The Duplex With a Non-Permitted Unit
You are appraising a two-story duplex in a California city for a refinance. The county records show a legal two-unit property built in 1968. During inspection you find that the lower rear storage area, roughly 400 square feet, has been converted into a third living unit with a kitchenette and full bath; the owner says the work was done in 2019 and no permits were pulled. The lender's order form asks for an opinion of market value of the property 'as-is' with the income approach emphasized. Zoning is R-2, which permits two units on the lot; a third unit would require a conditional use permit. Comparable sales in the neighborhood are all legal duplexes, and none has an unpermitted third unit. The owner insists the extra unit 'adds $90,000 of value' because it rents for $1,450 per month.
1. How should you treat the unpermitted third unit in your highest and best use analysis and in your value conclusion?
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Highest and best use must be legally permissible, physically possible, financially feasible, and maximally productive. The third unit fails the first test: zoning allows two units and a third requires a conditional use permit that has not been granted, and the conversion lacks building permits. So the as-improved use of three units is not legally permissible.
The property's highest and best use is therefore the legal two-unit configuration. The 400 square feet of converted space should be described in the report, but its contribution must be measured as legal two-unit duplex space - typically as bonus or storage area - not as a rentable third unit. The $1,450 rent cannot be capitalized at full market rates because it is an illegal use that a typical buyer could be required to discontinue. If you include any income from it, do so only as a clearly labeled, separately supported adjustment, and consider the cost to cure (removing the kitchenette and bath and restoring storage) as a deduction. Do not simply add $90,000.
2. The lender asks you to complete the appraisal 'subject to' the third unit being legalized. What do you do?
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You may accept a subject-to assignment only if the extraordinary assumption is reasonable and you clearly disclose it. Legalizing the unit requires a conditional use permit, and the outcome is outside your control and outside your competence to predict. That makes the assumption speculative rather than an ordinary extraordinary assumption.
The better practice is to appraise the property as-is (two legal units), disclose the unpermitted conversion and its effect on value and marketability, and note that value could change if the unit were legalized. If the client insists on a subject-to-legalization report, you must state the specific conditions to be satisfied (permit issued, work inspected and signed off), identify the hypothetical condition, and make clear the value opinion is hypothetical and not the as-is value. You should not certify compliance with a permit process you cannot verify, and you should document the client's instruction in your workfile.