Anyone engaged an architectural consultant or architectural technician?

[Galileo]

We're looking at doing a side return extension with a builder whose been personally recommended to us. Architects' fees that we have been quoted are budget busting and seem little value given the (relative) simplicity of our project and likely increase in value of the property. So our builder recommended an architectural consultant with whom he has worked for a few years. We've met her and she is credible and likeable. Also, her fee is much more in line with our budget. She is partnered with a Structural and Civil Engineer who will do the structural calculations. She's sent through her terms & conditions and evidence of her professional indemnity policy. My query relates to the terms which state that her liability will cease upon practical completion of the project. I've read the relevant section of the Housebuilder's Bible which advises that good value can be achieved from using an architectural technician but that they won't have large professional indemnity policies because that would push rates up too high, but there is comfort to be derived from the building having passed building regs. If this is a normal way to engage services such as this then I am happy with the comfort from building regs but this is my first time engaging such services so I'm just trying to get an idea of what is normal. So, if anyone else has engaged the services of an architectural consultant or architectural technician, what were the liability terms?

Thanks in advance.