Frosty speaks the truth.
When you say, complete modernisation, though, what do you actually mean?
There's a massive difference between not having a kitchen and having a very old fashioned kitchen which you'd like to replace when time and finances allow.
There's also a massive difference between building works where you have 80% of the house fine, and 20% out of action, which I'm perfectly happy with, and building works where you have 90% of the house unusuable, either because there are builders in the room or because you have had to move the furniture from some rooms into other rooms. We're currently at 40% of house unusable, which is starting to get depressing.
New kitchen units = 1 - 2 weeks with no kitchen. Not really a problem if you've planned well in advance. Rest of house slightly dusty and has kitchen furniture in.
New bathroom suite = 1 - 2 weeks with no bathroom. Fine if you can wash somewhere else.
New windows = dust everywhere, I should think! Never tried this, but wouldn't be surprised if you have to box up / cover everything in the room.
New electrical works = dust everywhere
New central heating system = dust everywhere
New roof = no idea, but guess it involves a lot of dust...
To be honest, the problem I'd say is that you don't know it will affect you emotionally. I don't mind building works, DH finds them very stressful and genuinely upsetting. This means I'm then stressed on his behalf. If one of you hates building works, it will make the rest of the family miserable. They key thing is having somewhere to retreat to which feels normal.
Also, with three DCs, do you really have the time to manage building works as well?