I'd really appreciate if someone could point me to some answers/a
group/site/forum or even give some answers here to the following. I've
already spoken at length the EST and Low Carbon Homes people. Here's
what we (a couple) have, and have found.

We bought a small chapel which has been renovated some time ago. The
roof has very little insulation, but has a tiny loftspace with big
overhang, ie, nowhere to get much loft insulation. Sempatap has been
recommended by EST, but there's no grant for that.

The walls cannot be cavity as they are the original.

The cooker is an old Nobel (like an Aga) which is oil fired,
uncontrollable, on all the time, and heats the kitchen, tank of hot
water, and one radiator. Oddly, seeing as so much is wasted heating
hot water anyway, they had an electric shower! But I think this is to
do with water pressure as it's tank water (no mains).
However I'm sure mixing pump technology has come on since then?

There's an LPG boiler which ONLY does the CH rads, but it looks like
there were plans to get it to run the DHWC primary too.

Again, it seems there's no grant for any of the above any more (so
much for govt energy policy!).

Onto the futu I think the Nobel/Aga thing has to go, I'm sure it
was great when oil was 9p litre, but I have no plans to get another
oil delivery! But LPG tank gas is even more expensive; however at
least the boiler can be controlled, and if we swapped the Nobel for an
LPG cooker, that would help. Unless someone out there is making a
compatible used chip fat equivalent of standard home heating oil
cheaper?!

So, let's assume we get rid of the Nobel. Then we need to heat water.
As the roof needs to be done at some point, I was thinking of solar,
but along the lines of buying my own £800 evacuated tube panels and
get a qualified plumber to install it, rather than pay some ripoff
solar company £6000 for the same.

Solar thermal is the green thing I'm going to do - I know some will
disagree, but I've done the sums, and it's the only thing which works,
and it needs to. I'm steering well clear of solar PV, wind, and wood-
chip boilers seem not only expensive and unreliable, but the chips are
rising fast in price, and are expensive to get delivered, and even a
modest boiler burns a lot of woodchips.

I initially thought no to ground source as the garden is small, but
air-source sounds interesting for winter heating. I need to dig up the
kitchen and bathroom floors anyway, so maybe air-source underfloor
might replace what the Nobel gave off? The only thing with that, is
that electricity supply is flaky round here.

The other thought is to replace the current efficient fairly new
Clearview wood burner with a water heating equivalent, and use a
thermal store. As I understand it, I can input wood stove, solar, air/
ground source, gas and/or economy 7 electricity, and then the system
which needs it just takes it off via its own heat exchanger. I know
that sounds expensive, but it does allow diversity of supply.

The reason I'm asking here is that all companies seem pushy on
expensive impractical stuff - I want an engineer not a salesman. And a
lot of forums I find just descend into people arguing about climate
change. I'd just like to stick to practicalities! And publications
like Green Bible are just full of adverts for the energy equivalent of
homeopathy, and the more solid books are out of date with prices.

So, any pointers greatly appreciated!