In 2 Sam 7, David seeks to make a house for the Lord, but God declares that He will establish a house for Israel, a promise fulfilled in Christ.
Isaiah 7-12 concerns a prophecy to King Ahaz. A virgin or young woman will bear a son, and call him Immanuel, or God with us. This may have been a double prophecy, with multiple meanings, but it is clear that by the time of the translation of the Septuagint, the woman was considered to be a virgin. This is a promised heir to the throne of David.