Keen to hear from anyone who has successfully increased the water pressure in their double-storey house... My 2020-built house has 3 showers (one downstairs, two upstairs), but water pressure is very low if more than 1 shower is used at the same time, and hopeless if all 3 are used together. A plumber who visited said it's because 0.5-inch pipes were used instead of 0.75 inch that they would use for a house with 3 bathrooms. Apparently, there are no building regulations for that, so poking the builder is a no-go. What can I do without changing plumbing? Is there a water pressure booster pump I can add, like the one in the link below?
Water pressure is just over 9 litres per minute, but when 2 or more bathroom showers are used at the same time it becomes a trickle. I have already checked that the shower heads don't have any flow reduction devices in them.
https://www.scintex.com.au/products/water-pressure-booster-pump-with-controller