The firm has secured the contract for the Harrow Small Sites Capacity Study and Design Code with the London Borough of Harrow.
According to a government tender document, the value of the contract is £185,000.
The document says that the small sites capacity study is intended to "determine what sites could be available to facilitate a small site development in line with the criteria within the draft new London Plan".
"This will assist the council in having an understanding of the potential numbers and capacity of small site type developments that could come forward to assist in meeting the housing targets," the document adds.
The small sites design code "would be to build on the capacity study and develop design codes based on small site development typologies".
Troy Planning + Design said it would carry out the work in partnership with architects Hawkins\Brown.