A legally binding guarantee? I doubt anyone will give you one. But if you're buying a home you have other options - for example, you can just buy a house that

A legally binding guarantee? I doubt anyone will give you one. But if you're buying a home you have other options - for example, you can just buy a house that already has a working broadband connection. The homeowner will give you the wifi password to run a speed test if you ask nicely. If the property doesn't have broadband already, there are other signs you can sometimes spot - cables going into other people's properties, street cabinets and handholes with the company's branding, nearby wifi networks with supplier names in the SSID, and suchlike.