SAP Fail

[the_r_sole]

7 minutes ago, nubbins said:

Interesting you say this, so as it stands building has not yet signed off, need SAP pass (with an air permability test first)

The SAP calc as it stands has been frozen as failed and not fully submitted (I think)

SAP guy has said he has done different calcs on air permability of 5 and 2 X 300 panels and that will pass

SAP guy has said  let him know air perm score and arrange for panels to be fitted then he will submitt straight away with the details (Panels, inverter?). I am guessing he might want to see a quote or something with a future date and what exactly would be fitted.

 

My thinking is get the air test done, get a quote for a 2 panel 600w installation, show him that and get the SAP passed and then onto building control for their final inspection. Would BC pick up on no panels and not sign off at that point, they could of course be installed straight away if it caused problems.

 

yes they would it's a simple thing to pick up - you would also have to lie to your assessor as they usually have a sign off form which requires you to sign off that the house is built in line with the details you have supplied for the calculation. I know it's not a major thing but I've seen assessors and building control officers taking exception to deliberately incorrect information being supplied. Have you had inspections throughout the build?

[Gone West]

38 minutes ago, nubbins said:

Interesting you say this, so as it stands building has not yet signed off, need SAP pass (with an air permability test first)

The SAP calc as it stands has been frozen as failed and not fully submitted (I think)

SAP guy has said he has done different calcs on air permability of 5 and 2 X 300 panels and that will pass

SAP guy has said  let him know air perm score and arrange for panels to be fitted then he will submitt straight away with the details (Panels, inverter?). I am guessing he might want to see a quote or something with a future date and what exactly would be fitted.

 

My thinking is get the air test done, get a quote for a 2 panel 600w installation, show him that and get the SAP passed and then onto building control for their final inspection. Would BC pick up on no panels and not sign off at that point, they could of course be installed straight away if it caused problems.

Did you do a full plans submission to building control. BCOs are very different in their approach to checking but it's a bit of a risk if the SAP says PVs and he looks for them. My BCO was relaxed about our build because be hadn't dealt with a Passivhaus before and was happy to accept a PHPP assessment instead of an as designed SAP.

[Gone West]

1 hour ago, nubbins said:

SAP guy has said he has done different calcs on air permability of 5 and 2 X 300 panels and that will pass

Where has the air tightness figure of 5 come from. It seems a very poor level.

[nubbins]

Prodave - nothing against them per se but at this moment in time its the cost  time and hassle factor. Half way through the build we went into the loft which has eaten into our budget. Im now running on fumes, trying to get it signed off by BC which in turn allows the 10 year warranty to be signed off which in turn allows me to get a small mortgage (which is currently going through) to pay the many bits and pieces. 

 

Yes all plans and everything else was submitted the BCO and Protek warranty chappie have been out at all the various stages and bc just want SAP and a drainage test. Unfortunately the SAP was overlooked by myself and architect from the beginning.

 

Im not necessarily wanting to deceive but more if I can get past the SAP and bc sign off and then get it done once some cash comes through. The more i look into solar im beginning to think a few more panels wouldnt go amiss, but as I said its more about speed and cost. Ive already tried to contact 4 or 5 installers without any response!

 

The air test of 5 came from the SAP guy.

 

 

[ProDave]

Okay you want bargain basement.

 

2 of these https://www.bimblesolar.com/solar/individual/canadian-solar-305w?sort=p.price&order=ASC

 

One of these https://www.ebay.co.uk/itm/600W-Solar-On-Grid-Tie-Inverter-MPPT-DC20-60V-to-AC230V-Pure-Sine-Wave-Inverter/402462006208?hash=item5db49adbc0:g:lYAAAOSwdvlfcY0T

 

Then add ac isolator, DC isolator, generation meter. And you have SAP compliance for about £300 plus a bit of sparky time.

 

Have you actually had a blower door air test done?  Or is that air test figures a guess at what it might be?

[AliG]

It seems like the PV is the way to go.

 

Looking at the SAP score, is 1.4 the actual U-Value of your windows or an assumed U-Value? If the actual value is materially lower it may get you over the line.

 

 

[nubbins]

1 hour ago, AliG said:

It seems like the PV is the way to go.

 

Looking at the SAP score, is 1.4 the actual U-Value of your windows or an assumed U-Value? If the actual value is materially lower it may get you over the line.

 

 

Not sure, i sent him the window suppliers quotation which was taken from windows schedule. The impression i got from mr sap was apart from solar or a change of heating system the result would be the same unless i had planned it properly from the beginning?

[nubbins]

1 hour ago, ProDave said:

Okay you want bargain basement.

 

2 of these https://www.bimblesolar.com/solar/individual/canadian-solar-305w?sort=p.price&order=ASC

 

One of these https://www.ebay.co.uk/itm/600W-Solar-On-Grid-Tie-Inverter-MPPT-DC20-60V-to-AC230V-Pure-Sine-Wave-Inverter/402462006208?hash=item5db49adbc0:g:lYAAAOSwdvlfcY0T

 

Then add ac isolator, DC isolator, generation meter. And you have SAP compliance for about £300 plus a bit of sparky time.

 

Have you actually had a blower door air test done?  Or is that air test figures a guess at what it might be?

Thanks again Dave, i think something like this is definately doable so I will get onto it, i thought it would run into the thousands!!! i guess a bit of roofer time as well.

[PeterW]

1 hour ago, nubbins said:

The air test of 5 came from the SAP guy.

 

what sort of build is this ..??

 

£200 gets you an air test, get a 2.5 instead of 5 and your issue goes away. 

[ProDave]

4 minutes ago, nubbins said:

Thanks again Dave, i think something like this is definately doable so I will get onto it, i thought it would run into the thousands!!! i guess a bit of roofer time as well.

That suggestion was the bargain basement stuff.  But you do need a serious think would you actually want solar PV?  you can get a 4kWp kit for about £2000 plus install costs (a day for a roofer and a day for an electrician) which would be a better prospect and much more useful in terms of real energy produced, most of which you should be able to self use.

[nubbins]

1 minute ago, ProDave said:

That suggestion was the bargain basement stuff.  But you do need a serious think would you actually want solar PV?  you can get a 4kWp kit for about £2000 plus install costs (a day for a roofer and a day for an electrician) which would be a better prospect and much more useful in terms of real energy produced, most of which you should be able to self use.

I giving serious thought to that. Do you have any pointers to the kits?

Thanks

[ProDave]

Something like this? https://www.ebay.co.uk/itm/4kW-4000W-Domestic-Solar-PV-Kit-System-TRADE-DIY-Cheapest-in-UK/401879970422?hash=item5d91e9b276:g:7wwAAOSw81Jdd7Zu

[nubbins]

6 minutes ago, PeterW said:

what sort of build is this ..??

 

£200 gets you an air test, get a 2.5 instead of 5 and your issue goes away. 

 

Detached 3 storey house as shown, his exact words "As Designed with PV (2 No Panels) with Air Test Result of 5"

Am i missing something

[PeterW]

So have you had an air test or not ..? There should be a blower door certificate. 

[nubbins]

No, trying to get someone around to do one. Hopefully next week.

[the_r_sole]

To get your completion you need an as built epc, not an "as designed" one, so that will require an air test result plugged in, the correct uvalues for the windows and doors etc.

 

It's very worrying that yout Architect didn't know you'd need a sap calc done! That's more than an oversight now you are having to add some micro generation to get your completion!

[Dan F]

On 18/01/2021 at 12:57, Thedreamer said:

 I looked at these but are you not paying for points? I might be tempted if my layout was that my showers were close to my to the hotwater tank.

 

What do you meant paying for points?   It will also save you a lot of gas (assuming you shower rather than use bath)!

 

Showers don't actually need to be close to the hot water tank.  You can use them in "system B" where the WWHRS just pre-heats the cold feed to the shower.  It's not quite as effiecient, but still saves a fair bit and will give you almost as many SAP points.

 

[A_L]

2 hours ago, PeterW said:

£200 gets you an air test, get a 2.5 instead of 5 and your issue goes away. 

 

If the ventilators for a design of 5m³/m².hr have been tightly specified they will not be large enough (about 40% more)  for less than 3m³/m².hr

 

The house looks like it has high ceilings, reducing from 5 to 3 will save about 1kWh/m².yr but he has to save about 5kWh/m^2..yr to get the required CO₂  savings.

[Thedreamer]

9 minutes ago, Dan F said:

 

What do you meant paying for points?   It will also save you a lot of gas (assuming you shower rather than use bath)!

 

Showers don't actually need to be close to the hot water tank.  You can use them in "system B" where the WWHRS just pre-heats the cold feed to the shower.  It's not quite as effiecient, but still saves a fair bit and will give you almost as many SAP points.

 

 

If you need to spend a bit of money to get the SAP, I would go for PV.

 

I looked at these before, but just seem to very little gain.

 

In my set-up having a bath is actually more efficient in extracting waste water heat.

[Dan F]

5 minutes ago, Thedreamer said:

I looked at these before, but just seem to very little gain.

 

Depends on if you shower, how long you shower for, how long you plan to live in the house and how much you pay for your DHW.  For us 30+ % reduction in costs of heating hot water (as well as 30% more effective UVC capacity for showers) is very much worth the £450 this unit cost, given we plan to live in the house long-term.   For others, may make less/no sense...

 

Quote

In my set-up having a bath is actually more efficient in extracting waste water heat.

 

How does this work?

Edited January 19, 2021 by Dan F

[A_L]

7 minutes ago, Dan F said:

How does this work?

 

Let it cool to ambient in the bath! ?

[Thedreamer]

22 minutes ago, Dan F said:

 

Depends on if you shower, how long you shower for, how long you plan to live in the house and how much you pay for your DHW.  For us 30+ % reduction in costs of heating hot water (as well as 30% more effective UVC capacity for showers) is very much worth the £450 this unit cost, given we plan to live in the house long-term.   For others, may make less/no sense...

 

 

 

So is it that longer showers allows the waste water recovery unit to be more efficient? If my layout was different and the shower was close to the cylinder perhaps one of these would have been considered, but it just wasn't top of the priorities at design stage.

 

Waste Water Heat Recovery Unit (earthsaveproducts.com)

 

22 minutes ago, Dan F said:

How does this work?

 

I have an exhaust style heat pump, the showers have steamy air extracted (but the hot water is lost), but if we have the occasional bath I can leave the water in till it's cold and a proportion of the heat goes back into the system.

[Dan F]

3 minutes ago, Thedreamer said:

So is it that longer showers allows the waste water recovery unit to be more efficient?

 

Yes, but only marginally due to the intial heat-up time.   The main thing is that a 30-50% saving is worth a lot more (in monetary terms) the more you shower.

 

3 minutes ago, Thedreamer said:

If my layout was different and the shower was close to the cylinder perhaps one of these would have been considered, but it just wasn't top of the priorities at design stage.

Waste Water Heat Recovery Unit (earthsaveproducts.com)

 

An instantaneous WWHRS doesn't need to be close to cyclinder.   Not seen this one, any idea how it differs to showersave/recoup?  Is it not instantaneous and therefore more bath-compatible?

 

3 minutes ago, Thedreamer said:

I have an exhaust style heat pump, the showers have steamy air extracted (but the hot water is lost), but if we have the occasional bath I can leave the water in till it's cold and a proportion of the heat goes back into the system.

 

Interesting!