How long does it typically take to build a Rocket Mass Heater?

How long does it typically take to make a rocket mass heater? I was going to buy the $50 blueprints online and build one from that. I would be heating 320 square feet.

I really need to get some sort of heat source going before winter and I think this is the best option. I just want to make sure that it's not too complicated. I'm a very handy person and as long as I have clear instructions then I'm good.

Also are there any "general ideas" of how much building one can cost? I'm pretty frugal so I can usually come up with ways of getting things cheaper. I just wasn't sure how much materials would cost.

I appreciate everyone's help!

rocketstoves.com - all the info you will need if you commit to spending time reading. If you can go out and buy all the ideal materials, maybe a few days to build as a first timer. my $.02, if you can afford the ideal materials - firebrick, vermiculite, tin ducting and all that, it makes it much easier. I tried v1.0 with improvised and repurposed materials. It kinda worked. v1.1 and v2.0 were done with firebrick and ducting. The ease of use, and more precision in the build I thought were worth the money, and it works much better.

Getting my clay dirt, (to make the cob filler) did consume alot of my time, it kind of depends on your weather now, harvest more dirt than what you will need, and get it moved close to your build site, I guess you could do it in the rain, but it is easier when dry. I got lucky this year with a drought, which made handling the clay dirt kind of easy compared to when the moisture is higher. I used 1/4" screen to sift out the rocks & roots, which took alot of time. If your going make your clay slip/mud, you might want to strain the dirt further...thru a window screen and have that fine dirt already sifted & available, stored with a tarp or something over it...it doesn't cost anything, this dirt...but it does require alot of time to refine it. I never refined clay before so it took me a while, plus I didn't want to just dig a hole in the yard, so where I got my clay was some distance. Have some extra buckets around, and a tough clean trash can might help if your going to make your own clay slip/mud. Once you fill a couple buckets full of wet slip, it takes maybe a day for the water to rise out of the dirt, pour the standing water off to get a clean sticky mud.

Once you get all your stuff together, building the thing is pretty fast, took me about 3 days. I spent alot of time because I'm not really a sheet metal mechanic & I had to find & repair some scrap air-duct to make the exhaust mass heater tubes (check with your local heat & air business, see if they have a scrap pile out back, for some free duct & elbows & manifolds, the stuff I got had screws in it already, reuse the self-tapping screws) the build of the thing would of been faster if I had the air-duct supplies already on hand.

Pile up some wood early to become very dry by the time you want to test the thing. Consider some time for alterations & tuning of the thing.

good luck!

james beam