winter .]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2952 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2952 Mon, 17 Nov 2008 01:33:09 +0000 tony
Then I took the wadding out of the multifoil and reassembled it between newspaper!

Here are the multifoil results]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4731 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4731 Fri, 23 Oct 2009 21:53:32 +0100 delboy
I'm wondering if they could do a couple of calcs for my CAT thesis? It really wouldn't be a lot of work and I'd really value it.

Would be great to include PHPP data - at the moment I'm relying on IES and SAP.

If anyone can help, I thank you in advance.

Cheers]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4128 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4128 Tue, 09 Jun 2009 11:24:47 +0100 RobinB
I've put together a SAP-ish spreadsheet, I'd love to know if it's too simplistic, faulty or actually a bit useful. 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 add 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]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4566 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4566 Fri, 18 Sep 2009 22:00:38 +0100 tony https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1850 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1850 Tue, 03 Jun 2008 20:16:53 +0100 ludite
Environmentally speaking, which is best; stores own bran NON bio washing powder or a 'proper' eco brand like ECOVER? or should it be washing balls all the way?

With all the 'rainwater harvesting' reduced flush toilets etc, what happens to the drains and the concentration of effluent with less rainwater passing through them?

Solar powered garden lights. When I was cleaning mine the other day I realised they have batteries in them. Are these things eco friendly or are they just a product PRETENDING to be green. If I took them apart, could I use the pv cells for anything else - that is, If I was technologically minded?

Welcome any opinions on this or any other stuff you might have wondered about yourselves.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4554 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4554 Mon, 14 Sep 2009 17:51:39 +0100 arnyj Supply and fit £425

The window is likely to be African Cedar the section of frame used is 80mm deep & 70mm thick (Stormproof window)

I see from green building bible, material section.

Thermal Conductivity's are.... Hardwood - 0.160 & Softwood - 0.120.

How do you convert that into figures to make a calculation?

I also got a quote for Aluminium window that was D/glazed unit only 1.1 argon, Combined 1.6,,,
Which is suprizing given that Thermal Conductivity is 198.000

Supply and fit £280 inc vat

I look forward to any replies Arnold]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4509 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4509 Fri, 04 Sep 2009 21:41:46 +0100 tony
What do the rest of us think?]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4507 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4507 Fri, 04 Sep 2009 21:10:14 +0100 sinnerboy That works in a similar manner to Buildesks U Value + Condensation Risk tool ?

And ....

I know we have the Bath Ice database for EE+C02
http://www.bath.ac.uk/mech-eng/sert/embodied/

Is there an authoritative GWP database for construction materials ? ( As opposed to chemical elements )
http://www.climatechangeconnection.org/Emissions/documents/GWP_AR4.pdf]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4477 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4477 Sat, 29 Aug 2009 11:16:14 +0100 Geoff We are getting a house built by a local builder.
The house will be timber frame on a concrete slab (insulation under and around the slab) about 80-100m2, single storey.
The architect and builder have spent a lot of time refining the design to remove cold bridging and air leakage and increase insulation.
They have offered to achieve a certain score on the HERS rating (we are in New Zealand), but the HERS is a prediction not a measurement.
We have discussed including two tests at the end of the build before they get the last ~10%. Those tests would be air leakage and insulation success (for want of a better expression) by thermal imaging.
I see the benefit of this as two fold:
-> if the builder knows there will be a test at the end he will ensure all the work is done correctly (as I'm sure he will anyway).
-> if anything relevant to thermal performance gets missed during building (or design for that matter), it will show up in the tests.

Can anyone suggest a form of words that could go into a contract?
Something like:
-> For cold bridging, "no area greater than 100 mm2 will be more than 4 deg C different from any other 100mm2 within 1 m"
-> For air leakage, "no leaks of more than 10 m3/hour per 100 m2 of floor area per 0.5 bar pressure"

-> What values are reasonable for each of those figures (above)?

-> The house should be finished around March, which is late summer here, but still hot during the day (and night sometimes). Do I need cold weather for a good test?, ie should I wait for Winter (generally cold clear nights, sunny days).

-> Are there any other moderately priced tests that I should include to ensure good thermal performance.

Cheers,
Geoff.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=3974 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=3974 Tue, 05 May 2009 19:47:25 +0100 Mike George
Is he anywhere near right?]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4479 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4479 Sun, 30 Aug 2009 10:01:45 +0100 RobinB
1/0.19 = .5261
1/0.3 = 3.333

5261
+ 3333
= 8594

1/8594 = combined U value of 0.116]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4227 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4227 Fri, 03 Jul 2009 12:04:18 +0100 bellarby We have built a passiv haus and had it tested for airtightness by the university. We never bothered about certification but the ecology building society is now offerring a discount if we meet certain energy standards. We should be able to meet level 6, 5 or level 4 worse case but we cant find anyone to certify! The EST came out and said they weren't able to certify to this level and they didn't have the expertise to do it!

James]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=3359 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=3359 Thu, 22 Jan 2009 11:52:29 +0000 SimonH


Key things to note.
These calcs are done with an older version of the RDSAP software Dating from Mid 2007. Upgrades have been made since, but they're still close enough to show what it can do.

Energy Use doesn't reflect appliances or home electronics etc.

RDSAP Assumes heating is 21 degrees in the lounge 19 deg elsewhere. 9 hours week days and 16 at weekends.

Saving's possible don't take into account lifestyle effects - using showers, lower room temperatures. These are “standard occupancy” figures established by BRE using research in different households. This isn’t a personal energy prediction but what the ”average family” would get if they lived in your house.

Basic EPC is set to low expectations - it only thinks 63(E)/57(D) are possible. 82(B)/79(C) is possible if the cash is available! This is due to the EPC only highlighting cost effective measures. It wont list fuel source switching, or external wall insulation on cavity built properties.

SAP doesn't model large thermal stores fed from an ASHP run only on E7. Regardless of that - ASHP Has a sizeable drop in running costs & CO2 compared to original gas boiler.

Wood Burner is listed as more expensive than a gas fire - despite my wood being free. SAP Assumes market rates and therefore the rating drops from 56 to 55. Yet kWh/m2/yr & £/yr for heating goes down!? I guess they assume you don't use it as much as a gas fire as it's more hassle! It does add 3 point to the environmental rating.

Despite building a bigger house - it's possible to make it use less energy.

The CO2 is based on grid electric. If you switch to 100% green you effectively have none - apart from a few gallons of [bio]diesel to collect your logs. That's a 100% reduction.
Some of the assumed U values (below) for new build/extensions are lower than I intend to build. So a proper SAP instead of RDSAP assessment would be more accurate.

It appears that having 30% of you roof covered in PV doesn’t lower the cost of running the ASHP. That don’t look right guv’na ! Hope that’s been updated by now!

Appendix of Inputs. U Values have been looked up from SAP 2005 documentation - Appendix S.

As bought House has:
Total Internal Area 104 m2
Heat Loss Perimeter: 33m
Pre-1998 Fan assisted boiler (61% Efficient)
Timer and Room Stat.
130-170L Spray foam tank with thermostat
Pre 1998 Open Flue gas fire. (51% Efficient)
Cavities unfilled (U1.6)
75 mm Loft insulation in main section (U 0.50)
"As built" insulation in flat roof extension (U 2.3) *1
Post 2002 Double Glazing in 85% of the windows.
100% Tungsten lighting

Basics Add:
95% CFLs
Cavity in sections that can take it
Increase to 300mm loft insulation in main house (U 0.13)
Add TRVs
Insulate under suspended floors (N/A in my version but you can now specify additional floor insulation if there is evidence.

Wood Burner:
Replace Gas Fire with Open Flue Enclosed room Heater Log Fuel

External Alternative Wall :
Replace 35m2 of current cavity as built(20mm cavity = unfillable) (U 1.6)
This involves cutting out the external face of bricks - leaving single inner skin,
Add insulation and then timber clad or render.
Enter as solid brick external insulated 2007 or later. (U 0.21)

ASHP + Big Tank :
Specified ASHP as main heating (250% Seasonal Efficiency)
Added Large tank 160mm insulation (although large is only listed as 170L+ )
Add time & temperature Zone Control

Solar HW:
Get to tick a box - will assume size based on floor area :-(
Not the 10+ m2 I plan to install.

New Extension + Full External Insulation.
Adds 32m2 over 2 storeys, timber frame 2006 building regs insulation assumed (U 0.30) :-(
New Flat sedum roof with assumed insulation (250mm). (U 0.25) :-(
Convert old flat roof to pitched and upgrade insulation to 300mm (U 0.13)
Add 150+ mm brings whole house up to 2007 regs.

Is that of any use to anyone?]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=3749 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=3749 Sat, 14 Mar 2009 19:23:38 +0000 sinnerboy
In Ireland the primary energy factor for electricity is 2.7 i.e. for every kw delivered 2.7kw has been consumed in the generation and distribution of that energy

For oil ( kerosene ) and natural gas the factor is 1.1

Can anyone post links to show how these factors compare with the UK and better still other countries too ?

And anything on how these factors are derived ?

Thanks in advance .]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4231 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4231 Fri, 03 Jul 2009 22:34:53 +0100 tony
My only source of heat apart from lighting and incidentals is the sun -- effectively my boiler is solar powered and I make all my hot water from this and the surplus heat is stored underground

My boiler is almost infinitely efficient ( will be when I get a solar powered pump) as it is the sun

Anyone fancy a crack at the calcs?

http://www.tonyshouse.info/]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2868 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2868 Wed, 05 Nov 2008 13:41:58 +0000 Energy Saver
I've been hovering over these boards for sometime but never registered and now I have a bugging question that I hope someone can offer some detail.

I'm very interested in having an air tightness test on my home to reduce carbon emissions, preserve energy and to reduce my bills. Want I want to know is there a formula that I can use or partly use to convert an air tightness result i.e 10 m3/h/m2@50PA to how much energy and money can be saved?

Many thanks in advance]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4145 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4145 Fri, 12 Jun 2009 17:32:23 +0100 Ben GreenHomes
I'm trying to answer the following question:

"Is there, by chance, a simple comparison between our 40 cm brick wall lined with Sempatap and painted with the Thermilate enhanced paint and a thinner modern wall with a filled cavity?"

Can anyone help me out here? Are U-Values cumulative or is there a specific formula for this? Can someone point me in the direction of any sites that compare these types of products?

Cheers,

Ben]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=3914 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=3914 Thu, 23 Apr 2009 09:31:04 +0100 kokomalti Anyway i was hoping to do this course a couple of years back and now would love to start this. Can anyone tell me if this course would suit a mere timber man like me. I do have a loose understanding of the building trade as i have been involved for some twenty years.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1538 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1538 Sat, 05 Apr 2008 17:11:28 +0100 Mike George https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=3384 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=3384 Sat, 24 Jan 2009 20:56:35 +0000 sunshine
Thanks]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=3846 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=3846 Wed, 08 Apr 2009 19:41:11 +0100 jo10000_6
I am looking for advice of how to handle/progress my problem.

In this day and age of wanting to be as green as possible and at the same time attempting keep energy costs under control I was fairly comfortable that when I purchased a new 4 bedroom house 4 years ago that I was buying a house that was reasonably energy efficient.

Perhaps assumption that I had bought a reasonably energy efficient house (SAP Rating 101/120) made me ignorant to the fact that I hadn’t.

I have spent over a year researching “U” Values / “R” Values, Cavity Wall Insulation, BTU’s just to try and understand why my house is so cold – we are not talking a one-off room – we are taking within a degree the whole house being the same.

To put it into perspective, as you know the temperatures over Christmas dropped to 0 Degree’s. My house, without heating would be approx 10.5-11 Degree’s internal inside temperature. A relative’s house, approx 35 years old with cavity wall insulation installed a few years ago would be approx 17-18 degree’s. Therefore I would take approx 1.5-2 hours to get from 11 to 19 whereas they would take less than 30 minutes to get to a nice temperature. After asking questions to numerous people I now realise that something is wrong – forget about “U” Values and take it as being as simplistic as my starting internal temperature is far to low to be right

Now, as the temperature starts to increase, my internal temperature is still less than my relatives house at Christmas, even though the temperature outside has risen to 10/11 degree’s my inside temperature hasn’t gone past 15.5. In fact it appears to stay at 15.5 even when it gets to 12 outside.

What do I do ? Do I have any comeback….I prepared to make a nuisance of my self but where do I start. Any advice / suggestions appreciated.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=3873 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=3873 Tue, 14 Apr 2009 13:07:38 +0100 ClaireR https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=3820 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=3820 Fri, 03 Apr 2009 14:40:49 +0100 ralphd http://members.chello.at/tkornicki/body/products/software/AnTherm.htm

One thing that seems to be lacking is cold surface convection modeling. I've been very impressed with recent window thermal modeling I've seen that factors convection (the cold down draft) on windows. I understand the basic physics involved (conductivity, specific heat of air, etc) but haven't been able to form a mental picture of how all the factors interact.

-Ralph]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=3755 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=3755 Mon, 16 Mar 2009 13:20:34 +0000 James Norton
General jist is that they want to charge a fortune to badly over clad my maisonette. - trying to get my head round what the effect on the gas bills would be.

Sooooo....

A quick calc with areas and U-values shows that the heat loss through fabric is roughly halved.
Current heating and hot water is a B rated condensing combi
Air leakage probably medium but not helped particularly by the bad/partial over cladding
Current gas bill ~£60pcm

Very roughly, any idea how much that would all end up as in terms of £££s? ie allowing for heat loss through leakage and gas spent on water?

Thanks,

J]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=3699 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=3699 Thu, 05 Mar 2009 10:46:43 +0000 Aid1987
Can anyone help me find solutions to improving energy performance of existing non-domestic properties?? i.e. factories, retail units, government buildings etc.

I know basic things such as double glazing, energy efficient lighting and PIR sensors are obvious changes that can be made and can be done fairly easily, but what about other options? and improvements to M&E systems?

Thanks,

Aidan]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=3588 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=3588 Mon, 16 Feb 2009 12:19:23 +0000 Noyers
http://www.vesma.com/tutorial/uvalue01/uvalue01.htm
http://www.celotex.co.uk/Other-Resources/U-value-Calculator

Anyone know a solution? i am interested in calculating heat loss through the following construction: -
600mm Stone (rendered both sides)
25mm- 38mm air gap
Multifoil
25mm - 38mm air gap
20mm Polystyrene
12mm Plasterboard
All joints sealed and vermin proof, (the stone wall will just have to breathe through the outer skin - I am installing (sealed) inspection sites so I will be able to tell you in due course, using an endoscope, whether there really is mould growth between the wall and the multifoil).
PS External insulation impossible for several reasons.]]>