HANOVER — Christ Redeemer Church is appealing a ruling by the Hanover Zoning Board late last year that thwarted its efforts to build a 21,000-square-foot church on Greensboro Road, saying a Hanover zoning ordinance that requires a special exception to build a church in most areas of town is unconstitutional.

The church, which has sought to build in Hanover for more than 16 years, will argue its case Thursday evening before the Zoning Board, which has agreed to rehear the case.

In a Jan. 4 letter to the town, the Christ Redeemer Church says the board wrongfully denied it a special exception needed to build a $5 million church for 400 congregants at 28 and 32 Greensboro Road.

The board failed to provide evidence the project would “adversely affect the character of the area” and also asserts that Hanover’s zoning ordinance unlawfully discriminates against a religious organization by requiring a special exception where other buildings serving large numbers of the public don’t require one, according to the letter.

“Churches are restricted not based on size, parking or traffic but on the content of their speech and the purpose of their assembly,” wrote the church’s attorneys Thomas Hanna and Michael Tierney. “It is practically impossible to build a new church anywhere in the town of Hanover.”

Their filing notes that the last new church in town, the Catholic Student Center at Dartmouth/Aquinas, was built almost 60 years ago, and before that the most recent church construction was in 1900, before the town had any zoning.

The board voted, 3-2, on Dec. 6 to deny Christ Redeemer Church a special exception that would have allowed the church to build on two lots within Hanover’s residential zones. In their discussions and decision, the board expressed several concerns with traffic, noise and the scope of the proposed building project.

Neighbors also had concerns that the project was out of scale with their residential neighborhood, would produce too much noise and traffic, and could potentially encroach on nearby wetlands.

But the church argues the board never backed up its assertions with facts or evidence.

For instance, the Zoning Board said “a great deal more noise would emanate” from the property if the church were to be built and occupied. That runs contrary to the testimony of a noise engineer hired by Christ Redeemer Church, who found its activities wouldn’t adversely affect neighbors.

“Neither opponents nor the Board retained a noise expert to challenge the applicant’s expert,” the church said in its letter.

The same is true of the Zoning Board’s ruling that the project could lead to “fugitive parking on the undeveloped portions of the site, including wetlands or their buffers,” the church said.

“Such speculative reasoning is unlawful, to say nothing of unreasonable,” the letter said. “The Church satisfies the minimum parking requirement for its proposal, and the Board accepts this fact.”

Three Zoning Board members also expressed concerns about a concentration of traffic associated with the project, even though engineers hired by the church said traffic would be “off peak” on a state-maintained highway and wouldn’t cause safety problems, according to the church’s letter.

Throughout the letter, the church details concessions offered to neighbors and planners, and faults them for not offering conditions or alternatives that would allow for the project to move forward.

The proposed building’s footprint was reduced by 40 percent, and the church offered to increase the amount of landscaping used to shield abutters from the new building, the letter said. Christ Redeemer Church also proposed reducing the number of parking spots to 104, down from an initial 134 planned for the site, and were open to installing a security gate and hiring a traffic coordinator on Sundays.

“The Church bent over backwards to accommodate concerns,” its letter said. “Yet the Board majority did not give serious consideration to imposing reasonable conditions of approval to address its concerns.”

The church also argues that the Zoning Board and town are in violation of the Religious Land Use and Institutionalized Persons Act — a 2000 federal law that protects the rights of religious organizations seeking to build — by denying the special exception.

The only area in town where a church can be built without a special exception is the industrial zone, which is mostly owned by Dartmouth College, the Hanover school district and St. Denis Catholic Church.

And while there are a few small homes in the industrial zone that technically could be sold for a new church site, they’re not on big enough parcels to develop a new church capable of meeting zoning and planning requirements, the church argues.

Churches also are allowed in the downtown zone, where there are few properties on the market and even fewer suitable for a church, according to the letter.

Taken together, the zoning restrictions effectively mean a new church cannot be built in Hanover, which amounts to discrimination, the letter said.

That’s especially true in the residential areas where Christ Redeemer Church hopes to build, church officials said. While a new church would require a special exception, Hanover’s zoning ordinance allows for the construction of a 400-seat auditorium, school or government building in the same such zones without the Zoning Board review.

Robert Houseman, Hanover’s director of planning, zoning and codes, declined on Wednesday to comment on claims that the zoning ordinance violates federal law, saying it would be “inappropriate” to discuss the matter before the Zoning Board makes its decision.

Meanwhile, Chris Audino, the church’s executive pastor, said he’s optimistic the Zoning Board will reverse its decision. If the board approves the church plans, they’ll then go for another review before the Planning Board and New Hampshire Department of Environmental Services.

“We’re hopeful that this will provide a good result,” Audino said in a phone interview.

The Zoning Board will rehear the Christ Redeemer Church case at 7 p.m. on Thursday in Town Hall.

Tim Camerato can be reached at tcamerato@vnews.com or 603-727-3223.