The city recently hired an architect and a project manager to do the planning on a two-level parking deck at the Walnut Hill lot downtown. Through the Woburn Redevelopment Authority, the city awarded a $441,595 contract to Desman Associates of Boston to design the project and serve as construction administrator, and a $112,750 contract to Daedalus Projects of Boston to serve as project manager, according to Edmund Tarallo, the city’s planning director and the Redevelopment Authority administrator. The two decks will add about 300 spaces to the existing 248-space lot. The cost of the design, which is expected to be completed in July, and of the project manager are being funded by a $455,000 City Council appropriation and $103,000 donated by the Woburn Development Corp., which was established by the state to assist in the revitalization of downtown. Tarallo said officials are currently exploring financing sources for the deck’s estimated $7 million to $8 million construction cost.