Barclay House, one of the newest levels in Clayton's crown, is 17 stories of solid luxury living for apartment dwellers. When it opens this summer, it will bring the flavor of Miami Beach's plus hostelries to Brentwood boulevard with a heated swimming pool shaped in a "B" for Barclay - and 30 Florida-type cabanas. Ninety apartments will be rented on lease basis from $160 a month for studio to $1250 for one of the large penthouse units. The building, opposite Shaw Park, is at 230 South Brentwood bl. The units are 50 per cent leased. The first eight floors will be ready for occupancy in mid-July and the rest in mid-August. The tone of the decor is set by two-story-tall lobby enclosed in glass and golden-hued aluminum. Walls opposite the elevators are leather-covered. The restauraut-and-bar is on the ground floor and a patio will permit outdoor dining. All-tropical landscaping has been designed by an Arizona landscape architect. The concret and glass structure houses apartments done in sophisticated colors, rare woods, colored bath fixtures and all-electric kitchens with virtually every appliance. Many apartments have built-in bars, some with hot and cold running water. A dial-type air conditioning system will provide heat or cool air to any apartment any time of year. Closed-circuit tv will prmit occupants to see who is calling at the building entrance. Other tenants and shops in the building may be dialed by three-digit numbers by means of a new automtic telephone switchboard billed as the first of its type in the St. Louis area.