About to embark on a project... any tips?

[jellyandsoup]

Hi wise folk, we are about to embark on a pretty big project to open up.the back of our house. A have a 1930s demo with a fairly big single story extension on the back, which unfortunatly was carved up into 3 rooms. We are planning to have the walls taken out, the ceiling will hopefully be vaulted to follow the line of the roof with skylights as the rooms which were originally at the back of the house arewuitr dark. This will create a large kitchen diner wwithith an island, a playroom coming off it, we also have a living room at the front of the house so not all open plan.
We have had a structral engineer draw up the plans for the beams we need to support the roof when the walls are removed, and about to start talking to builders.
Any tips in undertaking this kind of a project, we are pretty confident with most diy, have fitted our own kitchen, happt with laying the flooring etc but never taken on anything like this.
Thanks

Sorry for typos - must read properly before posting. Semi not demo

Will the upstairs be affected?

Rent a storage unit for a few months - put everything from those rooms affected, plus nice crockery etc and any nice soft furnishings in storage - the house will be covered in dust and will get everywhere.

Think about what are the necessities - will you lose the washing machine and dryer for instance? How long will you be without a Kitchen? Without water? Can you perhaps plan those times to occur at half term or a weekend when you can go away and leave kitchen fitters etc to get on with it?

Do masses of research now so you can make decisions quickly. If you're going to order big items (kitchens / flooring etc) look at when they have sales / offers and what their lead in times are.