Hi there

My first post here so please be gentle!!

I am looking to do quite a lot of work on the house I am in but am
having trouble finding reliable honest advice - so I'm kind of hoping
some of you good people may be able to help....

Ok, I bought the house I am in 18 months ago. Built c1870 -
traditional 4 bed house - door in the middle (the type children draw),
with a 60' long two story barn attached - by an extension of unknown
age. (picture on www.thehawthornes.org - the thumbnail photos are
small but the full size are getting on for a meg each for any non
broadband users!)

The central heating system has 11 rads, with microbore pipe,
yourkshire twin end return radiator valves and a floor standing
Potterton Kingfisher 2 boiler. The boiler has two seperate circuits,
and I have an electronic thermostat fitted on each (an upstairs and a
downstairs circuit). I have a hot water tank and a header tank in the
loft.

The barn is in pretty good shape - although it does have two tie bars
running the full 60' - on the inside - visible running along the first
floor. The roof is dry but very old and one of the walls at the top
corner needs some work doing (seems to be leaning out very slightly.).

I want to add a loft conversion, and renovate the barn. The loft will
have a large bathroom with bath and I'd like a mains water
thermostatic shower. I will also need at least two radiators. The
barn will need the roof replacing and the wall/structure sorting out.
I plan to leave the first floor as one long empty room for now (may
convert into a flat in a few years - with electric immersion heater
and storage heaters - so no gas). The ground floor consists of a
garage at the front, then a 35' long room with an old stable type room
at the back. The long room will need maybe 3 radiators (currently has
3 non-working storage heaters).

Ok, here come the questions.....

1 Will my boiler cope with pumping water to the loft for the
bath, shower & radiators?

2 Will my boiler cope with the additional strain of 3 rads in
the barn?

3 Can I add thermostatic rad valves throughout? If I want to
change them from the yorkshire type, will I have to change the
microbore pipe?

4 How much of a job is fixing the roof on the barn and how much
is it likely to cost?

5 To convert the 35' room, I'd like to plasterboard it - maybe
with some sort of insulation on the back of the board - is there
anything in the market place like this?

Thanks in advance - I know I am expecting a lot but I'm sure the
comments I'll get will be a honest and give me a starting point.

Thanks in advance

Simon