Not from chartered accountant but from an authorized property evaluator, typically these are law firms who visit your house and create a detailed report on property's value. Also, nothing is mandatory in SOWP, lot of things depend on VO who is reviewing your file, if your spouse doesn't have work experience you can still apply without it however work experience shows a pull back factor for the spouse. Else this could be considered as a weak home country tie, and applicant is less likely to return because of no job in India. Hope that helps!