Mechanically can you create a house or a castle using spells? Discounting home summoning spells.

I mean a home that will last forever

I would imagine it is possible using spells such as Wall of Stone and Stone Shape.. 

What you are probably looking for is Fabricate, and you just need a large pile of stones, wood, and whatever other raw materials you need. It might take a long time though waiting for your spell slots to recharge.

Galder's Tower

You can create a permanent tower by casting this spell in the same location and with the same configuration every day for one year.

Quote from Kaemgen >>

Galder's Tower

You can create a permanent tower by casting this spell in the same location and with the same configuration every day for one year.

I thought about that and Mighty Fortress too, but when I reread the OP, I realized they did not want to just summon a house.

I was going with the "Home that'll lst forever" bit thinking perhaps they didn't notice the every day a year option and just wanted something permament. 

wall of stone

fabricate

true polymorph

move earth

stone shape

Went through the entire spell list, and here is a list of all home/castle related spells that I can think of that are permanent or semi permanent:

CANTRIPS
Druidcraft (in conjunction with Plant Growth)
Mold Earth

FIRST LEVEL
Create of Destroy Water (Pools, Ponds, Moats, etc.)

SECOND LEVEL
Arcane Lock
Continual Flame
Magic Mouth
Shatter (demolishing existing structures, turning a boulder into a pile of smaller rocks for Fabricate, etc.)

THIRD LEVEL
Create Food and Water
Erupting Earth (permanent difficult terrain until cleared)
Galdr's Tower
Glyph of Warding
Major Image
Plant Growth (you can stack it with difficult terrain)

FOURTH LEVEL
Blight (you can plant a bunch of trees around your house and then Blight them to have for that haunted look)
Fabricate
Mordenkainen's Private Sanctum/Private Sanctum
Stone Shape

FIFTH LEVEL
Hallow
Teleportation Circle
Transmute Rock (pair it with Dispel Magic via Glyph of Warding to trap creatures)
Wall of Stone

SIXTH LEVEL
Bones of the Earth
Druid Grove
Flesh to Stone (if you like statues)
Forbiddance
Guards and Wards
Move Earth
Programmed Illusion
Word of Recall (if you are building a religious building)

SEVENTH LEVEL
Sequester (you can cast it on every brick, beam, etc. as you build your house to make your house see through)
Symbol
Temple of the Gods

EIGHTH LEVEL
Abi-Dalzim's Horrid Wilting (Basically mass Blight)
Earthquake (create fissures)
Mighty Fortress

NINTH LEVEL
Ravenous Void (create craters in the ground)
True Polymorph (turn anything into a statue)