As heated debate continues to swirl in Chilmark and beyond over how and whether to regulate very large houses, town planning board leaders said this week they were ready to send a draft bylaw to town counsel for review.

“It’s time to start floating ideas to [town counsel] with the understanding that everything isn’t crystallized yet . . . to see if we can add an extra layer of review and if the paths we’re starting to go down have legal merit,” said planning board chairman Janet Weidener rat the board’s meeting on Monday. “If not, we should know that sooner rather than later.”

In an informal conversation with the Chilmark selectmen, Ms. Weidner said the board agreed that “it was time to get the ball rolling.”

Extra rules for extra-large houses have occupied much discussion at the planning board this year. In January the board appointed a large-house subcommittee charged with examining existing zoning bylaws and recommending what changes, if any, should be made to regulate house size. The subcommittee includes planning board members Ms. Weidner, Dan Greenbaum, Catherine Thompson and appointed members Joan Malkin and Andy Goldman.

The bylaw now under consideration by the board would be a temporary measure that stays in place for two years. After that it would be re-evaluated.

There are two versions of the bylaw; both call for extra review for houses over 3,500 square feet.

In a proposal from Mr. Greenbaum, a former transportation planner, houses of that size would be referred to the town site review committee, which is made up of one selectman, one member each of the board of health, zoning board and planning board, and one at-large member. The committee reviews building projects within districts of critical planning concern and makes discretionary recommendations.

The site review committee would evaluate a series of eight checks: Location (is the project in a DCPC; is it visible from public areas?), size in relation to neighboring properties (is the project’s full area ratio 20 per cent greater or more than the median residential development?), environmental impact and energy efficiency (does the project drain into a body of water; does the project include clearing of more than one acre; does the project cut and fill more than 1,000 cubic yards; is the project lacking energy conservation measures?).

If the answer to any of the triggers is yes, the project would be referred to the zoning board of appeals for a special permit. The zoning board would consider the same questions in weighing permitting options.

In a similar proposal from subcommittee member Andy Goldman, requests for building permits that result in 35 per cent coverage of a buildable lot also would be sent for a more extensive review. The intent of the extra measure is to regulate auxiliary structures, including detached bedrooms and garages, and reduce maximum coverage of a lot size. Mr. Goldman has also suggested eliminating the site review committee in favor of having the building inspector take on the review.

Questions remain about how to measure the full area ratio of a house on its lot, whether the town can regulate gross living area, if the board should include new advertising and notification procedures, and whether the proposed numbers are the right measurements of size.

On Monday, the planning board continued to refine the draft bylaw. Board member Richard Osnoss recommended that the bylaw include a change notification system so all town boards are notified when any changes occur on an ongoing project.

In the coming weeks the planning board also will set up a meeting with the zoning board of appeals. Land surveyor Chris Alley noted the discretionary decision-making process across town boards that can lead to confusion.

“One thing the site review committee does do is determine if a site is open or wooded,” he said. “But then the ZBA goes out and has their own site visit and makes their own determination and they’re not always the same . . . they almost always take the site review committee’s recommendation, but there’s nowhere in the bylaw that says they’ve granted site review the authority to make that determination.”

Ms. Weidner said the site review committee “has the potential to be a good board” if it was given more authority.

“It has representation from all of the boards but it just doesn’t have any teeth,” Ms. Weidener said. “It’s loosey-goosey in that according to the bylaw, they then send a report to the zoning board of appeals, but they don’t have the power to veto something.”

Once the bylaw has been vetted with town counsel and further refined, it is expected to come before voters at a special town meeting, possibly in the fall.