Nearly every house that is standing now, will still be standing in 20 to 30 years as we do not seem to be building very many new ones (and of the new ones, many I see round here are destined to become modern slums, too small, too close, and almost  designed to encourage conflict between neighbours and to stress the occupants, I think many of these will need demolition first, sadly.) Many will still have the same decor, though some will have had the inadequate kitchen re-jigged 3 times in a futile attempt to make it bigger. Every piece of PVC cable in use now, that is not overloaded, will still be serviceable, and the majority  will still be in service, though hopefully some of the 1970s  unearthed lighting circuits will be getting rewired. Hopefully most fused neutral incomers will be gone, and hot wire fuse consumer units will be getting rarer. 

The other way to look at this is to look back - how much has changed in wiring practice since say 1980 or 1990 ? Some, but not that much, electricians probably do have a copy of the regs now, back then many would not have bothered, filament lamps give way to LED, but the the bayonet lamp holder is still going strong as the popular interface (and by 1990 we had CFL lamps already ). USB sockets may come and stay or come and go.

If anything as we have to use less energy, and it looks like  the next generation will rebel against consumerism generally ,  the rate of change may actually reduce.

Nearly every house that is standing now, will still be standing in 20 to 30 years as we do not seem to be building very many new ones (and of the new ones, many I see round here are destined to become modern slums, too small, too close, and almost  designed to encourage conflict between neighbours and to stress the occupants, I think many of these will need demolition first, sadly.) Many will still have the same decor, though some will have had the inadequate kitchen re-jigged 3 times in a futile attempt to make it bigger. Every piece of PVC cable in use now, that is not overloaded, will still be serviceable, and the majority  will still be in service, though hopefully some of the 1970s  unearthed lighting circuits will be getting rewired. Hopefully most fused neutral incomers will be gone, and hot wire fuse consumer units will be getting rarer. 

The other way to look at this is to look back - how much has changed in wiring practice since say 1980 or 1990 ? Some, but not that much, electricians probably do have a copy of the regs now, back then many would not have bothered, filament lamps give way to LED, but the the bayonet lamp holder is still going strong as the popular interface (and by 1990 we had CFL lamps already ). USB sockets may come and stay or come and go.

If anything as we have to use less energy, and it looks like  the next generation will rebel against consumerism generally ,  the rate of change may actually reduce.