Tenants' side of duplex won't stay warm in MN wint

[Michael Wade]

Hi all,

First-time homeowner (duplex) with first-time problems. Looking for advice on either heating or tenant-relations.

I bought an up-down duplex in Minnesota in March of this year and moved into one unit, renting the other. Turns out it has major problems retaining heat in my rental unit, majorly concerning the tenants and myself.

The building is circa 1900, about 1600 sf, and each unit is 2/1. I live upstairs with a roommate and dog, highly-effective baseboard heating, and no heat retention problems at all. Downstairs are two tenants and a dog; central heating and a/c with a furnace installed in the cellar in 2019, and a smart thermostat installed a few months ago by the Xcel Energy Squad. About 65% of windows are new, the rest are old. (Some old windows have storm windows, some not.) Most of the building is insulated with woodchips; had the remaining 2 rooms (plus a couple walls here and there) insulated with cellulose just a few weeks ago. The attic is already insulated. While the smart thermostat indicates the temp is reaching around 65/69 degrees, the tenants placed a couple other temp gauges around, which are showing temps in the low 60, upper 50s, and now that the outside temp is going consistently negative (remember, MN), showed one overnight reading of lower 50s. The downstairs bedroom seems to be the coldest; one obvious issue is that the bedroom is directly over the cold underground cellar hallway (entrance from outside), without insulation between the cellar hallway and the bedroom floor, causing a cold floor. Otherwise, the furnace blows nonstop, and the smart thermostat doesn't seem to reflect the colder temps around the house.

Having just bought the house not expecting to make a major capital expenditure right away (everything else is in good shape), the insulation blew my nascent Capex budget. Had an insulator look at the cellar hall/bedroom floor area, and he said it would take major major work to insulate that, including digging out a bunch of the cellar to access the walls like they would need to. Apparently the crawlspace(s) are not adequate. The tenants have shrinkwrapped most windows. I gave them a space heater to use, which they use conservatively for safety and cost-saving reasons. Got a furnace maintenance guy scheduled to ensure the furnace/thermostat are working correctly.

To me, low 60s is manageable; low 50s and sleeping in a jacket is moving toward uninhabitable and definitely embarrassing as an owner.

Tips? I've considered offering to pay their natural gas bill during the winter months to empower them to spend whatever they need to on space heaters. My goals are to get them warm and to avoid vacancy. Thanks!

[Tim Swierczek]

@Michael Wade we have owned over 10 old 1900 built duplexes and these issues are common.  I would recommend you start by getting a thermal scan of the house.  You can hire a home inspector to do this, but I think it's possible you can get Xcel energy to do it cheaper.  Xcel offers an energy audit, it's more comprehensive than heat loss and I don't know that it includes a thermal scan.  The scan will show you the areas of the greatest heat loss and that will allow you to spend money where it will have the most impact. 

A few other thoughts, in my opinion, you run the risk of the tenants legally breaking the lease due to inadequate heat.  I don't think that consistent low 60's would be considered acceptable heat by a house court judge.  I would offer them some concession and show them you are trying to rectify the problem.  From the sounds of it I think you are trying to fix the problem but they need to feel that you are. 

I doubt that it's an undersized furnace, it's next to impossible to get a furnace too small for a 2/1 unit.  My guess is that it's a combination of issues, lack of or inadequate insulation, leaky windows, gaps between the foundation and the crawl space, and possibly issues with the venting.

One last tip, I recommend you put a thermometer in the basement to monitor the basement temp.  If this issue persists and the crawl space gets cold enough your pipes could freeze and that is no fun.  We have had this happen in four houses and it is less than fun.  PM me if you want to talk offline or if you want the name of an inspector who does thermal imagining.