There are many houses on the islands outside of Stockholm, though most are not main residences but are weekend or summer houses for the more wealthy Swedes. A boat trip through the archipelago is both scenic and interesting and makes for an excellent day trip from Stockholm.
There are in theory plenty of options and different islands/places to visit, but as we are out of main season the number of these are reduced. Without too much fuss we settle on the trip to Sandhamn which is on one of the outer island in the northern area. The boat leaves at 10am and takes just over 2 hours to reach Sandhamn and returns at 15:30 so we have about 3 hours on the island. This looks to me to be an ideal day trip as it also stops at Vaxholm which looks to be one of the more interesting towns and has a castle.
The weather today isnt the best, a little overcast but the wind is light so the boat trip is not rough and we can sit out on deck the whole way.
we easily walk around in our time there. Its a funny place, remote yet close to the city. I cant think many people live permanently here but it must be popular in the summer for day trips. The swedes are keen sailors and this makes a good weekend destination for a yachting weekend. As one of the outermost islands there is some history here as the island was the customs house for trade in and out of Stockholm and even today the pilot boats are based here. It is also the setting for a series of crime novels.
One final thing about this trip makes my day. We go past Viggso, the island where Abba famously had a holiday home in the 1970s. Though the boat doesnt stop there we pass close by. The house is now privately owned (the owners I expect are sick of visitors looking for the Abba house). In the Abba museum they have recreated the small retreat they used for songwriting.