Any one done their own Part O modelling?

[Duncan62]

On 26/01/2024 at 18:29, Duncan62 said:

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

 

 

Having tried with PHPP, and after initially positive conversations... I receive:

 

Quote

Thank you for your email and while I acknowledge that a key aspect of Passive house design is the control of solar overheating. I have not been able to confirm that submission of Passive house justification can be used to substitute the need to provide either a Simplified or Dynamic thermal model justification.  

 

In the case of Approved Document O for you to demonstrate that your proposal will achieve the requirements it is normal practice to submit a designer’s declaration, and these should follow the sections below.

I acknowledge that these only follow the use of the simplified or dynamic method. However,  I also note that to demonstrate compliance with dynamic method, the modelling method should utilise the CIBSE’s TM59 Methodology. Given that this is acceptable, I would consider it reasonable to accept PHPP as justification if you can confirm that PHPP design/justification also incorporates the CIBSE’s TM59 guidance.

 

If this is not the case then I would ask that you still undertake a simplified or dynamic model check for overheating.

 

 

So if I can justify PHPP is equivalent to TM59 criteria, its ok.

if not, do TM59 analysis.

Rather than accepting an alternative method of compliance (which is totally allowed), BC would like self builders to prove that PHPP = TM59

 

PH Trust have this document, but not useful https://www.passivhaustrust.org.uk/UserFiles/File/Policy papers/Overheating, Part O and PHPP v1.1 231107.pdf

With this for overheating risk in PHPP https://www.passivhaustrust.org.uk/UserFiles/File/Technical Papers/Dynamic Thermal Modelling v1.0 230830.pdf

 

TM59 analysis guide https://designbuilder.co.uk/helpv7.0/Content/CIBSETM59.htm

Potential software with 30 day trial https://designbuilder.co.uk/download/release-software

CIBSE weather data https://designbuilder.co.uk/software/cibse-weather-data-sets

 

Anyone any experience of actually doing/commissioning dynamic modelling with a positive result?

Design methodology for the assessment of overheating risk in homes.pdf

[Alan Ambrose]

>>> So if I can justify PHPP is equivalent to TM59 criteria, its ok.

 

This is from your BC? They should know that these are not the same, so unless that particular LPA has decided to accept PHPP (some will/do) then that's a somewhat polite way of saying TM59 or nothing.