Hello BIMfans,
In my last post, I introduced BRE‘s Standard Assessment Procedure (SAP) and began my SAP Calculations by importing Tŷ Crempog‘s areas and dimensions from my Architectural COBie. For this post, I’ve built on my initial calculations and have had a look at 2 Ventilation Rate and 3 Heat Loss.
As a Chartered Architectural Technologist, I’ve always tried to understand the science behind the built environment. When working in practice I did my own thermal calculations, and have previously designed to meet Passivhaus. This exercise has enabled me to rekindle that interest by combining thermal calculations, structured information, and information exchanges.
=COUNTIF(importrange(, “Component!A:A”), “*Fan*”)
This means that I cannot improve this value through refurbishment work unless I invest in Bathroom Dehumidifiers.
‘HasDraftProofing’ was chosen after reading BS 8541-4, which required Iuse CamelCase and indicating the data type expected. Draft [sic] is used in other parts of the IFC schema so I kept it for consistency. I used ‘Has’ over ‘Is’ as I am checking for draft proofing accessories, not checking the performance of the doors and windows (they could have draft proofing, but not be draft proof!). This new property was added to information model and exchanged into my Architectural COBie. Because all of my windows are doors are already draft proofed, sealing my floor or undertaking an air pressure test are the only ways to impact on infiltration rate.
My SAP calculations for ventilation rate can be seen below:
0.1220*TotalFloorArea + 6.875 = 16m²
While the impact is small, every little helps. Perhaps I need to check what values I can override if they are available.
My SAP calculations for heat loss can be seen below:
And there we have it. As I progress deeper into SAP using Tŷ Crempog‘s information model, I am beginning to discover what properties I should consider when planning refurbishment works. Fantastic, PLQ 3.4 is progressing well!
Operation and Maintenance
3.1 What are the sizes and condition of the windows & doors?3.2 What assets are in a poor condition?3.3 What costs can be attributed to my assets?- 3.4 What are the most cost effective thermal improvements that could be undertaken?
Now that my ventilation and heat loss calculations have been completed, I now need to look at Ty Crempog‘s hot water supply, internal gains, and solar gains…
Note: If you have any comments regarding my use of SAP, then please let me know either on Twitter, or by commenting below.