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ebuild is sad to announce its closure - it has become too time and resource intensive to develop, manage and maintain.

However, ebuild will remain on-line in archive mode (ie no posting facilties) for several weeks so that users can use it as an information resource.

The Hundredth Idiot


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#1 MarkH

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Posted 10 March 2016 - 12:02 PM

Hi,

A year ago I bought an amazing plot down the end of Wales with full permission for what now seems - as I get a better grasp of what makes an efficient modern building - a somewhat backward design given what is now possible: a cavity wall cottage with conventional block skins (inner skin blocks laid on flat), a rudimentary floor slab design and run-of-the-mill approach to air-tightness and insulation throughout.

My wife and I will quite possibly only build one house - this one - so we'd like to do as good a job as possible with the methods and materials now available but also have a project we can engage with; we both like a challenge, enjoy researching new tech and want to be interested in what we're doing. To give you an idea of our angle: we wanted to build a boat a few years ago and could (probably should) have built a plywood dinghy, a simple fibreglass sloop... something sensible. Instead we took four years to make a high-performance, high-tech ocean-going multihull. So we're probably asking for trouble again - self-building a house with limited prior experience... but it seems like fun.

I'm trying to work out the best way we can go about this build and so far I've concluded that a) cavity wall as specced in our plans is not the best option, and single skin blockwork with external insulation possibly is. I am completely open to all possiblities though.

This forum has already given me a lot to consider.

Thanks!

Mark

Edited by MarkH, 10 March 2016 - 12:06 PM.


#2 ProDave

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Posted 10 March 2016 - 12:12 PM

What finish is specified in the planning permission? i.e brick, render, timber etc?

Planning only concerns the look of the building, not how it is built, so knowing what material was approved for the outside will dictate what construction methods you can consder.

#3 MarkH

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Posted 10 March 2016 - 01:27 PM

Nothing special - 'rough render'. I don't think that limits us?

#4 ProDave

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Posted 10 March 2016 - 01:31 PM

A render finish opens up the posibility of a timber frame building a bit like ours. There is no masonry involved (apart from foundations) It's timber frame, well insulated, and the external finsih is a 100mm thick wood fibre board (adding more insulation) which is rendered directly. Our walls are a little over 350mm thick, all of it insulation of some form.

#5 MarkH

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Posted 10 March 2016 - 01:43 PM

We've got a large area of triple glazed window on the SSE facing aspect of the building which had led me to think thermal mass might be useful and important - I know the timber frame route can be very insulated but does it not lack thermal mass?

#6 notnickclegg

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Posted 10 March 2016 - 01:45 PM

View PostMarkH, on 10 March 2016 - 01:43 PM, said:

... but does it not lack thermal mass?

Uh oh. Might be worth a forum search on that term! :rolleyes:

There've been some really interesting threads around that topic!

Jack

#7 ferdinand

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Posted 10 March 2016 - 02:02 PM

View Postnotnickclegg, on 10 March 2016 - 01:45 PM, said:

Uh oh. Might be worth a forum search on that term! :rolleyes:

There've been some really interesting threads around that topic!

Jack

Lions and tigers and trolls, Oh My !

(Warning to OP: There be Dragons. In Tar Pits! Good spectator sport, and your opinions may / may not change.)

Edited by ferdinand, 10 March 2016 - 02:09 PM.


#8 MarkH

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Posted 10 March 2016 - 02:30 PM

Ah! Sounds like the equivalent of anchor threads on the sailing forums... If only there was an app to filter out the crazy, the dogmatic, the blinkered, the gullible, the blindly optimistic and the doom-merchants from the internet. Although that'd only leave a handful behind and I'm not sure I'd be one of them.

#9 SteamyTea

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Posted 10 March 2016 - 02:45 PM

I am tempted to build a boat, rather than a house. I shall avoid the internet then, though may make it onto the news pages.

Have you done a 'skills audit' on yourself/yourselves, and thought of doing some courses to fill in the homes.
Some things you can do yourself, like vented hot water systems.
Other things need qualifications, like electrical wiring in bathrooms.

I think the main thing is to keep it simple, don't get hung up on technology and remember that a house is just an insulated airtight box. So a basic understanding of thermodynamics (just the simple stuff).

Also have a read at what out mate, over at the other place, is trying to do all on his own (as far as possible):
http://edavies.me.uk/

#10 recoveringacademic

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Posted 10 March 2016 - 02:54 PM

View PostMarkH, on 10 March 2016 - 01:43 PM, said:

[...] but does it not lack thermal mass?

First of all welcome. New members are the key to this place. It stops us old farts from getting complacent.

You know what it's like when you make new friends. You have a period when you get to know them, and vice versa.

Well, there's this little thingy (a sort of Spoonerism if you like) we have on this site. It's name is Thermal Mass. When I first came here I thought there was such a thing. But there isn't. Honestly, there isn't. And it took me a good while to work out why. If you look hard on ebuild, there's plenty of explanations about why TM doesn't exist.

Strange but true. It took me a few days reading to convince myself that Jeremy Harris argument is correct. Scan his blog. Pour yer-self a large something or other and settle down for the night and have a good read.

Regards,
Ian

#11 SteamyTea

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Posted 10 March 2016 - 03:01 PM

View Postrecoveringacademic, on 10 March 2016 - 02:54 PM, said:

(a sort of Spoonerism if you like)
Mermal Thass

I am such a shining wit.

There are some lame jokes as well.

#12 MarkH

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Posted 10 March 2016 - 06:58 PM

View PostSteamyTea, on 10 March 2016 - 02:45 PM, said:


Have you done a 'skills audit' on yourself/yourselves, and thought of doing some courses to fill in the homes.
Some things you can do yourself, like vented hot water systems.
Other things need qualifications, like electrical wiring in bathrooms.

I think the main thing is to keep it simple, don't get hung up on technology and remember that a house is just an insulated airtight box. So a basic understanding of thermodynamics (just the simple stuff).

Also have a read at what out mate, over at the other place, is trying to do all on his own (as far as possible):
http://edavies.me.uk/

I worked with my dad a lot when he was a builder so have a reasonable grasp of nineties building methods, and their shortfalls. I've built an off-grid electrical system for the plot already (we live on site in a caravan) that will easily power the house when it is complete. We've got electrician friends, plumber friends and several buiilder friends but the latter are used to the local norm - block, partial fill, block - and don't like thinking outside of that box.

Keep it simple - no better advice, thanks. I'm not interested in gadgetry including heat pumps and heating systems beyond a wood stove. I'm beginning to be persuaded as to the merits of MHRV.

#13 ConstructionChannel

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Posted 10 March 2016 - 07:47 PM

View Postrecoveringacademic, on 10 March 2016 - 02:54 PM, said:

. It took me a few days reading to convince myself that Jeremy Harris argument is correct.

took me well over a week,,, in the end i decided to just accept he clearly knows better than i do so why question it :D
good to hear someone else actually did the maths and came to the same conclusion though :lol:

#14 SteamyTea

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Posted 10 March 2016 - 10:02 PM

Two point.

You may want to rethink wood burning for a number of reasons, won't bore you with them just yet.

Second point.
I did my Dissertation on varying the mass of internal structures with regard to thermal storage.
I have done the maths, about 98 pages of it.
Good fun to calculate (and I am still trying to find a simpler way to do it), but it basically makes no difference if your house walls weight 10 tonne or 500 tonne. It is the first tonne that makes the difference (sizes and mass of buildings may change).

Now tell us al more about this off grid electrical system you have, that is the sort of thing we like:
http://www.ebuild.co...how-hard-it-is/

Edited by SteamyTea, 10 March 2016 - 10:02 PM.


#15 MarkH

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Posted 11 March 2016 - 04:26 PM

View Postnotnickclegg, on 10 March 2016 - 01:45 PM, said:

Uh oh. Might be worth a forum search on that term! :rolleyes:

There've been some really interesting threads around that topic!

Jack

View PostSteamyTea, on 10 March 2016 - 10:02 PM, said:

Two point.

You may want to rethink wood burning for a number of reasons, won't bore you with them just yet.

Second point.
I did my Dissertation on varying the mass of internal structures with regard to thermal storage.
I have done the maths, about 98 pages of it.
Good fun to calculate (and I am still trying to find a simpler way to do it), but it basically makes no difference if your house walls weight 10 tonne or 500 tonne. It is the first tonne that makes the difference (sizes and mass of buildings may change).

Now tell us al more about this off grid electrical system you have, that is the sort of thing we like:
http://www.ebuild.co...how-hard-it-is/

OK... Ok. SeveraI thousand words read.

I probably won't ever bring up the TM thing again. Wow, there is a remarkable depth of knowledge here isn't there? Anyway the arguments put forward by Mr Tea, Jeremy Harris et al are convincing and comprehensive. The 'thermal mass' term is so commonly bandied about and intuitively makes some sense that I for one hadn't even questioned the wisdom of it. How remarkable that so many people are heading down a duff path.

Wood burning: I imagine reasons against include the excess of heat and required input of air? I'm beginning to grasp that an efficient house shouldn't need a box full of combustion to keep it warm but two things - a love of fires and a lifetime of cold houses - keep me from abandoning the idea. Also I've already got a few years worth of logs...

#16 DavidWright

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Posted 11 March 2016 - 05:18 PM

View PostMarkH, on 11 March 2016 - 04:26 PM, said:

Wood burning: I imagine reasons against include the excess of heat and required input of air?
On this occasion I think SteamyTea might be thinking more about the health side (yours & your families, as well as that of others) rather than just energy considerations?

Edit typo heath => health.

Edited by DavidWright, 11 March 2016 - 05:19 PM.


#17 joiner

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Posted 11 March 2016 - 06:23 PM

Biomass of any sort as a lifestyle choice is a - ahem - contentious issue. Mass of credible scientific/medical 'evidence' against its use, but I'm reluctant to argue against if (truly) off-grid and (arguably) rural with adequate/sustainable supply of timber. But otherwise the presumption is always against.

Edited by joiner, 11 March 2016 - 06:24 PM.


#18 ProDave

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Posted 11 March 2016 - 06:55 PM

Wood burning stoves are a very emotive thing.

No 1, they are NOT carbon neutral in my opinion. you burn the stove, CO2 goes up your chimney, you don't burn it, no CO2. So if your motivation is to be carbon neutral, don't fit one.

No 2, if you are not bothered about being carbon neutral, and have a supply of FREE wood, then you can think about fitting one. If you had to buy your wood, again I would not bother.

That still leaves the argument about whether you need the heat, and wherther it will overheat your house.

I am fitting one, the smallest little 3Kw Springdale, that has ducted intake for the combustion air. I have a plentiful supply of free wood and I like playing with a stove, so we are going to fit it. But I accept it won't get used as much as the one in our present house and may not get used very much at all.

One important design feature of our house is double doors from both living rooms into the hallway, so with all the doors open, the whole ground floor (apart from the uitility room) is one big space, open to the stair well as well. So I am hoping that will be a big enough area to heat to absorb the small output of the small stove. If not in a couple of years I might be on here saying don't do it, you will have to open the windows.......

Edited by ProDave, 11 March 2016 - 06:57 PM.


#19 MarkH

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Posted 11 March 2016 - 11:14 PM

View PostProDave, on 11 March 2016 - 06:55 PM, said:

Wood burning stoves are a very emotive thing.

No 1, they are NOT carbon neutral in my opinion. you burn the stove, CO2 goes up your chimney, you don't burn it, no CO2. So if your motivation is to be carbon neutral, don't fit one.

No 2, if you are not bothered about being carbon neutral, and have a supply of FREE wood, then you can think about fitting one. If you had to buy your wood, again I would not bother.

That still leaves the argument about whether you need the heat, and wherther it will overheat your house.

I am fitting one, the smallest little 3Kw Springdale, that has ducted intake for the combustion air. I have a plentiful supply of free wood and I like playing with a stove, so we are going to fit it. But I accept it won't get used as much as the one in our present house and may not get used very much at all.

One important design feature of our house is double doors from both living rooms into the hallway, so with all the doors open, the whole ground floor (apart from the uitility room) is one big space, open to the stair well as well. So I am hoping that will be a big enough area to heat to absorb the small output of the small stove. If not in a couple of years I might be on here saying don't do it, you will have to open the windows.......

Wood burning stoves are emotive? Man, first thermal mass isn't real now I can't have a fire? Is there a Santa thread here?

ProDave,

I agree fully with your carbon neutral point and have often been a dessenting voice when this has come up in conversation. The resequestriation argument seems absurd to me but people use it to prop up the choice of a 'natural' fire. I don't prioritise a carbon neutral lifestyle particularly but hey, if anyone is asking I currently live off grid and spent the previous four years living aboard a wind-propelled, solar powered boat.

I have a pretty much endless supply of wood (mostly deadfall and wind-felled ash from the wood around me) and like yourself, like playing with a stove. I'd also plan to get the smallest stove possible with ducted air. Our house design has one large open plan kitchen/lounge/dining room with vaulted ceilings and a mezzanine bedroom, perhaps we can lose the heat too. I think I would miss the centerpoint of a small stove in the lounge area, I'm sat typing this with a 4kW stove crackling away and the room (in a caravan) would be bleaker without it.

Why is biomass a contentious issue??? Medical evidence?? I'm missing something here...

#20 ProDave

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Posted 11 March 2016 - 11:22 PM

Biomass is being sold to people as carbon neutral and green etc. There seem to be a lot of people converting to that up here.

The main argument against is air polution. Amother thing I would say is I don't agreer with wood burners in a densely populated area. That would be going back to Victorian smog.

And my argument about free wood applies there. the last person i met who just had a big boimass boiler fitted (and lost half his double garage to the new heating system) was complaining that since it was installed, he has watched the price of heating oil fall, and the price of wood pellets rise. Have you seen how far some of these wood pellets travel to get to your hopper?

I don't think I have ever collected firewood from more than a mile away, and most of it is windfall.

Edited by ProDave, 11 March 2016 - 11:22 PM.