I know nothing about your area and I'll look forward to reading responses.

If you'd like to feel better while waiting, my utility rates differ significantly. I'll keep the numbers general. Electricity over a baseline of about 350 kwh per month this time of year is around 30 cents per. Gas over 2 therms per day is currently at $2.50. Imagine what you bills would be like with those prices.

Fortunately I'm in a mild weather area but people around here receive bills of your magnitude with half the usage.

PS - newer furnaces offer high efficiency - 95% and higher - and same too with newer AC equipment. It's past time to replace what's there if it's >25 years old. It may be best to wait until springtime to have it done (AC can't be turned on and tested until it's warmer) but you can get quotes and line it up now.

Your electric and gas usage seem to be high. Are the numbers you quoted from the most recent bill? Do you have a gas furnace or boiler? If so then are you also using electric heaters or have a gas fireplace?

I was thinking they were high as we'll. Gas Furnace... no electic heat that I'm aware of.

What kind of gas? natural or propane?

your electric and gas run $500 so what is the split? how much for gas how much for electric? what is the electric rate? cents per kwh?

What type of water heater/ how many occupants? Also 3 bed house with 3500 sq ft. sounds odd. Most 3 beds are well under 2000 sq ft. / Take some pictures of equipment indoor and out if you can and post them.

Not saying it can't be a Taj Mahal --- but Wisconsin? I want to see it.

Are you thinking they don't have large houses in Wisconsin? Not sure I understand your comment. No reason for me to give bad info? House has a very larger master with a very large master closet. The home has two furnaces and two AC. One for each level of the home. One unit that heats the down stairs also heats the basement which is partially finished but all heated.

3 people, don't know about the water heater. Likely old as well. Will gave to look when I get home. This month natural gas was about 300 and electricity was 200.

Are you thinking they don't have large houses in Wisconsin? Not sure I understand your comment. No reason for me to give bad info?

You'd be surprised the guessing games some people like to put us thru on this board.

The info you provided is incomplete. No one can come to any serious conclusion with the info you provided thus far.

A house that size, with an operational bill of that size... with older equipment (built in the 80's) sounds about right for your climate. Considering we still do not know what the electric rate is. (incomplete info)

The more room you have to heat and cool, the more it will cost you. A house that size could easily have more than one water heaters. Not that common for them to be bigger for residential as Mike suggests, but could be.

So you want us to guess? You can do that yourself.

We live in North Carolina and our gas bill (two 95% efficent furnaces) is between $200 and $300 a month. Our electric bill is $100-$120 a month (we have a small heatpump for the 3rd floor). Our home is 3200 sq ft, so I'm thinking your bills may be typical.

Just to drop some detailed input of my scenario. South of Green Bay, WI.

House details:

8135 sq ft (6 bed, 5 bath, 1200 of the 8135 sq ft is heated Garage), built in 2022. Radiant below subfloor (staple up) natural gas heat.

Insulation characteristics:

R70 in attic space. Double stack(second is perpendicular to minimize vertical thermal transfer over truss members) of Owens R38.

R26 in walls. Rockwool Comfort batts to minimize slump.

R39 in floor (R38 with cork underlay). Owens R38 nonfaced.

16% window to wall surface, Double pane, low E.

R4 on roof sheath.

I've not insulated the headers or the Floor OWT perimeter which is where my heat leaks are beyond the windows. No thermal curtains on windows yet either. So I may be able to get another 6% energy improvement if I did the floor perimeter and when I 4-5% when I add curtains.

Environmental:

Sitting right next to a 1 1/2 acre pond. Near continuous wind through the property.

Consumption:

Total therms for December 2022 was 218. Total therms for this January 2023 was 187.

Conclusion:

I've a hunch if you went through and redid your insulation, you should be closer to 100 therms. 7 year ROI if you do most of it yourself.

Your electrical consumption is about average.

Those looking at my roof will notice something odd but intentional. I applied Grace water and ice across the entire roof sheath, used 1x4 diagonals across the roof 16 O.C., with 4x8' radiant sheets, ripped to fill the gap between, aluminum reflective facing up. Creates a passive vent in the roof structure. On a 94 degree day as this day was, the interior ambiently sat at 72. End of the day when the sun is shaded out by the wall of trees on the western edge, the roof has condensate on it. It doesn't have condensate under it (I've checked) but just in case, the whole roof is covered in Grace.