Building methods for passiv standard?

beyondpassive

Eoghan Barra wrote: »

Sas (or anyone else in the know), would you mind sending me a pm naming the Irish companies you would consider buying passive standard (not cert.) windows off if you were in that position now?

Cheers.

PM sent,

In going from mere building reg standard to passivhaus you make a series of interventions to improve the efficiency and comfort of the building. These are justified on a cost benefit balance which includes the compound cost of finance but also includes a conservative estimate of projected fuel costs at 6%. A time horizon of 20 years is set as some items will need replacing. For instance on one particular build:

(Some intentions cost less than others, design improvements cost virtually nothing, but we'll ignore this one as design is most often ignored in the interest of getting planning quickly and cheaply).
-Extra insulation, airtightness below 1, MHRV can have a payback of 7 years,
-solar store- 8 years
-thermal bridge free junctions 12 years. All easily justified.

Windows are a different matter, treble glazing alone costs very little above double so its really about the frame. You can have treble glazed in a cheap 1.4 U-Value frame and it will pay back in 10-12 years. But for good surface temperature comfort and condensation risk reduction the frame should be thermally broken, The top end windows have a cork core wheras the new cheaper passivhaus windows have a layer of insulation behind the aluclad. The former can be twice as much costwise as the latter, but in truth they look it. I'd love to use I..m or P..n the Bose sound system of windows, but instead use one of 3 cheaper systems, 2 of which are also imported, only 1 is a small operation they are T..e, H..r and M..y. The high end stuff looks like it would last forever but the sales and service guys are all bluster and it can be infuriating getting them to rectify installation issues. The mid range stuff is fit for purpose, but without paying a such a high premium you get better service.

So what about Passivhaus? You get so many people building one off's that were planned before they ever heard of passivhaus. I would never even suggest these guys set their hearts on a cert unless they have a build as compact as a crate and able to catch all the winter sun. As SAS, Fclauson and I found out independently, the cost benefit sweet spot for irish detached typology is around 17-20kWh, depending on location and shape, whereas you need to be at least 13.5kWh/m2 for passivhaus. So If your going certified passivhaus, you really should go for the high end windows, certified passivhaus with tilt and slide doors which can be upwards of €20k above a mid range thermally broken window.

That last intervention is a game changer for most builds. Its a lot of money for 3 or 4 kilowatts a €50 annual running cost saving and a snazzy glass plaque Its a frying pan over the head for the decision maker, if the slider jams after you've moved in. These windows are the bugatti Veyron of the fenistration world, as long as they're not serviced by your backyard mechanic.

Great credit to SAS and Syd for a fantastic Passivhaus, it really is a joy to visit it on a sunny december morning. However, at least You didn't put as much money into the build as this guy: http://www.youtube.com/watch?v=beK0O25O9aY#video

JPJ

beyondpassive, here are the steel details

Can you PM the window details to me too please?

Eoghan Barra

sas wrote: »

I'd consider the unthinkable

Apparently the window is very good, doors less so from an airtightness point of view.

Thanks for that, sas. I presume you're talking about MJ?

Thanks beyondpassive and kboc for your pms; you both actually mentioned the same company, which means they definitely must be worth checking out. Nice one.

fclauson

beyondpassive wrote: »

... However, at least You didn't put as much money into the build as this guy: http://www.youtube.com/watch?v=beK0O25O9aY#video

I have to call this out - think of the dinner party comments "so how much did it cost to build this place" !!!!!:D

fclauson

JPJ wrote: »

My BER report states that the house has a primary energy demand of 73 kWh/m2/year with C02 emissions of 18 kg/m2/year. Is this what you are asking for?

At these levels of insulaiton you have to do a PHPP (or dig into the DEAP spread sheet version to extract numbers from the ER1 sheet) to get under these figures

H/W and elec at these levels can really damage you BER rating and give meaningless numbers for heat demand

portwest

sas wrote: »

The issue is that the heating system I didn't have to pay for would have cost less than the stove I need to provide hotwater and backup heating in winter. You can't exactly go to waterford for one of this.

I accept the comfort and well being aspect, it should really add to our quality of life.

I don't really care about my carbon footprint. If I did, I wouldn't have built a large concrete house (blocks, concrete floor upstairs, concrete stairs etc) 5 miles from town.

The PH attraction for me was always lower running costs.

I will say that there has never been a better time to build a PH in Ireland. I look through the forums and the magazines and am very jealous of the availability of the systems and knowledge now. I should underline wide cavity was in it's infancy when I started on my journey, this would absolutely be cheaper than the EWI route that I went. With Irish PH certified windows available etc., you could make a real go of it for alot less than we've payed out.

So in summary my recipe for success the 2nd time around:
1. Get PHPP done, forget about certification.
2. Build wide cavity block structure. TF is great, wide cavity is cheaper.
3. Buy windows locally made i.e. PH certification optional
4. Go with rising walls and standard strip foundation system or locally made insulated raft. That german one I imported while great was SOoo expensive.
5. Install HRV system (probably same one I have now).
6. Install oil\lpg backup heating\dhw system
7. Room heating stove only, no PH mandated flue dampers etc
8. Smaller solar array and tank.
9. Install 1 electric shower in the house due to 8.
10. Consider monopitch roof (if planners allowed)
11. Go for a design, not a box shape. It's a home at the end of the day, not a building.
12. Go for a smaller house, divorce not withstanding.
13. Use the same carpenter\foreman. He is the only thing keeping me sane.
14. Take less than 2.5 years to build it

Hi sas,
What heating/dhw system would you recommend to back up with oil/lpg? and why a monopitch roof?

BryanF

JPJ wrote: »

beyondpassive, here are the steel details

Can you PM the window details to me too please?

is it too late to put the steels inside the window frames

Tifosi

[QUOTE=beyondpassive;76702309

. I'd love to use I..m or P..n the Bose sound system of windows, but instead use one of 3 cheaper systems, 2 of which are also imported, only 1 is a small operation they are T..e, H..r and M..y. The high end stuff looks like it would last forever but the sales and service guys are all bluster and it can be infuriating getting them to rectify installation issues. The mid range stuff is fit for purpose, but without paying a such a high premium you get better service.

[/QUOTE]

I think I know who the first two window companies are, the latter three I have no idea, I would be grateful if some could send me a PM to enlighten me.

How about N...n

BryanF

beyondpassive wrote: »

So If your going certified passivhaus, you really should go for the high end windows, certified passivhaus with tilt and slide doors which can be upwards of €20k above a mid range thermally broken window.

1. as the guinea pigs (no personal attacks intended) you and others are pushing the building standards of 'low energy homes' - are we not now seeing an increase in the quality of the components and prices coming down?
2. and is the lack of industry training and 'giving a hoot' / the allowance for such crap on the market, that has caused the purchaser to pay part of this increased premium for quality - what is the PH window premium in Germany for instance?
3. also have any of ye looked into using an unheated porch or 'sunspace' as a buffer to reduce the spec of the PH rated window/door units? (i appreciate this in its self is an extra cost, but you do get a few watts in the BER for your porch, woohoo!)

JPJ

BryanF wrote: »

is it too late to put the steels inside the window frames

BryanF, If you mean that the window will be side by side with or overlap the steel, and there will be a covering over the steel that matches the window, yes I think we are doing that. If you mean something else, please describe again.

Assuming we both have the same understanding, then, the problem I am afraid of is that the steel post will be connected to cold and uninsulated raft foundation, making everyting colder than it might otherwise be. That steel post is not only supporting the window, it rises to support an over window steel beam that supports other elements, hollowcore, walls, etc.

Choolips

Hi Beyondpassive and kboc,

Could you send me on you window supplier recommendations too? Thanks v much!

keru

Hi Beyondpassive and kpoc ,
Could you also PM me your window recommendations?
Am I correct in understanding that the difference between a good window with a thermally broken frame and a Certified passive window is only in the order of 5 to 10 Kw energy consumption saving over the year?

sas

Eoghan Barra wrote: »

Thanks for that, sas. I presume you're talking about MJ?

Yes, I am.

sas

portwest wrote: »

Hi sas,
What heating/dhw system would you recommend to back up with oil/lpg? and why a monopitch roof?

Stove of some sort. Possibly a room heating (i.e. no back boiler) stove. The boiler stoves that are suitable for low energy houses are big money e.g. 5k for the one I'm looking at.

Solar for hot water when possible. Electric shower somewhere in the house to cover times when there is no viable solar but the weather is too mild to have oil\lpg running.

I like monopitch roofs. I'd do it as part of an overall design. I went for a box to keep the construction complexity down and also with the hope it would be cheaper. I don't think our home would ever be described as have "kerb appeal".

beyondpassive

keru wrote: »

Am I correct in understanding that the difference between a good window with a thermally broken frame and a Certified passive window is only in the order of 5 to 10 Kw energy consumption saving over the year?

kW is the SI unit for load or power, usage or demand is in Kwh's. Passivhaus used kWh/sq.m to measure demand. So 15kWh/m2 x 250 = 3,750kWh for space heating alone. If a lesser quality window and door frame is used this might go out to 17kWh/m2 which is 4,250kWh. Simplified 500kWh costing 10cent per kWh with LPG incl standing charges and VAT is €50 euro extra running charges.

portwest wrote: »

Hi sas,
What heating/dhw system would you recommend to back up with oil/lpg? and why a monopitch roof?

Can I butt in! attached below is the schematic of the heating system with Thermal Store, we generally use for Ultra low energy homes. Its a lot of kit, but its made of simple components and the lower 40 degree halp of the tank diverts spare solar heat into the structure. Can be up to a 1,000kWh free solar heat into the space heating. Even in summer we can have put our overheat into the wetroom underfloor circuit for comfort and humidity control. The logic of this system is, you've done the hard yaka of lowering your heat demand to the minimum within your budget constraints. You've got a big solar array, and buffer tank to comply with Part L, lots of 36degree water, perfect for low grade heat, your MHRV wants a constrant 19 degrees year round, and you couldn't be arzed importing seasoned timber and cleaning stoves. Simples.
passivhaus heating.jpg

BryanF

JPJ wrote: »

Also 12 Velux windows in the roof - most likely triple glazed - but fast running out of cash

id be as worried about the heat loss from these 12!! rooflights as much as the thermal bridges from the steel posts

BryanF

JPJ wrote: »

BryanF, If you mean that the window will be side by side with or overlap the steel, and there will be a covering over the steel that matches the window, yes I think we are doing that. If you mean something else, please describe again.

Assuming we both have the same understanding, then, the problem I am afraid of is that the steel post will be connected to cold and uninsulated raft foundation, making everyting colder than it might otherwise be. That steel post is not only supporting the window, it rises to support an over window steel beam that supports other elements, hollowcore, walls, etc.

if the steel posts are not already fitted why not place the steel posts 'room side' of the windows, inside the thermal envelope. where the windows are butted to the steel (steel in-line with the wins) and insulation space maybe a problem for the cover flashing, consider using aerogel

sas

beyondpassive wrote: »

Can I butt in! attached below is the schematic of the heating system with Thermal Store, we generally use for Ultra low energy homes. Its a lot of kit, but its made of simple components and the lower 40 degree halp of the tank diverts spare solar heat into the structure. Can be up to a 1,000kWh free solar heat into the space heating. Even in summer we can have put our overheat into the wetroom underfloor circuit for comfort and humidity control. The logic of this system is, you've done the hard yaka of lowering your heat demand to the minimum within your budget constraints. You've got a big solar array, and buffer tank to comply with Part L, lots of 36degree water, perfect for low grade heat, your MHRV wants a constrant 19 degrees year round, and you couldn't be arzed importing seasoned timber and cleaning stoves. Simples.
passivhaus heating.jpg

I'm playing with the idea of not buying a back boilered stove and instead going with a room heating one. Spending the savings on an lpg boiler.

It would likely cost less than the boiler stove I'm looking at but would offer alot more control i.e. you can't set a solid fuel stove to come on an hour before you get home.

I'd really like to see what the solar will actually contribute before I do this. We're likely to get the chance too because we're moving in in April and I don't think we'll be able to afford the stove until August!

Do-more

sas wrote: »

Electric shower somewhere in the house to cover times when there is no viable solar but the weather is too mild to have oil\lpg running.

What about hot water demand other than showers? Will you be washing pot & pans with lukewarm water?

BTW Have you gone for hot fill appliances?

sas

Do-more wrote: »

What about hot water demand other than showers? Will you be washing pot & pans with lukewarm water?

BTW Have you gone for hot fill appliances?

Showers would be by far our largest immediate hot water need. If I have a large number of dishes to wash then the dish washer will be used. I would only purchase one that heats it's own water with an option for a hot feed if possible. I'm open to correction here but I've not seen warm fill as an option commonly available in the last few years.

If I need a little hot water to wash a few items I'll boil a kettle, this wouldn't work for showering for obvious reasons.

fclauson

sas wrote: »

I'm playing with the idea of not buying a back boilered stove and instead going with a room heating one. Spending the savings on an lpg boiler.

It would likely cost less than the boiler stove I'm looking at but would offer alot more control i.e. you can't set a solid fuel stove to come on an hour before you get home.

I'd really like to see what the solar will actually contribute before I do this. We're likely to get the chance too because we're moving in in April and I don't think we'll be able to afford the stove until August!

SAS as I have said before - this is a good plan - LPG works on the button - every time - does not complain - does not need to have timber sawn up for it - does not mean going out in the snow to get more logs etc etc etc

Do-more

sas wrote: »

I'm open to correction here but I've not seen warm fill as an option commonly available in the last few years.

I can't say for sure myself but I did have a conversation with an architect about them last year, but when he mentioned that they were 2-3 times the cost of basic appliances and stressed the need to consider the cost as part of an holistic approach, I kind of tuned out! :pac:

sas

fclauson wrote: »

SAS as I have said before - this is a good plan - LPG works on the button - every time - does not complain - does not need to have timber sawn up for it - does not mean going out in the snow to get more logs etc etc etc

And I'm leaning even further away from my original plans now. I don't like the idea of being tied into a contract with one of the LPG suppliers unless it's very short. I await a response from 1 of them on this question, the person I spoke to didn't know!

Then I decided to look at internal oil boilers with balanced flue. I can buy a 15 - 21kw unit for €1300 (list price). I won't be tied to any contract. It would easily have the power to heat my 1000 litre tank. I'm hearing that smells are alot less of an issue with the modern balanced flue models.

In time I might add a dry stove or even the original stove or similar depending on how successful the oil set up is.

just do it

What I'm taking from this thread (and what I've read on another thread regarding new building regs) is the deciding factor on going passiv or not is the window and door spec.

There is a positive cost benefit on all other elements i.e. design, low u-value foundations, walls and roof, airtightness to less than 0.6 ACH & MHRV, detailing out thermal bridging. The cost of windows and doors however just isn't justifiable on financial grounds. Of course this might change with one or two new Irish entrants with passiv spec windows and doors!

(1 being provincial and the other being smart;-) )

BarneyMc

BryanF wrote: »

1. also have any of ye looked into using an unheated porch or 'sunspace' as a buffer to reduce the spec of the PH rated window/door units? (i appreciate this in its self is an extra cost, but you do get a few watts in the BER for your porch, woohoo!)

This is an interesting idea. Has anyone used this in their design or come across it?

BarneyMc

Not bumping this thread by any means but a lot of interesting points have been raised concerning the 'sweet spot' for 'near passive' houses. I posted a thread some time ago and would like to know if the general design/form of the house is ok. It is to face west and this is more or less constrained due to the site layout. The south side has lots of glazing which is good. My only concern is that the rear projection does not fit in well with the compact design principle. Plans, etc. are here. Thanks.

BryanF

BarneyMc wrote: »

Not bumping this thread by any means but a lot of interesting points have been raised concerning the 'sweet spot' for 'near passive' houses. I posted a thread some time ago and would like to know if the general design/form of the house is ok. It is to face west and this is more or less constrained due to the site layout. The south side has lots of glazing which is good. My only concern is that the rear projection does not fit in well with the compact design principle. Plans, etc. are here. Thanks.

answered on other thread

Eoghan Barra

Eoghan Barra wrote: »

I'm using 200mm of rockwool fullfill, which costs about €7/m2, as opposed to about €100/m2 for external insulation, for example.

Sorry folks, made a mistake. That should be €14/m2, not €7/m2.

Certified

Hello Ireland!

<snip>

Happy building
Certified

Moderator: Please don't preach at posters here and read the forum charter before posting again.

just do it

Certified wrote: »

Hello Ireland!

<snip>

Happy building
Certified

Welcome to boards!

What's your line of business? Passive house design?

Certified

Hi just do it,

Thanks, yes I am involved in the design and build of Passive buildings. I've been lucky enough to have been involved with many different projects through the years, Passive, nearly passive and no where near Passive. looking back now, Im the first to put my hand up to admit that I have made mistakes in the past but in fairness the knowledge and products that exist today just were not around 5 years ago or maybe even 2 years ago.

It really isnt that difficult or expensive to build to the Passive standard today.

Anyway I felt I should say my little bit as I do have some experience under my belt in building in Ireland.

Regards,

Certified