Hi Thursday, Fantastic news that you're considering doing this. Currently, there will be a relatively high upfront cost, but you may get some support from the government / council for that and you'll still hopefully make savings over the longer term - as illustrated by someone on twitter who's installed one already:
There're some great resources out there - Waltham Forest Council recently did a 'super-eco' retrofit a semi-detached Victorian home, which apparently you can actually visit until the spring. https://astongroupuk.com/projects/retrofitting-a-victorian-property-in-london/ Do keep us updated with your progress.
