Any one done their own Part O modelling?

[cheekmonkey]

On 13/03/2023 at 11:55, Alan Ambrose said:

@cheekmonkey - is your 'failure' pre or post-planning sign-off?

 

@Alan Ambrose our failure is post planning. We bought the plot / barn with planning already approved and have only now started regs submission. Its rather silly application of new regs. If planning was granted we should build to regs at that time as removal of windows in theory is in breach. 

Hopefully find out more later today on options to try get it to pass. 

[Furnace]

@Susie@Alan AmbroseEncouraging reply from Sevenoaks Building Control

Thank you for your email. The regulations are what we use as a guide for ‘conventional’ construction. Where you are building a Passive House we would certainly favour the PHPP compliance as it is much more appropriate for the mechanics of a passive house. Provided that overheating is considered as it would be, we would have no objection to you demonstrating compliance via another set of principles outside of Part O. I hope that this helps

[Alan Ambrose]

Wow, fantastic result! Now I just have to convince East Suffolk LPA to take the same approach...

 

Also v. useful to know that BC have some flexibility and don't need to adhere slavishly to the 'rules'.

Edited March 14, 2023 by Alan Ambrose

[Gone West]

2 hours ago, Alan Ambrose said:

Also v. useful to know that BC have some flexibility and don't need to adhere slavishly to the 'rules'.

In 2010 when we started our PH build BC were happy to accept my PHPP results instead of a 'Design' SAP.

[Adsibob]

19 hours ago, Furnace said:

I'm having brise soleils and MVHR on my passive house build, but the Simplified model allows no benefit for either.

Can somebody please explain what perceived benefit there is of using MVHR to keep a house cool? I have MVHR but I don't find it does anything to cool the house down in summer (even with summer bypass activated). The flow rates just aren't big enough for it to cool effectively.

[Furnace]

21 minutes ago, Adsibob said:

Can somebody please explain what perceived benefit there is of using MVHR to keep a house cool? I have MVHR but I don't find it does anything to cool the house down in summer (even with summer bypass activated). The flow rates just aren't big enough for it to cool effectively.

MVHR generally on its own doesn't help cooling or heating a great deal since the flow rates are low. I was making the point that in theory, PHPP could allow a design with no opening windows due to the presence of MVHR, whereas Simplified Part O wouldn't allow it.

I'm encouraged by the response from BC that PHPP would be an alternative to Part O. Although I appreciate this won't help everyone, it shows a flexible approach to Part O and that must be a good thing. Of course, the proof is in the pudding and I haven't yet got evidence that they will accept PHPP 'in real life'

[Susie]

1 hour ago, Adsibob said:

Can somebody please explain what perceived benefit there is of using MVHR to keep a house cool? I have MVHR but I don't find it does anything to cool the house down in summer (even with summer bypass activated). The flow rates just aren't big enough for it to cool effectively.

I guess at some point a forum member will pay to have their house dynamically modelled for part O and we will all learn how much the shading and a MVHR effects the pass or fail outcomes. 
 

My building regs have now been submitted by my architect with my spreadsheet for the simplified calculation so fingers cross BCO are happy with it. 
 

@Furnace I have no idea how much your PHPP modelling has cost but could perhaps make more people think of building a passive house if they can save money on the part O.   I wish it was in my budget now but too far into the design and timeline to make changes. 

 

[Furnace]

15 minutes ago, Susie said:

My building regs have now been submitted by my architect with my spreadsheet for the simplified calculation so fingers cross BCO are happy with it.

Yours may be the first one they've ever seen, but I'm sure it's accurate. And they may not even check it matches the drawings. And they may not check the exact dimensions when the BCO is on site. Do let us know how you get on.

 

15 minutes ago, Susie said:

I have no idea how much your PHPP modelling has cost but could perhaps make more people think of building a passive house if they can save money on the part O.   I wish it was in my budget now but too far into the design and timeline to make changes. 

About £1500 for two iterations. I was very tempted to do the PHPP modelling myself since I'm a nerd, but I ended up using a local-ish consultant as he had also recently built his own house and could give advice on some other aspects of the build process. PHPP aims to provide a scientific method to guide designs to fit into the goldilocks zone without the shaky guesswork, and negates the need for Design SAP/Part O fees.
 

Edited March 14, 2023 by Furnace
muppet

[Alan Ambrose]

For the people who have got their BC to accept alternative calculation methods - is this LPA BC or third-party BC, and if so, which company?

[Gone West]

21 minutes ago, Alan Ambrose said:

For the people who have got their BC to accept alternative calculation methods - is this LPA BC or third-party BC, and if so, which company?

Mine was LPA BC.

[Susie]

5 hours ago, Gone West said:

Mine was LPA BC.

Surely you were on the old regs though, so not the part O?

[Gone West]

Just now, Susie said:

Surely you were on the old regs though, so not the part O?

That's right, thank goodness 😁. The PHPP does do overheating, but it was just a comment about BC being able to be flexible if they want.

[Susie]

1 minute ago, Gone West said:

That's right, thank goodness 😁. The PHPP does do overheating, but it was just a comment about BC being able to be flexible if they want.

And was that before the move to Cornwall or have you had nice Cornwall BC as well. 😀

[Gone West]

8 minutes ago, Susie said:

And was that before the move to Cornwall or have you had nice Cornwall BC as well. 😀

No only done one self build and that was enough 😀.

[Susie]

Update

I finally have BC approval of my spreadsheet.

They accepted my first spreadsheet and the only condition was security on ground floor bedrooms, that are open at night, which I expected. 
The approval has dragged on due to a very slow architect.

I shall write more in my blog.

 

 

 

[SteamyTea]

1 hour ago, Susie said:

finally have BC approval of my spreadsheet

Is it an interactive spreadsheet i.e. useful to others, or just a final statement of what you intend to do?

[Pocster]

Any one done their own modelling?

 

yep !

[Big Jimbo]

I did the simplified version and failed. It really is a shower of shite. I have not sorted it yet. I'm going to have MVHR so i know it will be ok. I'm gonna be pi$$ed if i have to spend a bloody grand for a bit of paper. I might try to blagg it with BC, unless somebody can point me in the direction of something i can fill in myself that will take into account the MVHR.

[Big Jimbo]

22 minutes ago, Pocster said:

Any one done their own modelling?

 

yep !

You are the absolute b*llocks

[Susie]

The link is below to the spreadsheet Template I used it’s also on the first post.

 

 

 

[Alan Ambrose]

@Susie

 

Hi, I'm on the Part O/TM59 warpath again as it needs to be resolved for my designs.

 

>>> security on ground floor bedrooms

 

Can I ask what you used for this, presumably not prison bars?

 

p.s. from memory you had some rooflights? How did you handle these in the simple method? As though they were standard vertical windows?

 

TIA, Alan

Edited October 27, 2023 by Alan Ambrose

[Susie]

Downstairs bedroom windows open in wards fully in the day 90deg and top hung at night it’s a bit fingers crossed on one window, worst case is temporarily prison bars hand made with rebar removed completely later. Other bedrooms just scrape through it’s a constant tweaking of sizes and compromises which we didn’t want to change much on one bedroom window just incase in the future one of us in bed a lot. 
Velux windows open in the middle swing so can count as 90deg. 
I submitted two spreadsheets one to show we pass daytime and one for nighttime and spoke to BC to explain. 
so far our Local BC has been great now I’m in touch with him rather than architect who got too many things wrong on drawings. 

[Duncan62]

Hello, has anyone else had any luck using their PHPP data to comply with Part O?

[Alan Ambrose]

In shopping for BC providers, I asked my LPA and they said 'no' (even though I gave them the Cornwall and Kent examples), but a private BC near the plot said 'yes'.

 

The question was 'will you allow PHPP instead of TM59?'.

 

I have yet to do this 'in anger', but I've done the solar gain calcs in PHPP which seem to come out reasonably favourably. I mitigated the gain with external blinds and anti-solar-gain glass.

 

I guess even if your BC insists on TM59, you could do the design work in PHPP and then order a TM59 run to verify and maybe tweak - it should be fairly close by the time you've finished with PHPP.

Edited January 29 by Alan Ambrose

[Dan F]

On 29/01/2024 at 14:05, Alan Ambrose said:

I have yet to do this 'in anger', but I've done the solar gain calcs in PHPP which seem to come out reasonably favourably. I mitigated the gain with external blinds and anti-solar-gain glass.

 

Are you doing your own PHPP, or have someone doing it for you?