diff --git a/README.md b/README.md
index 0a33ceb..d7a606f 100644
--- a/README.md
+++ b/README.md
@@ -86,6 +86,81 @@ new ProjenStruct(project, { name: 'MyProjectOptions'})
   });
 ```
 
+### Updating multiple properties
+
+A callback function can be passed to `updateEvery()` to update multiple properties at a time.
+
+Use `updateAll()` to uniformly update all properties.
+A convenience `allOptional()` method is provided to make all properties optional.
+
+```js
+new ProjenStruct(project, { name: 'MyProjectOptions'})
+  .mixin(Struct.fromFqn('projen.typescript.TypeScriptProjectOptions'))
+
+  // Use a callback to make conditional updates
+  .updateEvery((property) => {
+    if (!property.optional) {
+      return {
+        docs: {
+          remarks: 'This property is required.',
+        },
+      };
+    }
+    return {};
+  })
+
+  // Apply an update to all properties
+  .updateAll({
+    immutable: true,
+  })
+
+  // Mark all properties as optional
+  .allOptional();
+```
+
+### Replacing properties
+
+Existing properties can be replaced with a new `@jsii/spec` definition.
+If a different `name` is provided, the property is also renamed.
+
+A callback function can be passed to `map()` to map every property to a new `@jsii/spec` definition.
+
+```ts
+new ProjenStruct(project, { name: 'MyProjectOptions' })
+  .mixin(Struct.fromFqn('projen.typescript.TypeScriptProjectOptions'))
+
+  // Replace a property with an entirely new definition
+  .replace('autoApproveOptions', {
+    name: 'autoApproveOptions',
+    type: { fqn: 'my_project.AutoApproveOptions' },
+    docs: {
+      summary: 'Configure the auto-approval workflow.'
+    }
+  })
+
+  // Passing a new name, will also rename the property
+  .replace('autoMergeOptions', {
+    name: 'mergeFlowOptions',
+    type: { fqn: 'my_project.MergeFlowOptions' },
+  })
+
+  // Use a callback to map every property to a new definition
+  .map((property) => {
+    if (property.protected) {
+      return {
+        ...property,
+        protected: false,
+        docs: {
+          custom: {
+            'internal': 'true',
+          }
+        }
+      }
+    }
+    return property;
+  });
+```
+
 ### Filter properties
 
 Arbitrary predicate functions can be used to filter properties.
diff --git a/src/builder/struct.ts b/src/builder/struct.ts
index 8f85b4a..e387fd9 100644
--- a/src/builder/struct.ts
+++ b/src/builder/struct.ts
@@ -34,48 +34,50 @@ export interface HasStructSpec {
 
 export interface IStructBuilder {
   /**
-   * Keep only the properties that meet the condition specified in the callback function.
+   * Add properties.
+   *
+   * In the same call, the first defined properties take priority.
+   * However later calls will overwrite existing properties.
    */
-  filter(predicate: (prop: Property) => boolean): IStructBuilder;
+  add(...props: Property[]): IStructBuilder;
 
   /**
-   * Only keep these properties.
+   * Mix the properties of these sources into the struct.
+   *
+   * In the same call, the first defined sources and properties take priority.
+   * However later calls will overwrite existing properties.
    */
-  only(...keep: string[]): IStructBuilder;
+  mixin(...sources: HasProperties[]): IStructBuilder;
 
   /**
-   * Omit these properties.
+   * Replaces an existing property with a new spec.
    */
-  omit(...remove: string[]): IStructBuilder;
+  replace(name: string, replacement: Property): IStructBuilder;
 
   /**
-   * Mark all properties as optional.
+   * Calls a defined callback function on each property, and replaces the property with the returned property.
+   *
+   * @param callbackfn — A function that accepts a property spec as an argument. The map method calls the callbackfn function one time for each property.
    */
-  allOptional(): IStructBuilder;
+  map(callbackfn: (prop: Property) => Property): IStructBuilder;
 
   /**
-   * Remove all deprecated properties.
+   * Update an existing property.
    */
-  withoutDeprecated(): IStructBuilder;
+  update(name: string, update: Partial<Property>): IStructBuilder;
 
   /**
-   * Add properties.
+   * Calls a defined callback function on each property, and merges the property with the returned property partial.
    *
-   * In the same call, the first defined properties take priority.
-   * However later calls will overwrite existing properties.
+   * @param callbackfn — A function that accepts a property spec as an argument. The map method calls the callbackfn function one time for each property.
    */
-  add(...props: Property[]): IStructBuilder;
+  updateEvery(callbackfn: (prop: Property) => Partial<Property>): IStructBuilder;
 
   /**
    * Update all existing properties.
    */
   updateAll(update: Partial<Property>): IStructBuilder;
 
-  /**
-   * Update an existing property.
-   */
-  update(name: string, update: Partial<Property>): IStructBuilder;
-
   /**
    * Rename a property.
    *
@@ -84,12 +86,29 @@ export interface IStructBuilder {
   rename(from: string, to: string): IStructBuilder;
 
   /**
-   * Mix the properties of these sources into the struct.
-   *
-   * In the same call, the first defined sources and properties take priority.
-   * However later calls will overwrite existing properties.
+   * Mark all properties as optional.
    */
-  mixin(...sources: HasProperties[]): IStructBuilder;
+  allOptional(): IStructBuilder;
+
+  /**
+   * Keep only the properties that meet the condition specified in the callback function.
+   */
+  filter(predicate: (prop: Property) => boolean): IStructBuilder;
+
+  /**
+   * Only keep these properties.
+   */
+  only(...keep: string[]): IStructBuilder;
+
+  /**
+   * Omit these properties.
+   */
+  omit(...remove: string[]): IStructBuilder;
+
+  /**
+   * Remove all deprecated properties.
+   */
+  withoutDeprecated(): IStructBuilder;
 }
 
 /**
@@ -138,43 +157,41 @@ export class Struct implements IStructBuilder, HasProperties, HasFullyQualifiedN
     );
   }
 
-  public filter(predicate: (prop: Property) => boolean): this {
-    for (const propertyKey of this._properties.keys()) {
-      if (!predicate(this._properties.get(propertyKey)!)) {
-        this._properties.delete(propertyKey);
-      }
+  public add(...props: Property[]): this {
+    for (const prop of props.reverse()) {
+      this._properties.set(prop.name, prop);
     }
 
     return this;
   }
 
-  public only(...keep: string[]): this {
-    return this.filter((prop) => keep.includes(prop.name));
-  }
-
-  public omit(...remove: string[]): this {
-    for (const prop of remove) {
-      this._properties.delete(prop);
+  public mixin(...sources: HasProperties[]): this {
+    for (const source of sources.reverse()) {
+      this.add(...(source.properties || []));
     }
 
     return this;
   }
 
-  public withoutDeprecated(): this {
-    return this.filter((prop) => null == prop.docs?.deprecated);
-  }
+  public replace(name: string, replacement: Property): this {
+    const current = this._properties.get(name);
 
-  public allOptional(): this {
-    this._properties.forEach((property) => {
-      property.optional = true;
-    });
+    if (!current) {
+      throw `Unable to replace property '${name}' in '${this._base.fqn}: Property does not exists, please use \`add\`.'`;
+    }
 
-    return this;
+    if (replacement.name !== name) {
+      this.omit(name);
+    }
+
+    return this.add(replacement);
   }
 
-  public add(...props: Property[]): this {
-    for (const prop of props.reverse()) {
-      this._properties.set(prop.name, prop);
+  public map(callbackfn: (prop: Property) => Property): this {
+    const keys = this._properties.keys();
+    for (const propertyKey of keys) {
+      const current = structuredClone(this._properties.get(propertyKey)!);
+      this.replace(propertyKey, callbackfn(current));
     }
 
     return this;
@@ -207,6 +224,16 @@ export class Struct implements IStructBuilder, HasProperties, HasFullyQualifiedN
     return this.add(updatedProp);
   }
 
+  public updateEvery(callbackfn: (prop: Property) => Partial<Property>): this {
+    const keys = this._properties.keys();
+    for (const propertyKey of keys) {
+      const current = structuredClone(this._properties.get(propertyKey)!);
+      this.update(current.name, callbackfn(current) ?? {});
+    }
+
+    return this;
+  }
+
   public updateAll(update: Partial<Property>): this {
     for (const propertyKey of this._properties.keys()) {
       this.update(propertyKey, update);
@@ -218,14 +245,41 @@ export class Struct implements IStructBuilder, HasProperties, HasFullyQualifiedN
     return this.update(from, { name: to });
   }
 
-  public mixin(...sources: HasProperties[]): this {
-    for (const source of sources.reverse()) {
-      this.add(...(source.properties || []));
+  public allOptional(): this {
+    this.map((property) => {
+      property.optional = true;
+      return property;
+    });
+
+    return this;
+  }
+
+  public filter(predicate: (prop: Property) => boolean): this {
+    for (const propertyKey of this._properties.keys()) {
+      if (!predicate(this._properties.get(propertyKey)!)) {
+        this._properties.delete(propertyKey);
+      }
     }
 
     return this;
   }
 
+  public only(...keep: string[]): this {
+    return this.filter((prop) => keep.includes(prop.name));
+  }
+
+  public omit(...remove: string[]): this {
+    for (const prop of remove) {
+      this._properties.delete(prop);
+    }
+
+    return this;
+  }
+
+  public withoutDeprecated(): this {
+    return this.filter((prop) => null == prop.docs?.deprecated);
+  }
+
   /**
    * Get the current state of the builder
    */
diff --git a/src/projen/projen-struct.ts b/src/projen/projen-struct.ts
index cfd8e86..3a85867 100644
--- a/src/projen/projen-struct.ts
+++ b/src/projen/projen-struct.ts
@@ -96,34 +96,30 @@ export class ProjenStruct extends Component implements IStructBuilder, HasProper
   public get spec() {
     return this.builder.spec;
   }
-  filter(predicate: (prop: Property) => boolean): this {
-    this.builder.filter(predicate);
-    return this;
-  }
-  only(...keep: string[]): this {
-    this.builder.only(...keep);
-    return this;
-  }
-  omit(...remove: string[]): this {
-    this.builder.omit(...remove);
+  add(...props: Property[]): this {
+    this.builder.add(...props);
     return this;
   }
-  withoutDeprecated(): this {
-    this.builder.withoutDeprecated();
+  mixin(...sources: HasProperties[]): this {
+    this.builder.mixin(...sources);
     return this;
   }
-  allOptional(): this {
-    this.builder.allOptional();
+  replace(name: string, replacement: Property): IStructBuilder {
+    this.builder.replace(name, replacement);
     return this;
   }
-  add(...props: Property[]): this {
-    this.builder.add(...props);
+  map(callbackfn: (prop: Property) => Property): this {
+    this.builder.map(callbackfn);
     return this;
   }
   update(name: string, update: Partial<Property>): this {
     this.builder.update(name, update);
     return this;
   }
+  updateEvery(callbackfn: (prop: Property) => Partial<Property>): this {
+    this.builder.updateEvery(callbackfn);
+    return this;
+  }
   updateAll(update: Partial<Property>): this {
     this.builder.updateAll(update);
     return this;
@@ -132,8 +128,24 @@ export class ProjenStruct extends Component implements IStructBuilder, HasProper
     this.builder.rename(from, to);
     return this;
   }
-  mixin(...sources: HasProperties[]): this {
-    this.builder.mixin(...sources);
+  allOptional(): this {
+    this.builder.allOptional();
+    return this;
+  }
+  filter(predicate: (prop: Property) => boolean): this {
+    this.builder.filter(predicate);
+    return this;
+  }
+  only(...keep: string[]): this {
+    this.builder.only(...keep);
+    return this;
+  }
+  omit(...remove: string[]): this {
+    this.builder.omit(...remove);
+    return this;
+  }
+  withoutDeprecated(): this {
+    this.builder.withoutDeprecated();
     return this;
   }
   public get properties(): Property[] {
diff --git a/test/projen/__snapshots__/projen-struct.test.ts.snap b/test/projen/__snapshots__/projen-struct.test.ts.snap
index 5887bc4..4f8631e 100644
--- a/test/projen/__snapshots__/projen-struct.test.ts.snap
+++ b/test/projen/__snapshots__/projen-struct.test.ts.snap
@@ -1,5 +1,24 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
+exports[`can map properties 1`] = `
+"// ~~ Generated by projen. To modify, edit .projenrc.js and run "npx projen".
+
+/**
+ * MyInterface
+ */
+export interface MyInterface {
+  /**
+   * This property is required
+   * @default true
+   */
+  readonly propFour: boolean;
+  readonly aNumber: number;
+  readonly aString: string;
+  readonly aDate: date;
+}
+"
+`;
+
 exports[`can mixin a struct 1`] = `
 "// ~~ Generated by projen. To modify, edit .projenrc.js and run "npx projen".
 
@@ -70,6 +89,18 @@ export interface MyInterface {
 "
 `;
 
+exports[`can replace a prop 1`] = `
+"// ~~ Generated by projen. To modify, edit .projenrc.js and run "npx projen".
+
+/**
+ * MyInterface
+ */
+export interface MyInterface {
+  readonly newProp: number;
+}
+"
+`;
+
 exports[`can update props 1`] = `
 "// ~~ Generated by projen. To modify, edit .projenrc.js and run "npx projen".
 
@@ -129,6 +160,29 @@ export interface MyInterface {
 "
 `;
 
+exports[`can updateEvery property 1`] = `
+"// ~~ Generated by projen. To modify, edit .projenrc.js and run "npx projen".
+
+/**
+ * MyInterface
+ */
+export interface MyInterface {
+  /**
+   * This property is required
+   */
+  readonly propThree: boolean;
+  /**
+   * This property is required
+   */
+  readonly propTwo: boolean;
+  /**
+   * This property is required
+   */
+  readonly propOne: boolean;
+}
+"
+`;
+
 exports[`can use struct as type in add 1`] = `
 "// ~~ Generated by projen. To modify, edit .projenrc.js and run "npx projen".
 
diff --git a/test/projen/projen-struct.test.ts b/test/projen/projen-struct.test.ts
index 714cfb1..518fe68 100644
--- a/test/projen/projen-struct.test.ts
+++ b/test/projen/projen-struct.test.ts
@@ -278,6 +278,127 @@ test('can rename a prop', () => {
   expect(renderedFile).toMatchSnapshot();
 });
 
+test('can updateEvery property', () => {
+  // ARRANGE
+  const project = new TestProject();
+  const spec = {
+    type: { primitive: PrimitiveType.Boolean },
+    optional: false,
+    docs: {
+      summary: 'This property is required',
+      default: 'true',
+    },
+  };
+
+  // ACT
+  const struct = new ProjenStruct(project, { name: 'MyInterface' });
+  struct.add(
+    { name: 'propOne', ...spec },
+    { name: 'propTwo', ...spec },
+    { name: 'propThree', ...spec },
+  ).updateEvery((property) => {
+    if (!property.optional) {
+      return {
+        docs: {
+          default: undefined,
+        },
+      };
+    }
+    return {};
+  });
+
+  // PREPARE
+  const renderedFile = synthSnapshot(project)['src/MyInterface.ts'];
+
+  // ASSERT
+  expect(renderedFile).not.toContain('@default true');
+  expect(renderedFile).toMatchSnapshot();
+});
+
+test('can replace a prop', () => {
+  // ARRANGE
+  const project = new TestProject();
+
+  // ACT
+  const struct = new ProjenStruct(project, { name: 'MyInterface' });
+  struct.add(
+    {
+      name: 'oldProp',
+      type: { primitive: PrimitiveType.Boolean },
+      optional: true,
+    },
+  );
+  struct.replace('oldProp', {
+    name: 'newProp',
+    type: { primitive: PrimitiveType.Number },
+    optional: false,
+  });
+
+  // PREPARE
+  const renderedFile = synthSnapshot(project)['src/MyInterface.ts'];
+
+  // ASSERT
+  expect(renderedFile).not.toContain('oldProp');
+  expect(renderedFile).toContain('newProp: number');
+  expect(renderedFile).toMatchSnapshot();
+});
+
+test('can map properties', () => {
+  // ARRANGE
+  const project = new TestProject();
+  const spec = {
+    type: { primitive: PrimitiveType.Boolean },
+    optional: false,
+    docs: {
+      summary: 'This property is required',
+      default: 'true',
+    },
+  };
+
+  // ACT
+  const struct = new ProjenStruct(project, { name: 'MyInterface' });
+  struct.add(
+    { name: 'propOne', ...spec },
+    { name: 'propTwo', ...spec },
+    { name: 'propThree', ...spec },
+    { name: 'propFour', ...spec },
+  ).map((property) => {
+    switch (property.name) {
+      case 'propOne':
+        return {
+          name: 'aDate',
+          type: { primitive: PrimitiveType.Date },
+        };
+      case 'propTwo':
+        return {
+          name: 'aString',
+          type: { primitive: PrimitiveType.String },
+        };
+      case 'propThree':
+        return {
+          name: 'aNumber',
+          type: { primitive: PrimitiveType.Number },
+        };
+      default:
+        return property;
+    }
+  });
+
+  // PREPARE
+  const renderedFile = synthSnapshot(project)['src/MyInterface.ts'];
+
+  // ASSERT
+  expect(renderedFile).not.toContain('propOne');
+  expect(renderedFile).toContain('aDate');
+  expect(renderedFile).not.toContain('propTwo');
+  expect(renderedFile).toContain('aString');
+  expect(renderedFile).not.toContain('propThree');
+  expect(renderedFile).toContain('aNumber');
+  expect(renderedFile).toContain('propFour');
+  expect(renderedFile).toMatchSnapshot();
+});
+
+
 test('can import type from the same package at the top level', () => {
   // ARRANGE
   const project = new TestProject();