Sayyed Mohammad Al-Musawi,
Sayyed Mohammad al-Musawi is originally from Iraq and heads up the World Ahlul Bayt Islamic League in London. Other than being involved in various humanitarian projects, he frequently responds to religious questions. In the past, he has also spent significant time in India guiding the community.
Yes, there are many authentic Hadeeths from the Prophet (SAWA) and Ahlul Bayt (AS) encouraging building their shrines. In Kitab Al-Tahtheeb ( V.6, P. 22 ) which is one of our most authentic books of Hadeeth, narrated by 'Omara Ibn Zaid, from Abi 'Aamir the preacher of Hijaz who sai: I went to Abi Abdillah Jafar Ibn Mohammad ( Al-Sadiq) (AS) and asked him about the reward of visiting and building the shrine of Ameerul Mo'mineen (AS). Imam Jafar Al-Sadiq ( AS) narrated from his father, from his grand fathers, from Imam Ali, from the Prophet (SAWA) great reward for those believers build the shrines of Ahlul Bayt (AS) and visit them. They will get special intercetion Shafa'ah of the Prophet and Ahlul Bayt and will be with the Prophet in the Paradise. Those who help in building the shrines of Ahlul Bayt (AS) will get the reward of helping the Prophet Sulaiman in building Baitul Maqdis holy Masjid.
There is another Hadeeth in this meaning in Al-Tahtheeb, V. 6, P. 107.