Knockdown Rebuilds and Non-Standard Blocks

A knockdown rebuild  gives you the chance to stay in the location you love while enjoying a brand-new home. Before you start down the journey to building your dream home, it’s important to determine whether your existing property is suitable for a rebuild. Every block is different, and some sites need extra planning or professional assessments. Ultimately, the more you find out early on, the easier the whole building process will be. 

Here at Eden Brae Homes, we know a thing or two about knockdown rebuilds on narrow and sloping blocks. In this article, we’ll explain the key factors that determine whether your land is ideal for this kind of project. We’ll cover block size, shape, slope, access for demolition and construction, soil conditions, drainage and council rules, so you can identify any early challenges. 
 

1. Block Size and Shape 

The size and shape of your block are the starting point for a knockdown rebuild. Most modern home designs will suit a standard block, but more unique sites may call for a more tailored solution. 

Standard Blocks 

A wide, deep and mostly level block opens the door to far more design choices, and it usually makes council approvals easier too. A standard block also means you can take your pick of Eden floor plans depending on your budget or ideal style of home.  

Narrow Blocks 

Worried about a knockdown rebuild on a narrow block? Don’t be. The reality is that most people who own homes in established suburbs have to deal with smaller blocks. If you’re planning on knocking down and rebuilding on a narrow block, it’s important to know that it’s absolutely possible. People build amazing homes on them all the time, like multi-level or smart single-level layouts that make the most of every metre. However, selecting a design that maximises natural light, functional flow and privacy is crucial. Setbacks and boundary rules can influence your final design, so an early site assessment is recommended. 

Irregular Blocks 

Some blocks have angled edges or are shaped like triangles. These can still be used for a knockdown rebuild, but you might need to make a custom design. A professional site assessment will help you figure out the best way to place the house so you can use the space to its fullest. 
 

2. Slope and Topography 

The way your land naturally slopes can affect your rebuild. A steep block doesn't mean the deal is off, but it does mean more planning and sometimes more money. 

Sloping Blocks 

A knockdown rebuild on a sloping block gives you the perfect chance to get creative and possibly even score some nice views. Split-level designs or homes with stepped floors really work well here, but you'll probably need things like retaining walls, special drainage, and additional engineering. It also means that you’ll need to ensure you get a detailed survey done before you settle on your plans. 

Flat Blocks 

Flat blocks are the simplest sites for a rebuild. They allow for standard home designs and require less earth-moving work. 
 

3. Access for Demolition and Construction 

A knockdown rebuild involves two major phases. First, removing the old home. Second, constructing the new one. This means your site must be accessible for machinery and trucks. 

Vehicle Access 

Demolition crews need room for their machines and trucks, and builders will want access for big deliveries like concrete and framing. If your street is narrow or your driveway is tight, the process can still work, but the builder may need alternative entry points or staged delivery options. 

Neighbouring Properties 

If your home sits right up against a neighbour’s fence or another building, the demolition team just has to be extra careful. A site inspection will determine whether you’ll need temporary barriers.
 

4. Soil Quality 

The condition of your soil has a big influence on the cost and complexity of your build. Soil tests are mandatory for all knockdown rebuild projects. 

Why Soil Tests Matter 

Soil type affects the design of your foundations. Reactive clay, rocky soil or soil with deep fills may need reinforced footings or specialised engineering. If your soil is stable, your build will be more straightforward. Soil tests also help identify underground services like sewer lines that may affect your home layout. 

What to Expect 

A geotechnical engineer will take samples from your block and sort the soil. This report will help your builder ensure your new home is safe to build and live in. 
 

5. Drainage and Water Flow 

Poor drainage can be a problem during construction and after you move in. Each block needs a clear plan for how water will flow across the site. 

Natural Water Flow 

A sloped block may send water to the back or side of the property. Flat blocks may experience pooling after rain. A good drainage system keeps your ground dry and makes sure the site meets council rules. 

Stormwater Management 

Your builder may need to add stormwater pits, upgrade pipes or redirect water flow. Some councils also want certain systems to deal with runoff. You can plan ahead by conducting a site assessment to find out what you need. 
 

6. Council Zoning and Planning Controls 

Local planning rules apply to all properties. These regulations influence the construction and location of your new home. 

Zoning 

Most residential areas allow a knockdown rebuild, but there are exceptions. Some heritage zones restrict demolition and some environmental zones require special reports. Checking your zoning early helps you avoid delays. 

Setbacks and Height Limits 

Councils set limits on how close your house can be to the front, side and back of the property. They might also set how high your new house can be. These rules are important for a knockdown rebuild on a narrow block, sloping block and an irregular block. 

Easements 

Most properties have easements for drains, sewer lines or utility infrastructure. You cannot build over these areas, so your home design may need adjustments. 
 

7. Existing Services and Infrastructure 

Your block must have access to essential services: water, electricity, sewer and stormwater. These need to be safely disconnected during demolition and reconnected or upgraded during construction.  
 
If your home is older, your sewer line may be shallow, narrow or in poor condition. Your builder will help you figure out if you need to replace pipes or meters.  
 

8. Potential Hazards or Site Constraints 

Some blocks include trees, overhead power lines or old retaining walls. These features can influence your rebuild. 

Trees 

Large trees may require council approval to remove, while some tree species may be protected and can’t be removed. 

Power Lines 

Overhead power lines may need temporary relocation during construction. 

Retaining Walls 

Old retaining walls might need reinforcement or removal before building begins. 
 

When to Seek Expert Advice 

While you can spot many site challenges yourself, a professional site assessment is essential for a safe and successful knockdown rebuild on a sloping block, narrow block or irregular block. Eden Brae Homes works with surveyors, engineers and certifiers to ensure your land is suitable and your design meets every requirement. 

A detailed site assessment will confirm: 

• If your slope needs engineering 
• If soil conditions affect your foundations 
• If drainage upgrades are required 
• If vehicle access is adequate 
• If council rules influence your design 

This information helps you plan with confidence and avoid unexpected costs.