Building a house is a long and involved process, and having a working knowledge of the steps between laying the first foundations and setting foot in the final product will allow you to better understand your expenses.

The more information you have, the more informed choices you can make to truly customise your experience, and help transform your house into a home. With this guide, Projex Group will take you through the process followed by construction companies encompassing planning, important milestones, technical knowledge, and the various phases of the build from the ground up.

Each builder will have a different timeline and scale for their projects; however, this guide should be able to tell you if you’re massively behind scale, or if there’s anything that hasn’t been done that really should be.


Before the first slab hits the ground, you will need to get the initial planning and preparation stages out of the way. Once you’ve purchased the land that you’ll be constructing upon, you’ll start budgeting and choosing your house plan. This is the time to decide what you truly need and want – now and in the future. If you want room to expand later, or put in a pool, a double garage, or a large window, you should be deciding this now rather than trying to retrofit it later.

You’ll also have to consult with your builder about site preparation and zoning control. Each state has a few different zoning controls for property, so make sure that your new house obeys all of them before starting work.

Step One: Excavation and Foundations

If you’re sitting on a lot that’s already had houses built upon it, and you don’t need any significant changes made to that land, then you can completely bypass this step. However, if you’re looking to make some changes, now’s the time to begin hiring some heavy movers to come in and shape the landscape.

Excavation can take several days, as it’ll quite often be combined with the initial setup of structural constraints for the pouring of foundational concrete. Once all the dirt has been cleared, you should already start to see the floor plan of the house.

Depending upon how complex the house layout is, and whether construction of one area prevents access to others, this step can take up to 4 weeks:

  1. ‘Footings’ are installed, which are essentially like guide rails for the floor plan of the house. This is the bedrock, and acts like a subterranean wall foundation.
  2. Concrete or a similar substance is poured into a mould within the cleared earth inside of the footings. This must be high enough to divert water away from the structure.
  3. Holes are knocked through the concrete for any utilities or power lines, pipes fed in, and the pipes resealed.

Foundations are legally required parts of construction. They not only provide a base for the house, but stop warping and expansion in some types of terrain. From a legal perspective, foundations are required to:

  1. Be designed by a structural engineer.
  2. Provide protection from water/moisture and termites.
  3. Provide ventilation for any sub-floor spaces.

Since concrete is not naturally waterproof, to provide this protection against moisture and termites most slabs will have a waterproofing membrane that extends about 100mm above soil height.

The reason that this waterproofing is so important is that many walls are constructed through excavation and backfill; quite often the surrounding soil must be re-filled past part of the height of the foundation after construction begins, so parts of them inevitably fall under the soil/ water level. By installing a membrane, you effectively seal the water below the surface as well as above it, preventing water from seeping into the porous underside.

Projex offers two solutions for waterproofing, which can also be installed at the foundational membrane level: Cosmofin and Wolfin. Both are high durability, German-engineered waterproofing sheet membranes that have been the Australian standard for more than 20 years within the industry, and provide the highest calibre of protection available for all areas of waterproofing.

The two options differ on their price and security points. Cosmofin is a durable and economical material that exceeds all Australian standard requirements in waterproofing. Wolfin also exceeds these requirements and is backed by a unique warranty, providing insurance against both equipment and labour.

Basements, cellars and garages

As an added note, subterranean and partially submerged rooms can sometimes mean that construction occurs beneath the water table. In this case, we use a method called ‘below ground tanking’, attaching a series of pumps to continually drain the water to the surface while construction is taking place.

This method continues past the initial foundation stage until the full construction and enclosure of walls around the area, creating an effective envelope for the room between the soil and membrane.

Once the room has finished exterior construction, the pumps are removed and soil is then backfilled above, enclosing the submerged areas without any risk of water leakage, and allowing the membrane to repel any further moisture.

Other preparations

Now is also the best time to start acquiring a line for any utilities you need at the house. Water, drains, electricity, internet, gas, and so on require time and permission to install. Your builder or contractor will handle this, but make sure that they’ve requested temporary electrical service during construction.

Step Two: Framing

Framing refers to the timber wall skeletons and outlines built by a carpenter. If the foundations and footings are the horizontal guide plan for the house, the frames help in building the vertical. Additionally, framing will start laying the tracks for the flooring, roof, doors, and windows.

If your construction company is not subcontracting carpentry duties (the easier option by far), be sure to spend some significant time vetting and choosing your company. The cost of framing is done in square feet, and quotes per square foot, which depend somewhat on a case-by-case basis, can be one of the most variable costs between companies.

Your carpenter will be one of the most significant contractors to work upon your house, so you’ll want to go with somebody who comes with the required reputation and one you can trust and consult with, going forward.

First, floor timber will be lined across any area with a wall, and then built upwards to resemble the basic rectangular outline of the walls. The actual walls won’t be built at this stage but you’ll be able to walk around and get a real feel for the interior.

Once erected, each of the wooden skeletons will be secured firmly using metal strapping, as they must be rigid enough to support the roof framing as well. Once the basic floor and walls are built and secured in this way, and the boarding is in place for doors and windows, work can begin on the roof framing.

Roof framing and slating

At this stage, the basic timberwork frame for roof slating will be erected. If you’re going for a flat roof rather than pitched, you’ll also be waterproofing it now at the substrate level.

Projex Group supplies waterproofing solutions for flat roofs; these solutions are designed to allow a multitude of finished effects after installation, or can remain exposed, as they are UV stable.

The essential process of waterproofing at the roof stage isn’t all that dissimilar to the ground membrane, but it’s important to talk about it separately from the rest of the framing process. Both Wolfin and Cosmofin are sold as complete systems, each comprising of the membrane, as well as the factory bonded PVC profiles, premade internal and external corners, detailing strips, adhesives and welding solvent, all coming together to provide the ‘total waterproofing solution’.

Slats and sheathes

This is the final major part of the checklist before work begins on the interior. Strand board is installed into the timber gaps as a rudimentary wall covering, closing the house off from weather and providing a true backbone for the internal and external walls.

At this stage, your carpenter will usually install your windows and doors for simple ease of construction. With these installed, sealed, and completed, the house is now effectively wind- and weather-proof, and fully ready to begin internal construction.

Start purchasing and planning your internal projects ahead of time: Having cabinets, installations, utilities, and work surfaces prepared well ahead of time means that your crew can begin work with the actual model specifications, and immediately slot them into construction.

Step Three: Presentational exterior

Now that the bare bones are fully completed, you can start creating the look of the house exterior. Your exterior siding will be applied here. Once veneers are completed, your house will start to take shape as a liveable form. However, there’s still a little left in the exterior to complete.

Unless there are multiple extraordinary factors at play, external work of this type can be done simultaneously with Step Four and any other internal design to save time.

Firstly, the finishing touches around the veneer, known as boxing, have to be completed. This is mostly a series of simple additions such as soffits, the covering of any architectural underhangs with tiles or slating, or any friezes you may want to present.

Next, the roof has to be tiled or shingled, and if you’re not using a flat roof with Projex’s Wolfin or Cosmofin solutions, then you’ll also need to flash with sheet metal or lead to prevent additional leakage or seepage.

This is also the time to decide on the positioning and inclusion of balconies and terraces around the exterior of your home. Whether the substrate of the balcony is concrete, timber, fibre cement sheeting or steel, waterproof membranes should be installed directly onto the substrate before tiling.

Step Four: Interior utilities

Lines and piping

The first sections of the interior that you should be covering are those that we laid the groundwork for during the foundation stage. Since the exterior and covering is complete, and the dry-in process has finished, there’s no risk to cable or piping from weather or environmental elements.

A short checklist of the things you should be planning for this stage: Permanent electrical fixtures (separate from any temporary ones used during construction); phone lines, TV lines (if separate); internet wiring; plumbing and sewerage; and any burglar alarm system.

After a quick (and compulsory) safety inspection, you’ll be ready to set these up in the future. Right now, all you’re doing is laying the groundwork in the shape of wires rather than actively connecting them to services and appliances.


Insulation bats will now need to be installed between the wall framing before any drywall/ plasterboard is put up. This can be done very quickly, and without much expertise, but it’s important to do so now rather than later.

Step Five: Presentational interior


Now that the insulation has been placed, you can begin securing your plasterboard (often referred to as drywall in America).

Plasterboard is attached directly onto the timber framework, and constitutes what you would think of as an actual interior wall. Once this is in place, the walls are functionally ‘done’, requiring only cosmetic additions from this point onward and finishing of fixture areas such as the doors and windows.

Next, depending on whether you’re going to be using a wooden trim or a painted trim, it can be worth your while to prime your plasterboard to prepare for painting later. The reason it’s a good idea to do this now is that without any other major surfaces to worry about, taping up doors and windows will ensure that you can be a little more sloppy with your coverage without worrying about getting primer on floor trim.

An added benefit of priming now is that you’ll be able to see plasterboard imperfections through the dried primer, making this the perfect time to fill them in as well. If your trim doesn’t require painting, then you can obviously skip this step.


The walls are done, and now it’s time to get the major steps of the floor down. This step includes sourcing, sanding, and finishing any hardwood, as well as the installation of any vinyl, stone, and ceramic tiles for bathrooms, patios, kitchens, or similar.

Interior trim

By now, you should have sourced any permanent utilities, work surfaces, and cabinets. Once these have been fitted to your floor plan, you can then begin to erect any further trimming you have planned for the interior.

You should also consider finishing any painting or further installation of trim at this stage, as it can lead to warping in the long term if left unmanaged.

Step Six: Final utilities


Assuming that you’ve already finished flooring and general installation of fixtures, you can now have a plumber come in to finish piping for any areas that require it. Your bathrooms will be installed at this point, as well as specific laundry fixtures, kitchen fixtures, and similar.

This is done in tandem with an electrician, who will work after the initial setup by the plumber to provide power to all the installations.

After this, the electrician will provide power to utilities that still require finalising, such as air conditioning, before beginning work on lighting, power points, and appliances.

Water retention facilities

If you’re installing a water retention facility such as a water tank on your property, waterproofing is obviously important to ensure it does its job correctly. Most tanks are concrete or concrete-filled blockwork, with Wolfin and Cosmofin waterproofing solutions being perfect for immediate application, as they are pre-formed sheet membranes supplied in a roll form. This is a much more efficient, secure and long-term alternative option to liquid membranes, which often need a substantial amount of time to harden and ‘cure’ before they can be put into use.

Step Seven: Tidy up, scrub out

At this stage, the house itself is ‘complete’. It resembles a liveable house, if not a home, and the vast majority of the subsequent work after this step is up to either you or an interior designer.

As a result of home construction, there’s going to be a lot of accumulated rubbish that’ll need to be hauled, soil to fill in, beaten paths to make pretty, and landscaping to be done.

You should finish all of this before continuing any further, as the rest of the remaining tasks require somewhat of a clean slate to even begin. Laying things such as indoor carpet is an important next step, but it can’t be done if there’s debris and dust everywhere from the installation process.

Step Eight: Final build

Construction has firmly begun to wrap up at this stage. A driveway is only really possible to build once the massive flow-through of construction equipment peters out, so you’re invariably going to be constructing it now rather than earlier.

Now is also the time to begin landscaping. Unless you’re going with pre-grown plants and a majority of rolled-out grass, this is a process that will take considerable time to get fully settled in, so starting now will save you time in the long term.

Enjoy your completed project

After final construction, the rest of your duties are mostly inspections, checks, finalisations of payment or loans, and furnishing and completing the interior of the house to make it liveable. Whether you’ve built your new house for you and your family or for investment purposes, you will realise now that the hard part is over.

If you’re considering building a house, get in touch with Projex Group today to discuss waterproofing solutions, protective matting and pipe sealing that will be necessary for building a secure and long-lasting home.