In this age of out-of-control house price growth, one thing's certain: we all want to know how much our next-door neighbours paid for their house.
Now a new tool allows you to find out just that. Upmarket estate agent YouHome has developed an online app which allows potential buyers (or, let's face it, nosy neighbours) to see at a glance how much people have paid for their homes - either on a per square foot basis, or by total amount.
Like the look of a certain area? The tool can show you local house prices as you wander its streets.
Although it's currently only available for Notting Hill and Bournemouth, Adrian Black, a director at YouHome, told City A.M. it will be rolled out further if it proves popular.
"We want to help increase understanding of the property market - and seeing prices and pounds per square foot graphically on maps really helps this," he said.
"Open markets are more efficient markets and that is great for consumers, who can build comfort faster and also transact faster as knowledge is more widely shared by all involved if it is in the public domain, which is what we are doing."
Fancy spying on next door? Check out the tool here.