You are very lucky to live in an area which is well supplied with resources for local history, and there is no way I can compete! The first stage of your research must be to local the property on old maps, such as the one by Dury and Andrew, a detail of which is shown here.
Bushey has a very good local museum. I understand it holds maps and other documents relation to the area, although I have no personal knowledge of establishment, so you should refer to their web site (see Bushey) for more details. The museum also sells a wide selection of local books (by mail order - but I am sure you can purchase them in person at the museum). The Friends of the Museum have regular public talks which you might like to attend.
In addition the Local Studies section of Watford Central Library (contact details on the County Council web site) is extremely good and will have a wide selection of maps, trade directories, etc., and reference copies of most relevant local history books.
If the open land you mention is common land, the Watford Borough Council may have additional information.
If you can add to the information given above tell me.
Page created January 2005