Carl's Sims 3 Guide - Skills, Traits, Careers, Rewards, and Lifetime Wishes for Ambitions and World Adventures

The Sims 3 Building Tutorials:

Making Homes with Multiple Stories and Basements

By Norma Blackburn

Build and Edit in The Sims 3
Edit TownEdit LotsHousesHouseholdsBasements/MultistoryGaragesRooms
PoolsRoofsSlopesStairs/ElevatorsWall CurvingMovingSwitch 'hoods

Building Multi-Story Homes

Building multi-floor homes in The Sims 3 is not that difficult, in fact it can be really simple. Let's look at a few ways to give our Sims a little bit more living space without them losing any of their back yard.

How far up and down can we go? The maximum height we can build our Sim house is 5 floors above ground and 4 levels of basement. It is worth noting though, that foundations and friezes also count as floors, so the number of floors you can build will be reduced by the addition of these.

In this image you can see the different combinations and how they affect how high your building can be. You could have more than one frieze, which would of course count as another floor. Whatever the combination, the maximum height is 5 floors.

Ideally, when you build your house, you should plan for future extensions. Even if you don't have the money to complete the house immediately, a little planning can make things a lot easier when you do.

The main thing with adding levels to your house is access. You are going to need some way to get from one floor to another. In most houses this will be in the form of stairs, either the standard staircases or the spiral stairs that were introduced with Generations. There is also the option of elevators which were introduced in Late Night.

The style and size of your house will determine what you use and how much space you need to allow for future development. We'll have a look at the different choices in a minute, but first there are a few things to consider about placement.

Traffic - how many Sims are going to be using the stairs on a regular basis? If a lot of Sims will be using the stairs, it might be worthwhile to make them wider than normal. Sims will become annoyed if they constantly have to wait for someone to come up the stairs before they can go down.

House size - If the house is large, a second (or even third) staircase may be a good idea. You Sim will probably appreciate not having to go the length of the house to go downstairs and then travel the length of it again to get where they were going.

Placement of stairs (what room) - Try to imagine where you would have stairs in a real house. Would you really have the stairs coming up into a main bedroom when there are other rooms upstairs? Personally, I try to have stairs in large public rooms like lounge rooms or in hallways, but this really comes down to your own idea of what works best. If there is only going to be one staircase, try and have it in a central position.

Types and Sizes of Stairs.

For detailed information on using stairs and elevators, including using them through friezes and foundations see the Stair Tutorial here.

The straight stairs that we can build all take up the same amount of space. The actual staircase will need 4 squares for the length plus 1 square at either end for the upper and lower landings. The default width of the stairs is 1 square, but you can change this to any width you like. If you are building a small house with the intention of building up later on, you need to allow space (maybe in a central hallway) for building the staircase when the time comes.

Taking up just a 2 by 2 square of space on both floors, the spiral stairs are great for small areas. Because of this, they are handy when building up on smaller pre-built houses.

Elevators are another way of getting from floor to floor. An elevator will need a space 2 x 2 for the actual elevator plus a 2 x 2 space in front of the doors on each level.

Let's look at going up first.: One thing to remember when building up is the fact that unless you turn it off, the auto roof feature will automatically add a roof to any enclosed room. Because of this roof, you may not be able to build stairs up to the higher level and unless you go up a level in view, you will not see the roof. I have wasted a lot of time trying to work out why my stairs can't be placed because of this problem. The answer is easy enough, go to the roof tool and remove all roof pieces and turn off the auto roof and then add the roof when you are finished.

To build up a level, either on a new build or a pre-existing house is quite easy. Go up a level in view and add floors and walls where you want them. Of course if this is an existing house, there will be a roof in the way, so, either go into the roof tool and remove all the roof sections or use the sledgehammer tool to remove the piece of roof that is in the way (depending on how the roof was constructed, the sledgehammer tool may still remove all the roof) Once the upper level is built add your stairs (of course, the stairs can be built from the lower level up before you even add any floor up there if you want to do it that way) Note that if you place floor tiles on the upper level and try to build stairs down from that level, you will need to remove the floor tiles from the stairwell because if there is no hole in the floor, the stairs will only try to go up.

Other things to consider when building up: Don't feel that the upper floor has to be the same size and shape as your lower level. You can add roof sections to the lower parts of the house that are not as high as the rest of the house. Of course, upper levels can also extend out over areas where there is no level below, just add support walls while building then remove the walls and place columns. This is useful for upstairs balconies.

Unless your upper level only consists of a single bedroom, consider adding another bathroom for your Sims' convenience.

Building Down: Basements

World Adventures added the basement tool to the building section of the game. Using this tool, we can now go down 4 levels into the ground. To place a basement, select the tool and when on the lowest level of your house, drag out a footprint for the basement. Once placed, you will see it as a blue area on the ground when the basement tool is selected.

If your house is not on a foundation, adding a basement is as easy as dragging out the outline of your basement and adding stairs. This makes adding a basement to pre-built houses without foundations extremely easy.

Your basement levels can be any size you want. When building stairs down to your basement, either remove a section of floor on the upper level to add the stairs or go to the lower level or build the stairs up.

Using a Foundation as a Basement

Before World Adventures, basements were built using the foundation tool. This method is not as easy as the basement tool, but it is a very useful method to use. Sometimes you may want a different type of basement. You may have a sloped block and want some parts to be in the ground while part of the same level is exposed. A normal basement can't be built in that manner; it all has to be under ground. You can however use the foundation tool to build such a level.

To build a basement using the foundation, start by building the foundation to the desired size. Then delete all but the outer blocks of the foundation. Removing all but the outer edges of the foundation is an invaluable step if you plan to have a basement later on. Even if you don't want a basement, it can be a great money saver as you are only paying for the edge foundation pieces instead of foundation under all the house.

Next grab some stairs and on ground level inside the foundation, build 3 sets of 4 steps going down into the ground. Remove the stairs and level the whole area with the level terrain tool. This is another step that is worthwhile doing even if you have no plans at the moment for a basement, because if you do decide to add a basement, it will be a lot easier to do if you have already done the ground work.

Now the ground inside the foundation is exactly one floor level lower than the top of the foundation and can be used as any other level, just add flooring and walls as needed plus stairs to the upper level. Using the foundation as a basement, you can now delete some of the foundation walls and build normal walls on areas that are not underground.

In this image, the white walls are where foundation walls have been replaces with normal walls.

One thing to note when building a basement this way is that to place things like wall decorations and light fittings on the foundation walls, you need to use the moveobjects cheat.

Building True Basements Under Foundations

If you have a house on a foundation and want to add a basement underneath, adding stairs can be a little bit tricky if you don't add them while building. For this reason, I would suggest that you turn the foundation into a basement level, even if it's just around the stairs because it will make the addition of stairs to the true basement so much easier.

Let's take a look first at adding stairs down through a normal foundation. Later, I'll show you how easy it is to add a stairwell down through a foundation/basement even on an already built house.

The simplest way to build stairs down through a foundation to a basement is to actually build the stairs up from the basement to ground level before you build the foundation. When you drag the foundation over the stairs the game will automatically leave a gap. Then you can just add a short set of steps from the ground to the top of the foundation. This is easiest to do when first building your house. The game mechanics are somewhat strange when you try to do this seemingly simple task when most of the foundation is already in place and often you will find you simply can't do it without tearing down a fair chunk of your house. Another easy way around this problem is to extend the basement out under the backyard and build a small garden shed with a set of stairs down to the basement.

Turning the foundation into a basement level is by far a less stressful way to add stairs down to the basement and can even be done on pre-existing homes with minimal disruption to the rest of the house. I've shown you how to make a basement this way when building your house, now let's look at how easy it is to do on pre-existing houses.

For this example, I've chosen Tish Cottage in Riverview.

As you can see from the layout, there is not a lot of room to play with, so I'm going to go with a spiral staircase in the kitchen area. To start, I'll need to delete a 2 x 2 area of the foundation. In this image, you can see that I have deleted 3 squares of foundation but not the last one.

That is because the game has told me it can't be deleted. Foundation cannot be deleted if there is something on top of it. This can be as obvious as a piece of furniture or it can be a little more obscure. Doors need a piece of floor on either side, so a door will prevent you from removing foundation. Windows will also prevent it as will light fittings on the ceiling. In this case it was the light fitting in the middle of the kitchen. Simply move anything that is in the way and delete the final piece.

Next we need the ground in this little hole to be a full level lower than the floor. We could fiddle with stair sections making the ground lower in this small area, but there is a far easier way. Let's go outside to the side of the house where there is plenty of room. Here we can build our three sets of stirs down to lower the ground to the desired level. Next use the level terrain tool and drag from this low level all the way across and under the house to where the foundation was removed.

We can also do this ground lowering under the house. I;ll show you how in the next example.

While we are doing this, we may as well lower all the ground under here just in case we want to make this a full basement later. Don't lower the ground all the way to the very edge of the foundation as this will cause the ground outside that is visible to lower and look strange. While we still have the level terrain tool up, don't forget to fix the ground outside where we lowered it.

Now we can build our basement and add stairs up (don't forget, spiral stairs have to be built from the lowest level up)

Let's have a look at one more example of building down on a pre-existing house. This time, we'll work on Cyprus Villa, again in Riverview.

First up we need to lower the ground to make our basement. Go down till you can see the ground under the house and build three sets of stairs. Remove the stairs and level out the ground from the lowest level

For this house we are going to build straight stairs down under the existing staircase, so we need to move that bookcase and delete the end wall on the stairs plus inside we need to remove the floor/foundation. *Note that stacked stairs like we are going to be making here will only work in one direction. For a full explanation of this behaviour check out the stair tutorial.

We still need one more piece of foundation removed for the lower landing of the stairs. The piece we need to remove is at the bottom landing of the existing stairs. Fortunately, we don't need to remove the stairs, but we will need to move the arch into the kitchen (when you put it back you will need to use the moveobjects cheat)

Build a basement under the foundation and then all that is needed is to remove some more foundation to add stairs up. As I have mentioned, the game can be strange when trying to add stairs where a foundation is involved (spiral stairs do not seem to have this problem) and I had to juggle the stairs around till I found the 'magic' spot that the game approved of.

In this image you can see where I have removed foundation and where the stairs ended up. All in all there was very little disruption to the house above.

Build and Edit in The Sims 3
Edit TownEdit LotsHousesHouseholdsBasements/MultistoryGaragesRooms
PoolsRoofsSlopesStairs/ElevatorsWall CurvingMovingSwitch 'hoods

Share Tips and FAQs (8)

Our Sims Forum is the place to go for faster answers to questions and discussions about the game. Use the form below to share your own experiences and provide helpful tips to other readers.

KathiT says...
I've tried to use both methods to build a basement and I'm not having much luck with either. I'm pretty sure I'm following your instructions with the foundation but when I try to add the normal walls on the exposed sides, it keeps telling me "covered with floor tile". I even tried to go down another 4 steps, but that didn't work either.
9th June 2014 11:39pm
Tora says...

I googled an easy method for adding a basement to a pre-existing building with a foundation. No foundation change necessary (I don't remember about the floor tile though). Starting on the first floor, select your stairs, hold SHIFT, and move your mouse in the direction you want them placed (test it without shift on the first floor so you can see the direction you want).

It might take several tries (I didn't realize the mouse movement was needed for awhile). But it adds the four steps in the foundation from the first floor to the basement and also adds the attached basement stairs. It's quite easy once you stop trying all the other complicated stuff (I avoid CFE).

Strangely enough, the foundation stairs are dark and no light source near them on the first floor will illuminate. You can use moveobjects to place a light source on the foundation level instead; you should probably keep it off the stairs (even if it's wall mounted) just in case.
3rd August 2014 5:06pm
jeric t. torres says...
the sims 3 is really really amazing
18th August 2015 3:38am
Sims3player says...
I cant manege to make a second floor. And when i do i cant get a roof on right.
There are quite a few building guides that could help. Try this one on building a roof. Roof Building!
18th June 2017 10:49pm
Sarah W. says...
Am I just so inept at this game that I can't figure out how to add a third story? It only seems to let me go up to two. What am I doing wrong?
1st November 2015 1:44am
Myka B. says...
If you add a set of stairs on the second floor, it should automatically add the third floor. Of this doesn't happen, make sure that your roof is completely off.
19th November 2015 10:36am
someone... says...
Thank you so much for this tutorial! For so long have i wanted a way to make entrances at several floors, directly connected to the terrain. I thought it wasn't possible in the vanilla game, so i tried to find mods for it (to no avail). Finally, with the foundation-basement trick, I'll be able to make what i've wanted to for so long!
14th February 2018 4:59pm
Mercedes Lashanti says...
I've made the basement prior to reading the exerpt so my issue lies with placing objects in the basement. I have stairs, I have a the walls closed. I can't use lights anywhere, on walls, the ceiling nor the floor so I attempted adjusting the room size a bit but no change, any advice on how to fix this?
30th September 2018 3:22am
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