I'm currently looking at our options for heating our house.

We both work from home.

It's about 100sqm floor area, two stories, 600+ years old in places, constructed originally in timber framing, though there is little to see outside now as most has been brick skinned, but a lot of timber remains inside. Aluminium DG was fitted some years ago.

Currently we have oil fired rayburn, very underpowered as we have 19 radiators. They get warm, but not hot. It's enough to keep the place unchilled shall we say. I've turned off several rads that are in rooms that don't need them and removed the two rom the kitchen - not sure why they were installed as the kitchen the warmest pace to be with the rayburn!!!
We also have a wood burner in the lounge, lovely and toasty when lit.
We are re-instating a chimney to the room my wife has as her office and will either have an open fire or install a small wood burner in there - she feels the cold.

At present we have a ready supply of loads of off-cuts of timber from a shed company, we could get 20x what we currently use. The timber doesn't burn for long and constant re-fueling of the fire is needed.

My options are,

A large wood burning boiler - we have space to fit it and a spare chimney to use where it could go. It'd need to be a largish one to accomodate the size of off-cuts we get rather than just pellets - I don't want to spend all my free time pelleting or cutting down the wood.
Benefits - good heat supply - not an awful amount of work needed to fit it - free fuel supply
Cons - will take up most of my work room - free fuel supply may stop at any time - some fueling and looking after needed

GSHP - We have plenty of land to lay underground pipes, most of which gets sun all day long when it's out. We also have a moat around 3/4 of the house, which is filled with water, as I believe a 'wet' system is more efficient.
Benefits - free fuel supply forever
Cons - cost to fit, as we'd have to come round/under/over moat to get pipes to the house if we had a land based system - heat supply? I'm not sure - but would it make our house nice and warm all day long in weather like today at -3' here now at 9.50am. If we had a wet system we'd need to make sure the moat didn't dry up, which last year it very nearly did.

We don't just burn our offcuts either, I've gradually made a nice picket fence and two gates to keep the dogs either in the front or back with us when we are out and the horses etc are out the other side.

So, what would be your decision?
Why?

What are the other pros and cons I've missed?
What should I also be aware of?

Graham

GSHP option seems wildly costly given the amount of wall insulation I think you have not got. Can you get hardwood logs. I realise the offcuts are free or cheap and heat very quickly, but you must spend half your life stoking the fire and de-tarring the chimney. Can you have a massive scheme of insulation? Then you will spend less on heating plant and running costs.

There is a product called builddesk whichyou can download for free it will help you to work out your u values.

http://www.builddesk.co.uk/sw49334.asp

What size was the HP for which you were quoted £6k? Ours was £7500 RRP (albeit with an integral HWC), and is 6kW (we reduced heat-load from c24kW unimproved to about 5.5 improved). Our bldg is c130m2. Yours does not sound like it has a small heat load. Sounds like you might benefit from an energy rating with its attendant calculations. I realise those in favour of exposed thermal mass might disagree but (assuming the ext of the bldg is something nice to look at) what about internal insulated 'dry-lining'? Easy DIY and a very good guide via the EST web-site.

I'm very interested in these prices

It makes the £12K plus underfloor heating I was quoted look very expensive

But surely £12 plus ufh is a lot more than you guys are paying?

Does it include the pipes under the ground?

How far under the ground do they have to be? As we are rural I know men with tractors/diggers etc (they call it "plant" apparently)

I wonder if the Strawbale will give me enough insulation to have a GSHP

My building is 20 m long and there is a field next to it - so it needs to be a metre deep & 2m apart - so in 20m I could get 7 lenghts about 30m long

Hmm how much can a man with a digger dig in a day?

I can have 5 days of digging (I have been lent the digger - I need to pay fuel (to get it there plus the job) & the drivers wage plus lots of bacon sandwiches while he is working)

I've got the septic tank and (i hope) 2 rainwater harvesting tanks plus the groudworks for the car park 600 sqm and 50 linear metres of path way

Could you do that plus the GSHP in 5 days (incl filling in) they don't need to be 5 concurrent days - but they do need to be whole days

Nick,

With you now, excellent.

Katymac
It all depends on what the ground is. We had a 500m (18"x36" deep) trench dug in two days, some of that was through hardcore, most was 15" top soil and then clay, up and down some slopes, under fences.....

If it is all soil then he should be able to dig a fair amount more, but beware that soil will fill itself in for you quite happily!!!!

I was laying the pipes as he was digging whilst it was snowing!!! Not a nice job.

Are you advertising Winterbourne? As a supplier you should keep your comments more of a general nature. My memory is a bit hazy but hasn't someone mentioned this to you before?

I've now got a wood burner with back boiler, solar tubes, rayburn all connected to a 900 litre buffer tank, and have heating now :)

What do you want to know? Ask and I'll try to answer.
Most of my learning came from reading poosts here and elsewhere.
I tried to get help here but it was limited, maybe I asked the wrong questions, I'm not a plumber, I don't understand the intricacies of the work, so at the end of the day after inviting loads of "experts" to come and quote on work and give me ideas, I picked a firm who I liked the chaps who came to see me, they were enthusiastic about the work, they could do it (most couldn't) and what they suggested as a plan to do what I wanted my heating to do sounded right, so that was that :)

buffer is 900 litres total with a 200 dhw tank of 200 litres inside it.
They fitted a whole host of controllers, so depending on what is happening depends on what's pumping, but we have what looks like quite a sophisticated solar controller, which if I remember right turns on the solar heating if the input is hotter than the output by 6' and also shows the upper tank temp and the lower tank temp.
Our back boiler and the oil fired rayburn both input heat into the tank as well, along with another pump if we used the rayburn to top up the tank by using the heating side of it, which we don't intend to use.
So all heat the big tank and this heats the smaller internal tank.