Car Park Inclusion?

[Complex Potential]

I'm trying to figure out if I need to include aux and lighting energy for an associated mechanically ventilated car park to my Part L2A 2013 model and EPC assessment.

The Non Domestic EPC Conventions for England and Wales Issue 5.0 appears to have removed the need to include mechanically ventilated car parks in EPC assessments (section 3.04). However, like much in the official guidance documents it stops short of saying explicitly that car parks can be excluded entirely.

I cannot find anything else written down anywhere so I would appreciate others' opinions.

Cheers

CP

[RossThompson87]

Hi,

It looks like Part L2a 2013 has pushed all the exemptions into an appendix.

If you have a look in appendix C it explains that buildings with low energy demand are exempt.

And then clarifies that this can also refer to 'parts of buildings', that are ;'not generally heated or cooled other than by process heat'

For this reason I'd say it was exempt from Part L. Obviously building controls decision though

I'm not sure on the EPC as you say, it was in the conventions and now its not. Does this mean an EPC is no longer required?

I hope this helps

Ross

[Complex Potential]

Cheers Ross

That was basically my thinking too but, as always, it sounds like it is still not entirely clear on the EPC side. I'll leave it out for now since trying to include car parks in IES compliance is actually a bit of a pain.

CP

[Phil OLoughlin]

I would check with the BCO if I were you. The reference to Appendix C paragraph 2ci is referring to buildings that are Industrial Sites, workshops and non-residential agricultural buildings with low energy demand only. You will find an NCM template for car parks within the VE that just gives a lighting load. One would question why this is there if not to be used.

[Complex Potential]

Unfortunately, most BCOs I've talked to know a lot less about Part L of the building regulations than I do. Also, they have nothing to do with EPCs since those are audited by accreditation bodies such as CIBSE (but good luck getting an answer out of them in a reasonable time frame). But it's always a good a$$ covering move, I'll agree.

You will find an NCM template for car parks within the VE that just gives a lighting load. One would question why this is there if not to be used.

Of course, the BRE is a professional and competent establishment that never makes illogical or inconsistent decisions and their "envy of the world" NCM reflects true building performance in every way.

You should read the above sentence in a hypnotised monotone.

[VVladinovsky]

Hi CC,

Apologies for the long reply. I am also modeling a building with a large underground car park. My understanding was similar to yours that a car park is now excluded from the heated/occupied activities as per a note under the section 3.04 stating ‘Removed from the Issue 5 1 September 2014’ and further to this there was no mentioning in the convention issue that it should be replaced with heated/occupied activity.
Car park is mentioned in the section 6.11 ‘Zones Without Fixed Conditioning Equipment’ and in the section 3.08 ‘Strongly Ventilated Spaces’ plus a reason that a car park will never achieve minimum required U-values led me to believe that I can assigning car park as ‘Other buffer space’ as this solution would allow me to assign the air changes to model the heat losses through the ground floor adjacent to a car park.

However the other buffer space is not modelled in the notional building and this consequently increases the average U-value of the actual building, thus penalising the overall BER.

So I contacted my accreditation body and here is their reply:

'I think that excluding the car park from the EPC assessment is not the correct approach. I do not think that there is anything in the Conventions that suggests that car parks should be excluded from the EPC.
If you are referring to the old Conventions 3.04, that has been removed
"The following should be used in SBEM v3.5 to define an enclosed or underground car park which has mechanical ventilation and therefore requires either its own EPC or inclusion in an EPC.
The activity must be set to “circulation”, the HVAC system must be set to “Zones without HVAC system” and the mechanical supply/extract system or the mechanical exhaust system must be used to enter the required “Ventilation” or “exhaust” via the zone level tabs."
please note that was done because the current software version actually have a car park activity. As a result, the work-around of assigning the space as “circulation” is not applicable anymore, it should be assigned as Car Park, as the activity now exists in the software. This does not mean that you should exclude the car park.

On the Part L calculations approach, including the car park zone is indeed problematic for the U value checks, exactly as you described. In most cases assessors do not include the car park and assign the ground floor (where the car park should be) as adjacent to outside air which we think is probably the best option available in the software.
However, as the Building Control Officers are responsible for the Part L checks, please liaise with them to ensure that they are happy with this approach. They are ultimately the authority that will accept or reject this modelling approach.'



There we go... the Solomon judgement (splitting the baby...car park) as always.

[Complex Potential]

Thank you for sharing that VVladinovsky.

It is always good to get the official responses of accreditation bodies recorded on these forums.