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March 04, 2024

“Found” Space Up on the Roof

In the past couple of weeks, we’ve been talking adding outdoor living to attached product. The next evolution in outdoor living for townhomes is the roof top deck. In restaurants and bars, roof top decks are an instant crowd pleaser. Perhaps you’ve seen the rooftop restaurant and bar on top of Restoration Hardware. Apparently, it is the place to be and to be seen – based upon the number of selfies taken during a recent visit. Ah – and let’s not forget the outdoor bar on top of the Vendue Inn or the Dewberry in Charleston.

Advantages of Rooftop Outdoor living

Why not consider a roof top deck for outdoor living in an attached townhome? You could say it is “found” space. If designed properly, you could add a third more “living” space to a three-story townhome. Add privacy screening between units and buyers can create their own ambiance.

Harleston Row | Charleston, SC

Harleston Row | Charleston SC

The rooftop location offers a unique viewpoint and, in a denser setting, longer views than might otherwise be available at lower levels. There also tends to be more breeze up on the roof. I’m told there are less insects on the roof than on the ground as bugs like to hang out where their food typically is.

Challenges to Consider

While the rooftop for outdoor living may be found space, it is certainly not free space. It also requires preplanning to make it awesome.

Height Restrictions

Before you get all excited about designing an awesome roof terrace, check the local zoning code. In some cases, the added “floor” may exceed a height restriction. You will need to understand how the height is measured: to the top of the parapet or to the top of the stairwell. Some zoning codes may only allow the stairwell and no other enclosures. Determining the occupancy load may also be critical with regards to a second means of egress.

Getting to the roof is another thing to consider. Obviously, you will need the stairs to go to the top level. And it you’re thinking of adding a roof deck to the three-story townhome, will buyers be willing to traverse that many stairs? You may consider adding an elevator for access to the roof. But be aware, if there are 4 units or more in the building, the entire unit and building may now have to meet the Fair Housing Act for accessibility.


First and foremost, the “flat” roof has to drain – which requires the service to be sloped towards a drain. This creates a less than ideal surface for furniture. Additionally, protecting the waterproof is paramount. One solution to address both issues is a deck elevated with sleepers on top of the roof. Synthetic decking materials like Trex are great for this as they weigh less than wood and require less maintenance.


Oh – did I mention weight? Of course, you will need to take into consideration both live and dead loads. Adding furniture to the roof isn’t an issue but be careful about things like hot tubs. An empty hot tub for two or three people empty weights about 500 pounds but when you add water at 64 pounds per cubic foot– is can be as heavy as 3,000 pounds.

Space Plan your Roof

While this may be found space, it does take a bit of space planning. You may need to avoid mechanical equipment like condenser units or various plumbing vents. Once these are nailed down, consider how to use the space. Perhaps a seating area around an electric fireplace or an outdoor TV. What about a table with chairs for dining? Check with the local fire marshal about adding outdoor grills to the top floor. Perhaps you can add a small outdoor wet bar with sink and under counter refrigerator.

Don’t forget to add ambiance like colorful pillows or cushions. Plants are a fabulous addition, so be sure to include a hose bid for watering them. One project in Charleston called Harleston Row designed by Julia F Martin has a whole garden on its rooftop with native plants – what a beautiful way to soften the space!

Harleston Row | Charleston, SC

You may also want to include some sort of storage for outdoor cushions when they are not in use.

Project by Builders Design

Sun Protection

Project by Builders Design

Adding shade to your rooftop deck is essential and tricky. A permanent roof structure may trigger a zoning/height issue. But a retractable awning may be allowed. Certainly an umbrella or canvas should be fine.

Olesia Bilkei/

Fall Protection.

Last but not least, you will need to provide fall protection. And while this may seem obvious, a solid parapet wall may block views. If there is a worthy view, you may consider a cable handrail or a glass half wall.

Ryan C Silmak/

There is a lot to consider when designing a roof deck. But chances are, adding such decks will differentiate your project and add the outdoor space so absent for many attached housing projects.

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This post was written by Housing Design Matters