See how it's much easier to identify the trends?
This graph is calculated by comparing Wellington house prices with New Zealand house prices.
When the line is going up, Wellington house prices are increasing faster than the rest of New Zealand.
When the line is going down, Wellington house prices are increasing more slowly (or declining more quickly) compared to the rest of the country.
While not a perfect replacement for the 'investment cycle' model. Taken together, they give a good indication of whether it's an opportune time to invest in a specific region.
Right now, the Wellington region appears to be 7.6% overvalued. From the graph, you can see the region is passed its peak. So, there are probably buying opportunities elsewhere in New Zealand.