Windows on the rising Symphony Honolulu condominium building look like several other towers that exist or are under construction in Kakaako. But there’s a problem with the Symphony’s glass.

According to the state agency regulating development in the area, views through Symphony units — including gazes into resident living spaces from outside — aren’t transparent enough.

This see-through issue, so far, uniquely applies to Symphony. And it has created a discord between the tower’s developer and the state regulator, the Hawaii Community Development Authority.

The problem has to do with an HCDA rule about tower glass that was revised in 2011 and to date applies to no other glass-sided towers except for Symphony.

Symphony’s developer, OliverMcMillan, argues that HCDA’s "glass rule" is flawed, and that it is impossible to comply with the rule without violating another rule mandating a certain level of energy efficiency.

Then there’s also the matter of having a rather clear look into the homes of high-rise denizens.

"This is particularly discouraging for future residents looking to live in Kakaako as any planned buildings will be located in an area already occupied by other high-rise buildings," said an April letter to HCDA from local law firm McCorriston Miller Mukai MacKinnon LLP, representing San Diego-based Oliver McMillan. 

"The ability of neighbors in adjacent buildings to look into a unit during daylight hours will adversely and negatively affect the unit owner’s privacy within their unit and thus the unit’s desirability."

HCDA notified Oliver McMillan earlier this year that the glass it is putting up on the tower violates the rule.

The glass window walls began going up last year and are installed up to about the 20th floor of the 43-story tower on the mauka-Ewa corner of Kapiolani Boulevard and Ward Avenue.

OliverMcMillan asked HCDA to administratively review the rule and suspend it until the agency can change its rules to an achievable and more reasonable standard.

However, the agency decided at a Wednesday board meeting that it can’t suspend or waive the rule, and that the developer will have to file a written petition to amend its development permit and obtain an exemption through a process that involves public hearings.

The agency also noted in a staff report that it has engaged a consultant to analyze the issue.

OliverMcMillan said it won’t stop putting up the glass as it works toward finishing the tower by the end of this year, and that it intends to file the petition to resolve the problem.

The rule says that glass on a tower above the ground floor must have visible light transmission, or VLT, of at least 50 percent.

The glass being installed by OliverMcMillan has a VLT of 28 percent. That compares with 27 percent for two other towers rising in Kakaako called Waiea and Anaha. VLTs for existing towers in Kakaako include 37 percent for Pacifica Hono lulu and Moana Pacific, 32 percent for Hawaiki, 22 percent for Keola Lai and 9 percent for Koolani, according to OliverMcMillan.

Outside Kakaako, tower VLTs include 8 percent at Century Center, 23 percent at ONE Ala Moana, 33 percent at Allure Waikiki and 40 percent at Watermark Waikiki.

Older existing towers in Kakaako were built under a prior version of HCDA rules that didn’t specify VLT. Other towers — including Waiea and Anaha, which started construction after Symphony, as well a couple dozen more slated to rise in the coming years on land owned by Kamehameha Schools and Howard Hughes Corp. — are grandfathered under the older rule.

It’s possible that other developers will encounter the same problem as Symphony if HCDA doesn’t 

adjust its rules, the McCorriston Miller letter said.

"This rule will certainly become a districtwide problem if left as is," the letter said.

One of Symphony’s design firms, Architects Hawaii Ltd., said in a letter included in the request by Oliver McMillan that leading window glazing manufacturers and experts recommend a VLT between 20 percent and 40 percent to balance light quality, interior comfort and energy conservation.

A VLT over 40 percent, the firm said, produces an undesirable heat gain, glare and shadows cast by home furnishings — motivating occupants to keep window shades drawn during the day. Running more air conditioning also is likely. 

Furthermore, Oliver McMillan said there is no commercially available tower glass that has at least a 50 percent VLT and can meet a separate HCDA rule to achieve a minimum Leadership in Energy and Environmental Design energy efficiency standard.

"The glass rule makes it impossible for a project with a window wall design, such as the Symphony Honolulu project, to meet both the glass rule and the required LEED minimums," the McCor riston Miller letter said.

Dan Nishikawa, senior managing director for Oliver McMillan, said he expects his firm and HCDA will reconcile the issue amicably.

"We’ll get it resolved," he said.