High Schools, High Tech Central To A Multimillion-dollar Facelift Of 40-year-old Radnor High Are Provisions For Computer Networks And Video Links. The Key, Planners Say, Is Building In The Flexibility To Adapt To Technological Changes.

What will the high school of the 21st century look like?

In Radnor, where the district is embarking on a $33.9 million make-over of its 40-year-old high school, the vision includes a state-of-the-art TV studio, an upgraded technology-education wing, four computer centers strategically situated near academic departments, and a sophisticated media center at its hub. Classrooms will have access to cable TV, the Internet, and a local computer network. They also will be equipped for two-way, interactive video presentations.

As is true for districts throughout the region, Radnor is grappling with twin problems - a baby boomlet that has brought overcrowding to its elementary schools and the upgrading of an outmoded high school building.

``The baby boomer schools were all built in the 1950s,'' said Harold L. Hart, senior project manager for Gilbert Architects, the Lancaster firm that has the Radnor contract. ``They are running out of steam. It is 40-some years later, and there are a lot of schools that are just outdated. There is a lot of work now in school construction.''

Great Valley, for example, plans to renovate one elementary school and build a middle school. High school additions are in the works in Hatboro-Horsham, Downingtown and Haverford. Methacton has proposed a $25 million high-school renovation. In New Jersey's Monroe Township, a $31 million Williamstown High School is being built. And Lower Merion, which has scrapped a controversial plan to merge its two high schools, is expected to consider a renovation project instead.

Since school districts are constructing for the future, it's no surprise that questions about how educational technology will be used and delivered to the classroom loom large: Will computers be clustered in labs or dispersed in classrooms? What kind of wiring should be installed? How many access lines to the Internet are required? And since technology is advancing so rapidly, how can educators be sure the building they design today won't be obsolete by the time the work's done?

Radnor is trying to make sure their plan is supple enough to accommodate change.

``We want to have the most flexible approach possible,'' said Maureen Reusche, the district's director of instructional technology. ``It is so hard to predict the future.''