What are Building Codes?

If you are embarking on a build you will probably hear mention of building codes. At N A Hill Designs, in our role as a building designer, one of our responsibilities to our clients is to have a thorough knowledge of the current building codes and to navigate these for you as part of the design process.

The term ‘building codes’ in Australia refers to the National Construction Code (NCC) which incorporates all on-site construction requirements into one single code. The NCC basically sets out the minimum requirements for the design, construction and performance of new buildings, and new building work on existing dwellings, throughout Australia.

The regulations cover everything from fire safety to energy efficiency and quite a number of regulations will affect how your home is designed and ultimately built. These regulations are mostly concerned with ensuring that liveable areas are safe and healthy.

You might find that some ideas you have for your build need to be tweaked to conform to regulations. This is where our expert knowledge (and that of your builder and contractors) is invaluable, helping you get the result that you want while also ensuring a safe, efficient and legal build.

We have examined just a handful of regulations to demonstrate how they affect building and design.

Windows or not?

Windows come under a few regulations, one of them being “daylighting requirements”. These regulations state that habitable rooms require permanent access to fresh air and natural light. This access is mostly through windows and skylights and requires that windows be of a size equal to at least 10% of the floor area and skylights at least 3%.

Most modern residential designs more than cover these requirements but there might be some rooms where you think windows are unnecessary, for example media rooms and home theatres, or even music rooms.

Habitable rooms are defined as those used for normal domestic activities such as living room, dining room, bedroom, sunroom, play room and so on. This includes media rooms and home theatres, thus making them subject to the daylighting regulations.

Spaces that are not classed as habitable rooms are bathroom, laundry, toilet, pantry, walk-in robe plus hallways and lobbies. Basically any space that isn’t occupied for extended periods of time.

Rooms like bathrooms and laundries are still regulated in respect to adequate ventilation but not by daylighting regulations, meaning windows can be dispensed with if required.

Ceilings, how low can you go?

Ceiling heights are regulated, with the NCC stating that habitable rooms (excluding kitchens) must have a minimum ceiling height of 2.4m. Kitchens, laundries, bathrooms and garages have a lower minimum height, 2.1m, as do hallways and corridors.

If your build includes an attic, more than 50% of the ceiling needs to be, on average, the minimum height. So if the attic was to be used as a habitable room that would be 2.4m. If it is purely for storage you can get away with a 2.1m minimum.

Your minimum ceiling height is typically measured from your floor finishes – your carpet, timber or tiles – so you need to ensure this is taken into consideration in the design process.

Decks and safety.

Regulations come into play outside your home too. If you are keen to add an entertainment deck to your home you will need to take the relevant codes into consideration.

Any deck or verandah that is raised 1 metre or more above the ground is required to have a handrail. At less than 1m it isn’t a requirement but depending on the site of the deck it may still be recommended for safety.

If your deck is over 4m from the ground your handrail needs to conform to additional regulations, including that there must be no climbable elements between 150mm and 760mm of the floor. This means that handrails must not include anything that can be used as a foothold, meaning that horizontal balustrades are out.

The handrail itself must be at least 1m in height with no more than a 125mm clearance from the floor. The space between balustrades should be no more than 125mm to prevent objects (or children) falling through.

There are other regulations that come into play depending on various contributing factors such as location, materials used and so on. For example, if your deck is sited in an area with strong winds, such as a coastal location, you might have to conform to extra regulations around the capacity for load on rails.

Decks and handrails are an area of particular investigation with respect to safety so regulations can be frequently updated. We always ensure we have the latest information at hand when taking on a project.

Bathrooms and wet areas.

There are quite a few regulations when it comes to bathrooms, dictating how a bathtub or shower must be installed and how far it must be from power points (0.6m, with conditions) but one of the most misunderstood areas of bathroom design is the waterproofing required.

Part of this is due to the wonderful interior images we have access to nowadays – great for inspiration but not always conforming to regulations. Bathrooms are the area of your home needing the most waterproofing. This is to protect the structure of your home from water damage which can occur unnoticed and can be extremely costly to repair.

Waterproofing regulations are pretty black and white. Entire shower floors need to be waterproofed as do the walls to a height of at least 1800mm. The rest of the bathroom needs the walls waterproofed to a height of least 150mm and if you go for a timber floor, or it is a second storey bathroom, the entire floor must also be waterproofed.

These are the regulated minimum requirements but often it makes sense to waterproof the entire floor and wall areas around the bath, toilet and sinks too. Waterproofing is done in stages so the decisions about waterproofing need to be made in advance.

Kitchen and laundries are also rooms with active plumbing thus needing to comply with waterproofing regulations. Another thing to consider in your kitchen is whether you will have a gas stovetop. While some waterproofing surfaces such as glass and metal splashbacks seem a good choice as they’re not flammable, they are extremely good conductors of heat. If you have these running behind your gas burners your builder may have to take extra precautions to cover regulations and also keep you safe.

We do the hard work.

Building codes can be time consuming to wade through and tough to understand if you are not in the industry. As you can see they also have an impact on both the design of your home and the build. And if they are not taken into account in the final design phase they can lead to expensive changes down the track.

At N A Hill it is imperative for all our jobs that we are familiar with, and experienced at working within, the current national codes. There are also codes that apply to only some regions and your build may need to be checked against these.

Ultimately building codes are there to protect you and ensure your home is safe. We will incorporate them as we design your home and only mention them, by way of explanation, if they have an impact on your vision.

If you have any questions regarding particular construction codes please don’t hesitate to ask us.