There is nothing wrong with it. I’ve seen parishes that were built when there were 400 families plus attending. Now there are only 50-60 people registered. They have mass in the basement. Keeping that huge church heated would be financially crippling to the community so they meet in the basement.
Hey, the first Christians met in graveyards underneath cities.
It is more of a waste to heat the big building above the basement. The more gas you use mean more wells have to be drilled. The more wells you drill the more nature gets polluted. Not to mention it is a waste of money, money that comes from people who break their backs earning.
Not to mention it is more than likely even harder this year, I live up north, natural gas bills are double this year than what they were last year. There plenty enough people that are juggling food, medicine or heat this year.
It might be easy to wrong having mass in the basement, but how many people will be upset when many other programs (the parochial school, etc…) suffer because it wasn’t kosher to have mass in the basement.
Even if someone wanted to donate money and pay for the gas bill it still would be a waste, because you could have donated that money to the St. Vincent de Paul society, the parish school, ccd classes, rcia supplies, insurance on the building, or any other real needs of the parish.