The house editor offers a selection of different houses that are available for purchase. As can be guessed, the sp cost for purchasing a house is considerable. Each house costs a fixed amount minus, 1/3 the sp cost of the previous house.You'll get back 25% of the purchase price if you sell furniture.
When You buy a new house, all furniture items purchased in the previous house are placed into the house editor inventory.
Walls and floor which are considered to be subject to wear and tear form an exception to this rule. Diamonds you've paid for furniture are lost and won't be paid back.
As a member of the Gold club you have a five minutes return right on all furniture. In this range of time you will get all SP and diamonds back, as long as you haven't used the piece of furniture in question and it hasn't been moved to your inventory.
The inventory in your house editor is not limited. Your inventory for equipment etc. is limited and can be expanded a little if you join the Gold Club.
(This does not apply to floor or wall alterations, you receive no refund when purchasing a new house)
For closer look of a house click on it and you'll get it bigger:
See: House Editor