The discussion surrounding the Palace of Westminster renovation, restoration and refurbishment could quite easily focus only on the projected costs. And why not? 

The figures banded about following the options appraisal report are truly eye-watering - £3.5 billion at a minimum and anything upwards of £5.6 billion in today's prices being more likely. That is before we consider what the 'whole life costs' will be, including added risks and contingencies, which take the projected cost well over £11bn.

The prospect of billions of pounds worth of Parliament repairs, which have been dodged for decades and are now finally coming home to roost, is understandably being met with a chorus of boos. 

With the current Government determined to continue its austerity agenda, regardless of the final cost, it will not be easily stomached by the public and rightly so.

But it is worth bearing in mind that the Deloitte report only considered a "like for like" restoration and did not look into changes to the way the Houses of Parliament are organised. 

Much of what goes on at Westminster perhaps seemed about right in 1915, but is utterly surreal and unworkable in 2015 – and not fit for a modern, working Parliament.

Do we really need to vote by queuing up in a division lobby to have our name scored off by hand? Couldn't we look at electronic voting within the Parliament estate? Is it right that we don't have enough seats in the Commons chamber for every MP? Does the House of Lords really fit into a modern, 21st Century democracy? 

We have to open this up for wider public consultation, discussion and scrutiny. Closing the debate within the pass holders entrances simply won't wash and will be a wasted opportunity to engage the public in shaping our political process. 

The Deloitte report talks about "UK-wide economic benefits" from the project, but it is difficult to see this as anything other than yet another hugely expensive capital project in London. 

We have an obligation to future generations to get all of this right. We need to protect the building, but we also need to decide how it is best used as a parliament.

The Scottish Parliament shows us what can be done. Although the Holyrood project infamously ran over budget we still have a building in Edinburgh which is far more functional, accessible and practical for £440 million.

The opportunity to create modern procedures and practices at Westminster is certainly worth spelling out to those who cling to a romantic idea that you can have a modern Parliamentary democracy within a Victorian museum. Simply restoring Westminster as a museum and squandering the opportunity for modernisation would be the worst of all outcomes.

Something has to give, and the public debate needs to be had.

Neil Gray is SNP MP for Airdrie & Shotts