Owners of single-family houses are hiring interior designers at a continually upward rate, according to the third quarter results of the American Society of Interior Designers’ (ASID) Interior Design Billings Index. Released today, the index shows an overall positive growth—scores of 50 and above indicate designers are seeing improved billings—but analysts exclusively attribute the headway to residential markets. The total index score for July came in at 51.4, with big jumps to 53.4 in August and up to 55.5 in September.

The residential sector shows a long record of sustained improvement with nine sequential months of numbers above 50. The average rate for residential billings is 52 for the third quarter, with future inquiries at nearly 60. Predictions for 2013 are equally optimistic. Looking at regional statistics, the northeast demonstrates the highest figures with an overall score of 55. Analyzing numbers according to firm size and type, small companies or sole practitioners have the strongest growth.