METRIC DESIGN GUIDE
Round metric lay-in type fixture sizes are used when using a round-metric-sized ceiling
grid. Many domestic manufacturers currently manufacture or can produce round metric
sizes of 600 by 600 mm and 600 by 1 200 mm. The 600 by 600 mm size with sockets on
one end is easier to manufacture in metric and may have more competition.
See PBS-PQ100.1 for GSA criteria for general ceiling lighting, including life-cycle cost
requirements. Caution must be used to not take an older design and merely round off
fixture dimensions or spacing because new energy requirements may substantially change
a lighting layout from previous ones.
American manufacturers have produced metric fixtures either by modifying existing
production machinery or they already had machinery that was specifically made for the
metric market. To date, metric fixtures are being sold, in building quantities, at the same
price as English sized fixtures.
Some manufacturers, even those who have competitively sold metric fixtures, claim that
their costs are higher for metric production. Sources and costs of these products should be
checked before requesting a project bid or proposal. Spare building fixtures forProperty
Management replacements beyond the Initial Space Alteration should also be considered
to extend the time required before small purchases are needed.