Also, yes to doing housework while 1.5 year old is napping! That's 1-3 hours free every day. If the OP's 1.5 year old doesn't nap, there's something wrong there, and the OP seriously needs to consider medical intervention or parenting intervention, as recommended.
Now child also needs medical assistance. Mum and child can book in for a 2 for 1 deal 
. Let’s preempt a medical problem with the 4yo next
.
This will curl your hair. One of mine never really slept of a day from birth. Had 10-15min catnaps here and there. Only woke once at night for a feed, went straight back to sleep and then slept through the night 10pm-6am from 5 weeks. Annoying as shit during the day but I was grateful for the full nights sleep. Told paed at the standard 6 week appointment and they just shrugged and said while not usual all babies are different and as they seemed healthy, growing etc just accept the luck of the draw that enabled a good nights sleep. They certainly didn’t seem concerned. Catnapping stopped at 9mths.
One of my other kids is at the other extreme and did nothing but sleep for well over the ‘typical’ time right up to school age.
There is this thing called a bell curve. Generally 90% of people lie in the ‘body’ of the bell (and are pretty much like the Borg) but 5% will lie in each tail on either side. That’s normal. In actual fact, so normal it’s referred to as ‘Normal Distribution’. So while 90% of kids that age may sleep for a certain amount of time (thus being considered typical), 5% will sleep for less and 5% will sleep for more and how much less/more gets more extreme as you move along the tail. That’s okay, it does not mean by default there is a medical problem, just not all kids are ‘typical’ and that’s actually normal.
The first baby I described is now an adult. Still not keen on sleep. Leads an incredibly active life (extremely high energy as they always have been from birth), physically healthy. Finds 5hr sleep per night more than adequate and can happily function on less. The second baby I described still loves sleep and on weekends or when on hols 11hrs is their default normal. So each has continued on with their more extreme pattern, it’s just part of who they are and normal for them.
Might add, first one has a rip roaring case of ADHD, but well controlled. ADHD not diagnosed until around 7yo, until then just considered a ‘high energy boy’ but it was obviously there from birth. Rugshade, as you are an expert, I want you to tell me what healthcare professionals are meant to do with these babies. Exactly what medical and parenting intervention is required for these babies/toddlers/young children, many of whom (not all, and not saying OP’s child is necessarily in this basket) will lie naturally on the tail ends of the bell curve including examples such as ADHD which can’t be diagnosed until older. I want you to be really specific here about the medical and parenting interventions that you know will fix this (given you are adamant it must be fixed). A whole lot of medical professionals and parents are waiting for your expert pearls of wisdom on this. And so much more no doubt. Actually, after imparting your wisdom here, put it all together in a book, maybe titled ‘Perfect child care for medical staff and parents’. Bestseller.