Virtual PE for a house building project - UK

I am planning to build a house for myself.
It requires lots of research and admin work to find out all necessary details. I am looking for an assistant who help me in this work. Looking for long term during the project time.

Duties:
- conduct research and collect result
- requesting offers via email/phone
- organising appointment
- administration

Please note I need help occasionally not like in a regular full time employment! I think in an average of 10-20 hours/per week. It might be more as the project proceed.

Experience/degree in similar field is an advantage.