Office build-outs in DC and Northern Virginia: a tenant's guide

Start with the work letter

The work letter in a lease sets out the landlord's obligations for tenant improvements. An SIOR Report primer advises deciding whether the build-out is turnkey or based on an allowance, notes that a larger allowance will likely mean higher rent, and suggests negotiating a voice in choosing the contractor and tying payments to milestones. It also points out that municipal approvals can affect the construction timeline.

The usual sequence

• Negotiate the lease: scope, allowance, who covers overruns, and how substantial completion lines up with rent start.
• Design: architect and engineers, code and accessibility review, and a cost estimate.
• Permits: plans reviewed and approved by the local building department.
• Construction and inspections.
• Certificate of occupancy, and allowance funding against approved invoices.

This outline follows the tenant improvement process published by Kenwood Management, a DC-area property manager.

Approvals in Washington, DC

Interior renovation of existing commercial space uses DOB's Alteration & Repair permit, with plans stamped by a DC-licensed design professional and filed through the Citizen Access Portal. DOB says you typically need a valid certificate of occupancy to use a building or space, including when a new tenant moves in, and that approval in its Certifi system typically takes about seven business days. Requirements vary by space and use, so confirm with DOB, (202) 671-3500, early in the lease process.

Approvals in Fairfax County

Fairfax County's commercial Addition/Alteration permit covers interior alterations and new tenant layouts, and a commercial certificate of occupancy is issued after all permits pass final inspection.

For small spaces, the county's Tenant Support Services pilot serves tenant spaces of 5,000 square feet or less in existing buildings of three stories or fewer with minor interior alterations. It offers a single county point of contact, early zoning and code review, and a target of 3 to 5 business days for expedited building review. The county advises contacting the program before signing a lease.

What build-outs cost

JLL's 2026 U.S. and Canada office fit-out cost guide, based on Q1 2026 pricing, gives national averages from $255 to $355 per square foot depending on layout and quality, and puts security, IT, and AV at about 10 to 12 percent of total cost. Its text gives no DC-specific figure. Colliers' Washington, DC occupier page lists total fit-out costs, including design and furniture, of $180 to $250 per square foot for Class A space, $140 to $200 for Class B, and $120 to $180 for Class C, without stating the year of the data. The two sources measure costs differently, so treat them as rough bounds.

Where Hawthorne Mason helps

We help tenants and owners define the scope, compare it with the allowance, introduce a vetted contractor, and keep everyone informed through move-in. The contractor performs and permits the work under its own contract with you. See our tenant improvements service, or start a project.