Start at the stoop.
Keep looking up.
From the sidewalk, a townhouse offers a convincing picture of itself: the entrance, the windows, the cornice and the rhythm it shares with the houses on either side. A renovation has to understand what sits behind that picture.
The roof may have been replaced more than once. A stair may connect rooms with very different histories. The cellar may contain the equipment serving every floor. Each has something to tell the architect and builder before the new plan is settled.
A brownstone is named for its facing stone; a townhouse can be faced in other materials. The useful distinction for the work is the actual construction, condition and legal use of the building. Those need to be investigated at the address in question.
The joints tell a story.
Look at a masonry wall closely and the repairs become part of its history. Some joints may be flush, others deeply recessed. A patch may be a different color. A surface that looks newly tidy from across the street can deserve a closer examination.
The National Park Service explains why repointing mortar must be compatible with historic masonry. A harder, less permeable replacement can harm softer brick or stone. The joint’s strength and ability to transmit moisture matter alongside its appearance.2
For an owner, the next step is a condition assessment and a repair approach suited to the existing wall. Ask for a sample area before approving extensive work. Review the joint profile, color and tooling in daylight. A uniform new finish is not automatically the right objective for an old facade.
LPC’s Rowhouse Manual is a useful companion for reading the rest of the exterior: doors, windows, cornices, roofs and stoops. Use it to arrive at the first meeting with better questions, rather than a repair specification copied from another house.1
The roof has neighbors.
A rooftop terrace or new equipment can change more than the uppermost floor. The proposal needs a place in the structure, a route for access and maintenance, and a response to drainage and the surrounding buildings. A small item on the roof can also be visible from the street.
At a landmark or within a historic district, exterior changes and additions may require LPC review. Compliance with zoning does not by itself establish appropriateness under the Landmarks Law. The architect should test both, along with the other applicable requirements.3
Before designing the outdoor room, establish the roof’s condition and the work needed below it. Ask how the finished assembly will drain and how its waterproofing can be maintained. Furniture is easy to change later; the arrangement beneath the terrace is a more consequential decision.
Moving through the house
Walk the plan vertically.
A townhouse is experienced through repeated journeys. Carry groceries from the entrance to the kitchen. Follow the laundry to the bedrooms. Imagine answering the door from the top floor. A floor-by-floor plan can look elegant and still make those trips awkward.
The stair takes up valuable space, but it also gives the house continuity. Before moving it, explore the consequences for landings, room proportions, headroom and the structure. If a lift is part of the brief, its route and supporting requirements deserve an early place in the plan.
The same vertical thinking applies to heating, cooling and plumbing. Trace the proposed routes through the floors, rather than resolving each room separately. A chase introduced upstairs can affect a ceiling or piece of millwork below.
Ask the team for a section through the whole house. It can make the relationship between floor levels, stairs, ceilings and equipment much easier to discuss.
Below the stoop
Understand the cellar before expanding it.
The lowest level is often where an ambitious plan becomes most complicated. More headroom, a gym, storage or another room can each lead to a different discussion about structure, water and permitted use.
HPD distinguishes basements and cellars by how much of their height is above or below curb level, and the permitted uses differ. Do not assume a finished lower level can be used as a bedroom or rented apartment. Verify the proposed use and any applicable conversion pathway before assigning it a role in the design.4
Lowering a floor introduces questions about the existing foundations and neighboring structures. DOB’s excavation guidance stresses engineering and protective measures. Underpinning or other support work must be developed for the actual conditions; it is not an allowance that can safely be inferred from the size of the room.5
Start by asking what has caused any visible dampness and how the proposed work addresses it. A new finish can hide a symptom without resolving the source. Establish drainage, water management, service access and the allowed use together.
What the house shares.
Owning the whole building does not remove the neighbors from the project. The work may affect adjoining structures, access or the condition of shared boundaries. These relationships need investigation before the construction plan is fixed.
Have the team identify the surveys, protection and monitoring appropriate to the work, and any access arrangements that need to be resolved. Record existing conditions. An adjoining owner should be able to understand what is proposed, who is responsible and whom to contact.
The same attention belongs at the curb. Where will materials arrive? How will debris leave? What can be brought through the house, and what needs another route? Plan these movements around the work, rather than discovering them when a delivery arrives.
Read the records as carefully as the rooms.
Check the building’s legal use before assuming it is a single-family home or can become one. A Certificate of Occupancy records permitted use; some older buildings may instead require other evidence of lawful use. DOB explains the circumstances in which a Letter of No Objection can be relevant.6
Compare the records with the existing layout and the proposed changes. A prior owner’s use of a room is not, on its own, proof that the use is authorized. Ask the architect to identify discrepancies that need resolving.
Then consider what is worth keeping. A stair, door, mantel or run of molding may deserve careful repair even when surrounding systems are being replaced. Record those decisions in the scope so the demolition and restoration trades are working toward the same result.
The owner’s brief
What makes this house worth the work?
In The Current Market, Scott Hobbs discusses renovation spending in relation to the property and the surrounding market. He also asks what it is worth to enjoy coming home. His remarks concern the owner’s experience as well as the eventual sale; they are not a current valuation of a particular address.7
He gives a more personal example in Super Houses. A client was considering three prices for ornate metalwork, one roughly twice the others. Scott thought the premium was difficult to justify. The client kept asking about the more expensive option. He came to recognize that the additional artistry mattered more to the client than it did to him.8
The account is about another, unnamed project. It raises a useful question for a townhouse owner deciding what to preserve or commission: which details will matter enough to you to justify the work? Decide which changes are essential to living well in the house, which preserve something you value and which are optional. Discuss the overall commitment with the design and construction team, and seek current valuation advice separately if resale is part of the decision.
A clear brief might be very specific: retain the parlor’s proportions, make the kitchen work for everyday meals, bring daylight to the stair, keep equipment accessible. Those choices give the team something more useful than an instruction to make everything new.
Explore Ivy Row in the portfolio, or learn more about Hobbs’s New York City work.
Builders, since 1954.
More About Hobbs
Hobbs, Inc. has been building and renovating homes since 1954. The Journal draws on that work and on conversations with architects and craftspeople about the decisions behind a finished home.
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For a closer look
- NYC LPC: Rowhouse Manual
A building-by-building reference for historic rowhouse features, maintenance and alteration.
- National Park Service: Repointing historic masonry
Preservation Brief 2. Mortar compatibility, joint profiles and repair methods.
- NYC LPC: Permits and making alterations
Exterior work, designated interiors and review of additions.
- NYC HPD: Basements and cellars
The distinction between these spaces and restrictions on their use. Confirm current eligibility and requirements for the particular property.
- NYC DOB: Excavation
Engineering and safeguards for workers, the public and neighboring properties.
- NYC DOB: Certificate of Occupancy
Checking the legal use of a building and the treatment of older buildings without a CO.
- Hobbs Conversations: The Current Market
Boroughs and Burbs, episode 33, November 11, 2021.
- Hobbs Conversations: Super Houses
Boroughs and Burbs, episode 23. Scott Hobbs’s account of a client choosing ornate metalwork.
A few practical questions
Does a historic district restrict interior renovations?
Interior work is not automatically exempt. LPC lists review triggers including work requiring a DOB permit, work affecting the exterior and work within a designated interior landmark. Establish the applicable review path for the property.
Can a townhouse cellar become living space?
Do not assume so. Classification, lawful use, light, ventilation, egress and other requirements matter. Have the architect verify the proposed use and any applicable conversion program before designing around it.
Is replacing old masonry mortar always an improvement?
It is not always an improvement. The repair needs to suit the existing masonry. NPS guidance explains that incompatible mortar can damage historic brick or stone. A condition assessment and appropriate sample work should precede a broad repair.
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