I tried to point it out, but perhaps it wasn't obvious.
There are different rules for underwriting residential mortgages and for underwriting commercial mortgages. One can't use the rules from one in an effort to refute statements regarding the other.
A few excerpts from the OCC Handbook on Commercial Real Estate Lending are pertinent:
In its simplest form, ADC (Acquisition, Development, and Construction) lending may finance the land acquisition, land preparation, and construction of a single residential or commercial building. Often, however, ADC lending finances a single- or multiple-phase development of many units. ADC is highly specialized lending that requires a thorough understanding of its inherent risks. This section discusses the underwriting, policies, and controls that are necessary for prudent ADC lending.
ADC lending presents unique risks not encountered in the term financing of existing real estate. Assessing performance on a development or construction loan can be challenging because most are underwritten without required amortization or project-generated interest payments. Absent such objective performance measures, examiners must fully evaluate the projected cash flow of the project, compare actual progress to the initial plan, and when applicable, analyze guarantor support. This analysis must consider the feasibility of the project, given current conditions, planned construction, and the level of fully funded debt.
A developer may wish to borrow on an unsecured basis, often in the form of a line of credit, to acquire a building site, eliminate title impediments, pay architect or commitment fees, or meet minimum working capital requirements established by other construction lenders. Repayment of an unsecured front-money loan may come from the first draw against a construction loan. The bank extending such an unsecured loan should require the construction loan agreement to permit repayment of the working capital loan on the first draw.
Appraisals used to support construction loans must include the current market value of the property (often referred to as the “as is” value of the property), which reflects the property’s actual physical condition, use, and zoning designation as of a current effective date of the appraisal. If the highest and best use of the property is for redevelopment to a different use, the cost of demolition and site preparation should be considered in the analysis. OCC Bulletin 2005-32, “Frequently Asked Questions: Residential Tract Development Lending,” provides guidance in the valuation of collateral for ADC loans.
The construction loan appraisal must also include a prospective market value. The prospective market value upon completion (“as-complete”) is an estimate of the property’s market value as of the time that development is expected to be completed.
For residential models, the bank ordinarily obtains an appraisal for each model or floor plan that a borrower is planning to build and offer for sale. The model appraisal typically includes the value of a base lot in a particular development without consideration to the costs of, or value attributed to, specific options, upgrades, or lot premiums.
If the bank finances the construction of a residential tract development, an appraisal of the model(s) provides relevant information for the appraiser to consider in providing a market value of the development. That is, the value attributable to the models is used as a basis for estimating a market value for the tract development by reflecting the mix of units and adjusting for options, upgrades, and lot premiums. The market value should also reflect an analysis of appropriate deductions and discounts for holding costs, marketing costs, and entrepreneurial profit.
For construction of units that are not part of a tract development, a model’s appraisal may be used to estimate the market value of the individual home, if the model and base lot are substantially the same as the subject home and the appraisal meets the agencies’ appraisal requirements and is still valid. In assessing the appraisal’s validity, the bank should consider the passage of time and current market conditions.7 When underwriting a loan to finance construction of a single home, the bank should consider the value of the particular lot and any options and upgrades relative to the values in the appraisal of the model.
There are limited circumstances, however, when the structure of a proposed loan mitigates the need to obtain a tract development appraisal. If all of the units to be developed can be built and sold within a 12-month period, no discounting is required and the bank may use appraisals of the individual units to satisfy the agencies’ appraisal requirements and as a basis for computing the LTV ratio. The bank should be able to demonstrate, through a feasibility study or market analysis conducted independently of the borrower and the bank, that all units collateralizing the loan are expected to be constructed and sold within 12 months. For LTV purposes, the “value” in this isolated case is the lower of the sum of the individual appraised values of the units (“sum of the retail sellout values”) or the borrower’s actual development and construction costs. The borrower should maintain appropriate levels of hard equity (for example, cash or unencumbered investment in the underlying property) throughout the construction and marketing periods.
If the bank finances a unit’s construction under a revolving line of credit in which a borrowing base sets the availability of funds, the bank may be able to use appraisals on the individual units to satisfy the agencies’ appraisal requirements and as a basis for computing the LTV ratio. This is the case if the bank limits the number of construction starts and completed, unsold homes included in the borrowing base and if the bank satisfies the conditions described in the preceding paragraph. If the borrowing base includes developed lots or raw land to be developed into lots, the appraisal obtained by the bank must reflect appropriate deductions and discounts.