if you have 40 bitcoin right now, i think you can buy a good house now
what you're talking about 40 bitcoin is only $16k, you cna buy a garage at most, not even a good one
no way you can buy an house with that amount, here for example you need 40k for a good condition one(2 room) 40-50mq
It obviously depends on the region you are living and the locality you prefer.I think you can buy one at least somewhere around the world