It was more than three decades ago that neighbors complained about the glare and heat coming from the new 41-story Century Center near the entrance to Waikiki. Then in downtown Honolulu a few years later, the glass-curtain walls at the Grovesnor Center, now Pacific Guardian Center, drew heated criticism.

Today, the cityscape in Kakaako is being altered by luxury condominiums jutting into the sky, sheathed in glass exteriors — some in highly reflective mirrored glass. And as they did in the late 1970s, area residents are complaining about the glare bouncing off the high-rise towers.

The disco-ball effect of the 45-story Symphony Honolulu, at the mauka-Ewa corner of Ward Avenue and Kapiolani Boulevard, has been the most problematic for the Honolulu Community Development Authority, which regulates construction projects in Kakaako. After numerous hearings, HCDA finally allowed Symphony to keep its glass, but last week the issue began anew with another project, 801 South St. Building A, and a final decision in that case is expected in December.

HCDA rules prohibit "highly reflective, mirrored and opaque window glazing," but the term "highly reflective" is not defined and so was deemed vague and unenforceable. In the end, while Symphony was allowed to keep its glass as planned, the developer agreed to pay $1 million to mitgate sunwbeams bouncing off the building.

The authority has acknowledged that it will need to amend its glass rules on visual light transmission (VLT, or the amount of light allowed to pass through) and reflectivity so that Kakaako doesn’t turn into a jungle of shiny towers that heats up surrounding areas by concentrating and redirecting sun beams, affecting the sight of passersby and area residents.

There is no direct correlation between VLT and reflectance, glass consultants have found, and it’s possible to have highly reflective glass that meets the VLT rule, rendering the rule ineffective.

"Regarding visual light transmission and reflectivity, we are in the process of reviewing our rules to see if there are any elements that need to be changed or clarified," said Lindsey Doi, HCDA acting asset manager. "If we make any rule changes it would take at least a year — if not more — to fully vet and research … It’s a long, long, process of research and, of course public hearings, public input. All of that goes into rule amendments."

For some who live, work and play in areas surrounding the glass towers, revising the rules won’t address current problems. The existing glass towers that give off blinding reflections need some sort of mitigation, critics contend.

"Somebody has to say ‘check your windows,’" said Robert Fowler, a retiree whose tennis game at Ala Moana Beach Park is at times interrupted by the sharp glare off Waihonua at Kewalo, a condominium tower on Waimanu Street. "Every building we have now is glass. I’m not going to be the only one in the future who will be complaining about that."

Fowler said he and fellow tennis players first noticed the reflection off Waihonua in the mornings during the fall of 2014. "I wear very dark sunglasses and you toss that ball up and if you look at the reflection, everything goes blank for a while. We’ve never had that problem — ever," Fowler said.

The glare reappeared this year for the first time at 7:44 a.m. Tuesday and lasted about 15 minutes.

"It was pretty blinding and everyone complained about that," said Fowler, noting the reflection was near the top of the tower’s darker glass walls and will likelydescend each day through the end of November. On Thursday, he said, tennisgoers had to stop their play as the reflection worked its way from court 10 to court six.

"It’s like a huge spotlight. You can feel the heat. It’s horrible," Fowler said.

Traveling near the glass towers at certain hours of the day can literally stop motorists in their tracks. With more luxury condos planned in Kakaako, the HCDA will no doubt be grappling with the glass issue for years to come.

The glass rules were added in 2011 when the 2005 Kakaako Mauka set of rules were updated. The 2005 set of rules did not address visual light transmittance. And about 20 towers that are part of master plans by Howard Hughes Corp. and Kamehameha Schools would be exempt because they are grandfathered under the 2005 rules.

Already under construction, Howard Hughes’ Waiea project in the Ward Village features a wave-like glass wall on one side of the 36-story tower.

In Symphony’s case, the glass violates HCDA’s rules on visual light transmittance. The minimum is 50 percent for glass above the ground floor. Symphony developer OliverMcMillan acknowledged that its VRE 1-30 glass violates the rule at 28 percent VLT, but contended HCDA’s rule on energy efficiency conflicted with its VLT rule.

"The issue on Symphony was that of energy efficiency and we got reflectivity as a side effect," said Symphony’s glass consultant Jon Weir of California-based JA Weir Associates. The VRE 1-30 glass is one of the most energy efficient glasses in the world, Weir wrote in an email.

It is also one of the most reflective.

After reviewing 100 glass window products from three dominant manufacturers, an HCDA consultant found the range of reflectivity was between 4 percent to 45 percent. The higher the percentage, the more mirror-like the surface appears. The reflectivity of Symphony’s glass is about 45 percent.

Weir is confident that newer technology will eventually eliminate the mirrored tower effect.

"As new glass types continue to come out into the market, these new towers will benefit from higher efficiency without reflectivity and so should not cause issue with surrounding properties or persons," Weir said. "Overall, I don’t expect you will be seeing many high-rise mirrors in the future."

Still, that brings little solace for some residents of 909 Kapiolani — which sits catty corner to Symphony — who struggle with the glare. Since the mirrored walls began going up, Neil, 78, who asked that his last name be withheld and whose unit sits on the Ewa side of 909, said he is forced to move to a different part of his condo when the glare from Symphony shines like a spotlight into his unit on clear mornings and afternoons.

"When it’s a nice day in the morning and afternoon, that’s when we get the glare," Neil said, noting his condo has window shades that allow 50 percent of light to enter. "The glare comes right through," he said.

Weir said most municipalities limit reflectivity without providing limits. The City of Los Angeles has an unwritten 20 percent rule "though this is not set in stone by any means," Weir said in his email. "A few cities actually cite limits but these are rare cases."

San Francisco, Dallas and Chicago have building codes limiting visible light reflectance to a specific percentage, said Rob Struble, communications manager for PPG Industries, Inc.’s Flat Glass Strategic Business Unit. In an email, Struble said he is only aware of one country, Japan, that has a national standard limiting visible light reflectance.

"In general, most people will start to take note of visible reflectance at levels greater than 20 percent," Struble said.