More people in the house doesn't always equate to more use of services.
If my husband lived alone with our children he'd use disposable nappies, cook ready meals, not garden, all producing more rubbish. He'd have to drive more because he wouldn't have the time to walk with the children.
In addition, as a SAHM I home educate my children (saving the cost of school places), and provide free care for some family and friends (saving the council care costs). We go litter picking, again, saving the council money.
In the past my voluntary work has included free EAL lessons and integration supportfor refugees, and mentoring and supporting former gang members in leading new lives which benefit society. Again, saving the council money in the long term.
We're one of only a couple of countries in the world where spouses can't be jointly taxed. This and the way child benefit is means tested make it more expensive to be a SAHM. Poll tax rather than council tax would add even more to this.
And let's remember that we have a housing crisis which would be beloved helped by more house-sharing and intergenerational living, and made worse by more single or small households. Poll tax would be a nudge in the wrong direction!