Sep 12, 2026 · by Carlos Mendoza
Buyers plan around the listing price. Then signing day arrives with a transfer tax, notary fees, mortgage costs, and sometimes VAT on a new home — often seven to ten percent on top.
For Propertia we put a calculator next to every listing. It estimates the down payment, the transfer tax on the price above the regional exemption, VAT for new homes, notary and registration fees, and mortgage costs, then shows the cash needed on the day.
Every assumption is written next to the number and can be edited. A calculator that hides its assumptions is just a nicer way to be wrong.
Engineering-wise it is a pure function and a form. Product-wise it changed the conversation from "how much is the house" to "can we actually do this".