The interior design market continued to grow in the first half of this year. The American Society of Interior Designer's (ASID) quarterly Interior Design Billings Index has shown industry growth at a moderate pace that is likely to quicken in the second half of 2013.

Based on a monthly survey of 300 firms, the index tracks performance data for billings, inquiries and product sales. Scores above 50 mean that billings increased, while scores below 50 indicate that billings decreased.

The index for June was 56.4, up from May's score of 53.7 and April's 55.5.

"The economy expanded more than expected in the second quarter of 2012, and this momentum should carry forward, albeit at a soft pace, in the remainder of 2013," said ASID chief economist Jack Kleinhenz in a press release. "The pace of growth is expected to lift to about 2.2 percent in the second half of 2013."

Thanks to higher billings and economic recovery, the ASID Business Outlook Index rose from 67.5 in May to 71.8 in June.

Average performance during the quarter was highest in the sectors of hospitality (60.3), multi-family housing (59) and single-family housing (57.3). All geographical regions reported increases during the quarter. At 57.9, the West had the highest score of the four regions, closely followed by the Northeast at 57.7. The Midwest and South scored 56.6 and 51.4, respectively.

After 14 months of growth, the index stumbled in the quarter ending Dec. 31, 2012: December's score of 47.2 was below November's 58.9. However, the industry recovered in the spring of 2013, with January's index scoring 55.3, February's 55.1, and March's 61. The reports of positive second quarter numbers suggest continued growth in billings looking ahead.