Aberdeen has just about got over Sir Ian Wood's proposal to turn the city's Victorian Union Terrace Gardens into, depending on your point of view, an Italianate piazza or a giant skateboard park.

As local opinion was evenly split, half the population is content with the status quo. However, there is near unanimity against the council's proposals to interfere with other well-loved buildings and open spaces.

Over the next few months, irrevocable decisions will be taken that will affect the future of three of the city's finest buildings, all of which are of local, national and indeed international significance.

The eminent father and son combination of AM and AGR Mackenzie designed Aberdeen's classical art gallery over a 40-year period. Its fine exterior and granite and marble central court and stairway are particularly admired. All are under threat from the council's plans for "modernisation" described by Private Eye as "insensitive to the point of barbarism". The council's proposal is topped by a copper portable-cabin type construction on the roof.

The insensitivity is compounded by the intention in this year of all years to interfere with the dignity of the approach to the Memorial Hall, part of the city's war memorial.

Not too far away, demolition of the council's former headquarters has provided a once-in-a-century civic and architectural windfall. The category A-listed buildings of Provost Skene's House and Marischal College have become fully visible for the first time in most Aberdonians' lifetimes. Skene's 16th-century house has, for generations, lain amongst tenement housing and latterly obscured by the now demolished council buildings.

Across the road, Marischal College, now the council headquarters, is the world's second largest granite building. Its sparkling gothic frontage is of international significance. The clearing of the area around the two buildings provides a never-to-be-repeated opportunity for literal and metaphorical vision.

Instead the council has entered into agreement with developers for yet more glass-fronted office and retail space. The city needs those as much as its sclerotic streets need more 4x4s. Aberdeen's Civic Society euphemistically describes the scale of the proposed buildings as overpowering. The volume of opposition to the council's proposals has resulted in a public hearing on Thursday. Astonishingly, the convener of the council's finance and resources committee is on record as saying the agreement with the developer is a "done deal" and the outcome is "already determined".

Being Aberdonians, those planning to attend the hearing may well question whether it is worth the bus fare. More seriously, they may also question local democracy.

Over the past four centuries the vision and energy of our ancestors created an architectural and cultural heritage including Provost Skene's House, Marischal College and the art gallery. We know that money talks. However, done deal or not, the council has an opportunity to bequeath something enduring. Our descendents won't thank us for a heritage of pound shops and fast-food outlets.