materials for new house

Ian7

Hi everybody, I'm sure this type of thread has been started before so I apologise if i'm dragging up questions that have answered before but I need to put my mind at ease. We are due to start building very soon and well, i'm in a bit of a moral dilemma. I suppose it's poor planning on my behalf but I'm worried about the un-ecofriendliness of the materials going into the house and don't know if I can afford to change to the alternatives so I want to put a few alternatives here and get some feedback on price differences.

1. would it cost anymore to replace 50% of the concrete with some sort of GGBS?
2. Are alu-clad windows a whole lot more expensive than uPVC?
3. Cellulose blown insulation vs glass quilt price?
4. Recycled content plasterboards like fermacell or something (am I allowed say a brand name here?) vs regular plasterboards price.

It would be great if someone can clear my mind on this. When it goes to site I will try to get somethings replaced but I'm not so optimistic about replacing the window types.

BryanF

Ian7 wrote: »

Hi everybody, I'm sure this type of thread has been started before so I apologise if i'm dragging up questions that have answered before but I need to put my mind at ease. We are due to start building very soon and well, i'm in a bit of a moral dilemma. I suppose it's poor planning on my behalf but I'm worried about the un-ecofriendliness of the materials going into the house and don't know if I can afford to change to the alternatives so I want to put a few alternatives here and get some feedback on price differences.

1. would it cost anymore to replace 50% of the concrete with some sort of GGBS?
2. Are alu-clad windows a whole lot more expensive than uPVC?
3. Cellulose blown insulation vs glass quilt price?
4. Recycled content plasterboards like fermacell or something (am I allowed say a brand name here?) vs regular plasterboards price.

It would be great if someone can clear my mind on this. When it goes to site I will try to get somethings replaced but I'm not so optimistic about replacing the window types.

can you expand on 'eco' - is this discussion also on health grounds or just environmental grounds?

1. roughly the same price - circa 40% lower Co2 emissions
2. yes, but Alu-clad are higher on the sustainablity list - they look better, easier to repair, last longer and can be recycled unlike upvc - less VOC's
3. cellulose possible a little more expensive, depending on where your putting it - cellulose while dusty has less respiratory issues associated than with glasswool
4. as its recycled with cellulose its a little more expensive but worth it for instance if you require them for a breathable wall structure - less formaldehyde (there's also PB made from calcium silicate worth a look)

Start by reducing the main materials in the house for instance blocks and EPS for timber with cellulose.. and go from there.. allow time for this process and if your serious employ someone with the credentials or have a read of http://perigordvacance.typepad.com/files/inventoryofcarbonandenergy.pdf


remember that this should be done in conjunction with reducing any demand for heating, HW and electricity in general and to that end I would recommend you carry-out a phpp (passive house) calculation.


if i can give you any advice it would be to plan, plan, plan - once on site things move to fast

and any-time you see 'eco' start by asking where and how the product is made and look for proof of its 'eco' credentials in figurative terms as outlined in the Ice database

Ian7

Hey, cheers for the reply Bryan

BryanF wrote: »

can you expand on 'eco' - is this discussion also on health grounds or just environmental grounds?

Both i think

there's also PB made from calcium silicate worth a look

might have a look at that yeah, more expensive too I presume?

remember that this should be done in conjunction with reducing any demand for heating, HW and electricity in general and to that end I would recommend you carry-out a phpp (passive house) calculation.

I'm not worried about that end of it. We have specified enough insulation to keep us nice and cosy:). it's just the material content that I'm worried about.

if i can give you any advice it would be to plan, plan, plan - once on site things move to fast.

too late for that but if I can alter any of the materials at this late stage I would be happy.

BryanF

Ian7 wrote: »

I'm not worried about that end of it. We have specified enough insulation to keep us nice and cosy:). it's just the material content that I'm worried about.

may i point out that the yearly fossil fuel requirement to heat and power even a passive house quickly surpasses the use of 'eco' materials in construction especially of the magnitude we have discussed.

so that's why I asked about how you intend to minimise your energy usage:

1. how your provisional BER looking?
2. what is your kwh/m2/yr? or expected heat demand requirement?
3. and what's your fuel source?
4. % glazing to South - shading and rating?
5. attention to detail - thermal bridging, air-tightness proposed, MVHR?
6. not forgetting the true 'eco' contradiction- what the transport options are for your commute to local amenities/work? as normally this car usage dwarfs most 'eco-ness'

just do it

Ian7 wrote: »

We have specified enough insulation to keep us nice and cosy:).

Good luck with the build. Out of interest what have you specified?

Ian7

Bryan, cheers for your reply there, you've given me plenty of food for thought, especially about transport and heating. I suppose i could narrow my concerns down to health issues now. Provisional BER is due to be completed by our engineer. Maybe i'm being over optimistic but I reckon it will be in the A3 region. I will let you know when we get it.

I might be able to save some money on site and divert it to other preferred materials.

just do it wrote: »

Good luck with the build. Out of interest what have you specified?

Cheers, well it's a concrete build and I think I will go with the 50% GGBS. (would have gone with the timber frame but was impossible to convince the other half so I had to find some balance)
150mm bead cavity fill.
+ 50mm insulated plasterboard on internal walls.
all opes taped up and vario membrane and taping to ceilings.
200mm quilt insulation in first floor. (hoping to switch to Cellulose)
300mm quilt insulation in attic. (hoping also to switch to Cellulose)
Intelligent/moisture sensitive background ventilation and mechanical extract.
Triple glazed uPVC windows. (trying my best to transfer savings over to get alu-clad version instead)

Heating & hot water =
Solar panal + triple coil insulated cylinder.
Wood burning stove.
3 zones and thermostatic controls for a Condenser Oil boiler to start with until I can build a garage for a wood pellet burner. I should have a good idea of the system requirements by then so I will have the pellet installation & requirements well sussed out.

By the way, I know there are people shouting from the rooftops about passive housing and MHRV systems but if i'm to be honest, I really don't think it's going to work in Ireland. Not at the moment anyway. We Irish can't regularly change the feckin' filters on cooker hoods never mind filters in ventilation systems. It would be a disaster waiting to happen unless the installers agree regular scheduled maintenance visits. But what happens if the installers/manufacturers go out of business?

BryanF

Ian7 wrote: »

Maybe i'm being over optimistic but I reckon it will be in the A3 region.

it would want to be as A3 is now the minimum rating;)

I might be able to save some money on site and divert it to other preferred materials.

yeah right. imo make your decisions now, and seek out competitive low embodied energy alternatives prior to going to site. you wont have time or patients for this at that stage.

150mm platinum bead bonded cavity fill.
+ 50mm insulated plasterboard on internal walls.

not very 'eco' at all.. why not change to mineral wool at least that's recyclable at end of life. and less VOC's for your family to breathe in

200mm quilt insulation in first floor. (hoping to switch to Cellulose)

why?

300mm quilt insulation in attic

take the 200 from first floor an put in attic

By the way, I know there are people shouting from the rooftops about passive housing and MHRV systems but if i'm to be honest, I really don't think it's going to work in Ireland.

you should seriously think some more about this -possible meet some passive house owners. for all your talk your 'eco' attemps are failing at every level - A3=circa 60kwh/m2.y whereas passive is at circa 15kwh/m2/py and as regards MVHR what the difference between what your putting in an MVHR only the heat recovery part..

It would be a disaster waiting to happen unless the installers agree regular scheduled maintenance visits.

you should do some more research here - filter can be change by the occupant - do you get your boiler serviced every year like your supposed to? at least on the mVHR systems you get a sensor that tells you to change your filter.. people are always afraid of change, but as we seal up our buildings with insulation and air-tightness why would you stick great big holes in wall to leave in fresh air? it makes no sense. Im all for the mechanical ventialtion in retro-fits but when you have the chance to build from scratch imo mvhr is the way to go

Ian7

yeah maybe I should have said A2?

About the insulation, might ask about changing to mineral wool though. the 200mm in the floor is for sound as well as heat. Would 500mm in the attic not be a bit excessive and would it squash down under it's own weight?

Look, thanks for your advice but not for telling me that i'm failing at every level. At least i'm trying to do the best with what I have, that's why I came on here. Why don't ya go lecture the 100,000+ people who built a house in the last ten years about what they did wrong?

It's the current situation and mentality that I'm talking about. Sensors will break or be purposely ignored. I don't need to research that to know the Irish mentality. Most of my friends, family and extended family never change their cooker hood filters and don't check or maintain their oil boilers. I'm the one who is always banging on about it to them to get it done and I don't even have an oil boiler to check myself. I even try to encourage people to get their walls pumped or solar panels installed but they'd rather fork out on fuel first and think about it later. It's true that we are too slow to change but it's the industries fault that we are this way and that people are resisting the all too new passive house standard. (all too new in Ireland that is)

BryanF

I meant no disrespect, best of luck with your project

Ian7

No bad feelings at all Bryan, I respect your opinion and as I said, your advice gave me a lot of food for thought and at least you're fighting for a good cause! .
If the construction industry had listened to people like you ten years ago we probably wouldn't be having this conversation.

And about passive houses, I just haven't fully accepted the idea myself yet and that's something I have to get over. I'm conflicted between the realisation that 10kw/m2/yr is a phenomenal achievement and also the need to have artificial/mechanical ventilation minus the traditional open fire/stove.

Ian7

I was just reading through another thread which is scarily similar to this one and spotted a suggestion by yourself for something called "demand control ventilation/positive input ventilation" can you tell me a bit more about this?

BryanF

imo these are better suited to retro-fit homes where its just not practical to get the air-tightness levels required for MVHR to be efficient. I see little point in the current standards of insulation, if they are not matched with high levels of air-tightness(simply put - no drafts), and I see no point in either of these, if your going to heat up the internal volume of air just to piss it out through wall vents and then heat cold incoming air up again..

http://www.constructireland.ie/Articles/Ventilation/How-do-demand-control-ventilation-and-HRV-compare.html

http://www.greenbuildingadvisor.com/blogs/dept/musings/designing-good-ventilation-system

http://www.aecb.net/PDFs/9Jan2009_MVHR_Final-2.pdf

I apologise if I seemed harsh, its really the place of your chosen arch to help you through this process and offer you the materials and strategies that suit your criteria and meet the building regs.