Gorham adopts zoning changes to encourage smaller buildings — not McMansions — along the lakefront.

The town has changed the rules for building along the Canandaigua Lake shore to reduce red tape for residents and — as a side benefit — potentially reduce runoff into the water.

Anyone who wants to tear down a seasonal cottage on the lake to replace it with a year-round home or new seasonal cottage can do so now without variances — provided the building doesn’t cover any more land and isn’t taller than the original structure. The building may be positioned differently on the parcel, for example, to move it farther from the property line.

Additionally, the roof cannot be higher than the width of the lot.

“It should cut down on large homes on small lots, and not change the character of the lakefront community,” Supervisor Richard Calabrese said.

The intention of this new rule was to let people replace homes without going through a cumbersome process of getting variances. Keep the house small, and approval is quick and easy. Build a McMansion, and you’ll need to wait for town officials to act on variance requests.

As a side benefit, smaller homes would keep more of the land open to absorb runoff, reducing the amount of sediments, lawn chemicals and other debris that flow into the lake, which serves as drinking water for about 60,000 people.

Also part of the new zoning rules:

• Year-round homes along the lakefront would have to be a minimum of 750 square feet, a reduction of 200 square feet from the previous rules. Year-round homes elsewhere would still have to be at least 950 square feet.

• Seasonal cottages as small as 400 square feet can be put up on lots that, under the previous rules, were too small to build on.

• The town would encourage people to build decks with a quarter inch between the planks to allow water to pass through. It would also encourage people to use paving stone or bricks instead of blacktop or concrete on driveways and sidewalks to further reduce runoff. Property owners would get “credit” for using such methods. For example, a 10-by-10-foot concrete patio would count as 100 square feet of lot coverage, but a 10-by-10-foot patio made of sand covered with paving stone would discounted by 30 percent, meaning it would only count as 70 square feet of lot coverage.

The Ontario County Planning Board commended the town for establishing redevelopment standards meant to reduce runoff.