The house in which the character Selisandra van Afflen Lopez lives as a young girl is based on a 2015/16 design by Minnesota-based ‘Architects for Society’ (a non-profit design practice) which they call the Hex House, for obvious reasons.  
 
Built of steel-and-foam Structural Insulated Panels (SIPs) it is 40 sq. meters (431 sq. feet), will last for 20 years and is really quite amazing. They can be arranged together to form extended community groups (and groups of groups). 
 
How will the house change in 150 years when the story is set? Certainly there will be new materials (extending the lifespan to maybe 100 years or more) and as the design is fairly high a false roof could supply storage space (in cupboards that drop down on extending runners?). Certainly the internal layout is pretty much perfect so I don’t think that will change much.  
 
I don’t believe the plan on the right is copyright but if it is then I apologise and will withdraw it immediately upon request. More information (with lots of illustrations and plans are available at: