Auckland could be a great city but it needs some work. It has an extraordinary geography, and a unique and diverse cultural mix, but its built environment suffers from a distinct lack of care. A great city needs self-respect, love of its communities and its heritage.

Heritage is not only about preserving our past, it is a vital part of who we are now. It's our character, it's what makes us interesting. Amidst the talk of preservation of historic architecture, our tradition of striking industrial buildings is often overlooked. These structures are often epic in scale and have a raw and unadorned beauty. They are part of who we are as much as the most ornate public edifice and may even have a greater resonance with our national psyche.

Some of the most exciting urban regeneration projects around the world have been based around industrial heritage structures. The recently completed High Line in New York transformed a disused railway viaduct into a vibrant urban park which weaves its way through the city, reconnecting dislocated neighbourhoods.

In London, a derelict power station was transformed into the Tate Modern Art Gallery, one of the most extraordinary public spaces in the world, and a catalyst for the rejuvenation of the surrounding area. Closer to home in Sydney, the old Railway Carriageworks have been converted into a highly successful centre for contemporary dance around which has sprung up art galleries and outdoor markets.

Adaptive reuse of heritage buildings is not boring or old fashioned, it is where some of the most innovative architectural work is happening and is at the core of urban regeneration. It is not only about restoration but imaginative transformations which breathe new life into old structures and have a ripple effect on the surrounding areas. Such developments create a centre of gravity, they have personality and charm and are loved by people in a way that new developments seldom are. They are sustainable in their very nature because to reuse what you already have saves resources and energy.

Here's a story whose ending is as yet unwritten. It is an Auckland story but it has universal relevance. It is a case study that goes right to the heart of what is wrong with this city and what we need to do to start fixing it. There is a heritage building involved but it may be one you have never heard of. It is about mending our fragmented city and the power of good ideas.

The Waipapa Valley is located between Parnell Rd and Auckland Domain and through its centre runs the railway line that connects Britomart to Newmarket and South and West Auckland beyond. In the valley sits a large flat area of land and at its centre is an epic industrial structure, 100 metres long and 12 metres high. It was the former Railways Workshop. The central interior space is magnificent with an elegant steel structure and sunlight streaming through clerestory windows. It is like a cathedral to industry, it makes the heart race and is one of the last such structures remaining in Auckland.

The building has been home to Mainline Steam, a privately funded organisation dedicated to the task of restoring old steam engines and giving train rides to the public.

A couple of years ago we (Stevens Lawson Architects) started working with Parnell Inc and the Parnell Community Committee to promote the establishment of a Parnell railway station in the Waipapa Valley, two minutes walk from Parnell Rd. It would service the Parnell business and residential districts and be a vibrant place where transportation, commerce, culture, community and recreation would come together.

We created a master plan for a destination station and innovative development centred on the old Railways Workshop building. In this proposal the historic Newmarket station, presently in storage, would be relocated as the new Parnell station. The iconic Railways Workshop building would be refurbished to house restored steam engines and spaces for community use, exhibitions and events. Two new public squares would be created and the original Waipapa Stream would be day-lighted and landscaped.

A ribbon of medium density mixed-use development around the perimeter of the site would ensure the place was alive both day and night. We envisioned a mixture of cafes, restaurants, galleries, offices, apartments and hotel accommodation, activated by the fourth busiest station in Auckland. This was not just a transport solution but also an integrated urban design solution, an urban regeneration project with heritage as the driver.

We also saw this as an opportunity to strengthen the historic connection from Parnell to the Domain with a grand gateway under the raised railway line. The Parnell Station would also cater to the crowds at the Stanley St Tennis Centre, large-scale events in the Domain, and for students.

We received enthusiastic support from key players, our local MP Rodney Hide, ARC chairman Mike Lee, Auckland City Councillors Aaron Bhatnagar and Ken Baguley and positive feedback from KiwiRail. The project seemed to be gaining traction, everyone thought it was a great idea and then three months ago KiwiRail, the owner of the land, dropped a bombshell.

It revealed to the local community that it was negotiating with Infratil to turn the entire area into a bus park to store 60 buses, with in excess of 120 bus movements a day, with buses travelling through the narrow historic back streets of Parnell from 5.30am until late at night.

The site would be ringed by security fences and floodlit at night for the foreseeable future.

KiwiRail is under pressure to maximise income from its asset but claim no obligation to the local community, even though the land was annexed from the Domain many years earlier specifically for railways purposes. In reality, our proposal creates potentially greater return in the medium term, a win-win solution.

Surely the publicly-owned KiwiRail should be developing strategies to increase rail patronage from commuters and visitors and adding value to this experience. Infratil presently has its bus park in a commercial area in the Wynyard Quarter where it intends a large-scale property development so is looking for cheap land around the city fringe. It has several other more appropriate options but the Parnell site is preferred and it has the support of Auckland City Council planners.

The Parnell community has reacted strongly against the Infratil/KiwiRail proposal and the local community board has condemned its incompatibility for this precious site and the arrogance of its proponents. We now have a new Auckland Council and it has a decision to make.

This case will be the first test of its vision for our city.

It seems extraordinary that the Parnell community's master plan can be derailed by the myopic vision of another publicly owned organisation.

We need leaders who can see the big picture and not be diverted into the mire of mediocrity. Great cities need great ideas and great ideas need champions, people with passion and perseverance who can turn vision into reality.