Building on Irregular Lots: What You Need To Consider Before Construction

Building on Irregular Lots: What you need to consider before construction

Irregular lots are an excellent opportunity to create something unique. From a developer’s perspective, it is a design challenge that allows them to use the full extent of their skills. From an owner’s perspective, they have the chance to build a custom home tailored to their needs. It may just be the perfect place to raise a family, retire to or resell in the future!

If you want to develop an odd-shaped lot, there are several things you need to consider before construction.

To effectively develop an irregular block, you must consider how to make the most of the block’s unique shape and features. You’ll need to work with an experienced builder to create a custom home design, maximising the use of space, function and aesthetics of the home. An unusually shaped block can be transformed into a beautiful family home or a great investment, as long as you have the right team working on the development.

If you’re looking to buy an irregular block, being informed about the pros and cons of different lot shapes can help you get the most out of your build. Read on to learn more about building on irregular-shaped blocks.

What Is Considered an Irregular Lot?

An irregular lot is any block that is not square or rectangular, has an asymmetric shape, or an unusual number of sides – whether that’s three (a triangular block) or more than four. Other examples include truncated blocks, cul de sacs or fan-shaped blocks, and battle-axe or hatchet-shaped lots.

Irregular lots are notorious for being challenging to develop, as many of them are very narrow or sit on sloping plots. However, when you partner with a specialist custom builder, you may find building on an odd-shaped block incredibly rewarding.

What Types of Irregular Blocks Are There on the Market?

Narrow Lots

Narrow lots are considered irregular blocks because they do not conform to the standard size of land for development. Though the size differs from state to state, blocks under 15 metres are typically considered narrow lots. Most structures built on narrow lots are in urban areas, but there are also some near shorelines.

People who want to develop narrow lots usually choose to build up. Achieving privacy, nice views and outdoor living space is a common concern with narrow lots. However, there are some clever options such as having a garden rooftop or a side courtyard. If you have a car, you can create a front-loading garage or opt for a separate parking space.

Triangular Blocks

Triangular blocks are also called pies, chips or corn chips. As their name implies, triangular lots have three angles and can be expansive or limited in area. Though they do pose some challenges when using standard house plans, triangular blocks are starting to gain popularity for unique, modern builds.

A regular-shaped house or structure can usually be built within a triangular block, leaving the odd angles as wedges for a garden, pool, or recreational area. Conversely, if the triangular block is small, you can develop the entire space and build a uniquely shaped home or office. Some people turn the tip of a triangular home into a window to let in natural light.

A variation of a triangular block is a fan-shaped block. Fan-shaped lots are usually attached to a cul de sac or a roundabout (traffic circle). It is typically narrow on the frontage (when it faces a cul de sac) and broad at the rear.
If the cul de sac is part of your property, this can give you a nice, long driveway for privacy or a unique landscaping opportunity.

Shallow Blocks

Shallow blocks are plots of land that are not as deep as they are wide. Most shallow blocks are also listed as wide-shallow lots. One problem with shallow blocks is that they can only adhere to limited floor plans because of the reduced depth of the lot. These will typically require a custom-designed home and often a multi-storey development.

Battleaxe Blocks

Battleaxe blocks (also known as hatchet-shaped blocks, hammerhead blocks, or flagpole blocks) are characterised by a narrow path or an L-shaped access corridor (like an axe handle) leading to a wider lot space, which can be regular or irregular in shape (like an axe head). There are varying types of battleaxe or rear strata blocks, so the access corridor may or may not be exclusively owned. Generally, only the larger rear section of a battleaxe block is suitable for building on.

Properties on a battleaxe lot can be good for peace, privacy, and safety, as the property is far from the street. However, rear strata blocks pose some unique challenges that require careful planning.

Wide Frontage Lot

A wide frontage lot refers to a block with a wider area facing the street than the rear. Blocks with wide frontage are usually characterised by a nice front yard or garden.

Corner Block

A corner block can also be considered irregular. It refers to a lot that is at the intersection of two streets and therefore has two frontages. Though some corner blocks take a regular square or rectangle shape, others are asymmetrical, dome-shaped, or a truncated triangle; it really depends on the street intersections.

Corner blocks have high visibility, so privacy is a common concern. Owners of corner blocks sometimes remedy that with plants and landscaping – an excellent solution since corner blocks receive more sunlight than standard properties.
Something to consider when building on corner blocks is that more local development restrictions can apply since the property is close to roads, which are public domain.

Asymmetrical Blocks

Asymmetrical blocks refer to odd-shaped lots whose shape cannot be divided equally down the middle. These usually have more than three angles and/or sides. For example, a truncated triangle block can be considered an asymmetrical block.

Since standard house plans are quite often symmetrical, these blocks often require a custom design to suit the unique shape of the lot. Houses developed on asymmetrical blocks can take advantage of irregular areas and turn them into unique outdoor features like garden zones, a koi pond, playground or a BBQ area.

Pros and Cons of Irregular Blocks

Pros of Irregular Blocks

  • Irregular blocks are typically less costly than standard blocks.

If you invest in an irregular lot, you can usually get a nice discount per square metre, leaving you with a little more capital to spend on your dream home.

  • Unique opportunities in architecture and design.

Irregular blocks also present buyers and developers with a unique housing opportunity. Those that sit on slopes or corners tend to offer more space, more natural light, and nicer views compared to landlocked ones. If you want a one-of-a-kind patio, balcony, or garden, you can achieve that with a house on an irregular block.

  • Great development and subdivision potential.

Irregular blocks can also have excellent development potential. For example, the right triangular block with a wide rear has the ability to be subdivided into multiple lots. This could allow two or more townhouses to be erected, creating a much bigger return for investors.

The uniqueness of houses built on irregular blocks also makes them an excellent site for a trendy Airbnb or striking modern home.

Cons of Irregular Blocks

  • Requires experienced custom designers and builders

Building on odd-shaped blocks can be complicated, so you really need to hire an experienced builder. Experienced architects and engineers who specialise in developing irregular blocks can help you assess the land (soil quality, stormwater requirements, etc.) and complete the necessary paperwork (council requirements, building restrictions, etc.).

  • Restrictions on potential floor plans and building styles

Irregular blocks on slopes can pose different challenges to your floor plan, like where to build the garage or how to deal with stormwater runoff. Trying to figure out how to address those on your own will be challenging, especially in the long run. Thus, it’s a good idea to invest in an experienced custom builder to ensure nothing is overlooked.

Building on Irregular Lots: Here’s How To Make It Work

Many people are concerned about investing in irregular lots, but developing odd-shaped blocks can actually be as easy as building on a regular block. As long as you have an experienced builder to do the job, you can create your forever home without feeling restricted.

Before you talk to your developer, here are some tips to help you understand construction on irregular lots.

Understand the Characteristics of Your Land

When eyeing out an irregular block, it is essential to have a surveyor check out the land first. This is the best insurance policy to ensure your land meets all the benchmarks required by law, and the home is designed using accurate dimensions. In addition, a surveyor will help you understand any building constraints and/or boundaries necessary before you begin planning. Considering the nature of irregular blocks, proper surveying is important to establish the legal boundaries of ownership, determine the right of way, and maximise the property’s usable area.

Before considering purchasing an irregular block, ask your realtor about the land. Apart from the size or perimeter, find out about the characteristics of the soil—is it mostly clay or loam? Is it chalky, silty, or saline? It’s a good idea to conduct soil testing on any lot before you start planning or building.

Knowing the features of your land can help estimate building costs— for example, if you need special equipment for excavation and building the foundation, or if it may be challenging to install piping and stormwater drainage. It can also help you prepare for natural mishaps— like whether the land is prone to erosion or mudslides.

Also, check out the surrounding areas around the block. Nearby trees, natural springs, aquifers, and other geographical features can affect the land you’re buying.

Understanding all these characteristics will allow you to carry out necessary site works before construction begins, taking care of the longevity and stability of your home.

Design According to Council Planning Requirements

Creativity and innovation are key to building on an irregular block. However, the property still needs to adhere to the building codes implemented by your local authority or council.

Work with your developer to design your dream home with these considerations:

  • how your housing development interacts with the streetscape;
  • how you place balconies and windows with regards to privacy;
  • what your minimum outdoor space should be;
  • how much space your plants and landscaping can cover;
  • how environmentally sensitive your design is; or
  • which way your house is allowed to face (aspect).

Use a Custom Builder, Not a Standardised House Plan

Getting a custom builder means you get to work closely with a team on a unique design for your block. Trying to squeeze a cookie-cutter home onto an irregular or odd-shaped block is a recipe for disaster and disappointment. Instead, find the right building partner who will help you maximise the utility and liveability of your future home.

If your irregular block is on a slope, is shallow, or has some geotechnical issues, it is best to get professionals to tackle these issues. Custom builders experienced in developing irregular blocks or challenging sites already have a network of experts and contractors who can achieve the results you’re looking for. They can work with any geographic feature or site constraint and incorporate it into your dream home.

Using a custom builder will also make it easier for you to make changes and adjustments to the plans instead of contacting numerous architects and contractors. This kind of flexibility can ease the process of developing your odd-shaped block.

Make the Most Of Your Outdoor Space

Your home is not just the building where your bedroom is; it is also your yard and outdoor spaces. Irregular blocks can have amazing landscaping potential, giving you private pockets of land to add features and fun outdoor living zones.

There are many options for designing the outdoor space of an irregular block. For example, you can focus on landscaping with plants, flowers, or trees; or be more creative with a vegetable garden, pond, kids cubby or a pool. As long as you’re within the parameters set by the council, you can let your imagination run wild.

How you decorate your outdoor space can even conceal the fact that your property is on an irregular block. This can help if you’re planning to resell the property later on – but as a rule of thumb, the shape of a lot is far less important to buyers than the value and lifestyle benefits it offers.

Design Your Home Around Central ‘Family Hubs’

Family hubs are spaces for big gatherings—it’s where the kids can play, friends can mingle, and your pets can enjoy themselves all in one place. That hub can be your kitchen, living room, or dining room. So first, decide where you want to put the biggest family hub—consider where you want it to face and how many windows you’ll be putting in. Once you have that set, you can start planning the adjacent rooms.

Some of the most successful home designs for irregular blocks focus on these central hubs and then build additional rooms around this point to suit the block’s shape. If anything needs to be changed, you can be flexible with the other rooms since you have already established the most important area in your house.

Adding Extra Living Spaces & Home Zones

You should expect odd-shaped rooms and spaces with irregular blocks – but this doesn’t have to be a negative thing! Those areas can be used to extend certain living spaces and add architectural interest to your home. For example, some builders use those odd-shaped areas to put windows for more natural light and create a pergola for an accent, or a balcony as an extra living space.

Perhaps you’ve always wanted to have a cosy reading nook or a built-in table and chairs off the kitchen. A custom builder can explore ways to achieve your unique lifestyle goals and deliver you an extremely rewarding family home full of added bonuses that make it perfect for you.

Alternatively, odd-shaped corners can be great for adding extra storage areas – consider a walk-in pantry!

Making the Most Of Sunlight and Ventilation

Some builders opt to use irregular angles in home designs for natural light and ventilation.

If you’re developing your irregular block, you can have bay windows or floor-to-ceiling windows at one point or angle, especially if the angle is small. Since furniture is not naturally designed for odd angles, you can maximise that odd-shaped spot by using it to let in some sun.

If you want the space to be more open, opt for a wrap-around balcony or pergola to increase your outdoor space and improve ventilation. Integrating indoor and outdoor spaces can be a great way to work with a challenging block.

Making a Grand Impression

Since properties on irregular blocks pose certain challenges that standard lots do not have, most of these houses are not cookie-cutter properties. Instead, owners and designers take advantage of the odd angles and/or slopes to make a grand impression. These design features can range from pergolas and balconies to fun landscaping or garden choices.

For narrow properties, you can try to make the space look bigger with large windows and add accent bars to maintain privacy. For wide-frontage homes and corner lots, a unique landscape is a go-to option.

For blocks that sit on steep slopes, you can build your home on steel stilts or create a walkout basement. Whatever the solution, irregular blocks are the blank canvas for absolutely stunning homes.

Build Up, Not Out

You can make the most out of a small, irregular or narrow lot by building up instead of out.

Building a multi-storey or double-storey home can multiply your home’s floor space, adding critical area to narrow-lot homes. Where odd-shaped lots can reduce the viable footprint or foundation of your home, adding height means you don’t have to compromise on size and liveability.

You can also take advantage of incredible views that you can only see when you build up, especially if you have a battleaxe block – adding not only enjoyment but also value to your home.

Are Irregular Shaped Lots Harder to Sell in the Future?

Irregularly shaped lots can be cheaper per square metre compared to regular blocks. So even though investors and builders need to spend more developing a home on an odd-shaped lot, it can make for a unique build, which can catch the right buyer’s eye.

If an irregular lot is undeveloped or lacks unique assets, it can be more challenging to sell. The same holds with smaller blocks. A good builder and designer will be able to help you maximise your property’s value. They can suggest the best ways to design for the unusual geography of the block and ensure every square foot is put to good use. Most buyers prioritise high-quality house design and liveability and tend to see lot shape as a second priority.

What Is the ‘Frontage’ of a Lot?

Frontage refers to the area or boundary between a buildable plot of land and the street. It can also refer to the width of a block, measured at the side facing the street. Sometimes, this is also written as Frntg. The frontage of a block has a significant impact on what can be built and the overall profile of a home.


This article is published in good faith and for general informational purposes only. It does not take into consideration your individual circumstances and does not constitute an estimate for any specific project. Central Avenue Homes does not make any warranties about the ongoing completeness, reliability and accuracy of this information. Construction costs and other financial details vary and you should always seek a specific quote. 

Greg Grainger

Greg has over 40 years of experience in the WA building industry starting as a carpenter joiner.

He is entrenched in the local industry and has served on the board for MBAWA (Master Builders Australia WA) for over 10 years and was a founding director of Wesbuilders Cooperative for over 11 years.

With this experience he is able to quote accurately on new projects without the huge increase to provisional sum allowances.

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