Since you are putting this on a foundation, a in-floor heating system
might be beneficial. When we built the chicken house this spring, we put
radiant tubing in the floor (for water to flow through). It now ends
three feet outside but will later be run through the bottom of the compost
bin to provide the little bit of heat to take the chill off in the winter.
I wanted the radiant heat because it is totally free after installation
and absolutely clean. Mine is in concrete because I wanted a concrete
floor to make the chicken house vermin proof; the floor has a drain so it
can be completely cleaned periodically and to drain any liquid that might
get spilled inside.

Even if you have a gravel base in your greenhouse, you can still put in
the radiant tubing; it really is rather tough though it won't be as
effective as in concrete as the concrete holds heat better than gravel.
There really is no need to connect it to anything yet as you can do that
later (being sure to leave plenty of pipe outside to connect) and finish
it as you have time and decide for certain what heat source you want to
use. It will cost you a couple of hundred dollars now but will pay off
over the years.

If you have the space, you can add the "heating run" 2-3 feet under the
ground in the garden. That is how many homes were heated in days gone by
and is coming into favor again with the heat source being a furnace to
heat the water in the pipes.

A greenhouse is in the plan for next year, but I have decide, in addition
to the piping in the floor for radiant heat, I want the foundation two to
three feet below ground level to help heat the floor from the surrounding
ground. There are several in our area built like that. It should also
help with cooling in the summer.

Of course, for your shelves, you can get systems to keep them warm as you
wish, that have heating cables built in.

I like the idea that is used in Europe but definitely not for us town
dwellers. Their greenhouse will have concrete walls 3-4 feet up with an
additional concrete wall 3-4 feet out and put their stock manure from the
barns in that "trough." As it decomposes, it provides all the heat that
is needed for the greenhouse and leaves behind wonderful compost. They
must also have a way to shovel the compost out from the outside edge of
the wall or maybe they rotate which walls they use each year so half have
good aged compost at all times.

These things pay off over the years but do take some pre-construction
planning.

Good luck, wishing you many, many years of happy green-housing.

Glenna

writes:
My wife bought an 8 foot by 12 foot greenhouse kit from Harbor Freight,
details at:

http://www.harborfreight.com/cpi/cta...emnumber=93358

Our neighbor bulldozed a level foundation last weekend and I took off
work
today to spend the day getting the frame leveled and secured. This
Saturday,
if it doesn't rain, I'll continue the project, adding the base plates and
constructing the walls. With any luck, I'll get the roof on, too.

If anyone out there has had experience with this sort of thing, I'd
appreciate any tips or potential problems in the construction process.
I'm
fairly skilled in home repairs and mechanical work, and this job looks
like
just bolting together a lot of aluminum rails, then clipping in the
window
panes. However, from my experience with similar projects in the past,
there's usually one or two unexpected complications that make the job
difficult, and I'd like to be forewarned.

Thanks,

Paul
Maryland, USA