(a) Only those sales or services to which the retail concept applies may be recognized as retail sales of goods or services for purposes of the exemption. The fact that the particular establishment may have a concept of retailability, in that it makes sales of types which may be recognized as retail, is not determinative unless the requisite portion of its annual dollar volume is derived from particular sales of its goods and services which have a concept of retailability. Thus, the mere fact that an establishment is of a type noted in § 779.320 does not mean that any particular sales of such establishment are within the retail concept. As to each particular sale of goods or services, an initial question that must be answered is whether the sales of goods or services of the particular type involved can ever be recognized as retail. The Supreme Court in Wirtz v. Steepleton General Tire Co., 383 U.S. 190, confirmed the Department's position that (1) The concept of “retailability” must apply to particular sales of the establishment, as well as the establishment or business as a whole, and (2) even as to the establishment whose sales are “variegated” and include retail sales, that nonetheless classification of particular sales of goods or services as ever coming within the concept of retailability must be made. Sales of some particular types of goods or services may be decisively classified as nonretail on the ground that such particular types of goods or services cannot ever qualify as retail whatever the terms of sale, regardless of the industry usage or classification.

(b) An establishment is, therefore, not automatically exempt upon a finding that it is of the type to which the retail concept of selling or servicing is applicable; it must meet all the tests specified in the Act in order to qualify for exemption. Thus, for example, an establishment may be engaged in repairing household refrigerators, and in addition it may be selling and repairing manufacturing machinery for manufacturing establishments. The retail concept does not apply to the latter activities. In such case, the exemption will not apply if the annual dollar volume derived from the selling and servicing of such machinery, and from any other sales and services which are not recognized as retail sales or services, and from sales of goods or services for resale exceeds 25 percent of the establishment's total annual dollar volume of sales of goods or services.

(c) Since there is no retail concept in the construction industry, gross receipts from construction activities of any establishment also engaged in retail selling must be counted as dollar volume from sales not recognized as retail in applying the percentage tests of section 13(a)(2). Also, since construction and the distribution of goods are entirely dissimilar activities performed in industries traditionally recognized as wholly separate and distinct from each other, an employee engaged in construction activities is not employed within the scope of his employer's otherwise exempt retail business in any week in which the employee engages in such construction work, and is therefore (see § 779.308) not employed “by” a retail or service establishment within the meaning of the Act in such workweek.

(d) Certain business establishments engage in the retail sale to the general public, as goods delivered to purchasers at a stipulated price, of items such as certain plumbing and heating equipment, electrical fixtures and supplies, and fencing and siding for residential installation. In addition to selling the goods they may also install, at an additional charge, the goods which are sold. Installation which is incidental to a retail sale (as distinguished from a construction or reconstruction contract to do a building alteration, or repair job at a contract price for materials and labor required, see § 779.355(a)(1) is considered an exempt activity. By way of example, if the installation for the customer of such goods sold to him at retail requires only minor carpentry, plumbing or electrical work (as may be the case where ordinary plumbing fixtures, or household items such as stoves, garbage disposals, attic fans, or window air conditioners are being installed or replaced), or where only labor of the type required for the usual installation of chain link fences around a home or small business establishment is involved, will normally be considered as incidental to the retail sale of the goods involved (unless, of course, the transaction between the parties is for a construction job at an overall price for the job, involving no retail sale of goods as such). In determining whether such an installation is incidental to a retail sale or constitutes a nonretail construction activity, it is necessary to consider the general characteristics of the entire transaction. Where one or more of the following conditions are present, the installation will normally be considered a construction activity rather than incidental to a retail sale:

(1) The cost to the purchaser of the installation in relation to the sale price of the goods is substantial;

(2) The installation involves substantial structural changes, extensive labor, planning or the use of specialized equipment;

(3) The goods are being installed in conjunction with the construction of a new home or other structure; or

(4) The goods installed are of a specialized type which the general consuming public does not ordinarily have occasion to use.

(e) An auxiliary employee of an exempt retail or service establishment performing clerical, maintenance, or custodial work in the exempt establishment which is related to the establishment's construction activities will, for enforcement purposes, be considered exempt in any workweek if no more than 20 percent of his time is spent in such work.