[2] He and his wife Marion Symesoune enlarged and embellished the house, the completion of the work being commemorated by the magnificent door on the south side of the house which incorporates the date 1611 and the motto (in Scots) "Excep the Lord Buld Inwane Bulds Man" and the Marjoribanks and Symesoune arms.

In 1746 it was owned by a surgeon named A. Nesbit, and later by James Syme, a slater, whose son, a Royal Navy Captain, later sold it in 1896 to James McNeill a mining engineer from Wishaw who had acquired the estate to work the coal.

An early 17th century chimneypiece was added in 1954 having been rescued from the demolition of the nearby Woolmet House due to mine workings.

The National Trust for Scotland did at one time consider making the house into a museum of painted ceilings - the house has several fine ceilings (beam and board painted in floral patterns and arabesques in egg tempera) in good condition, but this plan never came to fruition.

[5] In the former grounds of Northfield House stands a 16th-century beehive doocot (Scots for "dovecot"), also a Category A listed building.