## Which of your walls / roof face the outside and what is their area? You should illustrate this on the plans / sections drawn as part of week1 exercises / or if you are feeling ambitious, you can do a pull apart axo.

EXERCISE 4A : How good is my home at loosing heat?  As discussed in the lecture, there are two factors which you need to take into account :
1.Which of your walls / roof face the outside and what is their area? You should illustrate this on the plans / sections drawn as part of week1 exercises / or if you are feeling ambitious, you can do a pull apart axo.
2.What are these external facing walls made of? I want you to measure and draw your window and wall, and try and ﬁgure out its construction. I also want you to ﬁgure out the U-value of the Wall. Use this tool to work it out. http://www.british-gypsum.com/technical-advice/u-value-calculator
3.What are the external windows made of? Provide photos. You can assume the following Uvalues :
· Single glazed – 5.0W/m2K
· Double glazed – 1.4W/m2K
· Triple glazed – 0.7W/m2K
4.Based on the above numbers you should be able to work out the ‘heat-loss coefﬁcient’ of your home – or in other words – a measure of how good your home is at losing heat. Compare to the heat-loss of my OLD home (me being Giles), both in 2007 and 2018. Take a look at the youtube tutorial below – this tells you all you need to know. See also the attached spreadsheet.

EXERCISE 4b : What would it take to make it twice as efﬁcient in terms of my walls getting thicker and my home getting smaller?
The second part of this exercise is for you to try and reduce the heat-loss in your home by to half its original value.
5.What would you have to do to the walls / windows / roof to achieve this in terms of U-Value. You can use the above numbers for U-values for windows. For walls use this website to ﬁgure out the thickness of insulation you would need http://www.celotex.co.uk/technical-services/online-uvalue-calculator  (let’s assume you are insulating form the inside).
6.Finally, on the ﬂoor plan that you have drawn of your home, what spatial impact does this additional layer on insulation have on your furniture arrangement?  Does everything still ﬁt?