I am looking into purchasing my first home up in the fridged northern NH.  We experience 9000+ heating degree days.  This Home has 2400 sq ft of living space and is insulated through out to decrease drafts.  The previous owner burns through 15 cords of wood a year with an outide boiler and states that the heat loss is due to the basement siting on ledge and the over half of the basment floor is ledge (bedrock).  I would assume that normally, the square footage and age of this home would normally use up 6-8 cord depending on efficiency.  The home owner states that the ledge is like a heat sink and sucks out the warm air... which i understand.  There is no insulation on the foundation and there is water that runs down through an out the basement due to the hill Directly behind and up against the home. The H20 is not the problem with very adecuate drainage... i am certainly concerned about the heat loss.  how do i insulate the basement to lower the BTU load?... all of the plumbing runs through this basement so i do have to heat it, but i also need to ensure that the minimal h20 flow does not freeze for this can lead to problems. 

Can i insulate in between the floor joists to try to keep the heat up stairs on the main floor and the 2nd floor?

I have Considered using a jack hammer on a large piece of equipment, to dig down and around the home, my concern is that this would break apart the existing foundation...

Look forward to your responses... for this forum will lead me to either purchase this home or not...

M

thenudge79
I live in the central part of the state and burn a little over two cords forthe same square footage (in a tightened up old house), but I have built in the North Country so I am familiar with the changes in climate. 6-8 cords is still far too much for a well insulated home in your area so I think you are setting your goals too low; 15 cords is insane unless the windows are open. The first thing I would recommend is to ask the owner to get a detailed energy audit including blower door test and that you be be there with the auditor in the home looking at the problems. My guess is that there is a huge amount of air leakage and possibly not very good insulation. The water flowing through the basement is definitely a problem but I'll bet there are many more. Don't forget that the water will bring an excessive amount of moisture into the house that can lead to other problems we're not even touching on including mold, deterioration of the structure and others.

As far as the interior stream, it needs to go away. Look into solutions to diverting the water away from the foundation, including excavating, jack hammering or even blasting a drain uphill from the house.

When the basement is dry, either cover the ledge with 4" of XPS foam ("Styrofoam") or if the ledge is too uneven, have it spray foamed with closed cell foam, then cover with concrete. The ledge will draw heat away even without the water, so it cannot, under any circumstances be left exposed.

If the outside drain is not possible, the stream should be isolated from the basement. Install PVC drain lines, a thick layer of washed stone (probably 6-8"+), heavy layer of poly sealed at the edges, then the foam and concrete.

This house will be a challenge. If the price is right and the view is unmatched it may be worth it, but it will need to be fixed correctly.
Bob Irving

OK some ballpark math here.
1 cord of wood is around 25 million btu’s(hardwood) so 15 cord is 375 million btu’s. Assume the outdoor boiler is 6o% efficient and you are using 225 million btu’s.
 
If you translate that into a metric that is comparable, Btu’s/ft^2/heating degree day 225,000,000/2400ft/9000hdd = 10 btu’s/ft^2 per heating degree day.
 Look at http://www.homeenergy.org/consumeri...-usage.php  for more info. This puts you in the not terrible, but lots of room for improvement category.

While I think it is possible you could work with this home, it will have some serious challenges to improve efficiency, get rid of the moisture and running water in the basement, airseal and insulate. You are talking about a lot of time and money as there are not any easy solutions
 
Personally, unless there was a very good reason to buy this, I would look elsewhere

Cheers,
Eric