One of the oft-cited reasons for demolishing pre-1930s homes is that the cost of renovation can vastly exceed the cost of simply demolishing the property and building something new. This tends to be a roundabout way of saying that the costs of bringing old structures up to modern building standards can be prohibitive, in part because the standards have changed dramatically since WWII.
All building work – be it renovation, new construction or DIY jobs – needs to meet the standards laid down in the Building Code. These standards have gradually improved through the decades, with improvements to everything from structural strength to earthquake safety to thermal performance. The result is that a newly-constructed home is likely to be stronger, last longer and perform better than one from the early part of this century – or to look at it another way, it is very unlikely that a building constructed in 1900 (or even 1960) would be able to be approved under modern building standards.
In some areas, even the method of construction in some pre-WWII homes would no longer meet the appropriate structural standards – the owners of 63 Brougham Street have a good example. However once renovations commence, the owner is obliged to bring this non-complying structure up to modern standards, and there is no doubt that doing so can add cost and complexity to the project.
Leaving aside the costs, sometimes the process of code compliance means a scale of changes that leave little of the original building intact. By the time piles have been replaced or repaired, rotting studs replaced, the structure of the building upgraded to modern standards, interior and exterior linings replaced and a complete re-roof, it can be a bit hard to know what’s original and what’s not. And in these circumstances, the line between renovation and rebuilding can indeed be a blurry one.
Renovations in progress – but major surgery leaves little of the original house
This would seem to be a good argument for allowing demolition – after all, owners contemplating large-scale work would almost always be able to point at possible additional costs as justification for simply knocking the old structure over.
However starting with a blank section isn’t always a path to lower costs. One of the key reasons builders are able to provide fixed-price quotes on new construction is that – in theory – there are no surprises to be factored into the project. Yet even a bare piece of land can hold some unexpected consequences; in one case, the excavations exposed a natural spring, which required significant changes to foundations and a substantial drainage project. Another owner discovered the site was largely composed of loose fill than required piles more than 6 metres deep, while some projects in the inner city have uncovered pre-European archeological features that needed to be investigated and preserved. There were additional costs and complexities in all of these cases.
Not every project suffers from these challenges, of course. But it’s safe to say that no building project is ever completely straightforward – even one that starts from the premise of demolition. All competent project managers allow some time and financial contingency which is intended to cover these sorts of uncertainties, and the best that can be said for new construction vs renovation is that the uncertainties are lower, rather than non-existent.
So there is an argument that demolition and rebuilding can be cheaper than renovation. The question is, is this in itself a sufficient justification? Should the Council allow demolition simply because it’s a bit cheaper? That’s a subject for another post – and your comments.