A couple more things to add.  One

you read my mind, Jeremy :))) I would add one day to fix small halls, remove trash -so it is 3-5 days.

I'll add one caveat to the warning of a cachette under the snow.  

BuilderOnline.com has a lead article today, "Editor's Pick: New Ultra-Slim Fireplaces"

Bottom line - as long as you add the venting, you can add this fireplace to just about any place, without it having been planned...

I guess I have to add one more item to my rehab repair checklist . . .Cost of shooting roofer $__________

I'm not sure how you'd be able to track who's using the hot tub and who's not, if that were an add-on?  

I come across properties that have conversions and or add ons to the property ie granny flat etc, my question is, how does mail work for properties like this?

Find land, process entitlements, joint venture with another builder, with the "value add" on the land, the value you generated above the land purchase prices as your equity for the co-invest.6.

Keep us updated - I'm curious what made you decide to add on - that can be a big endeavor - and always look forward to budget saving revelations!!  

With the add-ons you really can run your business with more accurate and up to date data.