You need to be realistic and understand what YOU want first before appointing any Professional. How much design creativaty do you want? Do you want a landmark building or something you can get on a Barrets estate? You’ll quickly sour any relationship if ‘waste’ time being vague – although any Professional will have a terms that allow for their fees to be revised should the Instruction change signifficantly / repeatedly.
15% of the build cost is a good budgetry figure but you need to add VAT onto that too. Plus the other Professionals – Structural Engineer has already been mentioned depending on your spec a Services Engineer will be needed to. Then there’s the Planning Consent and Building Control applications and Warranty Indemities. Possible Party Wall matters too. Then QS and Project Management fees potentially too.
Budgeting the Build Cost is where you should start. A single detached house private development a rate of £1350 per sq m should allow for something very nice.
I use them to seat tubeless tyres too. But I also carry them in my trail pack to ‘quick’ inflate a tube if need be. My mini pump takes a ages to pump up a 2.35 tyre / tube. Whereas if I use a cartridge then it’s just a few pumps to get it up to pressure.
I should really buy one of theose mini track pumps from Lezine (sp?) but I spend enough on bike bits as it is.