Wexford Passive House

fclauson

For those who are interested I have built a face book page covering my build - please take a look (and like)

https://www.facebook.com/pages/Passive-house-Wexford/154344008104045

Clseeper

Francis,

Really good resource and thanks for your ongoing generosity with your data and advice.

Are you planning to partake in the Passivhaus open days this coming November? I know I'd travel to quiz you in person and also bring along some nice presents to thank you for your help to date

john_cappa

How many metres of PV is that?

fclauson

john_cappa wrote: »

How many metres of PV is that?

16@ 255pW per panel

fclauson

Clseeper wrote: »

Francis,

Really good resource and thanks for your ongoing generosity with your data and advice.

Are you planning to partake in the Passivhaus open days this coming November? I know I'd travel to quiz you in person and also bring along some nice presents to thank you for your help to date

Yes BUT please book through the organisers web site
I am also presenting at the "See the light" conference with Dr Faust

prewtna

Stupid question of the week!

What have you used to fix the marine ply to the block-work reveals? Express nails or the likes?

and then when fixing the windows, i presume you were fixing all the way through the ply to the blockwork inner leaf?

2nd stupid question - presumably the plywood would be considered merely as 'formwork' for the full fill insulation beads? in that, all its doing it stopping the beads from flowing all over the place when they are being pumped?

did your engineer have anything to say about not having a blockwork 'nib' at the reveal or did you increase the number of wall-ties around the opes instead?

apologies for the number of questions and the stupidity of them, but i have never done any domestic work (we do large scale commercial, pharma, etc etc at work) so i am fascinated by this project and the issues in it.

fclauson

prewtna wrote: »

Stupid question of the week!

What have you used to fix the marine ply to the block-work reveals? Express nails or the likes?

Think it was done with a Hilti gun or similar

and then when fixing the windows, i presume you were fixing all the way through the ply to the blockwork inner leaf?

yes - they put some screws into the ply and then some into the inner leaf
The ply is also attached to the outer leaf via an L metal section - I'll try and post some pics when I can

2nd stupid question - presumably the plywood would be considered merely as 'formwork' for the full fill insulation beads? in that, all its doing it stopping the beads from flowing all over the place when they are being pumped?

yes - but it also provide support for the internal window sill (we used sil stone for this) and the DPC around the whole box as per the posted pics

did your engineer have anything to say about not having a blockwork 'nib' at the reveal or did you increase the number of wall-ties around the opes instead?

not sure what you mean by nib Picture - https://www.facebook.com/photo.php?fbid=165903950281384&set=pb.154344008104045.-2207520000.1381439230.&type=3&theater
show just the bottom board in place with no return on the block at all

We did place a wall tie on every row all the way around the ope - again I'll try a post a pic over the week end

apologies for the number of questions and the stupidity of them, but i have never done any domestic work (we do large scale commercial, pharma, etc etc at work) so i am fascinated by this project and the issues in it.

I am just pleased to be helpful - there is a lot of new techniques and you will see from my other posts I never too "asha it'll do" as a method which I wanted to be used on my build. If we had done some of this in the Boom we would have had lots of energy efficient houses like mine which will costs around €0 to heat and h/w due to the way I have the PV as well as the HP

Ask away

Worriedmind

Hi Fclauson,

I'm just curious as to your own input in terms of the house design? From previous posts I gather that you're the client? Or were you the Architect/Engineer/Contractor?

Overall I'm curious to know wherther the significant construction cost difference between achieving A1 vs A3 rating is actually worth it?

fclauson

Worriedmind wrote: »

Hi Fclauson,

I'm just curious as to your own input in terms of the house design? From previous posts I gather that you're the client? Or were you the Architect/Engineer/Contractor?

I am the client - with an unprecedented level of attention to facts figures design and calculations

I had a fantastic team of folks who architected, designed, and built the house.

Overall I'm curious to know wherther the significant construction cost difference between achieving A1 vs A3 rating is actually worth it?

can't answer that - but all I can say is that with a zero cost heating & hot water bill I am fully pleased (see other posts on how this was achieved)

whizbang

I'm curious as to why you have the roof structure supported on the inner leaf, then you have used the low density blocks around the top.
If you used the outer leaf, you could simply insulate the top of the inner leaf. ???

Also, is it possible to float the entire inner structure on an insulated base.

Am i showing my construction ignorance, or are the low density blocks that good ?

Worriedmind

...ok, so how exactly then are you a self builder?

I'm a chartered Structural Engineer and have been involved with projects all over the world for the past 28 years. The term self builder perplexes me..

fclauson

whizbang wrote: »

I'm curious as to why you have the roof structure supported on the inner leaf, then you have used the low density blocks around the top.
If you used the outer leaf, you could simply insulate the top of the inner leaf. ???

Also, is it possible to float the entire inner structure on an insulated base.

Am i showing my construction ignorance, or are the low density blocks that good ?

You will need an engineer to help you here - but basically the roof is supported by both leaves. The reason for the inner leave row is to reduce the thermal bridge out through that junction. Its one of the weakest in any build to ensure you do not have a thermal bridge at this point.

On the foundation - yes you could (and there are systems out there - Google "insulated foundations" where the whole build sits on insulation. I just did not like this as an approach - personal choice.

fclauson

Worriedmind wrote: »

...ok, so how exactly then are you a self builder?

I'm a chartered Structural Engineer and have been involved with projects all over the world for the past 28 years. The term self builder perplexes me..

With any self build you need to employ skills and trades to make the build work. I am sure you would agree your skills would not cover electrical work, or architectural design, or thermal bridge modelling or insulation or ......

I was the project manager of this build - I employed engineers, architects, tech archs, electricians, plumbers, window installers ..... the list goes on

I think where I would draw the line between self-builder and not would be
a) Mr Architect or Ms Builder or Miss Estate agent I want I house let me know when its done please so I can move it vs
b) I want to be involved in every aspect of the build and make decisions and understand reasons of every facet of the build, cross check the calculations, verify what I am getting is what I want, and question every profession that they are working at the very top of their game. (I tuned down 4 structural engineers at interview because they just did not get why I wanted a 250mm cavity in the wall, 500mm of insulation in the roof and wanted to limit thermal bridges through out.)

BarneyMc

Francis,

Thanks for posting all these pics to your Facebook page - really helpful!

Regarding the L metal section you used to help support the sills, as shown here, can I ask how did you fix them on the outer leaf?

Did you build up the outer leaf first, wait until the wall dried, attached the metal section and then proceed with the inner leaf?

fclauson

Barney

The are rag bolts or similar - drill , screw to tighten the bit in the block and the nut and washer to hold L on

Check with your engineer that he is happy with the design - needs to support the sill and stop it tipping back into the cavity as the back edge of the sill is not resting on the inner leaf

On attaching - no done once both were in place which might not have been the best plan but that's how it was

BarneyMc

fclauson wrote: »

On attaching - no done once both were in place which might not have been the best plan but that's how it was

Thanks Francis, so it was a bit tight to work on getting all fitted but you still had enough space. The other method I proposed is not practical I suppose and would delay things too much. Thanks again!

fclauson

I just remembered - on some of them they had to knock out one of the inner blocks to get the drill in and then replace it

Best advice get them in as early as poss

hexosan

fclauson wrote: »

Barney

The are rag bolts or similar - drill , screw to tighten the bit in the block and the nut and washer to hold L on

Check with your engineer that he is happy with the design - needs to support the sill and stop it tipping back into the cavity as the back edge of the sill is not resting on the inner leaf

On attaching - no done once both were in place which might not have been the best plan but that's how it was

Can I ask what thickness is the L bracket and did you use them on every window or just windows with a large span.

fclauson

hexosan wrote: »

Can I ask what thickness is the L bracket and did you use them on every window or just windows with a large span.

Yes to every window

Not sure on thickness - check with your engineer - but perhaps 2mm

fclauson

fclauson wrote: »

Yes to every window

Not sure on thickness - check with your engineer - but perhaps 2mm

Also rember it's stainless steel -

john_cappa

Are they really needed? Are cills not cemented in place?

rampantbunny

fclauson wrote: »

For those who are interested I have built a face book page covering my build - please take a look (and like)

https://www.facebook.com/pages/Passive-house-Wexford/154344008104045

My heart leapt when I read this post .... until I remembered I had closed my Facebook account :rolleyes:

Time to commandeer the wife's account I think.

fclauson

john_cappa wrote: »

Are they really needed? Are cills not cemented in place?

Check with your engineer but two things
1 the sills are wedge shaped with more weight at the back than front
2 you are placing all the window weight on that heavier side and the can weigh a huge amount if triple glazed

mfceiling

rampantbunny wrote: »

My heart leapt when I read this post .... until I remembered I had closed my Facebook account :rolleyes:

Time to commandeer the wife's account I think.

Same as you!!

Carbonnet

I'd get someone to check that wall U-value calc for for. The effect of wall ties is VERY significant.

fclauson

Carbonnet wrote: »

I'd get someone to check that wall U-value calc for for. The effect of wall ties is VERY significant.

How do you quantify VERY in terms of percentage

Carbonnet

fclauson wrote: »

How do you quantify VERY in terms of percentage

Passive house target 0.15 W/m2K
Pumped 200mm Grey bead (No ties) 0.15W/m2K
Pumped 200mm Grey Bead taking account of s/s strap ties thermal conductivity 17, size 4mm x 15mm (?) quantity per m2 = 8? ( one every 250mm? and every 450mm height)

U-value 0.20W/m2K?

Ush1

Well done on the house, looks great.

Just curious what the advantages of using blown cellulose in the loft area over the rigid poly type used in the floors?

BryanF

Ush1 wrote: »

Well done on the house, looks great.

Just curious what the advantages of using blown cellulose in the loft area over the rigid poly type used in the floors?

decrement delay

&

Recycled content

Ush1

BryanF wrote: »

decrement delay

&

Recycled content

I see, so with timber frame construction the cellulose will compensate for the lack of thermal mass?

BryanF

Ush1 wrote: »

I see, so with timber frame construction the cellulose will compensate for the lack of thermal mass?

in part

BarneyMc

Carbonnet wrote: »

Passive house target 0.15 W/m2K
Pumped 200mm Grey bead (No ties) 0.15W/m2K
Pumped 200mm Grey Bead taking account of s/s strap ties thermal conductivity 17, size 4mm x 15mm (?) quantity per m2 = 8? ( one every 250mm? and every 450mm height)

U-value 0.20W/m2K?

For this house it's pumped 250mm & quantity per m2 = 4 I think

sydthebeat

Carbonnet wrote: »

Passive house target 0.15 W/m2K
Pumped 200mm Grey bead (No ties) 0.15W/m2K
Pumped 200mm Grey Bead taking account of s/s strap ties thermal conductivity 17, size 4mm x 15mm (?) quantity per m2 = 8? ( one every 250mm? and every 450mm height)

U-value 0.20W/m2K?

Thermal losses through wall ties in insulated cavities need to be taken into account if, in conjunction with thermal losses through air gaps in the insulation, they amount to 3% or more of the uncorrected thermal loss through the wall. Procedures for calculating these losses for ties and air gaps are given in BS EN ISO 6946 : 2007

Can you show please how you came to the additional 0.05 w/m2k?

Carbonnet

BarneyMc wrote: »

For this house it's pumped 250mm & quantity per m2 = 4 I think

Sorry folks my mistake - calculations done with a 200mm blown bead indeed -

Carbonnet

sydthebeat wrote: »

Thermal losses through wall ties in insulated cavities need to be taken into account if, in conjunction with thermal losses through air gaps in the insulation, they amount to 3% or more of the uncorrected thermal loss through the wall. Procedures for calculating these losses for ties and air gaps are given in BS EN ISO 6946 : 2007

Can you show please how you came to the additional 0.05 w/m2k?

You're absolutely right - you can IGNORE the additional heat loss in the calc under BR443; if you want to ignore the heat loss - why would someone building passive ignore the extra heat loss through wall ties?

fclauson

Carbonnet wrote: »

You're absolutely right - you can IGNORE the additional heat loss in the calc under BR443; if you want to ignore the heat loss - why would someone building passive ignore the extra heat loss through wall ties?

Because in the overall scheme of things its so minimal plus using thermal insulating ties is expensive and has a very long term ROI

Carbonnet

fclauson wrote: »

Because in the overall scheme of things its so minimal plus using thermal insulating ties is expensive and has a very long term ROI

Minimal? 0.17 instead of 0.15?

- plus the fact that there is 250mm of insulation wrapped around a lump of cold steel - this really increases the thermal bridging effect on the internal surface where the metal crosses all the insulation and embeds in the block (the chi value).

Keeping a reasonable cavity 150mm? and pumping using ordinary 5 wire ties/m2 would have resulted in a 0.20 U-value - not that different - and bridging effect reduced internally.

I'm not a fan of Basalt ties, I don't think they're necessary - but I don't think such big cavities at such expense and the difficulties in detailing/closing etc is worth it either.

fclauson

Carbonnet wrote: »

Passive house target 0.15 W/m2K
Pumped 200mm Grey bead (No ties) 0.15W/m2K
Pumped 200mm Grey Bead taking account of s/s strap ties thermal conductivity 17, size 4mm x 15mm (?) quantity per m2 = 8? ( one every 250mm? and every 450mm height)

U-value 0.20W/m2K?

4mm thick seems very thick the spec we used were 2.5mm

Carbonnet wrote: »

Minimal? 0.17 instead of 0.15?

- plus the fact that there is 250mm of insulation wrapped around a lump of cold steel - this really increases the thermal bridging effect on the internal surface where the metal crosses all the insulation and embeds in the block (the chi value).

Keeping a reasonable cavity 150mm? and pumping using ordinary 5 wire ties/m2 would have resulted in a 0.20 U-value - not that different - and bridging effect reduced internally.

I'm not a fan of Basalt ties, I don't think they're necessary - but I don't think such big cavities at such expense and the difficulties in detailing/closing etc is worth it either.

chi - can you point me to a reference

Carbonnet

fclauson wrote: »

4mm thick seems very thick the spec we used were 2.5mm


chi - can you point me to a reference

http://www.passivhaus.org.uk/filelibrary/Primers/KN4430_Passivhaus_Designers_Guide_WEB.pdf

fclauson

Further reference to what CHI is
http://www.southernhayconsulting.co.uk/thermal_modelling/default.html

MOTM

fclauson wrote: »

16@ 255pW per panel

Out of interest, what did this equate to in the DEAP assessment in terms of part L renewables kWh/m2 total thermal equivalent requirement?

What was the total thermal equivalent shown in DEAP/m2?

fclauson

MOTM wrote: »

Out of interest, what did this equate to in the DEAP assessment in terms of part L renewables kWh/m2 total thermal equivalent requirement?

What was the total thermal equivalent shown in DEAP/m2?

MOTM - DEAP treats PV different to Solar Thermal - for Part L you need either 4Kw electric per SqM or 10Kw heat

Check out the DEAP manual http://www.seai.ie/Your_Building/EPBD/DEAP/

See attached for my report

Standard Toaster

Kevin McCloud question.....how much did the build cost in the end??

fclauson

Standard Toaster wrote: »

Kevin McCloud question.....how much did the build cost in the end??

Not to be rude but :P

MOTM

fclauson wrote: »

MOTM - DEAP treats PV different to Solar Thermal - for Part L you need either 4Kw electric per SqM or 10Kw heat

Check out the DEAP manual http://www.seai.ie/Your_Building/EPBD/DEAP/

See attached for my report

35.1kWh/m2/yr total thermal equivalent. More than 3.5 times the Part L renewables requirement. Impressive (or excessive??)

fclauson

Meaningless

As mentioned elsewhere I will run my Heating and Hotwater for next to Zero Euros using the Grid as an inter-seasonal store

MOTM

fclauson wrote: »

Meaningless

As mentioned elsewhere I will run my Heating and Hotwater for next to Zero Euros using the Grid as an inter-seasonal store

I'm aware of that, and its great to see it working. But also as mentioned elsewhere that TGD L is foisting more renewables on the house than is necessary (the use of the term Eco bling springs to mind ). I understand why this is being said due to TGD L using an absolute rather than proportionate figure for renewables.
It seems the TGD L renewables check (x3.5) would've been met by choice to meet the zero euro goal anyway on this particular house.

fclauson

MOTM - not completely sure of your last sentence

Yet I have raised the need for Eco-bling in a well know construction magazine and even taken it up with the Dept. of Env.

There is an issue here - specifically TGD lays down a number and proposes you should use DEAP to demonstrate BUT leaves the door open for you local BCO to agree a lesser number. This has been discussed elsewhere extensively on this forum (for example http://www.boards.ie/vbulletin/showthread.php?p=76567184)

MOTM

fclauson wrote: »

MOTM - not completely sure of your last sentence

Yet I have raised the need for Eco-bling in a well know construction magazine and even taken it up with the Dept. of Env.

There is an issue here - specifically TGD lays down a number and proposes you should use DEAP to demonstrate BUT leaves the door open for you local BCO to agree a lesser number. This has been discussed elsewhere extensively on this forum (for example http://www.boards.ie/vbulletin/showthread.php?p=76567184)

I'm aware of and understand all of the above, including the need for eco bling as per the recent letter to the construction magazine to which you refer. The letter says that you'd "to add eco-bling to achieve compliance". You didn't have to add all of that "eco-bling" for compliance. Less than a third of it would've sufficed for TGD L assuming you'd still meet the MPCPC and MPEPC. The amount of renewables actually installed was to have the zero euro energy bills. This appears to have been a self imposed design criterion rather than to merely meet TGD L's renewables guidance.

fclauson

MOTM

you are right - I added more than needed - BUT in my defence this started out as an issue as to how to represent a HP in DEAP. We had to involve both the vendor and SEAI. At the time the rules where changing on HP contributions. With the initial HP numbers I had I would have needed around 11SqM of PV (from memory).

We resolved the HP number issue very late in the day (i.e. on about the third draft of the BER) with the clamps already on the roof (and the money in the budget for the system ) moving from 11 to 16SqM was not proportionally more expensive (fitting and Inverters do not go up linearly) and hence when I realised I could go to practically zero running costs it seemed like a good investment.

MOTM

OK understood thanks. Out of interest (and I know this is ifs and buts), knowing what you know now about performance, zero running costs, interseasonal stores etc, if you were to go back to earlier stages would you opt for the current level of installed renewable technologies or just meet the TGD L requirement with little or no surplus?