What do you need to know about party wall matters? That depends... how much of a glutton for punishment are you? If you intend to tackle a construction project that involves a party wall matter by yourself, then what you'll definitely need to know plenty about the complicated world of party wall matters. You can start with a free copy of the Office of the Deputy Prime Minister's handy 22-page Explanatory Booklet that we can provide you with a link to. But even that, as the booklet will tell you, is "not an authoritative interpretation of the law." You'll have to keep researching all the myriad details of your particular situation. For most people, this does not strike them as fun at all. And if you'll likely ever do but one or two projects involving a party wall matter, then the huge investment of your time required to master the various regulations is probably not worth it.