Can you demo and install new staircase while living in the house

A good joiner and labourer could remove existing staircase in a coulple of hours, the new staircase if designed corectly can then be utilised to access upstairs temporarily whilst the balustrades are fitted (dependant on the compexity of the landing). Max 3days work for 2experienced people who work full 8 hrs. Access to upstairs floor should not be interupted.

It should only take 2 men a day to remove and install a new stair case, depending on type (straight flight, half kite, full kite ect…) you would need atleast another day to finish installing spindles and balustrades. All in all, you’d be looking around 2-4 days depending on size of staircase

Answer YES, it can be done while living in the house — but only with careful sequencing. Your instinct about losing access to the 2nd floor is basically right if the job isn’t planned properly.