Door Anatomy | Guide to Parts, Terms and Functions

The anatomy of a door, exterior.

When it comes to historic preservation, the elegance of a door lies not only in its design but also in its anatomy. From grand entryways in landmark buildings to charming brownstone doors in New York City, understanding the parts of a door can help you make more informed decisions. Here’s a breakdown of the essential components that make up a traditional door system.

The Basics

Doorway
The doorway is the opening itself, the passage you walk through to enter a home or room.

Door Frame
Supporting the door panel, the frame includes three key parts: the head (top), jambs (sides), and sill (bottom). Frames are typically constructed from wood, steel, or aluminum, depending on the style and era of the building.

Door Panel
This is the main part of the door that swings open and shut. It can feature solid wood, glass panes, or decorative detailing, depending on the architectural style.

Structural & Functional Elements

Head (or Door Head)
The horizontal top part of the frame.

Jamb
The vertical sides of the frame where the hinges, latch, and strike plate are mounted.

Sill
Located at the bottom of the frame, it sits flush with the floor.

Threshold
Often a sloped piece installed over the sill, the threshold helps keep water and drafts from entering the home.

Weatherstripping & Door Sweep
These components are critical for sealing gaps and improving energy efficiency. Weatherstripping lines the perimeter of the door panel, while the door sweep covers the gap at the bottom.

In-Swing vs. Out-Swing
Depending on your building’s layout or historical context, doors may swing inward or outward. This is typically determined by the positioning of hinges and how the space is used.

Design & Decorative Components

Rails & Stiles
Rails are horizontal segments on the door panel, while stiles run vertically. These structural elements often define the style of the door and house the hardware.

Mullions
A mullion (or “mull”) is the vertical or horizontal element that separates and joins multiple door panels or connects sidelights or transoms to the main door.

Casing & Brickmould
These trim elements add architectural interest and help hide the transition between the door frame and wall—casing on the interior and brickmould on the exterior.

Grilles
Grilles are decorative dividers that mimic the appearance of individual glass panes. They can be surface-applied or installed between panes of insulated glass.

Dentil Shelf
A signature feature of craftsman-style doors, this is a small ledge typically placed below a window pane for decorative effect.

Glazing (Glass)
Historic doors often feature beautiful glasswork. Today, glazing is usually insulated and may include decorative patterns, beveled edges, or leaded details.

Sidelights & Transoms
Sidelights are narrow, vertical windows flanking the door, while transoms sit above it. Both let in natural light and add visual grandeur to an entryway.

Hardware & Security Features

Hinges
These allow the door panel to pivot open and closed. Styles range from exposed barrel hinges to concealed or pivot hinges in modern or minimalist applications.

Knob or Handle
The main mechanism for opening a door. Knobs are round, while handles can vary in design—lever or pull-style depending on preference and accessibility.

Lockset
This includes all elements related to door locking: the handle, latch, strike plate, and interior locking mechanisms.

Deadbolt
An added layer of security, the deadbolt slides a solid metal bolt into the frame and is usually operated by a key or thumb turn.

Latch
The latch retracts when the handle is turned, allowing the door to open. It extends automatically when the door is closed.

Mortise Plate & Strike Plate
These metal reinforcements are located in the jamb and receive the latch or deadbolt. They enhance security and durability by preventing forced entry.

Astragal
If you have double doors, the astragal is the vertical strip that seals the gap between both panels and helps keep the doors secure and aligned.

Planning a full exterior restoration? Don’t miss these window guides.

Understanding window parts is key to choosing, restoring, and preserving historic windows. Learn more in our Window Anatomy Guide, and explore glass types and glazing details in Glass: What a Pane.

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Restoring No. 17 St. Luke's Place | A Historic Greenwich Village Gem

Located in the heart of Manhattan's Greenwich Village, St. Luke’s Place stands as a testament to New York City’s rich architectural and cultural history. This charming block, made up of fifteen townhouses, numbered 3-17, showcases a cohesive ensemble of red brick homes, including No. 17, a triangular-shaped white stucco townhouse in the Anglo-Italianate style. This house, the focus of our restoration project, features custom windows by Parrett Windows, including double-hung and French casement styles, as well as custom exterior brick moulding and interior casing.

Built between 1851 and 1852, the homes along St. Luke’s Place were conceived as part of a master design, sharing architectural features like high stoops, arched doorways with triangular pediments, and ornate ironwork. The street itself was named after the nearby parish of St. Luke’s in the Field, a branch of Trinity Church, and was renamed in 1851 to honor this connection.

The architectural beauty and significance of St. Luke’s Place were meticulously documented by preservationist Evelyn G. Haynes, one of the pioneering members of the early New York City Landmarks Preservation Commission. In her detailed report, Haynes described St. Luke’s Place as "probably the last continuous row of houses of their period in Manhattan." This historical context adds depth to the aesthetic and cultural value of these homes, which have stood for more than 170 years.

Over the decades, St. Luke’s Place has housed a variety of notable figures, further cementing its place in New York City’s cultural fabric. Jazz Age Mayor Jimmy Walker, who embodied the spirit of the Roaring Twenties, called this street home. The area also attracted writers, artists, and intellectuals, including Author Theodore Roszak, Painter Paul Cadmus, Playwright and Screenwriter Arthur Laurents, Writer Max Eastman, Novelist Sherwood Anderson, Author Theodore Dreiser, Poet Marianne Moore, and Actor Robert De Niro.

Our restoration work on No. 17 St. Luke’s Place honors this legacy by preserving the home's historical integrity while incorporating modern, high-quality craftsmanship. The installation of custom windows, including the detailed exterior and interior finishes, ensures the home retains its 19th-century charm while meeting the needs of 21st-century living. This project exemplifies our commitment to balancing historical preservation with thoughtful, contemporary updates, maintaining the character of New York City’s architectural gems for generations to come.

NYC’s Preservation Laws | Restoring Historical Windows

New York City is home to countless iconic buildings, many of which are designated as landmarks due to their historical significance and architectural beauty. A critical part of maintaining these buildings is the preservation of their original windows. If you own or manage a landmarked property, understanding NYC’s preservation laws is essential when it comes to restoring or replacing historical windows. We specialize in custom historic windows and ensure compliance with all regulations, making the restoration process stress-free and seamless.

Why Preservation Laws Matter for Historical Windows

The Landmarks Preservation Commission (LPC) is responsible for overseeing modifications to landmarked properties in NYC, including window restoration and replacement. These guidelines are in place to protect the architectural integrity of buildings and ensure that any changes are consistent with their historical character.

If your building is under landmark status, making unauthorized changes to your windows, such as installing modern replacements that don't match the original style, can lead to penalties and costly retrofits. That's why it’s essential to work with an experienced window company near you that is familiar with LPC’s guidelines for historical windows.

Key Guidelines for Restoring Landmarked Windows in NYC

When working on landmarked windows in New York, there are several key guidelines you must follow:

1. Matching Original Materials and Design: Any restoration or replacement of historic windows must match the original design, material, and details. Whether your building features double-hung, casement, or arched windows, they need to be replicated as accurately as possible. Our window company in NYC offers custom historic windows that meet these exacting standards.

2. Energy-Efficient Upgrades: While LPC encourages maintaining historical accuracy, they also recognize the importance of energy efficiency. You can often install energy-efficient glass and materials as long as they don’t alter the window’s appearance.

3. Consultation and Approval: Before starting any restoration or replacement project, you must get approval from the LPC. They will review your plans to ensure the new or restored windows meet their guidelines. Our team handles this process, ensuring that every project adheres to local preservation laws.

4. Window Repair vs. Replacement: The LPC prefers that original windows be repaired rather than replaced. If your windows are beyond repair, they may approve a full replacement, but only if the new windows are an exact match to the originals in terms of materials, details, and craftsmanship.

Our Expertise in Custom Historic Windows and Restoration

As a trusted window company in New York City, we have extensive experience navigating these preservation laws and successfully restoring landmarked windows across the city. Whether you're restoring original windows or replacing them with custom historic windows, our team has the expertise to ensure your project complies with LPC requirements.

We use high-quality materials to restore windows to their former glory while incorporating modern features such as energy-efficient glazing. Our team can work with you throughout the consultation and approval process to ensure your project meets all necessary guidelines, saving you time and potential penalties.

When to Replace or Restore Your Historic Windows

Many property owners struggle with the decision to replace or restore historic windows. Restoration is often the preferred choice, as it maintains the building's authenticity and avoids any compliance issues. However, if the windows are too damaged for restoration, our window replacement services in New York City can create custom historic windows that match the original style exactly.

Whether you need repairs, restoration, or full replacement, we have the tools, skills, and experience to deliver top-quality results while adhering to all LPC regulations.

Contact Us for Expert Window Restoration in NYC

Restoring or replacing landmarked windows can be a complex process, but with our help, you can ensure compliance with NYC’s preservation laws while enhancing your property’s energy efficiency and value.

If you're looking for a window company near you that understands the intricacies of working with historical windows, contact us today for a free consultation. Let us help preserve your building’s heritage while meeting the demands of modern living.

Top 5 Architectural Window Styles in Historic New York Homes

New York City is known for its rich architectural history, with buildings that showcase a variety of window styles from different eras. These windows not only contribute to the aesthetic beauty of the buildings but also reflect the cultural and historical significance of the time in which they were built. Understanding the different window styles can help you preserve your building’s original charm while ensuring compliance with preservation laws.

As a leading window company in New York City, we specialize in restoring and replacing landmarked windows and custom historic windows. Below, we explore the top five architectural window styles found in historic New York homes and buildings, offering insights into how they can be restored or replicated.

Double-Hung Windows

Double-Hung Windows

One of the most common window styles found in historic New York homes is the double-hung window. These windows feature two vertically sliding sashes, allowing both the top and bottom panes to be opened. Double-hung windows were popular in many architectural periods, from Colonial and Federal styles to Victorian townhouses and brownstones.

If your building has original double-hung windows, preserving their function and appearance is essential. Our window company near you can restore or create custom historic windows that maintain the traditional look while improving energy efficiency with modern materials.

Casement Windows

Casement Windows

Casement windows, which open outward like a door, are another common feature of historic homes, especially in early 20th-century buildings. These windows offer excellent ventilation and were often used in high-end townhouses and early apartment buildings.

Restoring historical windows like casement windows requires precision and expertise to retain their original design. Our window replacement services in New York City ensure that any casement window replacements match the building's architectural period.

Palladian Windows

Palladian windows, known for their grandeur, feature a large central window flanked by two smaller, arched windows. This design originated in classical European architecture and became popular in New York during the 19th century, especially in grand estates and public buildings.

Bay Windows

These elegant windows are often focal points of historic buildings, making restoration critical. Our window company in NYC specializes in landmarked window restoration, ensuring that your Palladian windows retain their beauty and compliance with NYC preservation laws.

Arched Windows

Arched windows are a hallmark of Beaux-Arts and Romanesque Revival architecture, two styles that heavily influenced New York's historic buildings. These windows feature rounded tops and intricate detailing, often found in churches, libraries, and ornate residential buildings.

Restoring arched custom historic windows requires careful attention to detail to preserve their intricate design. Our team is skilled in restoring these complex windows, maintaining their structural integrity while upgrading them to meet modern energy standards.

Bay Windows

Bay windows, often found in late 19th and early 20th-century townhouses, extend outward from the building’s façade, creating more interior space and allowing for additional light. These windows are commonly seen in Victorian and Queen Anne-style homes throughout New York City.

Replacing or restoring bay windows can be tricky due to their unique shape and size, but our window company near you specializes in creating custom historic windows that perfectly replicate the original style. We also offer solutions for improving insulation and weatherproofing, keeping the look authentic while enhancing performance.

Why Custom Historic Windows Matter for Landmark Preservation

Preserving the original architectural window styles in landmarked and historic properties is crucial for maintaining the building’s authenticity and complying with New York City’s preservation laws. The Landmarks Preservation Commission (LPC) requires that any restoration or replacement of landmarked windows matches the original design and materials, ensuring the building retains its historical significance.

At our window company in NYC, we have extensive experience working with historical homes and buildings, offering custom solutions for window restoration and replacement. Whether you're dealing with aging double-hung windows or intricate Palladian windows, we ensure that every project meets the LPC’s guidelines and enhances the overall value of your property.

Contact Us for Historic Window Restoration in New York City

If you’re looking to restore or replace the windows in your historic New York home, our team is here to help. As a trusted window company near you, we specialize in landmarked window restoration and custom historic windows that retain the beauty and integrity of your building’s original design.

Contact us today to schedule a consultation and learn more about our window replacement services in New York City. Let us help preserve your property’s unique architectural style while improving its functionality and energy efficiency.

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Restoration Tips for Historical Brownstones

Clinton Hill, Brooklyn

Restoring historical brownstones in New York City is a labor of love that requires meticulous attention to detail, particularly when it comes to maintaining the authenticity of windows and doors. For homeowners and preservationists alike, understanding the nuances of window replacement in NYC is crucial to preserving the architectural integrity of these iconic structures.

Assessing the Condition of Existing Windows and Doors

Before diving into any restoration project, it’s important to thoroughly assess the condition of the existing windows and doors. In many brownstones, the original windows and doors have been in place for over a century. While these elements contribute to the building’s historic charm, they may also suffer from wear and tear, necessitating careful restoration or replacement.

Choosing the Right Materials for Window Replacement in NYC

Park Slope, Brooklyn

When replacing windows in historic brownstones, choosing the right materials is key. Wood remains a popular choice for its authenticity and aesthetic appeal. However, modern alternatives that mimic traditional wood while offering enhanced durability and energy efficiency are also available. Ensuring that new windows match the historical profile of the originals is essential to maintaining the building’s character.

Navigating NYC Preservation Regulations

Window replacement in New York City’s historic districts often requires navigating a complex web of preservation regulations. It’s important to work with professionals who understand the local guidelines to ensure that your restoration project meets all necessary approvals. This is especially true when it comes to replacing windows and doors in NYC, where strict guidelines often dictate the materials, styles, and installation methods that can be used.

Balancing Energy Efficiency with Historical Accuracy

One of the biggest challenges is balancing modern energy efficiency with historical accuracy. Upgrading to energy-efficient windows and doors doesn’t mean sacrificing the building’s historical integrity. Many manufacturers offer high-performance windows that are designed to replicate the look of traditional models while providing superior insulation and energy savings.

Working with Experienced Craftsmen

Historical Windows of New York has the expertise to repair your brownstone windows with precision and care. Restoring these windows is a specialized task that demands a deep understanding of historic preservation and the unique challenges of working with brownstone materials. Our skilled professionals ensure that your restoration is both effective and historically appropriate, preserving the character and integrity of your brownstone.

For more information on window replacement in NYC or to consult with our team of experts, contact us today.

Before | St John’s St, Brooklyn

After | St John’s St, Brooklyn

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A Window to the Past | Reviving 214 West 16th Street

Nestled in the heart of New York City, 214 West 16th Street stands as a captivating example of architectural evolution. Built in 1898, this brick building seamlessly blends the Federal Style with touches of Neoclassical, Beaux-Arts, and Baroque elements. The intricate design of its facade, shared with its sister buildings next door, reflects the pride and craftsmanship of a bygone era. From Limestone and Terracotta arches to detailed coursing and carvings, every aspect of this building tells a story of meticulous attention to detail.

In our latest project, we were honored to restore a piece of this history by installing period-perfect, 2 over 2 NorClad Double-Hung windows from Norwood Windows And Doors. These windows, approved by the New York City Landmarks Preservation Commission, were carefully chosen to match the original aesthetic while offering modern performance. The rear of the building now features these historically accurate windows, complete with custom exterior metal brick mould capping and interior casing.

This transformation was not just about replacing windows; it was about reclaiming the building's original charm. We said goodbye to the black aluminum inserts and single-pane windows that had previously marred the structure's beauty, embracing a solution that honors the past while enhancing the building's functionality.

We invite you to explore the before-and-after journey of this restoration, where history and modernity meet in perfect harmony.

Before

After