Green Building Forum - Building Regulations and Standards

Hygrothermal performance of materials

ali.gill — Mon, 09 Mar 2009 22:59:20 +0000

Between other commitments i'm trying to read up on hygrothermal performance of materials after recent discussions on here regarding rainscreen membranes, types of cladding, plastering over 'breathable' boards, etc.

Heres a nice easy one showing tests on brickwork, rainscreen membranes and sketch details for protecting openings in the wall.
http://www.buildingscience.com/documents/primers/bsp-063-water-managed-wall-systems/view?searchterm=stucco

I have the relevant BSi docs too if anyones interested and i'll post links to a few of the other relevant docs, in particular results from measuring moisture in straw bales.

Relevance ? Well how about the vast number of UK properties having their cavities filled as the gov's first step in tackling climate change.
Tony's house - cavity fill > any moisture sensors built into the construction ? V. interested to see output.

Moisture > humidity > health.

BuildDesk U

jamesbl — Wed, 14 Jan 2009 18:33:17 +0000

For a number of years I have appreciated the trusty U value calculator from Builddesk - but it is now is being withdrawn as a free service " in order to provide a better service to users" - or something .
Does anyone know of a similar service still free to users ?

from European Environmental Bureau (aisbl)

Brian Rochford — Tue, 17 Feb 2009 12:45:30 +0000

Fight climate change with the Buildings Directive
Zero energy homes require greater ambition

[Brussels, 16 February 2009]: In light of todayâ€™s public hearing before the ITRE Committee [1], EEB [2] welcomes the European Commissionâ€™s proposal to increase the scope of the Energy Performance of Buildings Directive (EPBD) as a potentially powerful tool in the fight against climate change. EEB applauds the move to expand the Directive to include all housing stock in the EU and not just large buildings, but would like to see stronger ambition, especially for new houses, such as a faster obligation for zero energy buildings.

â€œWhile expanding the scope of the Directive is a great step forward, it should require new buildings be energy neutral as soon as possible, but no later than 2015, which is the date the UK has already set as their national deadline,â€ asserted Dr. Pendo Maro, EEB Energy Policy Officer. â€œThe UKâ€™s action shows that construction of zero energy buildings is not fiction, while examples already exist in several other Member States as well.â€

In order to fully exploit the energy saving potential in the building sector by 2020, the revision proposal needs to be further improved and combined with major financial support programmes.

EEB is suggesting the following amendments be added to the recast proposal before this Thursdayâ€™s deadline, ahead of Parliamentary votes later in the spring: [3]
Â· Minimum energy performance requirements for existing buildings
Â· Zero or positive energy requirements for all new buildings by 2015
Â· Requirements for public authorities to lead by example
Â· Clear EU criteria for independent energy experts
Â· Define â€œmajor renovationâ€. The Commission proposes a threshold of cost for renovation to be higher than 25% of the value of a building. This is much too high and will lead to very few cases where the Directive will be applicable. EEB proposes 5% as the threshold instead.

To view EEBâ€™s complete position paper on the EPBD recast, including suggested text for amendments, visit
http://www.eeb.org/activities/energy_policy/090213-EEB-EPBDPositionpaper-FINAL.pdf

For more information contact:-
Dr. Pendo Maro, EEB Energy Policy Officer, Tel: +32 2289 1302, pendo.maro@eeb.org
John Hontelez, EEB Secretary General, Tel: +32 2289 1091, hontelez@eeb.org
Vanessa Bulkacz, EEB Press and Publications Officer, +32 2289 1309, press@eeb.org

Notes:-
[1] Industry, Research and Energy
[2] EEB is Europeâ€™s largest federation of environmental citizensâ€™ groups with over 150 member organisations throughout Europe.
[3] The ITRE Committee will vote on the EPBD on 9 March 2009; it will then be voted upon in the April plenary session of the European Parliament.

EPCs & piece-meal internal wall insulation

dan_aka_jack — Thu, 08 Jan 2009 11:45:28 +0000

We have an end-of-terrace solid walled house. We are planning to start adding insulation to the interior faces of most of our external walls. We plan to hit the Energy Saving Trust's "best practice" u-values and I also fully intend to notify Building Control about our thermal upgrades. My question is this: when we come to sell the house, will the Energy Performance Certificate take into account the thermal upgrades I will do, even if we don't get round to upgrading every single external wall? For example, our house has 3 bedrooms and a living room. If the living room's external walls have a u-value of 0.30 but bedrooms are all still 2.1 then will the Energy Performance Certificate "see" the improved performance of the living room's walls? Or do I have to upgrade every external wall in the property before the EPC will register any improvement?

(We are actively researching external-wall insulation but I expect it'll be too expensive for our budget).

Many thanks,
Jack

new extension on cottage

ludite — Mon, 02 Feb 2009 11:16:57 +0000

I hope people can answer the following queries.

Concrete lintles have been specified. Would/could wood or steel ones be any better?

Glazing has been specified as 28mm wide to BS6206 class C. What does this mean? Is it any good?

GF doors have been specified as 80mm opening - is this wide enough for disabled access?

12.5 mm plaster board and skim. . . . . is this ok?

UPVC gutters are specified. Would reclaimed cast iron, or any other material be any better?

50mm kingspan above and 100mm between rafters. . . . . . . . is this enough?

Foundations are 150mm type 1 hardcore
100mm thick concrete floor slab
100mm kingspan
1200g visqueen DP membrane
75 mm sand and cement screed
20mm clients floor finish

I've never been sold on UFH, but saw a holiday cottage yesterday and almost fell for it. Are these foundations the type of thing that is used for UFH. Is there any other - greener method of having foundations? Can solar power and a wood burning stove do UFH instead or radiators?

Load requirements for a domestic roof

ha55an_a — Fri, 22 Feb 2008 20:37:18 +0000

Does anybody know what the minimum loading requirements are for; (1) domestic flat and pitched roofs and, (2) Commercial flat and pitched roofs?

Thank you,

H

Room vents for new Wood Burning Stove

Poplar — Fri, 05 Sep 2008 19:54:44 +0100

We plumped for a Clearview Pioneer 400 which is rated at 5KW.

My reading of the Building Regs is that a stove above 5KW needs air brick or similar to vent the room.

What is people's experience??

Do people err on the cautious side and would a builder insist on knocking a whole in the wall (knowing fine well that we'd just cover it up again!!!)

Rammed Earth and Part L

alexc — Thu, 28 Jun 2007 14:43:21 +0100

Hi,
Does anyone have any experience of meeting Part L requirements and rammed earth structures? For instance does the high U-value mean they will always fail to pass? And how can they be treated in SAP 2005?

thanks
Justin

Building Regs - How fussy can they be ?

storm — Sun, 23 Nov 2008 15:01:33 +0000

Recently had Planning permission come through for an extension to our old Welsh cottage. Still waiting, however, for the Buildings regs to be approved. Received the drawings from our architect on Friday with all the various materials to be used etc, I have not yet signed this though as there are one or two details which I am not quite happy with.

PVCu gutters have been specified on the plans, yet I have recently had some brand new gulvanised metal gutters added to my property and I wish to have the rest of the property fitted with the same quality gutters. Also Jeld-wen or similar PVCu windows have been specified, yet, if I can afford it, I would like wood framed windows throughout. Celotex / Cetotex has been specified for between rafters and mineral wool or quilt for batts of partition walls. Yet I wish to have Pavetex used and mineral wool is not a particularly pleasent material to work with and, quite apart from other considerations, I wish to save my builders from the misery of working with the stuff ! I do not wish to be responsible for poisoning my builders with ingesting any toxic materials, so it is organic paints, varnishes etc, wherever possible.( incidently, at formation level, proprietry weed killer has been specified, is there any environmentally frindly alternative to this ? ) I wish to have the external walls lime rendered and yet Lime has not been specifically refered to in the Building regs.

Do I need to return these plans to my architect to insert the specifications that I want ? I do not particularly wish to do so as this will waste time and money both of which are at a premium. I have been told by someone who regards himself as somewhat of an authority on the subject that it is not important to declare these minor changes and that building inspectors will not be bothered if I digress from the exact materials cited. Yet is there a risk that the building work might have to be undone if I use alternative materials ? My cottage is completely isolated, so there are no neighbours to complain about what I do with my cottage, but just how pedantic can these building inspectors be ?

What's the cheap way to access BS6399?

Justin — Sat, 15 Nov 2008 14:09:57 +0000

I want to look, at BS6399 part 1 to check out some straightforward rafter dead loads.

I'm not in the mood for Â£80 to buy the BS document at the moment. Despite extensive looking, I can't find any on-line calculators, or documents providing rafter loading calcs. Are there worked examples, tables from the standard, or on-line loading calculators available for the amateur who wants to keep budgets tight?

CSH - October 2008 released

10100 — Wed, 08 Oct 2008 14:45:57 +0100

The updated version of the CSH is available for download, grab it here http://www.communities.gov.uk/publications/planningandbuilding/codeguide or the summary of changes here http://www.communities.gov.uk/publications/planningandbuilding/codeguidesummaryoct08

happy reading!

breach of regulations?

chiefgod — Wed, 13 Aug 2008 17:50:44 +0100

Hello everybody,
First post.here goes.

My Partner and i purchased an apartment in a renovated church last year and soldiered through an incredibly cold winter due to a few things which i will list below.
First, an idea of the area that is the problem. Our living room is the old entrance to the church which was an external space. What we have been left with is an exposed timber roof/ceiling (extremely aesthetic) which had no insulation at all internal or external. Underfloor heating which has now buckled the oak floor and double glazed steel windows with no thermal break.

Since the purchase we have complained and building control instructed the developer to insulate from the exterior with tri iso super 10.
The installation of the tri iso is unnoticeable. When the temp outside is 0c internally the temp is max 11c.
Further inspection reveals that there are large drafts coming into the room through the sarking boards and also through gaps left where the roof meets the end walls.

The architect and developer are ignoring our correspondance and i have no idea where to go from here. the energy required to heat this room to a comfortable 20c in the winter is ridiculous and extortionate so we really need to find a way of:

a)keeping ourselves warm this winter without destroying the planet on our own.
b)figure out why this has happened to a grade2 listed property.
c)get someone to take responsibility and remedy the situation.

I can upload some Pictures if this helps.

Thanks in advance.

Thermal Bridging Details - A dark art??

Peter A — Thu, 11 Sep 2008 11:32:23 +0100

Hi, not been about for awhile, so perhaps one of the miriad of experts on the forum might aready have given an answer:)
I have been trying for a while to get some sense out of official sources about the thermal bridging details and in particular enhanced ones that will give 0.4 rather than the accredited 0.8 in SAP.
Does anybody know how these can be simply done, people keep talking about thermal modelling!!! With other's saying enhanced details coming soon!!!
Any advice gratefully received, polite of course:)

Biomass Stoves Efficiency - Part L

TomN — Thu, 11 Sep 2008 12:29:12 +0100

Does Part L's "84%" minimum boiler efficiency apply to biomass stoves as well?

I'm looking at one that's 81% efficient but can find anything in Part L that mentions any distinction between boiler types.

Anyone have any experience in this?

Where can I find opinions on the Code For Sustainable Homes?

Mike George — Fri, 04 Jan 2008 20:33:35 +0000

Or anyone want to share theirs?

I need to do some in depth research into the CSS. Can anyone recommend any publications/Links please? Also anyone have an opinion on the Code?

Thanks in advance

Mike

Barn Conversion with room in the roof style upper floor

njtkc — Sun, 22 Jun 2008 20:25:03 +0100

we are limited on the ridge height increase with our barn conversion. the room in the roof style upper floor bedrooms will have a height restriction if we don't find the most efficient and space saving insulation around that complies with the building regs or better.... HELP

Part L and Part F of the Building Regulations in the UK

doodledoo — Mon, 25 Aug 2008 20:37:41 +0100

The Requirements of Part L basically sate that reasonable provision shall be made for the conservation of fuel and power in buildings buy: Limiting Heat gains and losses through thermal elements and other parts of the building fabric; and from pipes, ducts and vessels used for space heating, space cooling and hot water services; AND Providing and commissioning energy efficient fixed building services with effective controls.

In the Secetary of States's view the requirement of Part F will be met where a ventilation system is provided that, under normal conditions, is capable of limiting the accumulation of moisture, which could lead to mould growth, and pollutants originating within a building which would otherwise become a hazard to the health of the people in the building.

I have found a unit that ticks all the boxes for Building Regulations Part L and F.

The ECO HP3.2TW - A ventilation unit that is capable of heating and cooling, powered by an air source heat pump.

Can anybody tell me the cons of Air Source Heat Pumps? They claim it is 70% cheaper that convection heating and storage heating . . . . . . .

See for yourself at www.ecoheatpumpdistribution.co.uk

Are their claims valid.

Your comments please.

Building warranties

Sally M — Tue, 02 Sep 2008 18:33:37 +0100

I've read the discussions on Zurich and NHBC and I am a bit concerned about the experiences of the contributors!
We are about to start a new build. Could anyone recommend the best course of action, or any other options available?

avoiding drylining

tregay — Sun, 10 Aug 2008 11:14:13 +0100

We are renovating a very old farmhouse. It is not listed. Most of the walls are around 20" thick or thicker, made of stone (brown slate) with cob or lime mortar. It is not rendered externally (although the walls have been painted in places with what looks like an unbreathable paint.) Various other bodged and unsypathetic works have been carried out on the house over the decades eg UPvc windows which have failed & hardboard/fibre board drylining. In one section of the house we want to gut the house internally, remove the drylining and existing fibreboard partition walls and re-configure the room layouts (we have checked and do not need PP). We would like to go back to the stonework internally and bag-lime plaster the walls so that we max interal room dimensions and can see the shape of the stonework. Our architect is telling us, under the building regs, we have to insulate internally by drylining. Excuse my ignorance but is this true? It seems to me that this would compromise the character of the property and that the walls I would end up with, would look the same of those in a 70s semi which is not what I wanted. And on theses forums and elsewhere I have seen reference to research into 'the thermal mass of solid stone or brick walls, which stabilises internal temperatures and can make buildings more energy-efficient than they might seem'. Is there anyone, please, who could point me to such research so that I can bring it to the attention of the architect/building control?

loft insulation - u values?

ps_mrwonderful — Fri, 11 Jan 2008 13:47:56 +0000

Having just moved into a property with no insulation, I am going to get the loft insulated. I was looking at using environmentally friendly materials... then I saw the cost of sheeps wool! Also I don't really want warmcel as its loose fill. This pretty much leaves glass wool (which I'm told uses recycled glass, so better than rockwool I believe).

I have two questions:
1) how much insulation? Part L says a u-value of 0.16, the Approved Document L1B says 250mm of mineral wool will do that. I want to exceed this though, but my research and calcs seem to show that it'll take 15-20 years to payback an extra 100mm of insulation at the minimum... is this everyone else's findings? Will extra insulation make that much of a difference?

2) Secondly, the roof sits very low on the house, so internally at first floor round the perimeter is a sloping plasterboard piece (see very bad photo attached!). The gap in the roof space from the top side of this plasterboard to the roofing felt is 4inches. I'll need to keep 25mm for ventilation to the roof - so I only have 75mm for insulation around this part. What do you suggest I use? I was thinking some insulating board with better R-value than mineral wool. Any ideas?

Ta!

Mandatory Levels for CFSH

simple153 — Fri, 15 Aug 2008 11:01:49 +0100

Does anybody know when the Code will become mandatory at various levels. I know it is mandatory now on all new build, but you can have a Nil-Rated certificate. I have in the back of my head that the building regs will change in 2010 to try and make Code Level 3 Mandatory!! Any help would be appreciated

Simon

Code for Sustainable Homes - Awareness

Chadd — Fri, 21 Mar 2008 20:57:58 +0000

Hi everyone,

I am currently conducting a research project on the levels of awareness in the UK housebuilding industry
with regards to the Code for Sustainable homes. I believe that there is a direct link between the size
of a firm and it levels of knowledge, expertise and awareness to the code.

Looking at the major UK house builders they have their own departments purely dedicated to sustainable
development yet I feel that the small 5 man teams working around the country may find themselves left behind.

Could anybody point me in the right direction or provide some links on where to find information to back up my theory?

Kind regards

Chris

Self Build Stoves and Regs.

Carol hunter — Thu, 31 Jul 2008 09:45:44 +0100

Please, anyone out there with any experience and or knowledge about building a stove and getting it passed Building Regs.?
Hope to build a rocket stove after fairly extensive study on my partner's part and a course with Ianto Evans, the rocket stove guru - initial soundings with the Building Inspector are not looking favourable...

Why do we still need to vent soil stacks externally?

Julian — Tue, 01 Jul 2008 22:26:49 +0100

I'm told by the building inspector (approved inspector) that soil stacks still have to be vented externally. With the advent of durgo type air admittance valves is this out of date? Why can't a durgo type air admittance valve placed in a well ventilated roof void (right near a nice big soffit vent) do the job properly but without penetrating the roof covering?

Timber extension.

woodbutcher — Sun, 06 Jul 2008 14:53:17 +0100

Hi guys,new member and wanted to ask a question.

I have recently bought a 1930's semi and want to build an extension on the side.Being a joiner i was wondering if there is any reason why i couldn't build it from timber instead of the usual brick/block route?Are timber walls acceptable to building control nowadays with the advent of timber houses in recent years.

If i can do this it would be cheaper and faster than getting in a gang of brickies to put it up but more importantly to me is the green aspect of building with timber instead of concrete/concrete products.

Any info would be appreciated.

Thanks.

Insulated frames to wooden windows.

tony — Sat, 12 Jul 2008 18:52:46 +0100

These are becoming far more common in Europe and as we move to better insulated buildings and implement the Code for sustainable homes we will need these too.

Wood is a great material for window frames and combined with a lamination of insulation become tremendous.

30 min Fire Doors (FD30)

ecoworrier — Wed, 05 Mar 2008 21:01:52 +0000

Pricing up a job at the moment and it calls for the replacement of five Victorian 4 panel doors with FD30's.
Would it be possible to convert these doors?
The Hinges and fixtures are easily replaced and intumescent fire and smoke seals could be fitted, but what about the
structure of the door. (apart from screwing 9.5 plasterboard and 3mm ply on both sides)

What a waste otherwise.:sad:

Renewable energy plans for new builds in Wales - a step change or too little, too late?

helen@carms — Thu, 03 Jul 2008 21:29:59 +0100

Hi saw this today

Sorry for Wales only, but wondered what everyone thought, and thought some of you planning new builds would be interested, although most of you on this forum would probably think of these targets as a starter for ten........

Here's link to today's press release

http://new.wales.gov.uk/news/presreleasearchive/2355951/?lang=en

Impervious paving -- planning will be required!

tony — Wed, 09 Apr 2008 19:21:07 +0100

Are they serious! Paving of driveways and patios is adding to the risk of flooding!

The additional area of newly paved driveways last year was minuscule compared to the areas on which rain falls and runs off from.

Like so small it is in parts per billion! So this will contribute to reducing the risk of flooding like not spitting into a river would.

Crazy -- and the cost of setting up the laws, infrastructure and the non enforcement makes it all sustainable -- can government be described as unsustainable?

Heat loss through concrete

tony — Sun, 15 Jun 2008 22:07:32 +0100

If I could draw a picture and load it I would. Say we have a concrete 150mm thick with 100mm of insulation and then solid material like soil on the other side of it. We keep the top of the concrete at 17 C what temperature will the opposite side of the insulation attain in steady state? Remember that as heat is lost slowly through the insulation it will warm the soil. After a long time -- steady state -- the soil will warm to almost 17 C so long as heat is not lost too quickly through the soil.

Certainly the soil will warm up to some extent in all cases.

How do these facts impact on floor heat loss calculations?

Can you meet Building reguations with little or no expert knowledge

Katymac — Sun, 25 May 2008 22:05:13 +0100

Converting a chapel into a children' daycare nursery (in case you hadn't been paying attention :wink:)

So with the helpful man from building control, experts in water treatment, heating, mezzanine floors etc, can I make it all work without an architect?

I guess I will get a structural engineer to draw up plans for the tricky bits

Is this stupid/ill-advised/good idea/insane?

Air tightness of straw bale buildings

Jotham — Fri, 30 May 2008 10:59:07 +0100

Hi
Sorry if this has been done before but I am interested to know if anyone has air tested any straw bail house and what sort of figures they are coming out at. I am looking to design a Code level 4 house using straw but am concerned that that the air pressure test will not be up to scratch. I was intending to use bail and then cover then with Lime.

Fire resistance of Cob

SashaLacroix — Tue, 20 May 2008 20:46:22 +0100

Hello
I'm having trouble with my local London council regarding using cob bricks and buildings regulations. Because its not on their list of approved materials they are saying that I have to prove that it is sufficiently fire resistant for up to 1 hour.
I have used the term incombustible and even shown them pictures of cob ovens but they still insist on proof. Has anyone come across this before and is there any proof/tests that you are aware of?

They are happy for me to use concrete or bricks instead, which, I find astonishing in an age of increasing awareness about lessening our carbon footprint. How can a one government body be so clueless about cob compared to say the Devon councils?

I would be most grateful if you have any thoughts on the subject

Regards
Sasha

Rendered wall thickness

ali.gill — Fri, 22 Feb 2008 19:12:38 +0000

Just want to query your thoughts on construction of a rendered wall. Where adaptation of a building requires new walls that are rendered to match the existing walls standard practice seems to be to spec partial fill cavity blockwork; though i remember someone commenting on here that its not necessary to have the cavity where a waterproof render mix and suitable insulation are spec'd.
Understand the whole thermal mass/lightweight construction debate but want to know your thoughts on suitability of masonry cavity fill with spray urethane foam to achieve the airtightness discussed elsewhere. Any other solutions to this ..?

wood burning stove angle of pipes to cylinder

trotsky — Thu, 13 Dec 2007 19:58:12 +0000

I have vil lager wood stove with 5kw boiler which i am connecting to heat store on floor above using 28mm pipes.
I have chased the pipes into the wall at 45 degrees to promote strong thermo syphon reaction. does anyone know if this is ok for regs, and the best way to get hot water to heat store?
foil wrap insulation and plastered over?

U values

rooster — Wed, 19 Mar 2008 22:53:45 +0000

hi im new to all this but would appriecate a bit of info in relation to u values. an insulation installer gave me a quote for our house today with some u value detail, it reads like this.
slopes - insulate with 140mm high density insulation with 50 mm kingspan attached by 2by1 battens, gives you a u value of .20
attic - insulate between and over rafters with 350mm fibreglass insulation, gives you a u value of .11
partitions - insulate with 100mm aqustic insulation
ceilings - insulate with 250 mm fibreglass insulation, gives you a u value of .14
Seal around windows

Could anyone tell me are u values achieved by this amount of insulation the standard or better or worse...????????????????????????????????????????

Approved SAP Assessor (NHER)

agu — Tue, 29 Jan 2008 16:23:59 +0000

I have just started a new job in this area of work and am booked to go on a NHER Approved SAP Assessor course shortly, I was wondering if anybody could give me some tips of things I should try to familarise myself with before I go. Bearing in mind I have very little knowledge of U-values, building regs etc will all this be covered does anyone know?

Thanks

Between a Rock and a Hard Place, Problems with Stone Building

EdF — Sun, 02 Dec 2007 11:49:03 +0000

Over a year ago work started on converting my traditional Scottish 'steading' (farm outbuilding) into a house. The first builder disappeared with an advance payment for building materials and I'm suing him, an extremely drawn-out process, but that's another matter. I finally found another team of honest guys, two joiners and a brickie. The joiners thought the conversion of the stone part would be better if they built an internal wooden frame to support the roof, which was done, and the roof then went on and is complete. The building has the old stone part, which has one gable end in concrete blockwork following a runaway JCB accident which demolished the original before I bought the place, and a large kitchen/dining/utility extension on one side, again in blockwork.
After waiting 10 weeks for the brickie to make new window openings, etc., he told us he cannot now come as he has to have a serious operation before Xmas. Hopefully he'll recover, but in the meantime another couple of guys who had just 'blocked around' a new timber framed house nearby came and surveyed the job. It's fairly straightforward, but there are two windows to go into a gable end and they weren't keen on tackling that part as the stonework is somewhat 'shaky', with 80 year old crumbly lime plaster. Also, they felt they couldn't put 'needles' through the stonework to support it while the windows go in as there's now the timber frame lining the inside. They weren't keen on giving me a price, either, and I felt they were 'talking the job up', making more of it than it was. I have two queries about this. I feel it would be far easier to rip down the stone walls and rebuild in blockwork and I think the building inspector would be okay about it - we would get a DPC where none exists in the stone walls, and more importantly, air vents in the bottom of the walls. I think I'm correct in thinking that a timber framed building has to have vents to admit air between the frame and the outer wall. It would be a horrible job trying to put vents into the stonework, which is 18 - 20 inches thick random stone, not a straight edge in any of it. The submitted plans didn't allow for a timber frame, but building control okayed it. There's just one 'regulatory' glitch, though, I only got planning permission because the building is classed as a 'redundant farm building' and at the outset I asked Planning Dept if I could rebuild the walls in stone with proper foundations, an inner blockwork leaf with air vents and a DPM and the planner said 'no', as once it was demolished it was no longer a redundant farm building... Rules is rules, never mind the common sense.. Sigh.. I have no idea how to progress this, although a bulldozer keeps coming to mind.. I suppose Planning Dept will never see the building again, but it's a bit risky to go ahead. Photo attached.

window & door weather testing standards

Justin — Sun, 09 Mar 2008 13:42:57 +0000

Can anyone provide a short summary of the main differences in window & door weather resistance standards.
I am after a patio door for a relatively exposed site, and seem to have come across these competing standards. Someone in the know may be able to precis.

BS6375 Part 1
Din 18055 category C (or B)
PAS23

Part L1B for extension

Justin — Fri, 22 Feb 2008 13:55:35 +0000

Hi.

Just a sanity check here from anyone who knows part L1B well please. I'm 99 % certain my understanding is correct.

I'm planning a small extension (small floor area but with big expensive glass).

There are 3 potential levels for the calculations:
1)Basic 25% rule of floor area with allowance for windows and doors removed (no good for me, not enough glazing allowed)
2) Comparison of area weighted U value of all the extension elements as planned, with area weighted U value of a "theoretical" extension meeting the tabulated minumum U value standads and "opening area" of paragraph 15.
3) Full house SAP offset calculations.

Method 2 seems to be the way to go for me, if my understanding is correct, only it seems a little too "easy". I am making my "theoretical" reference extension based on 25% of the new floor area PLUS the area of windows/doors I will remove (this added area is significant because I'm taking out a 1970's single glazed front door and glass surround). This means that by using some reasonably decent glass (overall U < 1.4 say), and a good ceiling and floor, it's easy to have a really big glass area in the extension.

My question is then. Is it correct to assume that my "theoretical" extension I use for comparison with the real extension, is allowed to have glass+doors according to:
(a) 25% PLUS removed door/window area .
(b) 25% only, with no allowance for removed door/window area.

According to my understanding of paragraph 18 in L1B, I'm assuming (a) is the case, but have my slight doubts that building regulations controllers see method (b) as correct.

Radiation heat losses

tony — Sun, 17 Feb 2008 09:42:10 +0000

Are radiation heat losses correctly modeled in the hot box test?

I dont think so. The hot box is a double totally enclosed environment. Radiation heat losses from say flat roofs are sent to outer space some of the time where there is no incoming radiation -- at night. Therefore the heat loss will be a lot higher than the hot box suggests

Windows too loose heat by radiation and I think that in the cold side of the hot box the radiation losses will be far less than in the real world for the reason outlined above but to a lesser extent as the window is oriented such that it can "see" some terrestrial things. Roof windows do not benefit from that factor though so will be significantly less efficient than predicted. Large areas of glass suffer similarly.

This argument effects U values and these are the building blocks of nearly all energy predictive models --- do we have a problem?

BR Doc A - Structure: Wall Thickness and height

Captain Tuba — Thu, 07 Feb 2008 18:34:18 +0000

Hi folks - my first post to the forum.
I've been reading a lot of good stuff here - keep up the good work :-)

I'm researching how to refurbishing and extend our 1930's bungalow to maximise it's energy efficiency.
The current plan is to remove the roof and build a highly insulated timber frame upper storey and roof.

However I'm not sure how to interpret the height I can go to based on the current wall thickness.
Can you folks help?
----
The original cavity walls are nominally 2 x 4" leaves with a 50mm cavity.

From Document A (http://www.planningportal.gov.uk/uploads/br/BR_PDF_AD_A_2004.pdf)
Para 2C6 suggest a wall thickness of 1/16th the height of the wall
Para 2C8 for cavity walls say to use a wall thickness of "the combined thickness of the two leaves plus 10mm"
Does this thickness include the cavity?

As I want to add another floor the gable end wall height will between 3.5m & 9m.
Although most walls are less than 9m in length - the L shaped building does have two walls over 9m long (but less than 12m).
Table 3 suggests I'm OK for short walls - but it means my longest 250mm thick walls are limited to a 3.5m high.

Is this right?
Do these regs apply to a timber frame upper floor?

Cheers
C.T.

loft conversion & dormer - different question

pdurkan — Tue, 05 Feb 2008 21:05:35 +0000

it's timber frame with plasterboard, 100mm celotex, exterior-grade ply which is rendered, built 2005. like a caravan reallly - too hot in summer, too cold in the winter winds - dormer rather than slopey bit seems to be the problem.

Q1: is this compliant with regs? seems a bit rubbish
Q2: How long might it last (assuming well-built)? 5 years?

loft conversion & dormer & building regs

pdurkan — Tue, 05 Feb 2008 20:56:01 +0000

hmm - I'm v. confused. Bought our 3-bed semi with converted loft & dormer & self-closing fire door. My local building control say that the function of the door is to protect an occupant from a fire elsewhere in the house. However, I wondered if it might also be to reduce the updraught experienced when the door is open, which is presumably a fire hazard.

The reason I ask is I thought about installing a vent above the door as the ventilation in the conversion is very poor (unless there's a strong south-westerly) - building control say no, not without an automatic fire detection system. The room is mainly for guests, so now I'm thinking, on the balance of probabilities (likelihood of a fire whilst room occupied by heavy sleeper vs need to ventilate).... leave the door open - got to be the best green option ???:confused:

cavity wall insulation

bertie — Thu, 31 Jan 2008 19:32:24 +0000

I bought a new bungalow with an attached garage which was built in 2002 . I have noticed that the dividing wall between the dwelling and the attached garage which is a cavity wall is not insulated, all the other outside walls are insulated . Is this the normal procedure or can I approach te builder to have wall insulated.

bertie

what is the point of building an energy efficient extension on to an energy inefficient house?

tony — Sun, 20 Jan 2008 22:51:59 +0000

What is the point of building an energy efficient extension on to a nightmarishly energy inefficient house?

Low Rise Building

Mr.Terry — Tue, 22 Jan 2008 05:37:08 +0000

Can anyone give me concrete definition of low rise building.All this time, some people said that building with 3 stories are consider as low rise building, other said that building below 50 feets also consider as a low rise building. Is there any standard code like BS, describe about the definition of low rise building and types of a low rise building in the construction industries nowadays.

Thanks everyone.

How far can I change a traditional conservatory?

DavidND — Tue, 09 Oct 2007 21:14:13 +0100

We've just bought a house with a, 'worn out' with a capital K!, conservatory. Its traditional double wall polycarb roof and knackered dg units. I want to raise the dwarf walls to normal height (and fully insulate) have a wall of glass at the end (triple glazed) and put a very well insulated tiled roof on with a single velux (or similar).

Some questions:
a) can I just do it? or
b) would I need planning permission?
c) does teh fact I want to conserve energy have ANY clout whatsoever?

Thanks in advance peeps.

Part L1B 25% rule

Justin — Fri, 18 Jan 2008 21:25:32 +0000

Hi,
Section 15 reads:

"..plus
b. The area of any windows or doors which as a result of the extension works, no longer exist or are no longer exposed"

So can "windows which no longer exist" be in a different part of the dwelling to the area of the extension? I'm unsure quite what's meant by "as a result of the extension works". Clearly openings specifically covered over by the extension are additional basic allowance, but do openings which I might shrink or cover over elsewhere in the dwelling during the same work, also add classify as an additional allowance against the 25% rule?

(Yes I'm aware of the "optional approaches", and have been looking carefully at those, but want to ensure I've fully understood this basic one first)

Lifetime Homes Standards rewritten?

Peter A — Thu, 17 Jan 2008 10:01:15 +0000

Has anybody heard anything about the Lifetime Homes Standards that government are getting rewritten, I assume this is ahead of Lifetime Homes becoming a mandatory section of CSH as threatened for 2010?
I guess they will try them out ahead of this when certifying code submissions.