Deck Access Options: Replacing a window or adding a slider.

Over the past few weeks we have been really excited to see our deck being built. One of the things that we are looking forward to the most about our place is unwinding at the end of the day by lighting up the grill, having a glass of wine, and enjoying the outdoor space.

Adding a deck is on the plan for a lot of renovators. It’s one of the things that people reach out to us the most about. Unfortunately, it can easily slip out of budget. It’s all relative. Adding a deck is up there with increasing the number of bedrooms and bathrooms for the amount of value it can add to your place…if not more. So it’s usually a good decision and not only for those evening glasses of wine. 

It was a high priority for us to have one so we found ways to make sure we could squeeze it into the budget. One way was by saving on how we created the access to it. It’s popular to create a large opening for a glass slider or double door, but we went with the more budget friendly approach of installing a glass door in place of a window. For those of you who are in the same boat we thought we would share the things we considered. 

Here were our options:

Option 1: Replacing a window with door. This option only requires demo of the window itself and bricks below it. The lintel above the window can stay in place and none of the masonry above and on side of it is disturbed. 

Option 2: Creating larger opening for glass slider or double door. This option requires a lot more structural work. Our favorite architect, Dick Boschen of Boschen Design, describes the process this way: ”Typically, you can make a big opening by taking out the brick between any 2 of the 3 windows (for most Brooklyn townhouses that have 3 windows across the back), and adding a beam (or lintel) that spans the whole new opening.  But you have to make sure the wall above doesn’t collapse into the hole you’re making, so it’s actually done in the opposite order.  First they make the beam, then they remove the wall under the beam.”

So now that we understand our two options let’s consider a few things.


As you can imagine option 1 will get you an easier time at the DOB. You aren’t changing anything structural about the exterior of the building, so it’s possible to do this on an Alt-2 (DOB less involved in the specifics of your project). Although you’ll need to send a letter to all of your backyard neighbors letting them know about the project. The letters need to be sent and date stamped through certified mail a couple weeks before you file and need to be provided when you do.

For option 2, Dick says, “you must have an Alt-1 filing (DOB more involved in your project).  That’s because you’re doing structural work that could hurt workers, residents & the public in general. So the D.O.B needs to know that 3 main issues have been considered: 1. There is a lintel above the window that can support the weight above. 2. The work doesn’t weaken the remaining wall. 3. Temporary shoring is planned to hold up the building while the work is being done.” You’ll need more drawings, more inspections, and this will no doubt bring more problems.

Scope of work

Obviously from the description above option 2 is much more involved. That’s not even taking into consideration the shape of the brick to support the new features. A lot of times almost the entire back of the building is rebuilt for it. Option 1 might be a day or 2 of work and won’t compromise the existing wall.


The cost for option 1 is minimal. Demo of the existing window and bricks might cost $1,000, the cost of the door and installation might be $2,000 (depending on the kind of door…etc).

The cost just for just the work for option 2 is likely to be a minimum of $15,000, with the wind still blowing through the new big opening you created (as Dick put it). There is a lot of glass to buy, which will cost several thousands dollars, not to mention a more expensive installation. We would assume option 2 might cost $20,000.

Original features

One of our considerations that might not be the case for everyone was the original wood moulding and window casings we would need to remove. We bought our 1880’s brownstone because we loved those features. We would have lost 2 window casings and probably some plaster moulding above it to have a larger opening. We‘re looking forward to seeing the new glass door inside our original window mouldings!

If you already have a big project and are filing an Alt-1, you have the budget, and you‘re not concerned about saving original features it could be worth the effort of creating the larger opening. For us, it was an easy decision not to.

The other area we found to create some savings is in the decking material. More about that soon! Thanks for reading! Subscribe below for updates and don’t forget to follow us on Instagram.