My husband and I just bought a townhouse in the chilly and snowy town of Mammoth Lakes, CA. It's two floors and approximately 1200sf. This post is concerned only with the lower (~600sf) level, which consists of the garage, 1/2 bath, kitchen and living room.

Issues: It's bloody cold. Typical morning temps on the lower level are about 40F. Our only heating source is a wood stove that, if we have chugging away all day, can maybe get the temps up to 65-70F. After work when there's only a few hours to heat, we hit 55F tops. And of course most of the heat finds its way upstairs.

We haven't had a chance to do a ton of exploring yet, but suspect that there is little or poor quality (likely around since the glorious 70s) insulation in the outside walls or in the underfloor crawlspace. It's also quite drafty with at least one large single-paned window above the entry door right next to the wood stove. The other windows are double-paned but old, and floor-to-ceiling with a nice 4ft pile of snow covering the bottom.

Wants: To keep the house at a comfortable temp. We're hardy mountain people, so a 55F morning temp would feel like a Hawaiian breeze. To not spend a mint on electricity costs. To stay as environmentally friendly as possible, both for us (we're the no VOC types) and for the planet. 

Pros: We are committed to ripping up the entire first floor (can't wait to get rid of the pink carpet!), including redoing the drywall and insulation. We hope to do a lot of the work ourselves to save $, but also don't want to scrimp now and hate ourselves later (oh that gray area of now vs the future). Since we like being somewhat warm, we are considering a hydronic radiant floor system for most of the first floor, for reasons such as: energy efficiency, relatively straightforward install (i.e. no ducts to add), and that awesome warm floor feeling. There will be no better time than during this remodel to fix the heat problem. Also not sure if we'll survive another winter without doing something.

Cons: It's a relatively small space when considering a hydronic system. We want bamboo floors which rules out electric radiant systems. Have investigated heat pumps as an alternative and it gets too cold here for them to work well. Electric costs are high so would rather not use electric heaters. Perhaps re-insulating, new double-paned windows and sealing all the drafts would help immensely, but I don't want to find out otherwise when we've redone everything and are still living in an icebox. We have some money saved but not a ton. Would ideally like to spend no more than $10k on steering this ship away from Antarctica.

Questions: Is hydronic worth it in our situation? Could we run it off of our current hot water heater, or should we get a mini electric boiler? Could we figure out how to do some or most of the labor ourselves? What's a realistic cost if we're living in la-la land thinking we only want to spend 10 grand? Is there a leftover WarmBoard market for small projects like ours? Any other suggestions for heating if hydronic is a no-go?

Rough floor plan attached. Thanks in advance for your time and expertise.

Cheers

10K dollars may seem like enough to do this project, but radiant flooring, insulation, and electric boiler will consume that very quickly. What is the electric rate in Mammoth. Have you looked into a propane tank and a forced air furnace.. How are you heating your water. Radiant would work great if it was well engineered. The problem I see is the electrical service necessary to power the electric boiler. Do you presently have a backup generator for those cold days when the power goes out. Another possibility is a multifuel furnace or boiler(wood, pellets,gas) but I am not sure about Calif. Title 24 and CARB regulations on that type of equipment.

I would design a hydronic radiant floor using a combi sealed combustion condensing water heater for space and domestic hot water all in one. Electric, propane or a cobination. I have bamboo over mine with great effect.

I concur with badger that this is most likely tank water heater territory, and we would both agree that separation between hot water and heating water would be required.

My installation was in concrete so different than yours, but I have posted detailed pricing in this thread on my DIY radiant system for my house.

http://www.greenbuildingtalk.com/Forums/tabid/53/aff/12/aft/78083/afv/topic/Default.aspx

-Rosalinda

not clear if this is a slab or platform. Will assume platform.
I (hawker that I am) recommend a dedicated electric boiler. You are heating about 650 square feet in the high country, may want a glycol. You have mentioned already that your fuel is electric. Why rig an heat exchanger and pump pack on a cheep electric water heater that will be taxed.
Boiler, single loop, RHT floor panel system, one zone.
B-10 Thermolec modulating boiler 38,000 BTU, with out door reset. I know overkill but you may want to toss some pipe upstairs once you get going. You could go smaller to a 20,000 btu unit but the price is almost the same.
Boiler, pump, parts, air scrubber, exp tank, so on...$1,600.00 +or -.
Floor system pipe, heat plates, manifold, plywood turns and site purchased 3/4 ply fill...650 square feet x $3.50 + or - = $2,275.00
your in for less than $4,000. and elbow grease.
Dedicated system, when the power is out build a fire.
Capacity to add more should you build or decide to take over the garage.
Dan