Ask Hannah Holmes

Hannah Holmes

Home Rx

Realtor/science writer/self-proclaimed “house geek” Hannah Holmes on heating a slab foundation, why home buyers are settling for “ludicrous,” and more.

Illustrations by Christine Mitchell Adams

Have a question for Hannah?

Send your Maine home or garden conundrum to [email protected] and we may feature it in an upcoming column.

We are building a home on a slab in Sedgwick and are wondering which works better — radiant heating in the slab or above the slab?

radiant heating and a slab foundation

Wet or dry, that is the question! Wet installation means you lay the heat tubing on a cement slab, then spread wet concrete over it, entombing it. Dry installation can happen as a retrofit, by tucking the tubing in between floor joists, for example. In terms of efficiency, there’s not much difference.

Where you can maximize your efficiency is in the insulation process. In essence, you want to create an insulated box that forces heat to flow in only one direction: up. Then, for the top of your box, you want a material that allows heat to move quickly. The most radiant-friendly floors include concrete, ceramic tile, various vinyl products, and some engineered woods. Natural woods are middling; and putting carpet, cork, or rubber flooring over radiant heat is like putting parkas on your radiators.

You might also consider how “responsive” you want the heat to be. A massive slab of concrete will take longer to heat up and cool down; a dry installation that’s tasked only with heating the flooring material will respond much more quickly.


We will be spending our first winter in rural Maine. Do we need a generator?

stand-by generators in rural Maine

There are many aspects of our homes that, from a distance, don’t look like brilliant investments. I’m thinking of my fancy dual-fuel Dacor range, which arguably cooks a pancake no differently than any other range. And my replacement windows, which likely don’t insulate much better than the prior windows and storms with a couple layers of curtains over them. But, day after day, those dubious financial investments make my home a more fun place to be, and my life a bit richer.

For each of us, there’s a point where a house ceases being a financial instrument and becomes a major player in our quality of life. Perhaps a stand-by generator, which kicks on automatically when the power goes out, is that point for you. Will your daily cares ride more lightly on your shoulders if you cross “power outage” off your list of things to worry about? Are there hidden costs to not having a generator: food that spoils; hotels that you move to; medical- or job-related equipment that won’t function?

Regarding resale value, most buyers settle for a house that offers the best “package deal,” as opposed to any particular feature. That’s why you’ll never recoup 100 percent of any upgrade you make. So invest in the ones that deliver the best “fun dividend” for you.

Do I really have to forgo a home inspection if I want to buy property right now? This seems incredibly risky.

why skipping a home inspection seems incredibly risky

Of course you don’t have to waive the inspection! Any broker who advised that would be crazy. But I can assure you that in this white-hot seller’s market, another buyer will forgo the inspection. And offer $100,000 over the asking price, waive the appraisal, let the sellers stay in the house at no charge for two months after closing, and they would be truly honored to accept any rusty paint cans, pesticides, and barrels of nuclear waste the sellers might want to leave in the basement. So if you don’t waive the inspection, your offer price had better be exceptionally ludicrous.

Acclimating to this market is a process. Most buyers lose two, three, a half-dozen homes before deciding that “ludicrous” is slightly preferable to “homeless.”

One helpful exercise is to consider the worst-case scenario without an inspection: The furnace is on its deathbed: $10,000. The septic system needs replacing: $15,000. The well water has radon in it: $2,000. And so on. (To estimate prices, consult a Ouija board, because contractors are too busy to return your call.) If you waive the inspection, you will have to accept that $27,000 risk. See? Nothing to be concerned about!


For years, we have burned our paper trash and yard waste, as opposed to recycling or composting. But lately we’ve been reflecting on carbon emissions. Is one approach better than the other?

burning paper trash and yard waste vs to recycling or composting

Carbon happens. As long as we continue to burn stuff to produce heat and energy, we’ll continue to release carbon dioxide into the atmosphere. But there are ways to minimize the impact of this nasty human habit.

Many fireplaces, woodstoves, and outdoor fires burn at relatively low temperatures, which send complex new molecules into the atmosphere. These are often toxic, carcinogenic, and otherwise unwelcome. Even burning table salt can produce dioxin, for example.

Your best bet is to “reduce, reuse, and recycle” (and compost) all the paper and yard waste you can. After that, the usual options are: sending trash to a landfill, which produces a certain set of pollutants; sending it to a municipal waste incinerator, which produces a different set of pollutants; or burning it at home. Of these, home burning will likely create the most air pollution. When you do build a fire, keep in mind that the hotter it is, the cleaner it will burn.

Hannah Holmes is a real estate broker at Keller Williams Realty Greater Portland and the author of four science titles, including The Secret Life of Dust and Suburban Safari. A veteran renovator of old houses, she blogs about humans and their territorial issues at