Buying a house is a good idea long term.
Currently all indicators are downwards for prices, so you need to consider your timing. Public sector job losses have yet to kick in fully.
Overpayment is a great idea. The nitty gritty of doing it monthly is a different matter.
If you ever pay higher rate tax or your employer offers to match your contributions to a pension then not paying into a pension would be a bad thing to do, but I realise that might not be your circumstances.
I don't personally think you would unlock "lots" of capital if you are going from a 3 bed semi.
My in-laws downsized 8 years ago, they sold their 3 bed semi for £135K and bought a flat for £100K.
I know prices have gone up in the last 8 years, but the point is that the capital released is the wrong ball park to significantly supplement a pension and flats are not a great deal cheaper than your average family home.
I don't think you should count on an inheritance in your financial planning.
Apart from the fact that it could go to the toy boy/cats home, more realistically it could be spent on long term care or you could find you are retired well before you get it with people living longer.
