What you need to know before you build a 2nd Storey Extension

Brighton renovation and restoration

Let’s face it, 2nd storey extensions are in demand with higher land prices. Building a 2nd storey extension is a great way to add living space and mod-cons without the cost and hassle of selling your home and finding a new one. It is also a way to retain your backyard space, avoid excavation costs and add value to your home.

We have put together a list of key items to consider before you build your 2nd storey extension.

Block size

If you have a small block size going up is a good way to maximise your living areas.  Study the precise shape and surroundings of your block. Consider things such as orientation, nearby trees, buildings, the elements etc. Is the ground level? Where are the access points? All these issues will help determine the right home design for your block.


It’s always worth checking with your local planning authority (local council), however, the basic rules are that planning permission may be required if the extension:

  • covers more than half the area of land surrounding your home
  • extends towards a road
  • increases the overall height of the building
  • extends more than 6m from the rear of an attached house
  • extends more than 8m from the rear of a detached house
  • is taller than 4m
  • is more than half the width of your house
  • uses different materials to those of the original house
  • includes a balcony or raised veranda

Councils may not provide you with a permit if you don’t meet their regulations and/or your neighbours complain about the nature of your home extension. With this in mind, it is always recommended that you consult your neighbours when developing your ideas as to how you are going to extend your home.


Consulting your neighbours early in the process can help maintain your relationship and they can also be a good source of ideas for your home. When you work closely with your neighbours you can overcome objections and delays to obtaining a planning permit by compromising and coming up with a plan that suits both parties.


You have probably heard the “facing north” is the golden rule for a home as they get all day sun, keeping the home warm in the winter and give the backyard sun in the summer. You need to discuss with a designer on how best to orientate your floor plan to maximise your site’s orientation.

Controlling the climate

It is worth discussing the following with your builder to plan your home to maximise your costs in heating and cooling your 2nd storey extension.

Window placement: With open plans, it is nice to have the kitchen and living areas downstairs facing north and the master bedroom upstairs also has the benefit of north facing light. Avoid windows facing west to help keep the sun at bay or at the very least have good window fittings for shade.

Cross Flow Ventilation: having windows on opposite sides of the room or vented via a skylight that opens is a way to increase airflow.

Effective insulation: for Australian double storey homes, insulation between the ground and the first floor can reduce energy loss. In addition, floor joists can be adjusted to accommodate the ducts.

Solar panels– can reduce your energy bills.

Water tanks – these can now be fitted under decks as large bladders which can reduce your water consumption costs.

The budget for your renovation

Setting a realistic budget can be difficult prior to the build, here are some costs to consider.
-Purchasing the land – if a new build
-Design and purchase costs
-Site costs
-Construction costs

Why not download our Two Storey Extensions LookBook Today?

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