Cambridge Rent Control Administrator William J. Corkery announced yesterday a new standard for determining fair net income for landlords under the city's six-month-old rent control law.

The new standard-which sets fair net profit at between eight and 12 per cent of the property's market value starting March, 1970-is significantly lower than the old guideline of between ten and 15 per cent instituted by temporary Rent Control Administrator Philip M. Cronin '53.

In announcing the standard, Corkery said, "Rent increases given under the old temporary standard were rarely as high as 13 per cent. When we went that high it was only for hardship cases. Generally we found that increases to more than 12 per cent were too high."

Corkery announced the new standard almost a month after holding a public hearing where tenant groups denounced the temporary standard-supported by the landlords-as much too high.

Corkery also announced that the rent control administration will move to a new office at 678 Mass Ave, as of April 5. The old office will be kept to hold adjustment hearings.

Since institution of the law, the rent control office has received 766 petitions for rent adjustments. So far, 273 hearings have been conducted but only 22 decisions on adjustments have been reached.