Deciding on the layout of your new house is an important decision. A well designed floor plan can create a home that’s appealing to look at, functional to live in and comfortable all year round. Starting with a good floor plan design can also reduce construction costs potentially allowing for a higher quality finish or extra space.
As a professional building designer with over 12 years experience designing new houses, I’ve helped hundreds of people create beautiful, practical and energy efficient house plans. I’ve written this house floor plan design guide to explain some of the basic principles of designing a good floor plan and give some expert tips and advice to help you design your own home.
Design To Your Budget
The first step you should take, particularly if you have a tight budget is to get an approximate cost per square meter. This will help you design a house floor plan that’s not too big for your budget and will also tell you if you have extra space available to use up.
The cost per square meter to build a new house varies between states and cities but as a rough guide these are some average costs per square meter for building a new home in Australia:
Internal Living Space
$1000 – $1600 for a basic finish level
$1500 – $1900 for a medium finish level
$1800 – $5000 for a high finish level
Decks, Patios & Carports
$300 – $900
$600 – $1000
Some factors that can add to the cost per square meter of building your house:
- Building in rural areas or small towns where materials need to be transported and trades need to travel.
- Steep blocks which require significant earthworks or retaining.
- Clay or unstable ground that will likely need larger footings than normal.
- Limited access (if materials need to be carried through are around the house by hand this will increase the labour costs).
- Small houses (your bathroom, kitchen and laundry cost more per meter so small houses where these rooms make up a larger proportion of the house are likely to cost more).
- Using unique or non standard building methods and materials. This can make it difficult to find a builder or contractors as many will not want to work with materials or methods they’re not familiar with. Many builders will also increase their quotes to allow for problems they may find while working with a new material or method.
- Complicated shape (a square house uses less materials than one with lots of corners or protruding rooms).
- Large glass panels. Large windows are not necessarily expensive if they are broken into smaller panels with transoms and mullions (horizontal and vertical frames within the window). However having large panels of glass without transoms and mullions cost more because they need to be made from thicker and stronger glass. Wide windows also need larger lintels to support the roof above (the wider the window the stronger the lintel needs to be).
- Bushfire or flood zones. When building in these areas you need to use materials that are bushfire or floor resistant which can cost more.
- Building a two story house on a site suited to a single story house, check out my article on Single Story vs Double Story for more information on how this can affect your build cost.
Calculating a cost per square meter
A good way to find out what your cost per meter is likely to be is to look at some similar house designs advertised by building companies in your area. You can calculate the cost per meter by dividing the cost by the size of the house (eg a $300,000 advertised build cost divided by 200 square meters equals $1500 per square meter).
When estimating a cost per square meter be careful to check what the advertised cost includes. Advertised costs generally don’t allow for earthworks or other site specific requirements. Other costs such as floor coverings, window treatments, landscaping and air conditioning are also often not included.
Room Types & Placements
Before you can start drawing your layout you’ll also need to decide on what rooms you want to include in your house floor plan design and where these rooms are going to be located.
I always start designing a floor plan by sketching roughly scaled bubbles or circles with the room names in them on an outline of the land. This way I can workout which rooms are going to be next to each other and which rooms will have a view or get the north facing sun.
This also helps you make sure your house layout fits on your block and makes the most of the space available.
Some good house layout tips:
- Make sure every habitable room has a window. It’s a requirement of the National Construction Codes that all habitable rooms have access to natural light and ventilation. This doesn’t apply to non habitable rooms. Non habitable rooms are “spaces of a specialised nature occupied neither frequently nor for extended periods”. Some examples are: bathrooms, laundries, robes, pantries and passage ways.
- While not required it’s a good idea to have windows in bathrooms, laundries and toilet/WC’s where possible.
- Keep the kitchen close to the garage so that it’s easier to bring in the shopping.
- Make sure all bedrooms are near a bathroom and that you don’t need to walk through a living space to get from a bedroom to a bathroom.
- Allow for furniture and make sure it won’t block the flow of traffic (For example, don’t place passages or doors that make the shortest route through a dining room right through the middle if there’s going to be a dining table in the middle of the room).
- Keep the laundry and linen cupboards near access to an outdoor drying space.
- Make sure doors aren’t opening into furniture.
Floor Plan Design Sketches
Once you have a rough layout of the room types and placements you can start drawing a more detailed layout showing the room shapes and sizes, hallways or passage ways and doors or openings. You should also allow for wall thickness as this can add up to quite a lot of extra space. You’ll also need to allow for fixtures and make sure there is enough space to move around comfortably.
Minimum space for comfortable movement (in mm):
- Hallways & Passages – 930 (preferably 1000)
- WIR space between shelves – 700
- Bathrooms – 800
- Kitchen space between benches – 1000 (preferably 1200)
Standard door sizes (in mm):
- Bedroom, Living area & Laundry doors – 820 wide
- Bathroom doors – 720 wide
- WC & Pantry doors – 620 or 720 wide
- Doors for disabled access 870 or 920 wide
Standard wall thicknesses (in mm):
- Double Brick – 230 – 250
- Brick veneer – 230 – 250
- Timber or steel framed – 90
- Internal walls (framed or brick) – 90
Standard fixture sizes (in mm):
- Bathroom vanities – 350 – 600 wide
- Small shower – 900 x 900
- Small bath – 1575 x 750
- Laundry bench – 600 wide
- Kitchen bench – 600 wide
- Robe, linen & pantry shelves – 450 wide
Building Regulations, Energy Efficiency & Structural Design
In addition to designing a practical and attractive home floor plan you also need to consider other requirements and principles like building regulations, energy efficiency and structural design principles.
Many of these requirements can be quite involved so it’s very important to either thoroughly research all of these principles yourself, hire a professional who can help you create a house floor plan or use a professional pre-drawn house plan that’s suited to your needs.