Does anyone have experience with air permeability testing courses? I am looking to perhaps get into this sector but currently its more of a feasibility study to see how much it would cost in total. Google isnt giving me many answers! I already cover the SAP side so perhaps a package deal would be good for clients.
Many thanks.

Based in Cheltenham (UK) but traveling isnt a problem for courses

I did my training with BSRIA and also bought my equipment from them.
At the time they were the only option but now Stroma, based in Yorkshire, also train and supply equipment.
You may also want to speak to the B.I.N.D.T. who run the accreditation scheme, they were very helpful to me.

I'm sure you've already started thinking about the financial planning but its a sector that already has a lot of competition. I'm based near Manchester so we won't be rivals.
Make sure you budget for £200 B.I.N.D.T. annual renewal and £800 annual equipment callibration (+VAT).

There are a few big companies that do nationwide testing that have contracts with major developers, these include BSRIA, Stroma, and NHBC.
The new building regs that come out in October will require a greater number of tests on sites but I'm not confident that that will make huge difference in income.