Windward and Leeward forces - Semi Detached Timber Frame

[raligt]

When calculating horizontal wind loadings and designing the racking resistance of the timber frame, Would you design Plot 1 for both windward and leeward forces? or windward only?

The two properties will be connected through party wall straps effectively which provide some level of racking resistance transfer between structures (Cullen PWS = 1.7kN per strap).

Due to high wind load on site, some of the internal racking walls will require double OSB sheathing IF windward and leeward forces are considered in a single plot. We are trying to remove need for double OSB sheathing.

Extremely unlikely scenario that one property were ever to be demolished. I would design wind to side for both windward and leeward forces. But in the direction shown below i believe only windward would be considered.

 

[phamENG]

That's a local code issue. Here in the states, they typically have to be designed in isolation because, as remote as the possibility of one unit being torn down may be, it is still enough of a possibility that we have to design for it.

There was an example just a few months ago on here - end unit of a row of 4 or 5 townhomes burned down. Owner didn't want to deal with rebuilding so they just tied the firewall into the structure to make it an end wall and wrapped it in siding.