You might have seen in our previous blog posts (‘Plumbing’ section of Construction Update 8, ‘First Floor Roof’ section of Construction Update 7, among others), a small 6’x3′ box sandwiched between the walls of two rooms. This box, from ground floor, goes straight to the roof. This type of area in a house plan is known as OTS or Open To Sky.
Open To Sky (OTS) is an area in a house plan, which doesn’t have a roof. It directly opens to the sky. Normally it is covered by fiber glass or some other translucent material. The main purpose of OTS is to bring light/air in an area where it is not possible to install a window that opens to the outside.
Why do I need an OTS?
Windows are created in walls to get the glimpse of the outside world and bring it into the room. Sunlight and fresh air are also necessary to make the room livable. No one wants to live in a concrete box right?
But sometimes we design a house plan that forces us to make a room without windows. That might seem like not a big deal, but in the long run, trust me it is. For example:
Let’s say you have two rooms adjacent to each other, sharing a wall. Your house plan only allows you to open a window in the wall that is shared by both the rooms. Installing a window in that wall won’t help with air flow and light. That’s where OTS comes into play.
You can create an Open To Sky box in that wall. It will go up-to the roof and bring light and fresh air. Now you can install windows in the walls of OTS, one for each room. It will not bring the outside into your room but it can greatly improve the quality of light and air flow. Bonus Tip: You can also put some potted plants in the OTS to fake the outside world.
But it will reduce the size of Rooms?
Technically Yes, it will take some space and most definitely will affect the size of rooms and location of windows. But if you plan ahead and rearrange the rooms in a way that accommodates OTS without sacrificing much square footage, then it’s a win win situation.
So what did you do?
Keep in mind that our plot is 7 marla/175 sq. yards, and it’s not a corner plot. Which means we can only have two open sides, front and back. We wanted to have a kitchen, two bedrooms with attached baths and one drawing room; each having its own window, all in one floor plan. Almost same arrangement will be on the first floor.
Now drawing room can have its window on the front side while kitchen, one bedroom and its bathroom can have their windows in the back alley, but what about the second bedroom and it’s bathroom? That’s where OTS helped us.
As you can see in the house plans, we arranged rooms and bathrooms to accommodate the OTS without loosing much square footage. Now the window for our second bedroom and its bathroom opens into the OTS, which greatly helps in ventilation. As an added bonus, we also added a window in OTS for the living area. The more windows the better!
Does OTS has any other use?
Other then air ventilation and light, OTS can be used for multiple other things. We are also planning to install the external unit of our ACs in OTS, as they will be nicely tucked away and it will make the house exterior looks clean.
The other thing we did is that we passed all the plumbing pipes coming from first floor through the OTS. Normally those pipes can be seen on the backside wall of the house, which in our opinion looks ugly. This way all the pipes come to the OTS, drop down to ground floor and merge with the ground floor pipes. Pretty neat hah!
In conclusion, we think OTS is an excellent solution for light and air flow problems. It is a multipurpose place where you can divert all those things that you don’t want to be shown on the walls. It can also act as a small in-house garden.
Let us know what you think. If we left anything unexplained or if you have any suggestions, feel free to comment below.
Hi
In NORTH FACING flat with NorthWEST Corner OTS is good or bad to the residents.
Hello! In a North facing flat, an Open to Sky (OTS) feature at the NorthWest corner can bring in favorable energy and light, enhancing the overall ambience. However, it’s essential to consider factors like climate and personal preferences for optimal comfort.
Planning a 300 sq yd house. We are planning OTS as our plot size is 32 x 84
Can u pls suggest minimum size for OTS as we have to decorate it by water body and planters
Hi Anu!
I recommend a minimum size of 10′ x 15′ for the OTS space. This would provide ample room for the desired features while maintaining a balanced aesthetic within the overall layout of the house.
Sir, I am from Chennai. I have purchased one flat consisting of 5 floors which is now under construction. The builder has allotted a parking to us at ground floor which is directly under OTS. The OTS doesn’t start from ground floor but it starts 10 feet above the ground floor. We fear threat of risk to life and property from OTS if any heavy metal objects falls accidentally from OTS into our parking slot.. Is such parking permissible under law. How to go about it. Regards B.Lakshmi Chennai.
Sir, I am from Chennai. My daughter has purchased a flat consisting of 5 floors which is now under construction. The builder has allotted a parking to us at ground floor which is directly under OTS. The OTS doesn’t start from ground floor but it starts 10 feet above the ground floor. We fear threat of risk to life and property from OTS if any heavy metal objects falls accidentally from OTS into our parking slot.. Is such parking permissible under law. How to go about it. Regards S Balaji Chennai.
If whole OTS is covered with translucent sheet at the top to prevent rain drops wetting the part of peripheral floor area around it in an highrise apartment complex during mansoon, then how can we get adequate sunlight and fresh air to all the flats surrounding it.During heavy wind how the air will leave through the top when it is covered.As per the building rules it is not permiited and the entire OTS opening should be kept open only.Please clarify.
Hi SRK, This article mostly focuses on the use of OTS in a house (not an apartment building), as it’s way more complex and challenging than a normal house. But if we design the OTS in a way to let the light and air through, that is possible too. For example, we can design the OTS, sort of like a chimney (example image). Raise the OTS base from the surrounding roof floor, then fix the iron bars at 4 corners and wrap the wire mesh to stop bugs, etc from entering the OTS. You can adjust the height according to your requirements. Finally, put the translucent sheet at the top. You can also paint the OTS with reflective paint to make the sunlight go as deep as possible. There might be some other options too, but this is all I can think of right now. Hope this helps. Regards,
Hi team
Ots in northeast corner of north facing flat in second floor.pls suggest
Hi Anu, I think that’s a great idea. You’ll not only get plenty of sunlight (from sunrise till late afternoon) but also the fresh morning breeze, improving the air circulation in the rooms. Hope this helps. 🙂
Hi team.. Thankyou for your response and the information provided was really helpful.. just curious to know if incase all buyers agrees upon installation of ac outdoor units in ots space and all buyers installs their outdoor units in the ots space provided then is there any chance the contaminated air from ac outdoor unit enters into others room having the windows opened? Hope my question makes some sence as i wanted to be aware if the situation rises as i couldint find any space outside bedroom apart from ots spac to install the ac outdoor unit for the buyers.. Thankyou in advance
Hi Augustine! Yes, 5 outdoor AC units in OTS might cause some problems, but not if their placement is carefully planned. A typical AC outdoor unit throws warm air in the front-upwards direction. So while installing the outdoor unit, if you make sure that there is no window directly in front of (or 3-4 feet above on the wall in front of the unit), then you’ll be fine I think. The warm air will not stay in the OTS for long, it will quickly rise up and disperse in the air, so there are almost zero chances of contaminated air entering through the windows. Just make sure that the outdoor unit doesn’t throw the air directly to the window of any other apartment. Hope this helps! 😃
Hi Team.. Appreciate your knowledge, time and effort in answering my queries. Thankyou! 🙂
Hi.. i am planning to buy an apartment in 2nd floor which has windows of both the bedrooms opened to ots space(8’×6′)provided in the building. The building has 5 floors and one apartment from each floor shares the commom ots space as like mentioned above. So what i doubt is whether the air circulated in my bedrooms will be fresh enough as 5 apartments share the common ots space and can i install ac outdoor unit in the ots space?
Hi Augustine! In my opinion the air will be quite fresh. The hot and stale air rises up and fresh air from the surroundings rushes in to take its place. 8’x6′ is plenty of OTS space to be shared among 5 apartments. Whether you can install outdoor AC unit or not, this completely depends upon the building rules followed by your apartment building. Generally, one is not allowed to install personal equipment in a shared space without permission. Hope this helps. 😀
I have a corner House facing east side? How many OTS will be required ?
Hi Shweta!
In a corner house, OTS is not a requirement. The main purpose of OTS is to bring sunlight and fresh air into the rooms without windows. You should design the floor plan so that each room has at least one window that opens to the outside. In my opinion, more than one OTS is just a waste of floor space. Hope this helps.
What will be the construction cost of ots for 6*4 and 5*5
Hi Chitti!
The construction cost varies depending upon the current labor rates, the area that you live in, and also the time of the year. It’s better if you consult your local builder/developer.
If the OTS has the water lines run through them, should one have a door to OTS?
If the OTS has the AC outdoor units in them, should one have a door to OTS?
If not how will the plumbing/AC works can be carried out in case of any issues?
Hi Ramnath!
In my opinion, window; instead of door is a better option. If you install a door, it will remain closed most of the time. Window will not only give you access to the OTS when/if required but it will also bring light and fresh air into the room. Either way, you should definitely add a way to access the OTS. Hope this helps
Regards,
Hello!
Could you please tell me what kind of material we can give on the wall of Shaft and also I would like to see the image of ready OTS that is also act as a small in-house garden.
Who should clean ots. Will it come under common maintenance or the flat adjacent should clean.
Hi Sowmiya! It mostly depends upon the rules set by your neighborhood. Generally, if my flat alone opens into the OTS, then it’s my responsibility. If more then one flat open into the OTS, then it’s a collective responsibility, but as I said before, each neighborhood has different rules.
In corner house how many ots is needed?
House is west facing.
Normally a corner house, having three sides open, doesn’t need an OTS. You should design the floor plan in a way to add windows to all the rooms (including bathrooms), without adding an OTS. If your floor plan already has an OTS, in my opinion, more then one OTS is a waste of space.