"We're not architects, we're not builders, but we review plans but we can do that from anywhere. We review them in terms of adaptability, accessibility and usability," Mr Penrose said.
He said one way to address the issue was to make sure a certain number of new houses were built to allow people to age "more easily and to live more comfortably in those houses".
Mr Penrose said some structural issues which would have an impact on older people were the entrance to building, the width of the door, the level of the light switches, the space in the bathroom and the placement of the toilet.
"If you have to go up some steps there are going to be some trip hazards...
Then in terms of getting in the dwelling... a slightly wider door is easier for someone coming in with a mobility device.
"The bathroom [needs] sufficient space incorporated into it so you can easily move around and for instance if the toilet is located next to the wall then it's easy to install, at a later stage, grab rails.
"It's about being adaptable. It's ready to be used when you need to use it," he said.
He said the lack of age-friendly homes was due to residents not knowing what to ask for when building, and designers and builders "who are just doing what they've always done".
Tauranga and Western Bay of Plenty Grey Power president Jennifer Custins said she had worked hard in the past with the Tauranga City Council to encourage more age-friendly homes.
She said Tauranga was actively an age-friendly city, but it was "disappointing" to hear only a small number of houses had passed the Lifemark criteria.
"Even 15 years ago I wouldn't have thought, 'why am I putting a cupboard up there, I won't be able to reach it'.
"I've noticed I don't have a handrail outside, it can often be those little things."
She thought the Lifemark criteria needed to be more widely available for new home builders and for those redesigning.
New Zealand Seniors Party chairperson Paul Rea said houses should be built to be safe for "young and old and the building industry should take this fact on board and start building housing that meet these standards".
"We have to think smarter to provide for future generations, not just keep building the same style of housing as we have done for years.
"Everyone grows old at some time and building age-friendly housing is the way to provide for future generations."
He thought there should be legislation in the building code to ensure every house met a basic age-friendly standard.
"If this was the case then serious injuries like falls would most certainly be reduced and this in turn would save on doctors and hospital bills."
Age-friendly homes
Lockwood homes general/project manager Soren Antonsen has helped to create age-friendly buildings in Denmark, his homeland and said the changes needed to make homes age-friendly were simple.
"What we've done here in New Zealand is we've got the local franchise, and they are an accredited member of Lifemark, we have built two houses last year that we thought we'd better test them... They received five stars, the highest rating."
He said 80 per cent of the houses they built were for retirees, who were "very much" part of the design process.
"I don't think they come in here because we're an accredited member of Lifemark, it's definitely not a downside, everyone is different."
Mr Antonsen said some customers would come in asking for a house suited for when they aged.
He said making changes to houses to make them age-friendly was not difficult.
"You've got to make sure you've got a level entry in and out of the home from the outside, you've got to have wider doors everywhere in the house... and then it comes to shower access and turning circles in the en suite and bathrooms."
Want to read Lifemark's age-friendly criteria? Go to: http://www.lifemark.co.nz/useful-tips