Research and more research and lots of planning. That is what it takes.

We did our radiant from start to finish. It is a small system, 1200 square feet, 2 zones in concrete on a deck above a crawl space.

We will be doing our new system in the 3000 sq foot range.


A couple of things will help. No pex connections in the concrete.
Don't run tubes under toilets, refridgerators, freezers etc.
You need  bleed valve for air in the highest part of the system.

Marc,

I'm right in the middle of my own first time DIY radiant installation.  I have pex in my 960 sq. ft. basement slab, and stapled up to my main and second floors.  I am a framing contractor and didn't think this would be too much of a stretch for my skills.  I hired out the boiler installation and manifold plumbing, ran my own tubing, and tried to make sense of all the staples/clips/aluminum plates/aquapex-heatpex/insulation-aluminum foil/tubing layout options.  I have an ICF foundation and SIP 2 story with sprayfoam insulation everywhere else.  I've read your other posts where you are leaning towards an ICF house with low heat loss.  Mine came in around 24,000 btu, but that's where things get a littly fuzzy.  When I filled my system I didn't get all the air out of the lines and quickly burned out one element in my boiler.   So my boiler ran all the time costing me much money in electricity plus the cost of replacing the element ($120 since I replaced both elements).   I now think my pumps are oversized, tubing is unbalanced, and boiler is on the small side... but I saved a few thousand dollars.  

I have $5000 in my system, not paying myself anything for running the tubes and the hours spent on the web trying to do research.   I'd suggest bringing in the help of a pro.  You'll do fine until something doesn't work... and then it's on your shoulders to figure out why.  I believe there are professionals on this site who offer their design services as well as manifold construction.  They insist you hire a local plumber to install the boiler, which is good advice.   You'll kind of hedge your bets, saving the expense of the labor running all that pex/insulation/plates, but not take on the full responsibility of design. 

Best of luck.  I hope this helps.
Ben in Iowa