Duplex vs. Townhouse
As a general rule, a duplex would be considered superior simply because it is one ‘step’ closer to a fully detached house. Also, generally with a half duplex, each owner’s share in the land (the lot) is larger than an owner’s share in the land with a townhouse. Usually, with a townhouse there are three or more units in the complex so each owner’s share in the land is usually smaller.
That being said, there are so many factors at play that there isn’t a black-and-white answer to this question. Location, square footage, number of bedrooms, age, number of bathrooms, interior finishings and design, lot size, etc. are all far more important than simply the property type. This is particularly the case in Vancouver, where attached properties (condos, townhouses, half-duplexes) are so common that the specific location becomes so important to market value.
Instead of worrying about the townhouse versus duplex debate, I recommend focusing on location, size, age/renovation year, and the number of bedrooms. Those are more important criteria and the ones I would be prioritizing.
The above answer, though, does change a little as we move out of Vancouver and further into the suburbs. Generally, in the suburbs, detached houses are more sought-after and attached properties are less desirable. As such, I would recommend in those cases aiming still to emphasize the above criteria — but also aiming to get something that’s as big and as close to a detached house as possible.
It’s also important to note the following piece of advice I always follow and give to my buyers: always try to buy something that has at least one major feature that is special. For example, let’s say you were looking for a 1/2 duplex in the suburbs. But, you came across a townhouse that was an end unit with a special architectural feature that was quite rare for a townhouse and it also happened to have an unusually large yard space. My advice here might be to seize this unique opportunity. In this case, the townhouse might be so special that it would always be unique and stand apart — making re-sale easier due to these exclusive features.