Such selection shall embrace the site of the dwelling and its appurtenances, shall be compact in form, and shall be so made as not unreasonably to affect the value of the remaining part. If the selection be not made within 20 days after notice of the levy, or if, when made, it be not satisfactory to the creditor procuring such levy, the sheriff shall cause such homestead to be set apart by a survey, beginning at a point designated by the claimant, or, if no such designation be made, at such point as the sheriff shall direct, and the cost of such survey shall be added to the debt and paid out of the proceeds of sale.