Required disk space to install UE5 from source

[BeyondLogicS]

Hi all!

I just had access to Epic console development and I’m trying to install UE from source for the first time. I followed all the steps, I cloned the repository from git, added the platforms I needed by copying them in the Platforms folder, launched Setup.bat first and then GenerateProjectFiles.bat.

After that the UnrealEngine folder was almost 160 GB on my disk and I still had around 60 GB left.

Then I opened the solution with Visual Studio by launching UE5.sln and started the build process.

Here is the issue. While building, Visual Studio quickly uses all my 60 GB left and I’m not able to finish the process due to lack of memory.

How much free disk space do I need to complete the process?

Thank you!

Luca.

[Extrone (Arjun Subhash)]

The last time (about 2 years ago) I built from source, it was around 400 GB. Though there are ways to reduce it to ~100 GB.

Couple resources I found on how to reduce the build size:

Reducing the size of UE5 source build

The exact command is very simple. ./Setup.bat (in WIndows) ./GenerateProjectFiles.bat The most important: ./Engine/Build/BatchFiles/RunUAT.bat BuildGraph -target=“Make Installed Build Windows” -script=Engine/Build/InstalledEngineBuild.xml -clean -set:HostPlatformOnly=true -set:BuiltDirectory=“D:\\FoldernameWhereYouWantTheFiles” Before the last command ,edit the file Engine/Build/InstalledEngineFilters.xml and add this two lines: [Screenshot 2025-11-11 at 5.29.10 PM] I use dSYM because I’…

Alex 🦅

Alex 🦅

500×500 2.84 KB

Hi guys, here’s some useful information for those who care about download size and/or disk space taken by the engine dependencies. By default, Setup.bat always downloads files for your current platform: Win32 and Win64 if you are on Windows and Mac if you are on Mac. But you will also get dependency files for iOS and Linux even if you won’t need them. It also downloads HLML5 dependencies if you have Emscripten installed and Android dependencies if you have NDK. This is quite clever but what if…

[BeyondLogicS]

Thank you very much for your answer, I’ll try and post here the result, so that it can be useful for others, too!

[BeyondLogicS]

So I followed the second and the third link you posted.

The first one to reduce the cloned repository folder size, cloning only the release I need, and the second one to exclude unnecessary dependancies.

That actually saved a lot of space, since I still had around 120 GB before building the solution.

Unfortunately, though, the building process still used all the 120 GB I had left at around 2/3 of the process…

I guess I need to make room on my disk

[zoe_wxq]

build UE from source code it needs at least 400G SSD space (including UnrealEditor , ShaderCompileWorker , UnrealLightmass , LiveLinkHub , ZenDashboard , UnrealPackageTool), needs extra 100G free space to run it

move DDC to other SSD driver can save a lot space while working on UE editor (if you know how to move)

I update the source code to the latest commit almost every month and build it on Win11 and Mac.