diff --git a/src/ifcopenshell-python/ifcopenshell/util/__init__.py b/src/ifcopenshell-python/ifcopenshell/util/__init__.py
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/src/ifcopenshell-python/ifcopenshell/util/element.py b/src/ifcopenshell-python/ifcopenshell/util/element.py
new file mode 100644
index 0000000000..e9325feabf
--- /dev/null
+++ b/src/ifcopenshell-python/ifcopenshell/util/element.py
@@ -0,0 +1,35 @@
+def get_psets(element):
+    psets = {}
+    try:
+        if element.is_a('IfcTypeObject'):
+            if element.HasPropertySets:
+                for definition in element.HasPropertySets:
+                    psets[definition.Name] = get_properties(definition)
+        else:
+            for relationship in element.IsDefinedBy:
+                if relationship.is_a('IfcRelDefinesByProperties'):
+                    definition = relationship.RelatingPropertyDefinition
+                    psets[definition.Name] = get_properties(definition)
+    except Exception as e:
+        import traceback
+        print('failed to load properties: {}'.format(e))
+        traceback.print_exc()
+    return psets
+
+def get_properties(definition):
+    if definition is not None:
+        props = {}
+        if definition.is_a('IfcElementQuantity'):
+            for q in definition.Quantities:
+                if q.is_a('IfcPhysicalSimpleQuantity'):
+                    props[q.Name] = q[3]
+        elif definition.is_a('IfcPropertySet'):
+            for prop in definition.HasProperties:
+                if prop.is_a('IfcPropertySingleValue'):
+                    props[prop.Name] = prop.NominalValue
+        else:
+            # Entity introduced in IFC4
+            # definition.is_a('IfcPreDefinedPropertySet'):
+            for prop in range(4, len(definition)):
+                props[definition.attribute_name(prop)] = definition[prop]
+        return props
diff --git a/src/ifcopenshell-python/ifcopenshell/util/geolocation.py b/src/ifcopenshell-python/ifcopenshell/util/geolocation.py
new file mode 100644
index 0000000000..53fc034e9c
--- /dev/null
+++ b/src/ifcopenshell-python/ifcopenshell/util/geolocation.py
@@ -0,0 +1,24 @@
+def dms2dd(degrees, minutes, seconds, milliseconds=0):
+    dd = float(degrees) + float(minutes)/60 + float(seconds)/(3600)
+    return dd
+
+def dd2dms(dd):
+    dd = float(dd)
+    sign = 1 if dd >= 0 else -1
+    dd = abs(dd)
+    minutes, seconds = divmod(dd*3600, 60)
+    degrees, minutes = divmod(minutes, 60)
+    if dd < 0:
+        degrees = -degrees
+    return (int(degrees) * sign, int(minutes) * sign, int(seconds) * sign)
+
+def xyz2enh(x, y, z, eastings, northings, orthogonal_height, x_axis_abscissa, x_axis_ordinate, scale=None):
+    if scale is None:
+        scale = 1.
+    rotation = atan2(x_axis_ordinate, x_axis_abscissa)
+    a = scale * cos(rotation)
+    b = scale * sin(rotation)
+    eastings = (a * x) - (b * y) + eastings
+    northings = (b * x) + (a * y) + northings
+    height = z + orthogonal_height
+    return (eastings, northings, height)
diff --git a/src/ifcopenshell-python/ifcopenshell/util/selector.py b/src/ifcopenshell-python/ifcopenshell/util/selector.py
new file mode 100644
index 0000000000..be3441a499
--- /dev/null
+++ b/src/ifcopenshell-python/ifcopenshell/util/selector.py
@@ -0,0 +1,156 @@
+import lark
+
+class Selector():
+    def parse(self, ifc_file, query):
+        self.file = ifc_file
+        l = lark.Lark('''start: query (lfunction query)*
+                    query: selector | group
+                    group: "(" query (lfunction query)* ")"
+                    selector: (inverse_relationship)? guid_selector | (inverse_relationship)? class_selector
+                    guid_selector: "#" /[0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz_$]{22}/
+                    class_selector: "." WORD filter ?
+                    filter: "[" filter_key (comparison filter_value)? "]"
+                    filter_key: WORD | pset_or_qto
+                    filter_value: ESCAPED_STRING
+                    pset_or_qto: /[A-Za-z0-9_]+/ "." /[A-Za-z0-9_]+/
+                    lfunction: and | or
+                    inverse_relationship: types | contains_elements
+                    types: "*"
+                    contains_elements: "@"
+                    and: "&"
+                    or: "|"
+                    comparison: contains | morethanequalto | lessthanequalto | equal | morethan | lessthan
+                    contains: "*="
+                    morethanequalto: ">="
+                    lessthanequalto: "<"
+                    equal: "="
+                    morethan: ">"
+                    lessthan: "<"
+
+                    // Embed common.lark for packaging
+                    DIGIT: "0".."9"
+                    HEXDIGIT: "a".."f"|"A".."F"|DIGIT
+                    INT: DIGIT+
+                    SIGNED_INT: ["+"|"-"] INT
+                    DECIMAL: INT "." INT? | "." INT
+                    _EXP: ("e"|"E") SIGNED_INT
+                    FLOAT: INT _EXP | DECIMAL _EXP?
+                    SIGNED_FLOAT: ["+"|"-"] FLOAT
+                    NUMBER: FLOAT | INT
+                    SIGNED_NUMBER: ["+"|"-"] NUMBER
+                    _STRING_INNER: /.*?/
+                    _STRING_ESC_INNER: _STRING_INNER /(?<!\\\\)(\\\\\\\\)*?/
+                    ESCAPED_STRING : "\\"" _STRING_ESC_INNER "\\""
+                    LCASE_LETTER: "a".."z"
+                    UCASE_LETTER: "A".."Z"
+                    LETTER: UCASE_LETTER | LCASE_LETTER
+                    WORD: LETTER+
+                    CNAME: ("_"|LETTER) ("_"|LETTER|DIGIT)*
+                    WS_INLINE: (" "|/\\t/)+
+                    WS: /[ \\t\\f\\r\\n]/+
+                    CR : /\\r/
+                    LF : /\\n/
+                    NEWLINE: (CR? LF)+
+
+                    %ignore WS // Disregard spaces in text
+                 ''')
+
+        start = l.parse(query)
+        return self.get_group(start)
+
+    def get_group(self, group):
+        lfunction = None
+        for child in group.children:
+            if child.data == 'query':
+                new_results = self.get_query(child)
+                if not lfunction:
+                    results = new_results
+                elif lfunction == 'or':
+                    results.extend(new_results)
+                elif lfunction == 'and':
+                    results = list(set(results).intersection(new_results))
+                results = list(set(results))
+            elif child.data == 'lfunction':
+                lfunction = child.children[0].data
+        return results
+
+    def get_query(self, query):
+        for child in query.children:
+            if child.data == 'selector':
+                return self.get_selector(child)
+            elif child.data == 'group':
+                return self.get_group(child)
+
+    def get_selector(self, selector):
+        if len(selector.children) == 1:
+            inverse_relationship = None
+            class_or_guid_selector = selector.children[0]
+        else:
+            inverse_relationship = selector.children[0]
+            class_or_guid_selector = selector.children[1]
+
+        if class_or_guid_selector.data == 'class_selector':
+            results = self.get_class_selector(class_or_guid_selector)
+        elif class_or_guid_selector.data == 'guid_selector':
+            results = self.get_guid_selector(class_or_guid_selector)
+
+        if not inverse_relationship:
+            return results
+        return self.parse_inverse_relationship(results, inverse_relationship.children[0].data)
+
+    def parse_inverse_relationship(self, elements, inverse_relationship):
+        results = []
+        for element in elements:
+            if inverse_relationship == 'types':
+                if hasattr(element, 'Types') and element.Types:
+                    results.extend(element.Types[0].RelatedObjects)
+                elif hasattr(element, 'ObjectTypeOf') and element.ObjectTypeOf:
+                    results.extend(element.ObjectTypeOf[0].RelatedObjects)
+            elif inverse_relationship == 'contains_elements' \
+                    and hasattr(element, 'ContainsElements'):
+                for relationship in element.ContainsElements:
+                    results.extend(relationship.RelatedElements)
+        return results
+
+    def get_class_selector(self, class_selector):
+        elements = self.file.by_type(class_selector.children[0])
+        if len(class_selector.children) > 1 \
+                and class_selector.children[1].data == 'filter':
+            return self.filter_elements(elements, class_selector.children[1])
+        return elements
+
+    def filter_elements(self, elements, filter_rule):
+        results = []
+        key = filter_rule.children[0].children[0]
+        if not isinstance(key, str):
+            key = key.children[0] + '.' + key.children[1]
+        comparison = value = None
+        if len(filter_rule.children) > 1:
+            comparison = filter_rule.children[1].children[0].data
+            value = filter_rule.children[2].children[0][1:-1]
+        for element in elements:
+            element_value = IfcAttributeExtractor.get_element_key(element, key)
+            if not element_value:
+                continue
+            if not comparison \
+                    or self.filter_element(element, element_value, comparison, value):
+                results.append(element)
+        return results
+
+    def filter_element(self, element, element_value, comparison, value):
+        if comparison == 'equal':
+            return str(element_value) == value
+        elif comparison == 'contains':
+            return value in str(element_value)
+        elif comparison == 'morethan':
+            return element_value > float(value)
+        elif comparison == 'lessthan':
+            return element_value < float(value)
+        elif comparison == 'morethanequalto':
+            return element_value >= float(value)
+        elif comparison == 'lessthanequalto':
+            return element_value <= float(value)
+        return False
+
+    def get_guid_selector(self, guid_selector):
+        return [self.file.by_id(guid_selector.children[0])]
diff --git a/src/ifcopenshell-python/ifcopenshell/util/unit.py b/src/ifcopenshell-python/ifcopenshell/util/unit.py
new file mode 100644
index 0000000000..42687afdee
--- /dev/null
+++ b/src/ifcopenshell-python/ifcopenshell/util/unit.py
@@ -0,0 +1,64 @@
+from math import pi
+
+prefixes = {'EXA': 1e18, 'PETA': 1e15, 'TERA': 1e12, 'GIGA': 1e9, 'MEGA':
+    1e6, 'KILO': 1e3, 'HECTO': 1e2, 'DECA': 1e1, 'DECI': 1e-1, 'CENTI':
+    1e-2, 'MILLI': 1e-3, 'MICRO': 1e-6, 'NANO': 1e-9, 'PICO': 1e-12,
+    'FEMTO': 1e-15, 'ATTO': 1e-18}
+
+unit_names = ['AMPERE', 'BECQUEREL', 'CANDELA', 'COULOMB',
+    'CUBIC_METRE', 'DEGREE CELSIUS', 'FARAD', 'GRAM', 'GRAY', 'HENRY',
+    'HERTZ', 'JOULE', 'KELVIN', 'LUMEN', 'LUX', 'MOLE', 'NEWTON', 'OHM',
+    'PASCAL', 'RADIAN', 'SECOND', 'SIEMENS', 'SIEVERT', 'SQUARE METRE',
+    'METRE', 'STERADIAN', 'TESLA', 'VOLT', 'WATT', 'WEBER']
+
+si_conversions = {
+    'inch': 0.0254,
+    'foot': 0.3048,
+    'yard': 0.914,
+    'mile': 1609,
+    'square inch': 0.0006452,
+    'square foot': 0.09290,
+    'square yard': 0.83612736,
+    'acre': 4046.86,
+    'square mile': 2588881,
+    'cubic inch': 0.00001639,
+    'cubic foot': 0.02832,
+    'cubic yard': 0.7636,
+    'litre': 0.001,
+    'fluid ounce UK': 0.0000284130625,
+    'fluid ounce US': 0.00002957353,
+    'pint UK': 0.000568,
+    'pint US': 0.000473,
+    'gallon UK': 0.004546,
+    'gallon US': 0.003785,
+    'degree': pi/180,
+    'ounce': 0.02835,
+    'pound': 0.454,
+    'ton UK': 1016.0469088,
+    'ton US': 907.18474,
+    'lbf': 4.4482216153,
+    'kip': 4448.2216153,
+    'psi': 6894.7572932,
+    'ksi': 6894757.2932,
+    'minute': 60,
+    'hour': 3600,
+    'day': 86400,
+    'btu': 1055.056}
+
+def get_prefix(text):
+    for prefix in prefixes.keys():
+        if prefix in text.upper():
+            return prefix
+
+def get_prefix_multiplier(text):
+    if not text:
+        return 1
+    prefix = get_prefix(text)
+    if prefix:
+        return prefixes[prefix]
+    return 1
+
+def get_unit_name(text):
+    for name in unit_names:
+        if name in text.upper().replace('METER', 'METRE'):
+            return name