Are you researching without any specific floor in mind?
If yes, good luck.
If not, tell more.
How large an area do you want to heat?
What is under the floor surface? What it is made of?

I have no clue. We are in the early stages of looking at house plans to build (on a slab). I was under the assumption that in floor heating was the most cost effective and assumed there was only one type until I recently saw something about electric rediant.

Electric heat is commonly one of the most expensive type to use.

You likely could have a lower set-point for in floor radiant, thus saving some energy over forced hot air electric.

Natural gas is often still the lowest cost if available though.

Electric companies burn natural gas to generate power (and occasionally even diesel for peaking power)

Electric is typically used for a small area, like a bathroom. For an entire house, hydronic is what is done.
This is usually more expensive to install than standard heating.

There are several factors to consider. Can you take advantage of solar water heating in winter? This would make it most efficient. On the other hand, if you also want AC go with forced air. If you do go with hydronic think about indoor air quality. You will need some sort of air exchange system if you have well insulated house.

slab on grade.
hmmm = it may be less than optimal to heat it, because of the contact it makes with mother earth and the heat lost to the ground.

with a thermal insulating layer, any heating system can be considered efficient, when you compare it to any other system installed without any insulation.

so, yes, it's efficient and effective ("... in floor heating was the most cost effective ....") but you cannot just take that as the truth in all circumstances.

lots more factors to take into consideration.

in large buildings, heating the concrete structure is good.

in a single family house, you have to be sure first of the envelope and insulation. Then, it makes sense to heat something structural when it is not going to thermal-bridge and conduct cold into your building and conduct heat out of your building. It is worth it: the sensation of comfort is very high when the structure is warm in winter. It is effective. But you have to know a lot about other things first. In northern climates they dig basements, and this means the "ground" floor can be heated hydronically or electrically, without bridging cold/heat into the ground. Or, they have insulated crawl spaces. Also cuts the direct contact with the ground. With a slab, it's not as easy to predict: you Even need to know a lot about the ground water. By the way, styrofoam is a great insulator and there are some kinds that can be used structurally. Just f.y.i. I predict that foams will be used in the future for underslab layers.

but, what climate are you in?

.

Nothing cost effective about infloor heating. Comfortable - yes but expensive to install.

Most places with slab on grade are pretty far south and don't justify the expense of infloor heating.

There is an HVAC forum also to check out.

My new construction is on a slab with radiant heat that uses water. There is a layer under the slab that is a moisture barrier. It has stones and foam of some type.

The 2nd floor has a separate furnace. Since the upstairs is just 2 bedrooms and a bath the furnace isn't large.

I do not know the initial cost - as it was a part of my construction costs.

I'm not living in the house yet, but I will say that from being partially moved in - I like the feel of the radiant heat on my feet and my furniture stays nice and warm.

The only negative I see (so far) you have to be careful of what type of flooring you use on top of the radiant.

Carpet requires a special type of pad and when I was putting in the hardwood it was suggested that I only use engineered wood and that the glue also had a moisture barrier. It was alittle more costly but I think in the long run it will be better than hoping the slab stays dry.

We installed hydronic in floor 9 years ago and haven't regretted it for a minute. We live in a high altitude (7500ft) town, Northern AZ. We built slab foundation one level home (2500sqft) which we insulated under slab with rigged foam to prevent heat loss from the ground. Cost was 10K installed with boiler system that runs off of natural gas. We run the floors 7-8 months a year. Highest cost per month is $200 gas bill. We also run a gas water heater and all gas appliances. I love love love the in floor heat and would never consider building with an HVAC system. Good luck on your decision!

"Comfortable - yes but expensive to install."

I don't think it's expensive?

I just installed radiant heating (1/2" PEX) in my basement slab because it was so incredibly cheap. ~$400 for all PEX, fittings and a stainless manifold. The boiler/heater is about $1500 and then you need a few pumps and valves.

It cost about $4000 for in-slab radiant heating in my house (which has three heated concrete slabs on two levels + basement, each about 750sf). In relation to the whole house cost, this is almost negligibly cheap.

It is usually considerably more expensive due to the extra plumbing involved. The number of zones and size of house /system affect the cost. You have to also consider the fact that you still need to have an A/C system on top of the heating. This means all the normal ductwork or a high velocity system using smaller ducts.( even more $$)

You do need to insualte under any slab to retain and reflect the heat back into the room.

As others have said flooring has to be looked at closely for a variety of reasons.

Comfort is usually the reason people use and love radiant floors. The heat in radiant systems is from the bottom up and cooling from the top down if done best.

An old saying I heard is that it is better to have warm feet and a cool head than a hot head and cold feet !

If your feet are warm and head cool ...you usually are warm and comfortable

If feet are cold but head is hot you are not !

Hydronic is the best way to go when doing the whole home. Electric is used mostly for spot warming like bath floors.

Yes - DIY radiant can be inexpensive but paying someone to do it isn't and it is an extra expense as BigK said.

While it is true that you do see slab in cold climates, as a general rule, they are seen in Florida and Texas (and similar areas). Frost heave is an issue for slab so that is why in the south it makes the most sense.

Here in NC, slab is used only on the cheapest construction, usually tract townhomes. Hydronic heat is a rarity - because it generally isn't cold enough to make it worth the money and you have to have a/c anyway. I looked into radiant/hydronic because it is great but wasn't worth the expense.

As a cautionary tale, before I built, I looked at a foreclosure. Really high end house. Hydronic heat. Because the house sat empty (possibly) there was a leak and a lot of water damage. Very unlikely obviously but possible. Now on a slab ranch - less of a concern.

Comfort is determined by the coldest spot in the room. This is one thing that many people don't know. The (subjective) feeling of comfort, or lack, is 100% due to warmth, or cold, uneven or even across a room, and the leaks or sources of heat or cold. Anything producing a cold source (heat sink) will lower comfort. This cannot be measured on a thermometer because it measures on a scale (a single number) while a body can feel the rate of heat loss (which is a "speed" not a single number). Heat loss is a vector field (temperature and rate of heat loss in a specific direction). Thermometers don't measure vector fields, just scalar.

When heat is all going in one direction, constantly, the body can feel that slope, all the time. If it's heat coming at you, fine, that's OK. If it's cold coming at you, that is less than ideal.

Heat coming from the floor makes the floor/wall junction a far far warmer area than without in_floor heat.

The OP now knows that a whole house solution is hydronic, with zones, with planning and with expertise, and 2ndly that a small area can be done with electric. A 3rd tip: in some places it is common to do a single loop of hydronic taken off a water heater as a DIY small area floor heat project. This is do-able but as with the previous two options it requires knowledge of constraints, risks, methods, etc. The cost of operation is not the big factor here. Especially if you know what insulation really is, and you know how to insulate.

I have put electric cables and hydronic pipes more densely spaced close to exterior walls, and more loosely spaced farther inside the building. It works to even out the heat field, counteracting the heat loss at the outer shell (exterior wall). This is a minor adjustment that makes sense, and I have never seen it put into print by anyone yet.

People put radiators near cold sources to counteract the heat loss, to produce a heat source next to a heat sink.

To the OP: DIY is good for a small area. Planning in advance for infloor heat is one challenge. Building a whole house is another. Don't worry about the "heave" comments above.

Foam is a great material that will be used more and more.