diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 89e92217fd584f5b4897e288639f6b52b0cce93a..dd6a776a1a21cad6296d92aa09fa406b59bdac51 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -15,7 +15,6 @@ Run tests:
     - apt-get install -y build-essential gcc tk openjdk-17-jdk
     - export JAVA_HOME=/usr/lib/jvm/java-17-openjdk-amd64
     - export PATH=$JAVA_HOME/bin:$PATH
-    - export THERMOGIS_JAR=$CI_PROJECT_DIR/resources/thermogis_jar/thermogis-1.7.0-shaded.jar
     - pixi install
     - pixi run pytest -rx tests/
     - rm -rf /var/lib/apt/lists/*
diff --git a/README.md b/README.md
index 62c4f1bb437f1be098d10e5c689197113ad8ddd4..f771aa804542c809f0fa6c384a4245879099015d 100644
--- a/README.md
+++ b/README.md
@@ -16,29 +16,28 @@ pixi run mkdocs serve
 
 pythermogis has been designed to be used as a python package you import into your own python projects.
 It works by creating a python API access to the ThermoGIS techno-economic application, which is written in Java. 
-Because of this dependency you need to Install a Java 17 VM and store the ThermoGIS Jar (a Java executable file) on your computer:
+Because of this dependency you need to Install a Java 17 VM.
 
-### 1. Install Java 17 and Download the ThermoGIS JAR
+### 1. Install Java 17
 
-This package requires a Java 17 VM (we recommend using [Amazon Corretto 17](https://docs.aws.amazon.com/corretto/latest/corretto-17-ug/downloads-list.html)) and a [ThermoGIS Jar file](https://ci.tno.nl/gitlab/ags_public/pythermogis/-/blob/main/resources/thermogis_jar/thermogis-1.7.0-shaded.jar?ref_type=heads) (Version >=1.7).
+This package requires a Java 17 VM (we recommend using [Amazon Corretto 17](https://docs.aws.amazon.com/corretto/latest/corretto-17-ug/downloads-list.html)).
 
 *(You can find the JAR in this repository's resources folder: /resources/thermogis_jar)*
 
-### 2. Create Required Environment Variables
+### 2. Ensure JAVA_HOME is set
 
-Create a file called ``.env`` in your project root folder. 
-This file should contain the following variables:
+When installing the Java 17 Virtual Machine (JVM), a global environment variable _should_ have been set: `JAVA_HOME`. This stores the path to the JVM that was installed in step 1 and enables pythermogis to read the core Java code.
+
+If, for some reason, this was not done during installation you can either set it yourself or create a ``.env`` file in your project root folder. 
+
+This `.env` file should contain the following variable:
 
 - `JAVA_HOME`: Path to the Java 17 installation
   *(e.g., on Windows: `C:\Program Files\Amazon Corretto\jdk17.0.0_0`)*
 
-- `THERMOGIS_JAR`: Path to the ThermoGIS `.jar` file; __including__ the name of the jar file
-  *(e.g. `/path/to/the/thermogis-1.7.0-shaded.jar`)*
-
-Example .env contents:
 
+Example `.env` contents (The specific path could be different depending on your OS, or file architecture):
 ```
-THERMOGIS_JAR = /path/to/the/thermogis-1.7.0-shaded.jar
 JAVA_HOME = C:\Program Files \Amazon Corretto\jdk17.0.0_0
 ```
 
@@ -68,7 +67,7 @@ git clone git@ci.tno.nl:ags_public/pythermogis.git
 cd pythermogis
 pixi install
 ```
-(Make sure you have followed the step installing a Java17 VM and saving the ThermoGIS Jar)
+(Make sure you have followed step 1 and 2: installing a Java 17 VM)
 
 ---
 
diff --git a/docs/changelog.md b/docs/changelog.md
index aab65ea5a216ae7a50d7233e884dd7321775d63c..56cfc0846e9dc349135a6a6b0646f00b9bda8ec5 100644
--- a/docs/changelog.md
+++ b/docs/changelog.md
@@ -1,5 +1,9 @@
 # Change log
 
+## v1.2.4 (23-1-2026)
+The ThermoGIS Jar is now packaged within pythermogis, this reduces the number of installation steps from users (no longer having to set a THERMOGIS_JAR environment variable) and means that multiple installations of pythermogis on the same 
+system won't break each-other (previously two or more pythermogis installations would use the same Jar, which could cause version conflicts). 
+
 ## v1.2.3 (6-1-2026)
 Added the calculation of `heat in place` and `potential recoverable heat`. These are part of the potential calculation of the original java code. 
 
diff --git a/docs/install/install.md b/docs/install/install.md
index 311cc563b3b138de22c57a65239489c22c91f1dd..128cefcb41caf091136ef1545eaec6c9b638f1bb 100644
--- a/docs/install/install.md
+++ b/docs/install/install.md
@@ -2,33 +2,31 @@
 
 pythermogis has been designed to be used as a python package you import into your own python projects.
 It works by creating a python API access to the ThermoGIS techno-economic application, which is written in Java. 
-Because of this dependency you need to Install a Java 17 VM and store the ThermoGIS Jar (a Java executable file) on your computer:
+Because of this dependency you need to Install a Java 17 VM.
 
-### 1. Install Java 17 and Download the ThermoGIS JAR
+### 1. Install Java 17
 
-This package requires a Java 17 VM (we recommend using [Amazon Corretto 17](https://docs.aws.amazon.com/corretto/latest/corretto-17-ug/downloads-list.html)) and a [ThermoGIS Jar file](https://ci.tno.nl/gitlab/ags_public/pythermogis/-/blob/main/resources/thermogis_jar/thermogis-1.7.0-shaded.jar?ref_type=heads) (Version >=1.7).
+This package requires a Java 17 VM (we recommend using [Amazon Corretto 17](https://docs.aws.amazon.com/corretto/latest/corretto-17-ug/downloads-list.html)).
 
-*(You can find the JAR in this repository's resources folder: /resources/thermogis_jar.)*
+*(You can find the JAR in this repository's resources folder: /resources/thermogis_jar)*
 
-### 2. Create Required Environment Variables
+### 2. Ensure JAVA_HOME is set
 
-Create a file called ``.env`` in your project root folder. 
-This file should contain the following variables:
+When installing the Java 17 Virtual Machine (JVM), a global environment variable _should_ have been set: `JAVA_HOME`. This stores the path to the JVM that was installed in step 1 and enables pythermogis to read the core Java code.
+
+If, for some reason, this was not done during installation you can either set it yourself or create a ``.env`` file in your project root folder. 
+
+This `.env` file should contain the following variable:
 
 - `JAVA_HOME`: Path to the Java 17 installation
   *(e.g., on Windows: `C:\Program Files\Amazon Corretto\jdk17.0.0_0`)*
 
-- `THERMOGIS_JAR`: Path to the ThermoGIS `.jar` file; __including__ the name of the jar file
-  *(e.g. `/path/to/the/thermogis-1.7.0-shaded.jar`)*
-
-Example .env contents:
 
+Example `.env` contents (The specific path could be different depending on your OS, or file architecture):
 ```
-THERMOGIS_JAR = /path/to/the/thermogis-1.7.0-shaded.jar
 JAVA_HOME = C:\Program Files \Amazon Corretto\jdk17.0.0_0
 ```
 
-
 ### 3. Import pythermogis into your own python projects
 
 You can use pip to install the package directly from the gitlab project:
@@ -55,6 +53,6 @@ git clone git@ci.tno.nl:ags_public/pythermogis.git
 cd pythermogis
 pixi install
 ```
-(Make sure you have followed the step installing a Java17 VM and saving the ThermoGIS Jar)
+(Make sure you have followed step 1 and 2: installing a Java 17 VM)
 
 ---
diff --git a/pixi.lock b/pixi.lock
index 0d84993bba41405a3d2f7707684329dcd92dbc8e..61f5e03e1937f6ac8801da8c3ff9c4d1509bbdfb 100644
--- a/pixi.lock
+++ b/pixi.lock
@@ -4920,8 +4920,8 @@ packages:
   timestamp: 1740946648058
 - pypi: ./
   name: pythermogis
-  version: 1.2.3
-  sha256: 6c8828289c71f3180f90af7d940428d8362b440e147bf8a6e533c4d28a8232d2
+  version: 1.2.4
+  sha256: 41970125f848a057eda9f00cac0c2046df6c0b149f67081432922484a4320b9d
   requires_dist:
   - jpype1>=1.5.2,<2
   - xarray==2024.9.0.*
diff --git a/pyproject.toml b/pyproject.toml
index 9b5f1e744fa11d434e3e0bcbe9a0accab7a85be8..4054d06a1d0c7f8f5028c9e81d382c27c34498ed 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "pythermogis"
-version = "1.2.3"
+version = "1.2.4"
 description = "This repository is used as a python API for the ThermoGIS Doublet simulations"
 authors = [
     { name = "Hen Brett", email = "hen.brett@tno.nl" },
@@ -37,6 +37,9 @@ markers = [
 [tool.setuptools]
 package-dir = {"" = "src"}
 
+[tool.setuptools.package-data]
+"pythermogis" = ["thermogis_jar/*.jar"]  # Ensure all files inside 'lib/' are included
+
 [tool.pixi.workspace]
 channels = ["conda-forge"]
 platforms = ["win-64", "linux-64"]
diff --git a/src/pythermogis/constants.py b/src/pythermogis/constants.py
new file mode 100644
index 0000000000000000000000000000000000000000..1b0c72f2fea07cad131dd067793fb88d834c481c
--- /dev/null
+++ b/src/pythermogis/constants.py
@@ -0,0 +1,5 @@
+from pathlib import Path
+
+THERMOGIS_JAR_PATH = (
+    Path(__file__).parent / "thermogis_jar" / "thermogis-1.7.0-shaded.jar"
+)
diff --git a/src/pythermogis/thermogis_classes/jvm_start.py b/src/pythermogis/thermogis_classes/jvm_start.py
index 2bff18505c33780cf828b982eacb37da39145b40..cabbdb7d3e1f89b77c5b48cb9eda1ba35416b851 100644
--- a/src/pythermogis/thermogis_classes/jvm_start.py
+++ b/src/pythermogis/thermogis_classes/jvm_start.py
@@ -1,25 +1,18 @@
 import os
-from pathlib import Path
 import jpype
 import faulthandler
 
 from dotenv import load_dotenv
-
+from pythermogis.constants import THERMOGIS_JAR_PATH
 load_dotenv()
 
 def get_thermogis_jar_path() -> str:
     """
-    From the resources directory, return the path to the ThermoGIS Jar
+    From within thermogis, find the thermogis-jar, return the path to the ThermoGIS Jar
     """
-    tg_jar = os.getenv("THERMOGIS_JAR")
-
-    if tg_jar is None:
-        raise ValueError("THERMOGIS_JAR environment variable is not set in the .env file.")
-    
-    thermogis_jar_path = Path(tg_jar)
-    if not thermogis_jar_path.exists():
-        raise FileNotFoundError(f"Jar file not found at {thermogis_jar_path}, check that you have downloaded the ThermoGIS Jar and set the THERMOGIS_JAR environment variable.")
-    return str(thermogis_jar_path)
+    if not THERMOGIS_JAR_PATH.exists():
+        raise FileNotFoundError(f"Jar file not found at {THERMOGIS_JAR_PATH}.")
+    return str(THERMOGIS_JAR_PATH)
 
 
 def start_jvm():
@@ -28,16 +21,12 @@ def start_jvm():
     This method ensures a clean startup of the jvm packaged with this repo
     :return:
     """
-    java_home = os.getenv("JAVA_HOME")
-
-    if java_home is None:
-        raise ValueError("JAVA_HOME environment variable is not set in the .env file.")
-
     if not jpype.isJVMStarted():
         # when running pytest with jpype a "Windows fatal exception" is thrown which in reality has no affect on the outcome or performance.
         # the current workaround from the jpype package is to disable the pytest faulthandler. (This will not prevent python or java errors in the test).
         faulthandler.disable()
 
+        # automatically looks up the java version in JAVA_HOME
         jpype.startJVM(classpath=[get_thermogis_jar_path()])
 
 def close_jvm():
diff --git a/resources/thermogis_jar/thermogis-1.7.0-shaded.jar b/src/pythermogis/thermogis_jar/thermogis-1.7.0-shaded.jar
similarity index 100%
rename from resources/thermogis_jar/thermogis-1.7.0-shaded.jar
rename to src/pythermogis/thermogis_jar/thermogis-1.7.0-shaded.jar