I just upgraded to premium membership, want a 2 storey house NOT a single level, can I change this?

[Griffin Ceawlin]

1. Choose World > About Land and click the General tab.
2. Click Abandon Land. After confirming, the land is removed from your account.

That's it! You can register for another Linden Home.

ETA: Warning: Please use this reasonably: if you abandon and choose a new Linden Home five times in 24 hours, you're temporarily blocked from choosing another. You'll need to wait after 24 hours have elapsed to register again.

http://community.secondlife.com/t5/English-Knowledge-Base/Linden-Home-FAQ/ta-p/700101

[Griffin Ceawlin]

1. Choose World > About Land and click the General tab.
2. Click Abandon Land. After confirming, the land is removed from your account.

That's it! You can register for another Linden Home.

ETA: Warning: Please use this reasonably: if you abandon and choose a new Linden Home five times in 24 hours, you're temporarily blocked from choosing another. You'll need to wait after 24 hours have elapsed to register again.

http://community.secondlife.com/t5/English-Knowledge-Base/Linden-Home-FAQ/ta-p/700101

[Charolotte Caxton]

https://secondlife.com/land/lindenhomes/member.php

[Innula Zenovka]

An alternative might be to look for a 512 mainland plot that's for sale -- it shouldn't be difficult to find some perfectly good ones you can buy for less than prices of a decent pair of SL shoes -- and built there, free of such constraints.    The 512-tier allowance you get as part of your premium membership applies to any plot of mainland you might acquire, not just one with a Linden home sat on it.

[Nyll Bergbahn]

Looks like you're in a quad at the moment.  Sure, you can abandon that by clicking World > Place Profile > About Land (make sure to take all your contents into inventory one by one before clicking that button) and choose another home. At the moment, both a two-storey Meadowbrook Skylight and Upper Skylight homes are available. Availability can change over short periods of time if by the time you abandon your home and these are gone from the selector. keep checking regularly as one could pop up at any time as people abandon and change homes to get one they're happy with. Otherwise, you'll need an alt to keep checking availability and if a two-storey home you want pops up, abandon yours and quickly log in and pick the one you want with your main avatar.