MARTINEZ -- The City Council on Wednesday approved the Laurel Knolls townhome development, over residents' objections.

Discovery Homes plans to build 76 three-story townhouses ranging from 1,431 to 1,930 square feet on a nearly 7-acre lot on Muir Station Road, near the Nob Hill shopping center. Discovery Homes is a branch of the Concord-based Seeno family homebuilding empire. The Laurel Knolls project has been in development since 2009.

The developer has reworked the site plan several times since March to address neighbors' and council members' concerns.

Nearby homeowners criticized the plan to convert two acres of open space to residential use, and said the development is too big for the site and it will add too much traffic to a road where motorists frequently speed. Residents of Donaleen Court said the project would compromise their privacy because the townhomes overlooked their backyards.

In response, Discovery Homes reduced the number of units from 80 to 76 and moved the buildings away from the property line and the hillside along the East Bay Regional Park trail. The developer also agreed to install a phased traffic signal at the intersection of Muir Station and Center Avenue to regulate vehicle flow, plant about 75 trees around the perimeter of the site and add 10 guest parking spaces. Discovery Homes also will put in a 5-foot-wide sidewalk along Muir Station Road from Laurel Knolls downhill to Alhambra Way.

Although the designated open space on the site won't be preserved, Discovery Homes has included a playground and community garden.

Lisa P. White covers Martinez and Pleasant Hill. Contact her at 925-943-8011. Follow her at Twitter.com/lisa_p_white.