<!-- edited with XMLSpy v2021 rel. 3 (x64)  -->
<!-- Version 0.4.1- July 26, 2021 - DRAFT  -->
<!-- Most recent version available at: http://standards.buildingsmart.org/IDS  -->
<xs:schema xmlns:ids="http://standards.buildingsmart.org/IDS" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:ns1="http://www.w3.org/2001/XMLSchema-instance" targetNamespace="http://standards.buildingsmart.org/IDS" elementFormDefault="qualified" attributeFormDefault="unqualified" version="0.4.1">
	<xs:import namespace="http://www.w3.org/XML/1998/namespace" schemaLocation="http://www.w3.org/2001/xml.xsd"/>
	<xs:import namespace="http://www.w3.org/2001/XMLSchema" schemaLocation="https://www.w3.org/2001/XMLSchema.xsd"/>
	<xs:import namespace="http://www.w3.org/2001/XMLSchema-instance" schemaLocation="http://www.w3.org/2001/XMLSchema-instance"/>
	<xs:element name="ids">
		<xs:complexType>
			<xs:complexContent>
				<xs:extension base="ids:idsType">
					<xs:sequence>
						<xs:element name="info">
							<xs:complexType>
								<xs:choice maxOccurs="unbounded">
									<xs:element name="ifcversion">
										<xs:simpleType>
											<xs:restriction base="xs:string">
												<xs:enumeration value="2.3.0.1"/>
												<xs:enumeration value="4.0.2.1"/>
												<xs:enumeration value="4.3.0.0"/>
											</xs:restriction>
										</xs:simpleType>
									</xs:element>
									<xs:element name="description" type="xs:string" minOccurs="0"/>
									<xs:element name="author" minOccurs="0">
										<xs:simpleType>
											<xs:restriction base="xs:string">
												<xs:pattern value="[^@]+@[^\.]+\..+"/>
											</xs:restriction>
										</xs:simpleType>
									</xs:element>
									<xs:element name="copyright" type="xs:string"/>
									<xs:element name="version" type="xs:decimal"/>
									<xs:element name="date" type="xs:date"/>
									<xs:element name="purpose" type="xs:string" minOccurs="0"/>
									<xs:element name="milestone" type="xs:string" minOccurs="0"/>
								</xs:choice>
							</xs:complexType>
						</xs:element>
					</xs:sequence>
				</xs:extension>
			</xs:complexContent>
		</xs:complexType>
	</xs:element>
	<xs:complexType name="entityType">
		<xs:sequence>
			<xs:element name="name" type="ids:idsValue"/>
			<xs:element name="predefinedtype" type="ids:idsValue" minOccurs="0"/>
		</xs:sequence>
	</xs:complexType>
	<xs:complexType name="idsValue">
		<xs:choice minOccurs="1">
			<!-- place for potential additional rules for idsValue -->
			<xs:element name="simpleValue" type="xs:string" minOccurs="1" maxOccurs="1"/>
			<xs:element ref="xs:restriction" minOccurs="1" maxOccurs="unbounded"/>
		</xs:choice>
	</xs:complexType>
	<xs:complexType name="classificationType">
		<xs:sequence maxOccurs="2">
			<xs:element name="value" type="ids:idsValue"/>
			<xs:element name="system" type="ids:idsValue" minOccurs="0"/>
		</xs:sequence>
		<xs:attribute name="location" use="required">
			<xs:simpleType>
				<xs:restriction base="xs:string">
					<xs:enumeration value="type"/>
					<xs:enumeration value="instance"/>
					<xs:enumeration value="any"/>
				</xs:restriction>
			</xs:simpleType>
		</xs:attribute>
	</xs:complexType>
	<xs:complexType name="applicabilityType">
		<xs:sequence>
			<xs:element name="entity" type="ids:entityType"/>
			<xs:element name="classification" type="ids:classificationType" minOccurs="0"/>
			<xs:element name="property" minOccurs="0" maxOccurs="unbounded">
				<xs:complexType>
					<xs:complexContent>
						<xs:extension base="ids:propertyType"/>
					</xs:complexContent>
				</xs:complexType>
			</xs:element>
			<xs:element name="material" minOccurs="0">
				<xs:complexType>
					<xs:complexContent>
						<xs:extension base="ids:materialType"/>
					</xs:complexContent>
				</xs:complexType>
			</xs:element>
		</xs:sequence>
	</xs:complexType>
	<xs:complexType name="systemType">
		<xs:simpleContent>
			<xs:extension base="xs:string">
				<xs:attribute name="href" type="xs:anyURI" use="optional"/>
			</xs:extension>
		</xs:simpleContent>
	</xs:complexType>
	<xs:complexType name="propertyType">
		<xs:sequence>
			<xs:element name="propertyset" type="ids:idsValue"/>
			<xs:element name="name" type="ids:idsValue"/>
			<xs:element name="value" type="ids:idsValue"/>
		</xs:sequence>
		<xs:attribute name="location" use="required">
			<xs:simpleType>
				<xs:restriction base="xs:string">
					<xs:enumeration value="type"/>
					<xs:enumeration value="instance"/>
					<xs:enumeration value="any"/>
				</xs:restriction>
			</xs:simpleType>
		</xs:attribute>
	</xs:complexType>
	<xs:complexType name="materialType">
		<xs:sequence>
			<xs:element name="value" type="ids:idsValue"/>
		</xs:sequence>
		<xs:attribute name="location" use="required">
			<xs:simpleType>
				<xs:restriction base="xs:string">
					<xs:enumeration value="type"/>
					<xs:enumeration value="instance"/>
					<xs:enumeration value="any"/>
				</xs:restriction>
			</xs:simpleType>
		</xs:attribute>
	</xs:complexType>
	<xs:complexType name="requirementsType">
		<xs:sequence maxOccurs="unbounded">
			<xs:element name="entity" type="ids:entityType" minOccurs="0">
				<xs:annotation>
					<xs:documentation>Make sure 'Name' value of requirements entity is the same as the 'applicability' node, or a wildcard (inclusive pattern).</xs:documentation>
				</xs:annotation>
			</xs:element>
			<xs:element name="classification" minOccurs="0">
				<xs:complexType>
					<xs:complexContent>
						<xs:extension base="ids:classificationType">
							<xs:sequence>
								<xs:element name="instructions" type="xs:string" minOccurs="0">
									<xs:annotation>
										<xs:documentation>Author of the IDS can leave instructions for the authors of the IFC. This text could/should be displayed in the BIM/IFC authoring tool.</xs:documentation>
									</xs:annotation>
								</xs:element>
							</xs:sequence>
							<xs:attribute name="uri" type="xs:anyURI" use="optional"/>
							<xs:attribute name="use" use="optional">
								<xs:simpleType>
									<xs:restriction base="xs:string">
										<xs:enumeration value="required"/>
										<xs:enumeration value="optional"/>
									</xs:restriction>
								</xs:simpleType>
							</xs:attribute>
						</xs:extension>
					</xs:complexContent>
				</xs:complexType>
			</xs:element>
			<xs:element name="property" minOccurs="0" maxOccurs="unbounded">
				<xs:complexType>
					<xs:complexContent>
						<xs:extension base="ids:propertyType">
							<xs:sequence>
								<xs:element name="instructions" type="xs:string" minOccurs="0">
									<xs:annotation>
										<xs:documentation>Author of the IDS can leave instructions for the authors of the IFC. This text could/should be displayed in the BIM/IFC authoring tool.</xs:documentation>
									</xs:annotation>
								</xs:element>
							</xs:sequence>
							<xs:attribute name="uri" type="xs:anyURI" use="optional"/>
							<xs:attribute name="use" use="optional">
								<xs:simpleType>
									<xs:restriction base="xs:string">
										<xs:enumeration value="required"/>
										<xs:enumeration value="optional"/>
									</xs:restriction>
								</xs:simpleType>
							</xs:attribute>
						</xs:extension>
					</xs:complexContent>
				</xs:complexType>
			</xs:element>
			<xs:element name="material" minOccurs="0">
				<xs:complexType>
					<xs:complexContent>
						<xs:extension base="ids:materialType">
							<xs:sequence>
								<xs:element name="instructions" type="xs:string" minOccurs="0">
									<xs:annotation>
										<xs:documentation>Author of the IDS can leave instructions for the authors of the IFC. This text could/should be displayed in the BIM/IFC authoring tool.</xs:documentation>
									</xs:annotation>
								</xs:element>
							</xs:sequence>
							<xs:attribute name="uri" type="xs:anyURI" use="optional"/>
							<xs:attribute name="use" use="optional">
								<xs:simpleType>
									<xs:restriction base="xs:string">
										<xs:enumeration value="required"/>
										<xs:enumeration value="optional"/>
									</xs:restriction>
								</xs:simpleType>
							</xs:attribute>
						</xs:extension>
					</xs:complexContent>
				</xs:complexType>
			</xs:element>
		</xs:sequence>
	</xs:complexType>
	<xs:complexType name="specificationType">
		<xs:sequence>
			<xs:element name="applicability" type="ids:applicabilityType"/>
			<xs:element name="requirements" type="ids:requirementsType"/>
		</xs:sequence>
		<xs:attribute name="name" type="xs:string" use="optional"/>
		<xs:attribute name="necessity" use="required">
			<xs:simpleType>
				<xs:restriction base="xs:string">
					<xs:enumeration value="required"/>
					<xs:enumeration value="optional"/>
				</xs:restriction>
			</xs:simpleType>
		</xs:attribute>
	</xs:complexType>
	<xs:complexType name="idsType">
		<xs:sequence>
			<xs:element name="specification" type="ids:specificationType" minOccurs="1" maxOccurs="unbounded"/>
		</xs:sequence>
	</xs:complexType>
</xs:schema>