Growing food in urban cores with the Urban Farm Unit

If the history of our website is an indicator, this question will for sure invite a heated discussion, but we welcome that : )  We’d choose a slab on grade over a basement almost every time, and in most cases yes, a slab is cheaper in our experience. But that is partly due to the way we build, where we’ve built, and variables that many builders don’t consider (durability, air quality, maintenance, etc).

Building basements properly is more expensive than the way most basements are built (ie: doomed to fail) so the problem off the bat is that most basement advocates are building wrong, and therefore comparing apples to oranges. But we have a page on that very dilemma, have a look here first: 

Slab on Grade or Foundation and Basement; Which is Best?

There are some cases when a basement makes more sense, like urban infill lots with height restrictions, but even then we’d go with an ICF hybrid to avoid some hidden costs, see our page about raft slabs for poor soil quality here. But where near Portland, is it urban or country? What type of soil, and how much space do you have? That’s key to finding the cheapest foundation method. 
 

Hi Matt, we're happy to hear you’re finding what you need on the site. So about your first question, air heated floors are just as effective and reliable as hydronic radiant floors for heating your house. This page explains the differences well –

Air heated radiant floors vs hydronic, which is best? 

We’re happy to help with all your questions, best to put them on individual threads to keep topics straight, so we will start with your slab questions. You are correct that air does not carry as much heat as water does, but it doesn’t need to. A hydronic floor will heat up a bit faster, but there is really no need to be turning it up and down anyway so that’s not something that happens every day. Both can maintain even levels of heat, but the air floors can actually do that better since they don’t overshoot temperatures due to the amount of heat in the water when the system shuts off.

Legalett slabs are a bit thicker at 8 inches rather than about 4, so there is more thermal mass for holding the heat over the course of a day, and just like hydronic systems it will top itself up as needed. The heaters are sized to provide the necessary heat for a given space in a given climate and the company takes care of that. You don’t need a rep to come visit your site, just go here to get a quote on a legalett slab and air heated floor.

We don’t have data yet on the solar air heated floor, but depending on your hours of available sunlight and how far north you are its hard to say if that’s really worth the investment for you rather than putting that investment perhaps into a heat pump instead to reduce energy consumption. Pop any follow up slab questions here, we’re happy to discuss.