diff --git a/docs/how_to_guides/how_to_use_ui_api.rst b/docs/how_to_guides/how_to_use_ui_api.rst
index f7cf6e009c..09f8d1ba80 100644
--- a/docs/how_to_guides/how_to_use_ui_api.rst
+++ b/docs/how_to_guides/how_to_use_ui_api.rst
@@ -11,22 +11,14 @@ How-to guide for the UI API
 Overview
 --------
 
-There are two distinct intended users for this API:
-
 .. image:: /_static/terminal-icon.png
     :height: 30px
     :align: left
 
-Model developers  can select which variables to "export" to the UI for each component of the model, and provide extra metadata (display name, description) for them.
-For flowsheets, they also should specify how to build and solve the flowsheets.
-
-.. image:: /_static/menu-icon.png
-    :height: 22px
-    :align: left
-
-User interface developers can "discover" flowsheets for inclusion in the UI, and use the API to serialize and update from serialized data.
-
-The rest of this page will provide more detail on how to do tasks for each type of user.
+This API is intended for model developers who would like to connect their flowsheets to the UI.
+Developers can select which variables to "export" to the UI for each component of the model, 
+and provide extra metadata (display name, description) for them. For flowsheets, they should also 
+specify how to build and solve the flowsheets.
 
 See also: :ref:`the UI flowsheet API reference section <ref_ui-fsapi>`.
 
@@ -44,67 +36,154 @@ Add an interface to your flowsheet
 In some Python module, define the function ``export_to_ui``, which will look
 similar to this::
 
-   def export_to_ui():
-       return FlowsheetInterface(
-           do_build=build_flowsheet,
-           do_export=export_variables,
-           do_solve=solve_flowsheet,
-           name="My Flowsheet")
-
-See :class:`FlowsheetInterface` for details on the arguments.
-
-User Interface Developers
---------------------------
-
-.. image:: /_static/menu-icon.png
-    :height: 22px
-    :align: left
-
-.. _howto_api-find:
-
-Find flowsheets
-^^^^^^^^^^^^^^^^
-Use the method :meth:`FlowsheetInterface.find` to get a mapping of module names to functions
-that, when called, will create the flowsheet interface::
-
-   results = fsapi.FlowsheetInterface.find("watertap")
-
-Note that the returned interface will not create the flowsheet object and export the variables until the ``build`` method is invoked::
-
-    first_module = list(results.keys())[0]
-    interface = results[first_module]
-    # at this point the name and description of the flowsheet are available
-    interface.build()
-    # at this point the flowsheet is built and all variables exported
-
-
-.. image:: /_static/menu-icon.png
-    :height: 22px
-    :align: left
-
-.. _howto_api-serialize:
-
-Serialize flowsheet
-^^^^^^^^^^^^^^^^^^^^
-Use the ``dict()`` method to serialize the flowsheet::
-
-    data = flowsheet.dict()
-
-.. image:: /_static/menu-icon.png
-    :height: 22px
-    :align: left
-
-.. _howto_api-load:
-
-Load a serialized flowsheet
-^^^^^^^^^^^^^^^^^^^^^^^^^^^
-Use the ``load()`` method to load values from a serialized flowsheet.
-This will raise a ``MissingObjectError`` if any of the incoming values are not found in the target flowsheet::
-
-   try:
-       flowsheet.load(data)
-   except fsapi.MissingObjectError as err:
-       print(f"Error loading data: {err}")
-       # print contents of list of missing items (key and variable name)
-       for item in err.missing:
-           print(f"Missing item: key={item.key}, name={item.name}")
+    from watertap.ui.fsapi import FlowsheetInterface, FlowsheetCategory
+    def export_to_ui():
+        return FlowsheetInterface(
+            name="NF-DSPM-DE",
+            do_export=export_variables,
+            do_build=build_flowsheet,
+            do_solve=solve_flowsheet,
+            get_diagram=get_diagram,
+            requires_idaes_solver=True,
+            category=FlowsheetCategory.wastewater,
+            build_options={
+                "Bypass": {
+                    "name": "bypass option", 
+                    "display_name": "With Bypass",
+                    "values_allowed": ['false', 'true'],
+                    "value": "false"
+                }
+            }
+        )
+
+There are 3 required functions: 
+
+1. ``do_export`` - This function defines the variables that will be displayed on the UI. See example below::
+
+    def export_variables(flowsheet=None, exports=None, build_options=None, **kwargs):
+        fs = flowsheet
+        exports.add(
+            obj=fs.feed.properties[0].flow_vol_phase["Liq"],
+            name="Volumetric flow rate",
+            ui_units=pyunits.L / pyunits.hr,
+            display_units="L/h",
+            rounding=2,
+            description="Inlet volumetric flow rate",
+            is_input=True,
+            input_category="Feed",
+            is_output=False,
+            output_category="Feed",
+        )
+        exports.add(
+            obj=fs.NF.pump.outlet.pressure[0],
+            name="NF pump pressure",
+            ui_units=pyunits.bar,
+            display_units="bar",
+            rounding=2,
+            description="NF pump pressure",
+            is_input=True,
+            input_category="NF design",
+            is_output=True,
+            output_category="NF design",
+        )
+        exports.add(
+            obj=fs.NF.product.properties[0].flow_vol_phase["Liq"],
+            name="NF product volume flow",
+            ui_units=pyunits.L / pyunits.hr,
+            display_units="L/h",
+            rounding=2,
+            description="NF design",
+            is_input=False,
+            input_category="NF design",
+            is_output=True,
+            output_category="NF design",
+        )
+
+2. ``do_build`` - This function defines the build function for a flowsheet. See example below::
+
+    from watertap.examples.flowsheets.case_studies.wastewater_resource_recovery.metab.metab import (
+        build,
+        set_operating_conditions,
+        initialize_system,
+        solve,
+        add_costing,
+        adjust_default_parameters,
+    )
+    def build_flowsheet():
+        # build and solve initial flowsheet
+        m = build()
+
+        set_operating_conditions(m)
+        assert_degrees_of_freedom(m, 0)
+        assert_units_consistent(m)
+
+        initialize_system(m)
+
+        results = solve(m)
+        assert_optimal_termination(results)
+
+        add_costing(m)
+        assert_degrees_of_freedom(m, 0)
+        m.fs.costing.initialize()
+
+        adjust_default_parameters(m)
+
+        results = solve(m)
+        assert_optimal_termination(results)
+        return m
+
+
+3. ``do_solve`` - This function defines the solve function for a flowsheet. See example below::
+
+    from watertap.examples.flowsheets.case_studies.wastewater_resource_recovery.metab.metab import solve
+    def solve_flowsheet(flowsheet=None):
+        fs = flowsheet
+        results = solve(fs)
+        return results
+
+Additionally, there are optional parameters to assign a category, provide build options, 
+and provide a diagram function among others. See additional examples below.
+
+Build function using build options::
+
+    def build_flowsheet(build_options=None, **kwargs):
+        # build and solve initial flowsheet
+        if build_options is not None:
+            if build_options["Bypass"].value == "true": #build with bypass
+                solver = get_solver()
+                m = nf_with_bypass.build()
+                nf_with_bypass.initialize(m, solver)
+                nf_with_bypass.unfix_opt_vars(m)
+            else: # build without bypass
+                solver = get_solver()
+                m = nf.build()
+                nf.initialize(m, solver)
+                nf.add_objective(m)
+                nf.unfix_opt_vars(m)
+        else: # build without bypass
+            solver = get_solver()
+            m = nf.build()
+            nf.initialize(m, solver)
+            nf.add_objective(m)
+            nf.unfix_opt_vars(m)
+        return m
+
+Custom diagram function::
+
+    def get_diagram(build_options):
+        if build_options["Bypass"].value == "true":
+            return "nf_with_bypass_ui.png"
+        else:
+            return "nf_ui.png"
+
+Enable UI to discover flowsheet - In order for the UI to discover a flowsheet, an 
+entrypoint must be defined in setup.py with the path to the export file. For examples, see below::
+
+    entry_points={
+        "watertap.flowsheets": [
+            "nf = watertap.examples.flowsheets.nf_dspmde.nf_ui",
+            "metab = watertap.examples.flowsheets.case_studies.wastewater_resource_recovery.metab.metab_ui",
+        ]
+
+
+For a complete overview of all arguments, see :class:`FlowsheetInterface`.
diff --git a/watertap/examples/flowsheets/RO_with_energy_recovery/RO_with_energy_recovery_ui.py b/watertap/examples/flowsheets/RO_with_energy_recovery/RO_with_energy_recovery_ui.py
index e416436f3c..fb1124b1f1 100644
--- a/watertap/examples/flowsheets/RO_with_energy_recovery/RO_with_energy_recovery_ui.py
+++ b/watertap/examples/flowsheets/RO_with_energy_recovery/RO_with_energy_recovery_ui.py
@@ -30,7 +30,7 @@ def export_to_ui():
     )
 
 
-def export_variables(flowsheet=None, exports=None):
+def export_variables(flowsheet=None, exports=None, build_options=None, **kwargs):
     fs = flowsheet
     # --- Input data ---
     # Feed conditions
@@ -373,7 +373,7 @@ def export_variables(flowsheet=None, exports=None):
     )
 
 
-def build_flowsheet(erd_type=ERDtype.pump_as_turbine):
+def build_flowsheet(erd_type=ERDtype.pump_as_turbine, build_options=None, **kwargs):
     # build and solve initial flowsheet
     m = build()
 
diff --git a/watertap/examples/flowsheets/case_studies/full_water_resource_recovery_facility/BSM2_ui.py b/watertap/examples/flowsheets/case_studies/full_water_resource_recovery_facility/BSM2_ui.py
index 003beb816a..1a95aabd6c 100644
--- a/watertap/examples/flowsheets/case_studies/full_water_resource_recovery_facility/BSM2_ui.py
+++ b/watertap/examples/flowsheets/case_studies/full_water_resource_recovery_facility/BSM2_ui.py
@@ -40,7 +40,7 @@ def export_to_ui():
     )
 
 
-def export_variables(flowsheet=None, exports=None):
+def export_variables(flowsheet=None, exports=None, build_options=None, **kwargs):
     """
     Exports the variables to the GUI.
     """
@@ -2844,7 +2844,7 @@ def export_variables(flowsheet=None, exports=None):
     )
 
 
-def build_flowsheet():
+def build_flowsheet(build_options=None, **kwargs):
     """
     Builds the initial flowsheet.
     """
diff --git a/watertap/examples/flowsheets/case_studies/full_water_resource_recovery_facility/__init__.py b/watertap/examples/flowsheets/case_studies/full_water_resource_recovery_facility/__init__.py
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/watertap/examples/flowsheets/case_studies/wastewater_resource_recovery/GLSD_anaerobic_digester/GLSD_anaerobic_digestion_ui.py b/watertap/examples/flowsheets/case_studies/wastewater_resource_recovery/GLSD_anaerobic_digester/GLSD_anaerobic_digestion_ui.py
index 5b4aa79931..a56697fd54 100644
--- a/watertap/examples/flowsheets/case_studies/wastewater_resource_recovery/GLSD_anaerobic_digester/GLSD_anaerobic_digestion_ui.py
+++ b/watertap/examples/flowsheets/case_studies/wastewater_resource_recovery/GLSD_anaerobic_digester/GLSD_anaerobic_digestion_ui.py
@@ -31,7 +31,7 @@ def export_to_ui():
     )
 
 
-def export_variables(flowsheet=None, exports=None):
+def export_variables(flowsheet=None, exports=None, build_options=None, **kwargs):
     fs = flowsheet
     # --- Input data ---
     # Feed conditions
@@ -424,7 +424,7 @@ def export_variables(flowsheet=None, exports=None):
     )
 
 
-def build_flowsheet():
+def build_flowsheet(build_options=None, **kwargs):
     # build and solve initial flowsheet
     m = build()
 
diff --git a/watertap/examples/flowsheets/case_studies/wastewater_resource_recovery/amo_1575_hrcs/hrcs_ui.py b/watertap/examples/flowsheets/case_studies/wastewater_resource_recovery/amo_1575_hrcs/hrcs_ui.py
index dcb1f06c74..109cfefda0 100644
--- a/watertap/examples/flowsheets/case_studies/wastewater_resource_recovery/amo_1575_hrcs/hrcs_ui.py
+++ b/watertap/examples/flowsheets/case_studies/wastewater_resource_recovery/amo_1575_hrcs/hrcs_ui.py
@@ -31,7 +31,7 @@ def export_to_ui():
     )
 
 
-def export_variables(flowsheet=None, exports=None):
+def export_variables(flowsheet=None, exports=None, build_options=None, **kwargs):
     fs = flowsheet
 
     def _base_curr(x):
@@ -760,7 +760,7 @@ def _base_curr(x):
     )
 
 
-def build_flowsheet():
+def build_flowsheet(build_options=None, **kwargs):
     # build and solve initial flowsheet
     m = build()
 
diff --git a/watertap/examples/flowsheets/case_studies/wastewater_resource_recovery/amo_1575_magprex/magprex_ui.py b/watertap/examples/flowsheets/case_studies/wastewater_resource_recovery/amo_1575_magprex/magprex_ui.py
index 5a2d1cb846..0d0a357e9a 100644
--- a/watertap/examples/flowsheets/case_studies/wastewater_resource_recovery/amo_1575_magprex/magprex_ui.py
+++ b/watertap/examples/flowsheets/case_studies/wastewater_resource_recovery/amo_1575_magprex/magprex_ui.py
@@ -31,7 +31,7 @@ def export_to_ui():
     )
 
 
-def export_variables(flowsheet=None, exports=None):
+def export_variables(flowsheet=None, exports=None, build_options=None, **kwargs):
     fs = flowsheet
     # --- Input data ---
     # Feed conditions
@@ -694,7 +694,7 @@ def export_variables(flowsheet=None, exports=None):
     )
 
 
-def build_flowsheet():
+def build_flowsheet(build_options=None, **kwargs):
     # build and solve initial flowsheet
     m = build()
 
diff --git a/watertap/examples/flowsheets/case_studies/wastewater_resource_recovery/amo_1595_photothermal_membrane_candoP/amo_1595_ui.py b/watertap/examples/flowsheets/case_studies/wastewater_resource_recovery/amo_1595_photothermal_membrane_candoP/amo_1595_ui.py
index 272c396370..222f507b98 100644
--- a/watertap/examples/flowsheets/case_studies/wastewater_resource_recovery/amo_1595_photothermal_membrane_candoP/amo_1595_ui.py
+++ b/watertap/examples/flowsheets/case_studies/wastewater_resource_recovery/amo_1595_photothermal_membrane_candoP/amo_1595_ui.py
@@ -31,7 +31,7 @@ def export_to_ui():
     )
 
 
-def export_variables(flowsheet=None, exports=None):
+def export_variables(flowsheet=None, exports=None, build_options=None, **kwargs):
     fs = flowsheet
     # --- Input data ---
     # Feed conditions
@@ -807,7 +807,7 @@ def export_variables(flowsheet=None, exports=None):
     )
 
 
-def build_flowsheet():
+def build_flowsheet(build_options=None, **kwargs):
     # build and solve initial flowsheet
     m = build()
 
diff --git a/watertap/examples/flowsheets/case_studies/wastewater_resource_recovery/amo_1690/amo_1690_ui.py b/watertap/examples/flowsheets/case_studies/wastewater_resource_recovery/amo_1690/amo_1690_ui.py
index 47815ab341..19dea1a4ef 100644
--- a/watertap/examples/flowsheets/case_studies/wastewater_resource_recovery/amo_1690/amo_1690_ui.py
+++ b/watertap/examples/flowsheets/case_studies/wastewater_resource_recovery/amo_1690/amo_1690_ui.py
@@ -31,7 +31,7 @@ def export_to_ui():
     )
 
 
-def export_variables(flowsheet=None, exports=None):
+def export_variables(flowsheet=None, exports=None, build_options=None, **kwargs):
     fs = flowsheet
     # --- Input data ---
     # Feed conditions
@@ -906,7 +906,7 @@ def export_variables(flowsheet=None, exports=None):
     )
 
 
-def build_flowsheet():
+def build_flowsheet(build_options=None, **kwargs):
     # build and solve initial flowsheet
     m = build()
 
diff --git a/watertap/examples/flowsheets/case_studies/wastewater_resource_recovery/biomembrane_filtration/biomembrane_filtration_ui.py b/watertap/examples/flowsheets/case_studies/wastewater_resource_recovery/biomembrane_filtration/biomembrane_filtration_ui.py
index 93ac5a5185..2a272340df 100644
--- a/watertap/examples/flowsheets/case_studies/wastewater_resource_recovery/biomembrane_filtration/biomembrane_filtration_ui.py
+++ b/watertap/examples/flowsheets/case_studies/wastewater_resource_recovery/biomembrane_filtration/biomembrane_filtration_ui.py
@@ -31,7 +31,7 @@ def export_to_ui():
     )
 
 
-def export_variables(flowsheet=None, exports=None):
+def export_variables(flowsheet=None, exports=None, build_options=None, **kwargs):
     fs = flowsheet
     # --- Input data ---
     # Feed conditions
@@ -657,7 +657,7 @@ def export_variables(flowsheet=None, exports=None):
     )
 
 
-def build_flowsheet():
+def build_flowsheet(build_options=None, **kwargs):
     # build and solve initial flowsheet
     m = build()
 
diff --git a/watertap/examples/flowsheets/case_studies/wastewater_resource_recovery/dye_desalination/dye_desalination_ui.py b/watertap/examples/flowsheets/case_studies/wastewater_resource_recovery/dye_desalination/dye_desalination_ui.py
index 23aee987d4..de63ce8734 100644
--- a/watertap/examples/flowsheets/case_studies/wastewater_resource_recovery/dye_desalination/dye_desalination_ui.py
+++ b/watertap/examples/flowsheets/case_studies/wastewater_resource_recovery/dye_desalination/dye_desalination_ui.py
@@ -31,7 +31,7 @@ def export_to_ui():
     )
 
 
-def export_variables(flowsheet=None, exports=None):
+def export_variables(flowsheet=None, exports=None, build_options=None, **kwargs):
     fs = flowsheet
     # --- Input data ---
     # Feed conditions
@@ -720,7 +720,7 @@ def export_variables(flowsheet=None, exports=None):
     )
 
 
-def build_flowsheet():
+def build_flowsheet(build_options=None, **kwargs):
     # build and solve initial flowsheet
     m = build(include_pretreatment=False)
 
diff --git a/watertap/examples/flowsheets/case_studies/wastewater_resource_recovery/electrochemical_nutrient_removal/electrochemical_nutrient_removal_ui.py b/watertap/examples/flowsheets/case_studies/wastewater_resource_recovery/electrochemical_nutrient_removal/electrochemical_nutrient_removal_ui.py
index f877ab9f72..77bae9565e 100644
--- a/watertap/examples/flowsheets/case_studies/wastewater_resource_recovery/electrochemical_nutrient_removal/electrochemical_nutrient_removal_ui.py
+++ b/watertap/examples/flowsheets/case_studies/wastewater_resource_recovery/electrochemical_nutrient_removal/electrochemical_nutrient_removal_ui.py
@@ -31,7 +31,7 @@ def export_to_ui():
     )
 
 
-def export_variables(flowsheet=None, exports=None):
+def export_variables(flowsheet=None, exports=None, build_options=None, **kwargs):
     fs = flowsheet
     # --- Input data ---
     # Feed conditions
@@ -541,7 +541,7 @@ def export_variables(flowsheet=None, exports=None):
     )
 
 
-def build_flowsheet():
+def build_flowsheet(build_options=None, **kwargs):
     # build and solve initial flowsheet
     m = build()
 
diff --git a/watertap/examples/flowsheets/case_studies/wastewater_resource_recovery/groundwater_treatment/groundwater_treatment_ui.py b/watertap/examples/flowsheets/case_studies/wastewater_resource_recovery/groundwater_treatment/groundwater_treatment_ui.py
index 56ba333eba..d0092e9b08 100644
--- a/watertap/examples/flowsheets/case_studies/wastewater_resource_recovery/groundwater_treatment/groundwater_treatment_ui.py
+++ b/watertap/examples/flowsheets/case_studies/wastewater_resource_recovery/groundwater_treatment/groundwater_treatment_ui.py
@@ -31,7 +31,7 @@ def export_to_ui():
     )
 
 
-def export_variables(flowsheet=None, exports=None):
+def export_variables(flowsheet=None, exports=None, build_options=None, **kwargs):
     fs = flowsheet
     # --- Input data ---
     # Feed conditions
@@ -725,7 +725,7 @@ def export_variables(flowsheet=None, exports=None):
     )
 
 
-def build_flowsheet():
+def build_flowsheet(build_options=None, **kwargs):
     # build and solve initial flowsheet
     m = build()
 
diff --git a/watertap/examples/flowsheets/case_studies/wastewater_resource_recovery/metab/metab_ui.py b/watertap/examples/flowsheets/case_studies/wastewater_resource_recovery/metab/metab_ui.py
index fc83603de1..ea2980c9cd 100644
--- a/watertap/examples/flowsheets/case_studies/wastewater_resource_recovery/metab/metab_ui.py
+++ b/watertap/examples/flowsheets/case_studies/wastewater_resource_recovery/metab/metab_ui.py
@@ -32,7 +32,7 @@ def export_to_ui():
     )
 
 
-def export_variables(flowsheet=None, exports=None):
+def export_variables(flowsheet=None, exports=None, build_options=None, **kwargs):
     fs = flowsheet
     # --- Input data ---
     # Feed conditions
@@ -887,7 +887,7 @@ def export_variables(flowsheet=None, exports=None):
     )
 
 
-def build_flowsheet():
+def build_flowsheet(build_options=None, **kwargs):
     # build and solve initial flowsheet
     m = build()
 
diff --git a/watertap/examples/flowsheets/case_studies/wastewater_resource_recovery/peracetic_acid_disinfection/peracetic_acid_disinfection_ui.py b/watertap/examples/flowsheets/case_studies/wastewater_resource_recovery/peracetic_acid_disinfection/peracetic_acid_disinfection_ui.py
index f3491efb84..42dab93fb4 100644
--- a/watertap/examples/flowsheets/case_studies/wastewater_resource_recovery/peracetic_acid_disinfection/peracetic_acid_disinfection_ui.py
+++ b/watertap/examples/flowsheets/case_studies/wastewater_resource_recovery/peracetic_acid_disinfection/peracetic_acid_disinfection_ui.py
@@ -31,7 +31,7 @@ def export_to_ui():
     )
 
 
-def export_variables(flowsheet=None, exports=None):
+def export_variables(flowsheet=None, exports=None, build_options=None, **kwargs):
     fs = flowsheet
     # --- Input data ---
     # Feed conditions
@@ -462,7 +462,7 @@ def export_variables(flowsheet=None, exports=None):
     )
 
 
-def build_flowsheet():
+def build_flowsheet(build_options=None, **kwargs):
     # build and solve initial flowsheet
     m = build()
 
diff --git a/watertap/examples/flowsheets/case_studies/wastewater_resource_recovery/suboxic_activated_sludge_process/suboxic_ASM_ui.py b/watertap/examples/flowsheets/case_studies/wastewater_resource_recovery/suboxic_activated_sludge_process/suboxic_ASM_ui.py
index acedd49757..5bb84a0651 100644
--- a/watertap/examples/flowsheets/case_studies/wastewater_resource_recovery/suboxic_activated_sludge_process/suboxic_ASM_ui.py
+++ b/watertap/examples/flowsheets/case_studies/wastewater_resource_recovery/suboxic_activated_sludge_process/suboxic_ASM_ui.py
@@ -31,7 +31,7 @@ def export_to_ui():
     )
 
 
-def export_variables(flowsheet=None, exports=None):
+def export_variables(flowsheet=None, exports=None, build_options=None, **kwargs):
     fs = flowsheet
     # --- Input data ---
     # Feed conditions
@@ -538,7 +538,7 @@ def export_variables(flowsheet=None, exports=None):
     )
 
 
-def build_flowsheet():
+def build_flowsheet(build_options=None, **kwargs):
     # build and solve initial flowsheet
     m = build()
 
diff --git a/watertap/examples/flowsheets/case_studies/wastewater_resource_recovery/supercritical_sludge_to_gas/supercritical_sludge_to_gas_ui.py b/watertap/examples/flowsheets/case_studies/wastewater_resource_recovery/supercritical_sludge_to_gas/supercritical_sludge_to_gas_ui.py
index 6a1c84d4a8..d3650ca061 100644
--- a/watertap/examples/flowsheets/case_studies/wastewater_resource_recovery/supercritical_sludge_to_gas/supercritical_sludge_to_gas_ui.py
+++ b/watertap/examples/flowsheets/case_studies/wastewater_resource_recovery/supercritical_sludge_to_gas/supercritical_sludge_to_gas_ui.py
@@ -31,7 +31,7 @@ def export_to_ui():
     )
 
 
-def export_variables(flowsheet=None, exports=None):
+def export_variables(flowsheet=None, exports=None, build_options=None, **kwargs):
     fs = flowsheet
     # --- Input data ---
     # Feed conditions
@@ -608,7 +608,7 @@ def export_variables(flowsheet=None, exports=None):
     )
 
 
-def build_flowsheet():
+def build_flowsheet(build_options=None, **kwargs):
     # build and solve initial flowsheet
     m = build()
 
diff --git a/watertap/examples/flowsheets/case_studies/wastewater_resource_recovery/swine_wwt/swine_wwt_ui.py b/watertap/examples/flowsheets/case_studies/wastewater_resource_recovery/swine_wwt/swine_wwt_ui.py
index 1af64af479..c4a2e412b5 100644
--- a/watertap/examples/flowsheets/case_studies/wastewater_resource_recovery/swine_wwt/swine_wwt_ui.py
+++ b/watertap/examples/flowsheets/case_studies/wastewater_resource_recovery/swine_wwt/swine_wwt_ui.py
@@ -31,7 +31,7 @@ def export_to_ui():
     )
 
 
-def export_variables(flowsheet=None, exports=None):
+def export_variables(flowsheet=None, exports=None, build_options=None, **kwargs):
     fs = flowsheet
     # --- Input data ---
     # Feed conditions
@@ -1154,7 +1154,7 @@ def export_variables(flowsheet=None, exports=None):
     )
 
 
-def build_flowsheet():
+def build_flowsheet(build_options=None, **kwargs):
     # build and solve initial flowsheet
     m = build()
 
diff --git a/watertap/examples/flowsheets/nf_dspmde/nf_ui.py b/watertap/examples/flowsheets/nf_dspmde/nf_ui.py
index 12b92a2388..60c1677211 100644
--- a/watertap/examples/flowsheets/nf_dspmde/nf_ui.py
+++ b/watertap/examples/flowsheets/nf_dspmde/nf_ui.py
@@ -9,8 +9,10 @@
 # information, respectively. These files are also available online at the URL
 # "https://github.com/watertap-org/watertap/"
 #################################################################################
-from watertap.ui.fsapi import FlowsheetInterface
+from watertap.ui.fsapi import FlowsheetInterface, FlowsheetCategory
 from watertap.examples.flowsheets.nf_dspmde import nf
+from watertap.examples.flowsheets.nf_dspmde import nf_with_bypass
+from watertap.unit_models.nanofiltration_DSPMDE_0D import ConcentrationPolarizationType
 from pyomo.environ import units as pyunits
 from idaes.core.solvers import get_solver
 
@@ -21,11 +23,27 @@ def export_to_ui():
         do_export=export_variables,
         do_build=build_flowsheet,
         do_solve=solve_flowsheet,
+        get_diagram=get_diagram,
         requires_idaes_solver=True,
+        category=FlowsheetCategory.wastewater,
+        build_options={
+            "Bypass": {
+                "name": "bypass option",
+                "display_name": "With Bypass",
+                "values_allowed": ["false", "true"],
+                "value": "false",
+            },
+            "ConcentrationPolarization": {
+                "name": "ConcentrationPolarization",
+                "display_name": "Concentration Polarization Type",
+                "values_allowed": ["calculated", "none"],
+                "value": "calculated",
+            },
+        },
     )
 
 
-def export_variables(flowsheet=None, exports=None):
+def export_variables(flowsheet=None, exports=None, build_options=None, **kwargs):
     fs = flowsheet
     # --- Input data ---
     # Feed conditions
@@ -337,6 +355,22 @@ def export_variables(flowsheet=None, exports=None):
         is_output=True,
         output_category="Process cost and operating metrics",
     )
+    try:
+        if build_options["Bypass"].value == "true":
+            exports.add(
+                obj=fs.by_pass_splitter.split_fraction[0, "bypass"],
+                name="NF bypass",
+                ui_units=pyunits.dimensionless,
+                display_units="fraction",
+                rounding=4,
+                description="Bypass design",
+                is_input=True,
+                input_category="Bypass design",
+                is_output=True,
+                output_category="Bypass design",
+            )
+    except Exception as e:
+        print(f"error adding bypass: {e}")
 
     for (t, phase, ion), obj in fs.NF.nfUnit.rejection_intrinsic_phase_comp.items():
         exports.add(
@@ -366,16 +400,48 @@ def export_variables(flowsheet=None, exports=None):
         )
 
 
-def build_flowsheet():
+def build_flowsheet(build_options=None, **kwargs):
     # build and solve initial flowsheet
-    solver = get_solver()
-    m = nf.build()
-    nf.initialize(m, solver)
-    nf.add_objective(m)
-    nf.unfix_opt_vars(m)
+    if build_options is not None:
+        if build_options["Bypass"].value == "true":  # build with bypass
+            solver = get_solver()
+            m = nf_with_bypass.build()
+            concentrationType = build_options["ConcentrationPolarization"].value
+            # print(f'setting concentration polarization type to {concentrationType}')
+            m.fs.NF.nfUnit.config.concentration_polarization_type = (
+                ConcentrationPolarizationType[concentrationType]
+            )
+            nf_with_bypass.initialize(m, solver)
+            nf_with_bypass.unfix_opt_vars(m)
+            nf.add_objective(m)
+        else:  # build without bypass
+            solver = get_solver()
+            m = nf.build()
+            concentrationType = build_options["ConcentrationPolarization"].value
+            # print(f'setting concentration polarization type to {concentrationType}')
+            m.fs.NF.nfUnit.config.concentration_polarization_type = (
+                ConcentrationPolarizationType[concentrationType]
+            )
+            nf.initialize(m, solver)
+            nf.add_objective(m)
+            nf.unfix_opt_vars(m)
+    else:  # build without bypass
+        solver = get_solver()
+        m = nf.build()
+        nf.initialize(m, solver)
+        nf.add_objective(m)
+        nf.unfix_opt_vars(m)
+
     return m
 
 
+def get_diagram(build_options):
+    if build_options["Bypass"].value == "true":
+        return "nf_with_bypass_ui.png"
+    else:
+        return "nf_ui.png"
+
+
 def solve_flowsheet(flowsheet=None):
     fs = flowsheet
     solver = get_solver()
diff --git a/watertap/examples/flowsheets/nf_dspmde/nf_with_bypass_ui.py b/watertap/examples/flowsheets/nf_dspmde/nf_with_bypass_ui.py
index 6234b2b9e9..0c4fec7aaa 100644
--- a/watertap/examples/flowsheets/nf_dspmde/nf_with_bypass_ui.py
+++ b/watertap/examples/flowsheets/nf_dspmde/nf_with_bypass_ui.py
@@ -29,7 +29,7 @@ def export_to_ui():
     )
 
 
-def export_variables(flowsheet=None, exports=None):
+def export_variables(flowsheet=None, exports=None, build_options=None, **kwargs):
     fs = flowsheet
     # --- Input data ---
     # Feed conditions
@@ -382,7 +382,7 @@ def export_variables(flowsheet=None, exports=None):
         )
 
 
-def build_flowsheet():
+def build_flowsheet(build_options=None, **kwargs):
     # build and solve initial flowsheet
     solver = get_solver()
     m = nf_with_bypass.build()
diff --git a/watertap/ui/fsapi.py b/watertap/ui/fsapi.py
index c83a00c76e..6706a2f1b3 100644
--- a/watertap/ui/fsapi.py
+++ b/watertap/ui/fsapi.py
@@ -19,7 +19,7 @@
 import logging
 from collections import namedtuple
 from enum import Enum
-from typing import Any, Callable, Optional, Dict, Union, TypeVar
+from typing import Any, Callable, List, Optional, Dict, Union, TypeVar
 from types import ModuleType
 
 try:
@@ -32,9 +32,6 @@
 from idaes.core.util.model_statistics import degrees_of_freedom
 from pydantic import BaseModel, validator, Field
 import pyomo.environ as pyo
-from pyomo.core.expr.numeric_expr import ExpressionBase
-from pyomo.core.base.expression import Expression, _ExpressionData
-from pyomo.core.base.param import ScalarParam
 
 #: Forward-reference to a FlowsheetInterface type, used in
 #: :meth:`FlowsheetInterface.find`
@@ -181,6 +178,41 @@ def set_obj_key_default(cls, v, values):
         return v
 
 
+class ModelOption(BaseModel):
+    """An option for building/running the model."""
+
+    name: str
+    display_name: str = None
+    description: str = None
+    display_values: List[Any] = []
+    values_allowed: List[Any] = []
+    value: Any = None
+
+    @validator("display_name", always=True)
+    @classmethod
+    def validate_display_name(cls, v, values):
+        if v is None:
+            v = values.get("name")
+        return v
+
+    @validator("description", always=True)
+    @classmethod
+    def validate_description(cls, v, values):
+        if v is None:
+            v = values.get("display_name")
+        return v
+
+    @validator("value")
+    @classmethod
+    def validate_value(cls, v, values):
+        allowed = values.get("values_allowed", None)
+        # allowed = list(allowed.keys())
+        if v in allowed:
+            return v
+        else:
+            raise ValueError(f"'value' ({v}) not in allowed values: {allowed}")
+
+
 class FlowsheetExport(BaseModel):
     """A flowsheet and its contained exported model objects."""
 
@@ -193,6 +225,7 @@ class FlowsheetExport(BaseModel):
     requires_idaes_solver: bool = False
     dof: int = 0
     sweep_results: Union[None, dict] = {}
+    build_options: Dict[str, ModelOption] = {}
 
     # set name dynamically from object
     @validator("name", always=True)
@@ -272,6 +305,21 @@ def add(self, *args, data: Union[dict, ModelExport] = None, **kwargs) -> object:
         self.model_objects[key] = model_export
         return model_export
 
+    def add_option(self, name: str, **kwargs) -> ModelOption:
+        """Add an 'option' to the flowsheet that can be displayed and manipulated
+        from the UI.
+
+        Constructs a :class:`ModelOption` instance with provided args and adds it to
+        the dict of options, keyed by its `name`.
+
+        Args:
+            name: Name of option (internal, for accessing the option)
+            kwargs: Fields of :class:`ModelOption`
+        """
+        option = ModelOption(name=name, **kwargs)
+        self.build_options[name] = option
+        return option
+
 
 class Actions(str, Enum):
     """Known actions that can be run.
@@ -282,6 +330,14 @@ class Actions(str, Enum):
     build = "build"
     solve = "solve"
     export = "_export"
+    diagram = "diagram"
+
+
+class FlowsheetCategory(str, Enum):
+    """Flowsheet Categories"""
+
+    wastewater = "Wasterwater Recovery"
+    desalination = "Desalination"
 
 
 class FlowsheetInterface:
@@ -320,6 +376,8 @@ def __init__(
         do_build: Callable = None,
         do_export: Callable = None,
         do_solve: Callable = None,
+        get_diagram: Callable = None,
+        category: FlowsheetCategory = None,
         custom_do_param_sweep_kwargs: Dict = None,
         **kwargs,
     ):
@@ -357,6 +415,11 @@ def __init__(
                 self.add_action(getattr(Actions, name), arg)
             else:
                 raise ValueError(f"'do_{name}' argument is required")
+        if callable(get_diagram):
+            self.add_action("diagram", get_diagram)
+        else:
+            self.add_action("diagram", None)
+
         self._actions["custom_do_param_sweep_kwargs"] = custom_do_param_sweep_kwargs
 
     def build(self, **kwargs):
@@ -395,6 +458,20 @@ def solve(self, **kwargs):
             raise RuntimeError(f"Solving flowsheet: {err}") from err
         return result
 
+    def get_diagram(self, **kwargs):
+        """Return diagram image name.
+
+        Args:
+            **kwargs: User-defined values
+
+        Returns:
+            Return image file name if get_diagram function is callable. Otherwise, return none
+        """
+        if self.get_action(Actions.diagram) is not None:
+            return self.run_action(Actions.diagram, **kwargs)
+        else:
+            return None
+
     def dict(self) -> Dict:
         """Serialize.
 
@@ -425,44 +502,87 @@ def load(self, data: Dict):
             # set value in this flowsheet
             ui_units = dst.ui_units
             if dst.is_input and not dst.is_readonly:
-                # create a Var so Pyomo can do the unit conversion for us
-                tmp = pyo.Var(initialize=src.value, units=ui_units)
-                tmp.construct()
-                # Convert units when setting value in the model
-                dst.obj.value = u.convert(tmp, to_units=u.get_units(dst.obj))
-                # Don't convert units when setting the exported value
-                dst.value = src.value
-
-                dst.obj.fixed = src.fixed
-                dst.fixed = src.fixed
-                dst.is_sweep = src.is_sweep
-                dst.num_samples = src.num_samples
-                # update bounds
-                if src.lb is None or src.lb == "":
-                    dst.obj.lb = None
-                    dst.lb = None
-                else:
-                    tmp = pyo.Var(initialize=src.lb, units=ui_units)
-                    tmp.construct()
-                    dst.obj.lb = pyo.value(
-                        u.convert(tmp, to_units=u.get_units(dst.obj))
-                    )
-                    dst.lb = src.lb
-                if src.ub is None or src.ub == "":
-                    dst.obj.ub = None
-                    dst.ub = None
-                else:
-                    tmp = pyo.Var(initialize=src.ub, units=ui_units)
+                # only update if value has changed
+                if dst.value != src.value:
+                    # print(f'changing value for {key} from {dst.value} to {src.value}')
+                    # create a Var so Pyomo can do the unit conversion for us
+                    tmp = pyo.Var(initialize=src.value, units=ui_units)
                     tmp.construct()
-                    dst.obj.ub = pyo.value(
-                        u.convert(tmp, to_units=u.get_units(dst.obj))
-                    )
-                    dst.ub = src.ub
+                    # Convert units when setting value in the model
+                    new_val = pyo.value(u.convert(tmp, to_units=u.get_units(dst.obj)))
+                    # print(f'changing value for {key} from {dst.value} to {new_val}')
+                    dst.obj.set_value(new_val)
+                    # Don't convert units when setting the exported value
+                    dst.value = src.value
+
+                if dst.obj.fixed != src.fixed:
+                    # print(f'changing fixed for {key} from {dst.obj.fixed} to {src.fixed}')
+                    if src.fixed:
+                        dst.obj.fix()
+                    else:
+                        dst.obj.unfix()
+                    dst.fixed = src.fixed
+
+                if dst.is_sweep != src.is_sweep:
+                    dst.is_sweep = src.is_sweep
+
+                if dst.num_samples != src.num_samples:
+                    dst.num_samples = src.num_samples
+
+                # update bounds
+                if dst.lb != src.lb:
+                    # print(f'changing lb for {key} from {dst.lb} to {src.lb}')
+                    if src.lb is None or src.lb == "":
+                        dst.obj.setlb(None)
+                        dst.lb = None
+                    else:
+                        tmp = pyo.Var(initialize=src.lb, units=ui_units)
+                        tmp.construct()
+                        new_lb = pyo.value(
+                            u.convert(tmp, to_units=u.get_units(dst.obj))
+                        )
+                        dst.obj.setlb(new_lb)
+                        dst.lb = src.lb
+                if dst.ub != src.ub:
+                    # print(f'changing ub for {key} from {dst.ub} to {src.ub}')
+                    if src.ub is None or src.ub == "":
+                        dst.obj.setub(None)
+                        dst.ub = None
+                    else:
+                        tmp = pyo.Var(initialize=src.ub, units=ui_units)
+                        tmp.construct()
+                        new_ub = pyo.value(
+                            u.convert(tmp, to_units=u.get_units(dst.obj))
+                        )
+                        # print(f'changing ub for {key} from {dst.obj.ub} to {new_ub}')
+                        dst.obj.setub(new_ub)
+                        dst.ub = src.ub
+
         # update degrees of freedom (dof)
         self.fs_exp.dof = degrees_of_freedom(self.fs_exp.obj)
         if missing:
             raise self.MissingObjectError(missing)
 
+    def select_option(self, option_name: str, new_option: str):
+        """Update flowsheet with selected option.
+
+        Args:
+            data: The input flowsheet
+            option_name: Name of selected option
+
+        Returns:
+            None
+        """
+
+        # fs = FlowsheetExport.parse_obj(data)  # new instance from data
+        self.fs_exp.build_options[option_name].value = new_option
+
+        # # get function name from model options
+        # func_name = self.fs_exp.build_options[option_name].values_allowed[new_option]
+
+        # # add functino name as new build function
+        # self.add_action("build", func_name)
+
     def add_action(self, action_name: str, action_func: Callable):
         """Add an action for the flowsheet.
 
@@ -473,7 +593,8 @@ def add_action(self, action_name: str, action_func: Callable):
         Returns:
             None
         """
-
+        # print(f'ADDING ACTION: {action_name}')
+        # print(action_func)
         def action_wrapper(**kwargs):
             if action_name == Actions.build:
                 # set new model object from return value of build action
@@ -485,7 +606,6 @@ def action_wrapper(**kwargs):
                     )
                 self.fs_exp.obj = action_result.fs
                 self.fs_exp.m = action_result
-
                 # [re-]create exports (new model object)
                 if Actions.export not in self._actions:
                     raise KeyError(
@@ -497,8 +617,13 @@ def action_wrapper(**kwargs):
                 # clear model_objects dict, since duplicates not allowed
                 self.fs_exp.model_objects.clear()
                 # use get_action() since run_action() will refuse to call it directly
-                self.get_action(Actions.export)(exports=self.fs_exp)
+                self.get_action(Actions.export)(
+                    exports=self.fs_exp, build_options=self.fs_exp.build_options
+                )
                 result = None
+            elif action_name == Actions.diagram:
+                self._actions[action_name] = action_func
+                return
             elif self.fs_exp.obj is None:
                 raise RuntimeError(
                     f"Cannot run any flowsheet action (except "
@@ -555,16 +680,9 @@ def export_values(self):
         self.fs_exp.dof = degrees_of_freedom(self.fs_exp.obj)
         for key, mo in self.fs_exp.model_objects.items():
             mo.value = pyo.value(u.convert(mo.obj, to_units=mo.ui_units))
-            if not isinstance(
-                mo.obj,
-                (
-                    Expression,
-                    ExpressionBase,
-                    _ExpressionData,
-                    ScalarParam,
-                    type(None),
-                ),
-            ):
+            # print(f'{key} is being set to: {mo.value}')
+            if hasattr(mo.obj, "bounds"):
+                # print(f'{key} is being set to: {mo.value} from {mo.obj.value}')
                 if mo.obj.ub is None:
                     mo.ub = mo.obj.ub
                 else:
diff --git a/watertap/ui/tests/test_flowsheet_interfaces.py b/watertap/ui/tests/test_flowsheet_interfaces.py
index 61c917dff0..71dcc63250 100644
--- a/watertap/ui/tests/test_flowsheet_interfaces.py
+++ b/watertap/ui/tests/test_flowsheet_interfaces.py
@@ -19,6 +19,7 @@
 from pyomo.environ import assert_optimal_termination
 
 from ..fsapi import FlowsheetInterface
+from ..fsapi import ModelOption
 
 
 @pytest.fixture(scope="class")
@@ -91,8 +92,23 @@ def test_solve(self, solve_results):
 
 @pytest.mark.parametrize("n_times", [2, 3], ids="{} times".format)
 def test_roundtrip_with_garbage_collection(fs_interface, n_times):
+    build_options = {
+        "Bypass": ModelOption(
+            name="bypass option",
+            display_name="With Bypass",
+            values_allowed=["false", "true"],
+            value="false",
+        ),
+        "ConcentrationPolarization": ModelOption(
+            name="ConcentrationPolarization",
+            display_name="Concentration Polarization Type",
+            values_allowed=["calculated", "none"],
+            value="calculated",
+        ),
+    }
+
     for attempt in range(n_times):
-        fs_interface.build()
+        fs_interface.build(build_options=build_options)
         data = fs_interface.dict()
         fs_interface.load(data)
         gc.collect()
diff --git a/watertap/ui/tests/test_fsapi.py b/watertap/ui/tests/test_fsapi.py
index b8e221d578..dd3cd14a3d 100644
--- a/watertap/ui/tests/test_fsapi.py
+++ b/watertap/ui/tests/test_fsapi.py
@@ -50,7 +50,7 @@ class SOLVE_STATUS:
     solver = SOLVE_STATUS
 
 
-def build_ro(**kwargs):
+def build_ro(build_options=None, **kwargs):
     model = RO.build_flowsheet(erd_type=ERD_TYPE)
     return model
 
@@ -82,7 +82,7 @@ class OutputCategory:
     revenue = "Revenue"
 
 
-def export_to_ui(flowsheet=None, exports=None):
+def export_to_ui(flowsheet=None, exports=None, build_options=None, **kwargs):
     fs = flowsheet
     exports.add(
         obj=fs.feed.flow_vol[0],
@@ -162,7 +162,7 @@ def test_actions(add_variant: str):
     v1.value = 1
     print(v1.display())
 
-    def fake_build():
+    def fake_build(build_options=None, **kwargs):
         nonlocal built
         built = True
         nonlocal m
@@ -174,7 +174,7 @@ def fake_solve(flowsheet=None):
         assert flowsheet == m.fs
         return SOLVE_RESULT_OK
 
-    def fake_export(flowsheet=None, exports=None):
+    def fake_export(flowsheet=None, exports=None, build_options=None, **kwargs):
         with pytest.raises(Exception):
             exports.add(obj=garbage)