Lawpack do a very good online form, which includes a checklist, so that you can see if your will is indeed 'straightforward' and can be done on-line, or if you need a solicitor.
M0nica - I'm sure you're correct, but I think that happens where people try to do complicated things themselves.
Anniebach - yours does sound straightforward, and Lawpack do help you ensure the correct wording.
Rainsong - you need a STEP solicitor, who specialises in trusts to talk to about whether that is possible (likely) or desirable (more difficult!)
I have known it done, and it can be useful, but there are loads of decisions like:
what line of inheritance and distribution of income?
trustee appointment in the future, and their specific repsonsibilities
maintenance responsibilities & decisions
conditions around a future sale.
In our village we have ended up with a dogs' breakfast around a couple of trusts set up with good intentions 80-90 years ago.
My own personal opinion is that it is only worth doing for a property that is both valuable and of special significance to the family. A friend of mine has one that is not very valuable in itself, but is in a popular holiday location, so she & her sibling run it as a holiday place for themselves and to get an income. It does take quite a bit of organisation, and they are wondering how to divi up jobs and income for the next generation.