Zero Lot Line Construction

What is a Zero Lot Line House?

A zero lot line house is a piece of residential property where the house comes up or very near to the edge of the property line.  A variety of properties can be considered zero lot lines, including town homes, garden homes, patio homes, and row houses.  These homes can have one or two side yards and can be attached or detached.  Typically, Zero lot line properties typically contain one side yard.   

As builders face the challenge of the lack of available lot space, high-end zero lot line homes are becoming a popular niche market.  There are advantages to building a home in this style, too!  Zero lot line homes are a cost-effective option for homeowners who are looking for low maintenance and simplicity in their next property.  With little to no outdoor yard space, means you do not have to worry about landscaping or yard expenses.  It also turns the space that would have been a yard into livable home space, maximizing the square footage of your home. 


Zero Lot Line Wall Construction

When building zero lot line properties there is the added danger of fire spreading from building to building.  For an added safety and privacy measure, zero lot line homes restrict the addition of windows on either side. This limits the placement of windows to the front and back of the house.

Because property lines are much closer than that of traditional homes, zero lot line construction differs slightly. Safety becomes a major consideration, especially with wall construction.  It is common to incorporate fire rated materials into construction to reduce the risk of fire transfer between homes.  In cities such as New York or Chicago where buildings are typically in zero lot line zones, architects and designers can incorporate fire rated glass to meet requirements without having to sacrifice windows or natural light.  

What are Fire Ratings for Architecture?

Fire ratings for architectural components are assigned time increments determined during rigorous laboratory conditions.  The rating indicates the length of time the material can resist heat before degrading and exposing interior objects.  Seves Glass Block™ from GBA is available with UL fire ratings of 45-, 60-, 90-, and 120-minute ratings.  According to, glass block is exposed to a propane gas-fired furnace for various periods according to procedures set by Underwriters Laboratories (UL) and The American Society for Testing and Materials Standard E119.  The survival period determines the fire rating.  Glass block that resists the fire’s impact for ninety minutes is thereby award a 90-minute rating.


Fire Rated Glass Block

Attractive, durable, energy-efficient, and capable of opening up dead and dark spaces, fire rated glass block is endowed with inherent fire-resistant properties. In many fire-safe buildings, fire rated glass block structural components furnish an additional level of safety that wood and drywall cannot.

Whether for interior walls, glass staircases, flooring, or exterior cladding and windows, structural fire rated glass block adds pleasing aesthetics and light while providing an added measure of fire protection. Fire rated glass block is available in a range of textures and degrees of transparency for privacy and safety.

Premiere™ Series 4" Glass Block

The 45-minute fire rated glass block offers the most design options of patterns sizes and shapes. Patterns for Premiere™ are Nubio, Light-Diffusing, Large Gross, Clarity, Cortina, Regent, and Arctic.

THICKSET® 60 Series Glass Block

This 60-minute fire rated glass block option is thicker block than Premiere and offers reduced sound transmitting properties. The block is available in Nubio, Clarity, and Spray patterns at a face thickness of 0.375”.

THICKSET® 90 Series Glass Block

Rated by UL at 90 minutes if fire resistance, this product is also available in a range of styles and is graded at a higher level of sound transmission. The nominal thickness is 3.75”. Styles available are Nubio, Clarity, and Endura.

VISTABRIK® Solid Glass Brick

The ultimate in security and safety, VISTABRIK® is a full 3-inches thick yet allows as much natural light as desired while capable of deterring firearm projectiles, hurricane and tornado-force flying objects, and forcible entry. The product is available in a variety of styles and patterns.

F-120 Wall Fire Rated Glass Block

Seves high performance F-120 glass block has been tested for fire safety in a controlled environment and was able to withstand fire exposure for 120 minutes.  With certification from the International Code Council, this fire rated glass block is rated to meet the 2-hour ASTM E119 standard for vertical wall ratings.  This glass block product has also been tested to meet UL 263-19 and CAN/ULC S101-14 standards. 

How Safe is Fire Rated Glass Block?

Seves Glass Block™, the world’s leading glass block manufacturer for architecture and construction, produces fire resistant glass block in classes of 45-, 60-, 90-, and 120- minute fire resistance that retains structural stability and strength while protecting occupants and objects from flames, smoke, forcible entry, and dangerous gasses.

As part of their Technology Line, Seves' fire rated glass block is available from GBA Architectural Products + Services. Besides fire resistance, products in this group of state-of-the-art glass block products are noise resistant, graffiti resistant, bullet and projectile proof, and secure.

Fire Rated Wall and Window Systems

The GPX Architectural Series, manufactured by SAFTI First, can be used in both interior or exterior wall applications with a fire resistance up to 2-hours when combined with SuperLite glass.  Wall-to-wall and floor-to-ceiling fire rated glass has many applications including fire rated aluminum doors, walls, openings, and more!  To learn more about the fire ratings and applications of this product, contact a GBA professional. 


The Warehouse on 520 W 20th Street • New York, NY
(Photo from SAFTI First)

Seves Glass Block™ Design Options from GBA

Seves Glass Block™ styles and patterns are all available through GBA.  We pride ourselves in having the largest available inventory of Seves glass block products in North America.  Seves fire rated glass block is distributed by GBA Architectural Products + Services with ratings of 45-, 60-, and 90-minutes. These products, useful for both interior and exterior applications, are available in several sizes, designs, and styles to match any architect’s imagination.

Contact GBA Architectural Products +Services

For designers and builders seeking the perfect marriage of beauty, durability, energy efficiency, and safety, fire rated glass block from GBA Architectural Products + Services is a logical solution. Check out their array of world-class products for a variety of applications. If you are looking for a building material that will last, provide plenty of light, lower energy bills, impart beautiful, ever-changing light effects, and provide superior fire resistance, architectural glass block is the perfect option

For more information about the full range of glass architectural products, like sidewalk vault lights, visit the GBA website product page.  View some of the incredible past architectural glass block and glass floor projects furnished and installed by the professionals at GBA.

If you have questions regarding the full range of applications of glass block products, contact the experts at GBA Architectural Products + Services at one of their three regional offices serving North America.

Here are the phone numbers to speak with one of the GBA professionals:

  • Midwest: (877)-280-7700
  • East Coast: (212)-255-5787
  • West Coast: (213)-634-7050

Or, you may complete the online questionnaire in the Contact Us section of the website and one of the GBA experts will contact you.

Tags: Fire Rated Glass Block, Glass Block