Improvement cost has to be added to the cost basis of the property, and deduct from the final sales proceed to calculate capital gain. (SFH imporvement can only be deducted from SFH sale)
Repair/expense can be deducted from current year capital gain (your condo).
Jenning suggest the trick to categorize SFH repair/improvement as repair/expenses, not improvement aka aquisition cost for SFH. You can talk to her for details.
2. every two years a person can claim 250K primary residence exlusion.
Just google it. "primary residence exclusion every two years"
3. maybe clarification on the condo sale might help you resolve your concern about SFH.
26 U.S. Code § 7201 - Attempt to evade or defeat tax
Any person who willfully attempts in any manner to evade or defeat any tax imposed by this title or the payment thereof shall, in addition to other penalties provided by law, be guilty of a felony and, upon conviction thereof, shall be fined not more than $100,000 ($500,000 in the case of a corporation), or imprisoned not more than 5 years, or both, together with the costs of prosecution.
这事比较搅合，我想了几天，也只想清楚了该如何问这问题，若能听到有建设性的建议就更好了。
我的朋友决定了买我的一个度假屋，他打算买下后自住，按他的话说，打算一直住到死。所以，他可以做所有对我卖房有利的配合。
这个度假condo我不会再用已打算卖（必卖），因为在卖另一个SFH，我原本打算把condo推迟到明年1月过户就可以了。那SFH地段其实挺好，就是房子太破旧要花精力和5万+做维修，修好后继续出租，地区有潜力值得保留。不合算的是，花5万+维修，租金只能提高500/月，又是远程。
问题一
若选今年卖condo留SFH，假如condo增值15万，修房子花5万，是否可以抵消5万增值? SFH的维修是否必须在今年完成或付费？维修包罗万象（等同买破房啥都得换，房顶窗户电线水池室内升级等等），若要最大化抵免，是否应该把这些活只包给一两个公司做对报税最好？
问题二
condo已作为投资房十年，我朋友说可以按我当初的买价买我的房，这么做可以免我多少税？我希望对双方都公平，已告诉他会按同样房子的卖价给他5%的折扣当省了我的agent费。他的25万自住免费额已用完，若不住到死卖房还得交税，若我们在增值的中间选一个成交价，我该给多少补偿合适？这样做是否值得？
问题三
是否该尽可能卖掉这个SFH还是选择修更好？这里还牵涉一个问题，我打算再卖一个远程房，直觉是明年卖比后年卖更好，可我又不想一年里同时卖两个（除非能做成1031，对此我没多大信心，目前是按卖房交税在考虑）。
感谢回答和建议！我不大肯定是否我把问题想得过多了，若你觉得是，也不妨提醒提醒我。
问题一
若选今年卖condo留SFH，假如condo增值15万，修房子花5万，是否可以抵消5万增值? SFH的维修是否必须在今年完成或付费？维修包罗万象（等同买破房啥都得换，房顶窗户电线水池室内升级等等），若要最大化抵免，是否应该把这些活只包给一两个公司做对报税最好？
SFH修房子不能抵消condo 增值。
问题二
condo已作为投资房十年，我朋友说可以按我当初的买价买我的房，这么做可以免我多少税？我希望对双方都公平，已告诉他会按同样房子的卖价给他5%的折扣当省了我的agent费。他的25万自住免费额已用完，若不住到死卖房还得交税，若我们在增值的中间选一个成交价，我该给多少补偿合适？这样做是否值得？
他的25万自住免费额已用完什么意思？25万每两年就可以重新用一次，又不是一辈子只有25万。建议你不要作假逃税。
问题三
是否该尽可能卖掉这个SFH还是选择修更好？这里还牵涉一个问题，我打算再卖一个远程房，直觉是明年卖比后年卖更好，可我又不想一年里同时卖两个（除非能做成1031，对此我没多大信心，目前是按卖房交税在考虑）。
似乎condo买主也可以配合你1031，为什么不做？
所以，那5万如果是repair，就能抵消，如果是improvement, 就不能抵消。可以用3 repair safe harbour 减掉费用小于2000的 repair。让维修公司好好准备invoice, 每个item小于2000的给safe harbour掉。
额呢，不过，我还是有些不肯定你是正确的，若每次都可以，岂不是人们可以一直买了卖？我朋友已经卖过的自住房，有了总共25万的抵税额。我不是想逃税，只想合理避税，而我的税务知识非常有限，想学习。
3，对1031没信心是指我认为不值得做，房价太高，做不到我想要的现金流。我也不认为可以无限制地让condo交易悬着，毕竟谁买房都是大事。若修房不能抵消condo的增值，我倒真不必去修SFH了。
谢谢柠檬。
1. Both I and Jenning were correct.
Improvement cost has to be added to the cost basis of the property, and deduct from the final sales proceed to calculate capital gain. (SFH imporvement can only be deducted from SFH sale)
Repair/expense can be deducted from current year capital gain (your condo).
Jenning suggest the trick to categorize SFH repair/improvement as repair/expenses, not improvement aka aquisition cost for SFH. You can talk to her for details.
2. every two years a person can claim 250K primary residence exlusion.
Just google it. "primary residence exclusion every two years"
3. maybe clarification on the condo sale might help you resolve your concern about SFH.
26 U.S. Code § 7201 - Attempt to evade or defeat tax
Any person who willfully attempts in any manner to evade or defeat any tax imposed by this title or the payment thereof shall, in addition to other penalties provided by law, be guilty of a felony and, upon conviction thereof, shall be fined not more than $100,000 ($500,000 in the case of a corporation), or imprisoned not more than 5 years, or both, together with the costs of prosecution.
记住safe harbour 是论item， 换十个窗户就是十个item。
说实话，99%都查不出来，但是做生意目的是减少危险，为什么要去给自己埋地雷呢？