Yes, it really depends on the number of sims you plan on having live in the house. In cases like Legacy or Dynasty play, you want to have a plan early on because it can get expensive rebuilding over and over again. Here are some general guidelines that I go by when planning a house:
- The very first thing I do before I build a wall or lay a square of foundation is map the layout of the house out using the free floor tiles. They're located in the wood flooring.
- Another thing that is handy to know when doing this is that if you buy furniture and sell it before you go back to live mode, you will get a full refund on the price. This can help when deciding how large you want/need to make a room. Just place it down (or something of equal size) and you can better visualize. If you enter live mode, even for a second, the item will depreciate in value, so if you don't plan on keeping it, sell it before you do.
- If you're planning a basement, take a look at this thread. It will save you a lot of time and some major headaches when putting it in.
- In "Legacy" houses (one where all the descendents will be living there), I like to have 2 master bedrooms. One for the older generation, and one for the generation that will take over after the older sims die off. I tend to make them between 6x6 and 8x8.
- I make 1 or two other bedrooms, with two twin beds in them for anyone else who will be living there on a temporary or permanent basis. If you have Late Night and want to have a butler at some point, plan on one extra bedroom in addition to these as well. I make these bedrooms 6x6, but you could go slightly smaller on the butler's room.
- One of the most important rooms in your house (in my opinion) is the kitchen. Decide early on if you want a dine in kitchen or a separate dining room. If you go the latter route, place them next to each other (obviously). The minimal size for dining rooms that will hold a table and chairs for 8 people is 4x6, but I tend to go with 5x8 to elevate pathing issues.
- Bathrooms are the second most important room in the house. Trust me on this: 1 bathroom in a house full of 8 sims just doesn't work. A minimal ratio of bathrooms to sims is 1 bathroom for every two sims plus 1 (so if you only plan on having 4 sims in the house at a time, 3 bathrooms will work well. If you foresee 8 sims in the house, you'll want to have 5). You can easily get away with having fully functional bathrooms, complete with showers and a sink, in a 2x3 room. I tend to stick with this size for most of the bathrooms, and have one or two larger ones with a shower and tub in a 4x4, 4x5 or 5x5 room. You can make larger bathrooms usable by two sims at once if you separate the tub/toilet part of the bathroom from the shower section with a wall and a door.
- One thing I typically have in every house is a library. I tend to make these somewhat large and furnish them with extra bookcases to make them look opulent. You'll want room for comfortable chairs, loveseats or couches (your preference) so 6x8 to 8x8 makes it extremely comfortable if you put seating in the middle of the room. If you just want to put a few chairs along the walls, you could reduce the size without making it look full.
- I also make studies/computer lounges separate from the library. A library is supposed to be a peaceful, quiet place and having someone playing computer games in the same room does not give me that illusion. There is no real set size for me when I make a study. It depends on how many desks I plan to put in there. Sometimes I don't even make a study, but instead put desks in the bedroom, living room, or use them to fill small areas of "waste space" in various locations.
- I tend to keep family/tv rooms separate from rec rooms. If you try to cram too much into a single room, it looks cluttered. The minimum size for a television room is 3x4, but you'll want to go larger if you want to include more than a television and a love seat. The best way is to experiment by buying cheap furniture and setting it up the way you want it. Include a minimum of 1 square on either side of the seating arrangement so that sims can get around it. Rec room sizes depend exclusively on what you want to put in it. It's best to put them in the basement in my opinion, as it's easier to adjust the size of the basement than it is to move walls around upstairs.
The best advice I can give you though is to experiment a little with building. Just go into an empty lot through "Edit Town" and have at it without the worries of budget constraints. Even if you don't move a sim into that house, the experience will help a lot.
Also, read through some of
The Official Building/Remodeling Showboat Thread. We're lucky enough to have some extremely talented builders here, and if you're having troubles or questions, you can post images there and get some extremely helpful advice.
Sorry if that was a bit long.
