Complete Capitol Hill Transformation

What Made This Project Hard

• The defining challenge of this project was structural: joining two separate, party-wall rowhouse units into one functioning home. Opening a passage between 431 and 433 New Jersey Avenue meant removing a chimney that ran through the roof, adding significant new steel framing, and installing three sets of double doors at the
• connection point between the units — work that turned out to be considerably more complex than the original drawings anticipated. Once engineers reviewed the conditions in more detail, additional structural reinforcement was needed, including tie-backs at the rear of the house and at a jogged section of the foundation, plus an underpinning evaluation to make sure the existing footings could support the combined structure.
• Beyond the structural work, the scope kept growing as walls came open. The team ended up replacing all of the water and waste lines above the basement slab, substantially expanding the electrical work throughout the house, and adding a full roof replacement with upgraded insulation. Because two previously separate homes were becoming one, sound transmission between the units was also a real concern, and the team brought in an acoustical consultant to test and recommend sound isolation measures. In the basement, the scope covered a full kitchen removal, new exterior doors and windows, a frameless shower enclosure, and new cabinetry throughout.

How We Solved It

Landis approached the project through its standard design-build sequence: a master planning and feasibility phase, followed by schematic design, design development, and construction documents, before moving into a fixed-price construction contract. Because the project involved combining two attached dwellings, the design team relied heavily on structural engineering to work through the connection between the units, the chimney removal, and the underpinning question before finalizing construction drawings. As those structural findings came in, Landis worked with the client to value-engineer the scope — adjusting items like insulation, window packages, and finish allowances — to keep the growing project as close to their goals and budget as possible. During construction, the crew sequenced the basement kitchen removal and the breakthrough between the units carefully, since that work affected both structural stability and the phasing of the rest of the renovation. Acoustic testing between the two units informed the wall and floor assemblies used to control sound transmission in the final combined home.

Budget

Only project with a detailed budget. 

• The design agreement for this project was $48,500, signed in December 2020, following an initial feasibility study. At that stage, Landis estimated a preliminary construction budget of $520,000 to $550,000, plus roughly $23,000 for recommended underpinning. As design development proceeded and the full scope of connecting the two rowhouses became clear — including the structural work, whole-house systems replacement, and roof — the signed fixed-price construction contract came in at $978,420 in April 2021. Change orders during construction added $168,776.84, or about 17% growth over the base contract, bringing the total project investment to $1,147,196.84. Construction took place over roughly a year, from April 2022 to May 2023.

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