Finding maps of your town is one of the most helpful activities when researching the history of your house. Maps can help fill in the gaps when you run into trouble with your deed research. Many old maps contain the names of the resident or property owner on them. This could be just what you need to break through an obstacle in your research.
Ancestry has 4 maps (in multiple files) of Belmont in its Historic Land Ownership and Reference Atlases, 1507-2000 collection. Ancestry.com is a paid subscription site but you can access the maps for free by using the computers at the Belmont Public Library.
Belmont Assessor Plans, 1931
Belmont, 1875 from a Collection of Middlesex County Maps
Belmont, 1889 from a Collection of Middlesex County Maps
Belmont, 1900 from a Collection of Middlesex County Maps
Sanborn Fire Insurance Maps
The Sanborn Fire Insurance Maps were created by insurance companies to be able to calculate fire risk. They never intended for them to be used by historical researchers. But the Sanborn maps are some of the most helpful in learning about houses over a period of time. These maps are available both in print form and in a database. The Waltham Public Library is the closest library in the Minuteman Library Network that still maintains this database.
The years available for the Sanborn Fire Insurance Maps for Belmont are 1905, 1910, 1915, 1922, 1931, 1931-1949 (incomplete).
You can even find maps embedded in history slide presentations, like this one about Belmont by Jane Sherwin (2009). The map on slide two shows a Belmont Soil Map from the US Deptartment of Agriculture. I'm sure you could find the map in another location but the audio interpretation presented here is very helpful in understanding Belmont.
The Town of Belmont has an online Zoning Map from 1944 that displays the usage of town land.
Unfortunately I didn't find any maps of Belmont in the Panoramic Maps Collection on the Library of Congress site, nor in the BPL online Map Collection, The Massachusetts Historical Society Map Collection or the Old Maps of New England website.
Belmont maps are also in numerous historical books about the town. You can find a complete list of Belmont books on the Belmont Library website.
Photo Caption: Detail of 1875 Belmont Map, Ancestry.com, Historic Land Ownership and Reference Atlases, 1507-2000 Collection.