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Why insulate


Russell griffiths

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Ok tin hat on. 

Why do I need to build a well insulated house ?

i have read a lot on all the houses with 300mm of cellulose in the walls and roof sitting on 300mm of eps, but the wife of the insulating guru wants a woodburner in the boot room/laundry cos it drys the washing well quick. 

 

So what are your reasons to insulate so well

 

lets say I get wood for free except the cutting and splitting labour. Why not build a good house that far exceeds current regs and on a chilly night light the woodburner. 

I see a lot of articles in self build mags that all have a stonking great wood fire in the front room, is it wrong to fit standard double glazing and let a bit of heat escape outside. 

I will be perfectly honest we are looking at windows at the moment and I have a complete dislike to all these super tilt and turn triple glazed euro offerings. 

I shall sit over here and wait to be properly chastised. 

Russ. 

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I am very pleased with my Euro top hung outward opening triple glazed windows.

 

I am on the side of wood burners, as long as you have free wood. I would not entertain the thought of having one and paying someone to deliver chopped firewood to your door.

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You can do what you want, within reason, but even if you just do the  very bare minimum to comply with Part L1a you will end up with a reasonably well insulated house.  Not great, but certainly well into the region where you my well find that a wood burning stove puts out far too much heat for an average sized room a fair bit of the time, so won't get used as much as you might think.

 

There's no doubt that a well-ventilated house (specifically with MVHR, as ventilation rates from these will, in practice, be lot higher) will dry things much faster.  It's one of the most noticeable things from fitting MVHR, second to the noticeably better air quality, that things like damp towels just dry a great deal faster with MVHR.

 

One conundrum with any combustion stove and even building regs airtightness levels is that you're pretty much pushed towards having a room sealed stove, which does little to improve ventilations rates.

 

Finally, there is your health, and that of your neighbours, to consider.  The particulates and other toxic emissions from burning wood are massively greater than from other well-known air pollution sources.  In very rough terms, a conventional wood burning stove is around 100 times more harmful than a diesel car, so you can roughly equate having one running to having around 100 diesel cars parked outside with their engines running.

 

Ultimately, it's your choice, but my guess is that we will see increased legislation against burning wood and coal before long, plus you may well find that, even if you build to the very worst energy performance standard that will still scrape through Part L1a you will still be stuck in a situation where a wood burner puts out far too much heat a lot of the time when you want heating, which then leads you towards having two heating systems, one that can be run when modest levels of heat are required, and the wood burner for days when the weather is very cold. 

 

 

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On some level I agree with your sentiments but...

 

For a start wait until you're I dunno, in your 70s (tin hat on :) ) or your partner / child(ren) needs the sort of care that means time to go and chop wood just isn't there...

 

I absolutely DREAD the day, with my crap pension forecast, when I'm old and in this house still with leaks and high fuel bills.

 

I LOVE the idea of sitting somewhere dry, warm and safe looking out of big 3G glazing and knowing a big bill for (in my case) oil won't be landing on the mat. 

 

You pay for insulation ONCE, you'll be paying for "fuel" even if "free" in other ways even if it's just the labour to chop it or the back boiler burning out periodically.

 

Anyway, you're ALL wrong. You should be going UNDERGROUND and letting the mass of earth and stable year round temperatures work for you! 

 

Tin hat on too! :)

 

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1 minute ago, Onoff said:

On some level I agree with your sentiments but...

 

For a start wait until you're I dunno, in your 70s (tin hat on :) ) or your partner / child(ren) needs the sort of care that means time to go and chop wood just isn't there...

 

I absolutely DREAD the day, with my crap pension forecast, when I'm old and in this house still with leaks and high fuel bills.

 

I LOVE the idea of sitting somewhere dry, warm and safe looking out of big 3G glazing and knowing a big bill for (in my case) oil won't be landing on the mat. 

 

You pay for insulation ONCE, you'll be paying for "fuel" even if "free" in other ways even if it's just the labour to chop it or the back boiler burning out periodically.

 

Anyway, you're ALL wrong. You should be going UNDERGROUND and letting the mass of earth and stable year round temperatures work for you! 

 

Tin hat on too! :)

 

 

 

Those were thoughts that certainly heavily influenced our decision to try and build a "no bills, no physical work required" house.

 

On your last point, this is my very first ever post on this forum's predecessor, ebuild: http://www.ebuild.co.uk/topic/6386-earth-sheltered-house-any-pp-tips/#entry22585

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22 minutes ago, JSHarris said:

 

 

Those were thoughts that certainly heavily influenced our decision to try and build a "no bills, no physical work required" house.

 

On your last point, this is my very first ever post on this forum's predecessor, ebuild: http://www.ebuild.co.uk/topic/6386-earth-sheltered-house-any-pp-tips/#entry22585

 

I knew I was right! :)

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2 minutes ago, Russell griffiths said:

I must admit even though all our wood is free I hate the amount of effort it takes to cut and split. 

And I have all the fancy tools to do it as well. 

 

Ok super insulated home it is. 

 

 

You know it makes sense! 

 

Put the saving towards a Raspberry Pi and a small (or large) flat screen set in a fire place and indpendent of the telly displaying the log fire of your choice!

 

...you'll also be able to play Space Invaders on it! :)

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the thing is, it needs to be one extreme or the other either super insulated and airtight with mvhr or poorly insulated and draughty. unfortunately you cannot do the latter due to building regs. anywhere in the middle is going to lead to condensation and damp problems in the future, and i fear it is going to be a big problem when it surfaces

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1 minute ago, Simplysimon said:

the thing is, it needs to be one extreme or the other either super insulated and airtight with mvhr or poorly insulated and draughty. unfortunately you cannot do the latter due to building regs. anywhere in the middle is going to lead to condensation and damp problems in the future, and i fear it is going to be a big problem when it surfaces

I am not sure I agree with that.

 

Our last house was built to normal standards for 2003. Actually I suppose it was cutting edge then as it was built with a 150mm timber frame. Just a year or 2 earlier the normal was a 100mm frame.  It had good under floor and loft insulation but no attention placed on air tightness, pretty standard basic timber double glazed windows and no mvhr.

 

It was a very comfortable house. Never a spot of condenstion or mould, even when hanging wet washingon the airer in the utility room to dry.  Annual heating cost was about £800 for heating oil (perhaps peaked at £1200 when the price of oil was higher)

 

Of course I hope the new house will cost less to run than that.

 

BUT the old house had solar PV at the original higher FIT rate, that was paying us about £750 per year, almost paying for the annual heating costs.

 

The irony of the whole downsize to a smaller, lower energy house plan we had, is that in the time it has taken, the FIT has dwindled to almost nothing, and for political reasons it was impossible to get the FIT until the house is complete so we were unable to install the solar PV while the FIT rate was worthwhile.

 

So the sad reality is, with no FIT then with, or without solar PV fitted, our new house will not in fact cost us anything less to live in than the previous one did.

 

There are some rather sore issues with this  that are like an itch that just keeps itching.  Sometimes I do wonder if we should have just accepted the old house was good, and our new "better" one may not actually in practice be any cheaper.

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2 minutes ago, ProDave said:

but no attention placed on air tightness

i think this is the reason you didn't have problems, modern houses do need to be relatively airtight and are relying on trickle vents for ventilation as well as the gaps in vcl various trades make and don't bother fixing. 

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I built a block house and all along the way I was aiming to build it to the highest standard that I could afford. I had a set budget and couldn't go 1p over. I spent extra on thermal blocks for the inside skin, put thicker pir on the underside of the roof and extra loft insulation to take it above building regs.

Where I really did put the effort in was in getting it airtight. Used membranes where I could and tape around the frames of doors and windows and this has made more of an impact per £ spent than anything else. It's fairly cheap step to take in the grand scheme of building a house, think my bill was £600 for all the membranes and tape I needed and I still have a few rolls left over.

As far having a stove I always wanted one but some how ended up with two, a woodburner and a pellet stove that provides all my heat and hot water. Have close on 3t of logs still to go through so maybe 5 years worth. My bill for pellets was £350 last year, thanks Arlene from the dup for covering my bill for years to come, and that is to provide all my hot water and heating. Have pv which takes care of the hot water for maybe 5 months of the year. My last house was half the size of my new build and oil was costing me £500 a year and twice as much in electric than what I am paying now.

It's your house build it how you like and put what ever you want in it. Any thing goes in my book with the exception of woodchip wallpaper you definitely will regret that.

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  • 1 month later...
On 26/10/2017 at 22:14, jack said:

 

Ouch!

 

Just done £900 on oil! If we're lucky that might see us through until Spring.

 

Friday night and I'm sitting in the lounge with a bobble hat on wrapped in a blanket. YES the boiler is working and CH is on for all the good it does. You know it's Christmas when you can sit and watch the ceiling decorations gently swaying in the multiple draughts.

 

If it wasn't for this place I would have thought that's just what you do in the winter.

 

Ah! There's the comforting sound of the boiler short cycling, aka pi$$ing money through the gaps in the "-----" (fill in walls / ceiling / floor) as appropriate!

 

:)

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Im with Jeremy on wood burners. Why? Girif, smelly AND busy trying to kill you with pollution at the same time!

 

In an old leaky house, maybe, but in a modern build? Why. Not needed.

 

Want to dry the washing. Get a de-humidifier. Simples.

 

Legislation will come as sure as night follows day. Frankly, im amazed we have allowed what happens now to continue, or more accurately, re-emerge as a means of heating.

 

London will be first.

 

 

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@Onoff  It sounds like you would be better off in our caravan.

 

This last week has been a bit testing. Well below 0 every night, barely up to 0 in the day, and a strong northerly wind. Oh and a bit of snow to add to the interest.

 

With the WBS and some electric heating we can keep it warm, but it goes cold very quick when you turn the heating off.

 

I have been working on an old  1920's bungalow for a week or so now. It has no insulation in the walls or under the floor. About 2" in the loft. It's been very cold in there while the plumber has been upgrading the central heating, but soon warms up when you pump 20Kw of heat into it. The owner does not seem at all bothered by that.

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50 minutes ago, Roger440 said:

Legislation will come as sure as night follows day. Frankly, im amazed we have allowed what happens now to continue, or more accurately, re-emerge as a means of heating.

 

London will be first.

 

Doubtful.... for many reasons !

 

Sadiq Khan won't bring in any legislation that harms his "patch" as for example the latest round of emissions charges makes the residents in the zone pay just 10%. A "woodburner" tax wouldn't bring in the revenue (try £3-400m PA for congestion charging) that another extended mobile charging scheme will. He's not interested in a static tax as it won't bring in revenue - motorists are his target market and they keep coming back for more...

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Quite an interesting topic. I used to live in an old Croft house with walls like a castle and cost us about £90 per month in oil. I will be starting a build in the spring which will exceed building regulations but not passive. In our house, I plan to have an stove right in the center of the house. We live on a croft with quite a bit of woodland, so plenty of logs and room to season. I am 31 so hopefully got 40 years of good wood chopping years ahead of me.

 

90% of the year I am not expecting to have any heating on and if we do need it will just be some little portable oil heaters that we wheel out and keep in a cupboard for the rest of the year. Not really fussed about paying £x month for heating in winter. I would quite like one today to invest in some renewable when I have the money like a turbine and perhaps this would then offset minor electricity usage. 

 

As a first time builder and first time property owner the aim here is to provide a fairly comfortable warm home, a room for my two kids and a mortgage that's manageable. If I could buy a house on the open market I would consider it but property prices are over inflated from holiday cottages etc in my area.  

 

 

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In my old farmhouse I had a small mutlifuel (? Charmwood ?) stove and a double skinned jetmaster but then again it has 2ft thick stone walls, no underfloor insulation in most GFL rooms and very leaky windows.  I also have a cottage in a village on one of the Greek islands, and I have one of these

images?q=tbn:ANd9GcQ2c7M4jelGW8FYBMOSaMFburning these   images?q=tbn:ANd9GcQkfA7zrYbEqOdk0HuAFvQ

From Oct-May,  I can get the ground-floor (one open room with open stairs) toasty by breaking up 2 or 3 logs into 50cm bits and chucking them and a firelighter into the stove, then clamping it right down once once everything is good and alight and letting it burn out.  Brilliant -- for a cottage with 2ft stone walls and leaky windows.

 

On 26/10/2017 at 19:02, Russell griffiths said:

... but the wife of the insulating guru wants a woodburner in the boot room/laundry cos it drys the washing well quick ...

... Why not build a good house that far exceeds current regs and on a chilly night light the woodburner ...

 

The basic formula of good insulation + good airtightness + MVHR means that you have a house that is airy and very cheep to heat in the winter, and keep cool in the summer.  The entire air in the house is swapped out every 2-3 hours with fresh air and this is ~10°C warmer than the outside at night, more in the winter, so the RH is always within a low, yet comfortable range.  So washing dries pretty quickly in any room with an MVHR extract in it without leaving moisture in the house.  If you do need to drop the RH a bit more, then as @Roger440 says, put a small dehumidifier in the room.  In economy mode these run at a 100 W or so and in fact can return more than double that into the room as heat (the waste energy from the heater, plus the latent heat from condensing out the water vapour).  This will give you a very efficient drying room.

 

It is the low RH of the drying room than accelerates cloths drying.  The main issue with an old fashioned drying room is that it achieves this by having a room maybe 10°C warmer than the rest of the house.  But what happens to all of the humidity driven into the air?  You either use an extract to dump the wet warm air out of the house (= a lot of kW heating the outside air), or you  let it circulate into the rest of the house where it then condenses on any cold surfaces: windows and their reveals, any wall area where there is enough thermal bridging to drop the wall temperature enough; and hence you get mould and damp problems.

 

IMO, there are two main issues with most wood burning stoves:

  1. You need the core of the burn / or exhaust gasses to get up to a minimum of ~1,000°C (yes that is one thousand).  Any less and the products of combustion don't break down properly and your stove will  produce more nasty products of combustion than your typical diesel car.  Stove manufacturers like to put a nice glass window onto this core.  (I did a quick search and not even the continental suppliers like Jotul and Nordica no longer seem to offer small fully closed stoves.).  This then emits a lot of radiant heat means that ...
  2. You find it hard to modulate your stove down to a minimum of say 2½ kW output, that's 60 kWh a day, which in my case is roughly 4× the amount of top-up heat that I need in winter months.  This heat is produced in one room, so even with a properly insulated house this is far more than a single room can take, unless you have a very large open plan area and even then you may need to actively redistribute this heat around the house.

Of course re (2) you might use a back boiler to heat the water but back boiler stoves needs a higher minimum output due to the heat losses into the water...   Any small manually fed stove will not have enough bulk capacity to keep enough supply in the burn chamber to run overnight and still be alive in the morning, so you will invariably need to relight the stove every day.  (Butane or Propane gas poker's highly recommended for this, BTW.)   

 

Your ideal stove would be something like a rocket mass heater, but I can find any standard pre-built stoves selling in the UK.  There are lots of self-build versions, but have fun finding a HETAS-certified installer or tame Building Inspector willing to sign off on an installation of the same.

 

Sorry but wood stoves and properly Part L1a compliant (average sized) houses don't mix.  Of course you do have the option that many builders seem to take, which is just to use partial, badly installed insulation or just omit it entirely on some walls so that your house leaks heat like a sieve, and accept the damp generated by the drying room running down the walls. :P

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9 hours ago, PeterW said:

 

Doubtful.... for many reasons !

 

Sadiq Khan won't bring in any legislation that harms his "patch" as for example the latest round of emissions charges makes the residents in the zone pay just 10%. A "woodburner" tax wouldn't bring in the revenue (try £3-400m PA for congestion charging) that another extended mobile charging scheme will. He's not interested in a static tax as it won't bring in revenue - motorists are his target market and they keep coming back for more...

 

Isn't he aiming to increase revenue from Council Tax by allowing Londoners to build willy nilly in their gardens etc? Should be a lot easier to get PP in London now as councils will have to hit quotas. The cynic in me says the housing need is in part being met by the "beds in sheds" landlords and his plans will legitimise this to some extent with retrospective approvals.

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13 minutes ago, Onoff said:

 

Isn't he aiming to increase revenue from Council Tax by allowing Londoners to build willy nilly in their gardens etc? Should be a lot easier to get PP in London now as councils will have to hit quotas. The cynic in me says the housing need is in part being met by the "beds in sheds" landlords and his plans will legitimise this to some extent with retrospective approvals.

 

Yes but to bring in another £200m he would need to build 100,000 new houses in London and that’s not going to happen because once they are built if the people don’t like what he’s doing then they can vote him out .... it’s the vehicles his policy team go after as they are an easy target and there is a constant churn of new “customers” for the congestion charging. 

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4 minutes ago, PeterW said:

 

Yes but to bring in another £200m he would need to build 100,000 new houses in London and that’s not going to happen because once they are built if the people don’t like what he’s doing then they can vote him out .... it’s the vehicles his policy team go after as they are an easy target and there is a constant churn of new “customers” for the congestion charging. 

 

Having just come back from three days in London I have to agree. The traffic just continues to be bonkers wth no sgn that increasing charges is having any effect.

 

The other very noticeable thing is the huge number of ‘for hire’ black cabs. I can remember it being almost impossible to get a cab in peak times in the centre but now every other one is available. The rank at Paddington is also 50+ Taxis deep waiting for a fare. I’m assuming this must be the Uber effect. No wonder tfl wants to shut them down!!

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