Best Insulation for Old Houses in Perth (What Actually Works)

If you're trying to find the best insulation for old houses in Perth, you're probably dealing with a home that just doesn’t hold temperature well. It heats up too quickly in summer, cools down too fast in winter, and certain rooms never seem comfortable.

That’s normal for older homes. Most weren’t built with modern insulation standards, and some have little to none at all. The good news is, you can improve things significantly — but only if you focus on the right areas.

This guide breaks down what actually works, based on how older Perth homes are typically built.

Why older homes feel harder to control

Older houses behave differently to new builds. They usually have:

  • minimal or no ceiling insulation
  • uninsulated external walls
  • gaps that allow air to move freely
  • roof spaces that heat up quickly

Because of this, even small upgrades can make a noticeable difference.

Start with ceiling insulation (biggest impact)

If your home doesn’t have proper ceiling insulation, this is where you’ll get the biggest improvement.

In Perth, a large amount of heat enters through the roof. Older homes often have outdated or very thin insulation, if any at all.

Upgrading to modern ceiling batts like:

can dramatically improve how your home feels day to day.

👉 You can compare options in the ceiling insulation range.

For most older homes, moving to at least R4.0 or R5.0 is a noticeable step up.

Can you add wall insulation to an old house?

This is one of the most common questions.

The answer is: sometimes — but it depends on access.

  • if walls are being opened during renovation → easy to install
  • if walls are already finished → more difficult and limited

Where possible, adding wall insulation improves both comfort and noise reduction.

Products like Earthwool R2.7 HD Acoustic Wall Batts are often used when walls are accessible.

👉 See more options in the wall insulation category.

What about underfloor insulation?

If your home is raised (common in older builds), underfloor insulation can make a noticeable difference — especially in winter.

  • reduces cold air coming up through the floor
  • improves comfort in living areas
  • helps stabilise temperature year-round

This is often overlooked but can be worth considering if access is available.

Do older homes need foil insulation?

In some cases, yes — particularly where radiant heat is a problem.

Foil insulation can help in:

  • metal roof sections
  • extensions or add-ons
  • sheds or garages attached to the house

👉 Explore options here: foil insulation

Like most insulation, it works best when combined with other materials rather than used on its own.

What R-value should you use in an older home?

You don’t need to go extreme — but you do want a noticeable upgrade.

  • R4.0 — solid improvement over old insulation
  • R5.0 — better performance for hot summers
  • R6.0+ — higher-end option if budget allows

If you’re deciding between options, this R4 vs R5 guide explains the difference clearly.

What actually makes the biggest difference?

In older homes, it’s not about doing everything — it’s about doing the right things first.

  • upgrade ceiling insulation first
  • seal obvious gaps where air leaks through
  • add wall insulation only where practical

This approach usually gives the best return without overcomplicating the job.

Common mistakes in older homes

  • trying to insulate everything at once
  • ignoring the ceiling and focusing on walls
  • choosing very low R-values to save money
  • not checking existing insulation condition

Often, a simple upgrade done properly beats a full system done poorly.

Getting the right setup for your home

Every older home is different, so the best approach depends on layout, access, and budget.

If you’re not sure what’s possible, it’s worth getting advice based on your specific house.

You can request a quote and get recommendations tailored to your home.

Final word

The best insulation for old houses in Perth isn’t about chasing the highest spec — it’s about fixing the biggest weaknesses first.

In most cases, that means upgrading ceiling insulation, then improving walls and floors where possible.

Get that right, and even an older home can feel significantly more comfortable without needing a full rebuild.

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