House Floor Plan Design

I’m a professional building designer and draftsman with over 10 years experience designing houses, extensions and renovations. I’ve written this house floor plan design guide to explain some of the basic principles of designing a good house 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 projects in Tasmania:

Internal Living Space

$1300 – $1600 for a basic finish level

$1600 – $1800 for a medium finish level

$1800 – $2400 for a high finish level

Decks & Patios

$300 – $900

Garages & Carports

$600 – $1000

Some factors that can add to your 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, 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). 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 over (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.

The best way to find out what your cost per meter is likely to be is to call some local builders, they will often give you a rough cost over the phone or might have standard floor plans that they can give you prices for that you can use to estimate your cost per meter. Even is your owner building this will give you a good idea of what to expect.

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

Standard wall thicknesses (in mm):

  • Double Brick – 230 – 250
  • Brick veneer – 230
  • 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 complected so it’s very important to either thoroughly research all of these principles yourself or hire a professional draftsman who can review your house design before you put too much time into it.

To find out more about some of the basic energy efficiency principles checkout my guide to Energy Efficient House Design.

Professional Design Sketches & Working Drawings

Once you’ve drawn a rough floor plan design sketch it’s a good idea to have a building designer produce professional drawing of your design. In Tasmania building plans for council approvals must be provided by a registered Architect or building designer.

I often provide house design drawings for clients who have already drawn their own sketches. I then review and re-draw their design sketch suggesting improvements along the way. It’s important to have an accurate CAD design drawing to ensure the design fits the block and complies with relevant building regulations, design principles, energy efficiency principles and is practical to build.

Your custom house design sketch can be used to get prices from builders and development approval. For building approval more detailed building plans will be required.

Checkout examples of my House Building Plans or get an obligation free quote for me to draft professional plan for your new house.