rating worse with addition of adiabatic wall

ps2008 · Posts: 45

I have a unit where one side is a party wall and adiabatic.

Now, if one the other, external side wall, I place an adiabatic component block, the rating gets slightly worse.

Is there a reason for this?

I'm only asking because I have done several identical units in this development, which were terraced (ie party walls on either side, not just one as in this case) and their ratings are worse than this one.

The owner is sure to quibble this result, he checks everything with a fine toothed comb Sad

File attached: simply take off the small side wall and re calculate again.

Andrew Bairstow · Site Admin Posts: 343 Location: Birmingham, UK

The Asset Rating is ratio of emissions of actual building: emissions of reference building (/2). When you increase the area of heat loss then you will thus increase the emissions from the building as it requires more heating, the emissions from the reference building will also increase as the reference building will also have increased heat loss. The effect on asset rating thus depends on the relative increases in emissions of actual and reference building. This building has both low U values and modern efficient heating system (lighting spec is most detrimental to AR) and thus the relative increase in emissions in the actual building is quite small. Putting this into figures with adiabatic wall: actual building has emissions of 38.7, ref 29.2 and for external wall: 39.7 and 31.8
AR (party) = 50 * (38.7/29.2) = 66
AR (ext) = 50 * (39.7/31. Cool

= 62

Regards
Andrew

ps2008 · Posts: 45

Thanks for the explanation Andrew, I am sure to need it Sad

Best

Paul

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