diff --git a/libsolidity/Compiler.cpp b/libsolidity/Compiler.cpp
index 0f4e89de1..db61cc4a1 100644
--- a/libsolidity/Compiler.cpp
+++ b/libsolidity/Compiler.cpp
@@ -274,10 +274,19 @@ void Compiler::appendReturnValuePacker(TypePointers const& _typeParameters)
 
 void Compiler::registerStateVariables(ContractDefinition const& _contract)
 {
+	vector<VariableDeclaration const*> variables;
 	for (ContractDefinition const* contract: boost::adaptors::reverse(_contract.getLinearizedBaseContracts()))
 		for (ASTPointer<VariableDeclaration> const& variable: contract->getStateVariables())
 			if (!variable->isConstant())
-				m_context.addStateVariable(*variable);
+				variables.push_back(variable.get());
+	TypePointers types;
+	for (auto variable: variables)
+		types.push_back(variable->getType());
+	StorageOffsets offsets;
+	offsets.computeOffsets(types);
+	for (size_t index = 0; index < variables.size(); ++index)
+		if (auto const* offset = offsets.getOffset(index))
+			m_context.addStateVariable(*variables[index], offset->first, offset->second);
 }
 
 void Compiler::initializeStateVariables(ContractDefinition const& _contract)
diff --git a/libsolidity/CompilerContext.cpp b/libsolidity/CompilerContext.cpp
index f2bb1de20..7cade367c 100644
--- a/libsolidity/CompilerContext.cpp
+++ b/libsolidity/CompilerContext.cpp
@@ -37,15 +37,13 @@ void CompilerContext::addMagicGlobal(MagicVariableDeclaration const& _declaratio
 	m_magicGlobals.insert(&_declaration);
 }
 
-void CompilerContext::addStateVariable(VariableDeclaration const& _declaration)
+void CompilerContext::addStateVariable(
+	VariableDeclaration const& _declaration,
+	u256 const& _storageOffset,
+	unsigned _byteOffset
+)
 {
-	m_stateVariables[&_declaration] = m_stateVariablesSize;
-	bigint newSize = bigint(m_stateVariablesSize) + _declaration.getType()->getStorageSize();
-	if (newSize >= bigint(1) << 256)
-		BOOST_THROW_EXCEPTION(TypeError()
-			<< errinfo_comment("State variable does not fit in storage.")
-			<< errinfo_sourceLocation(_declaration.getLocation()));
-	m_stateVariablesSize = u256(newSize);
+	m_stateVariables[&_declaration] = make_pair(_storageOffset, _byteOffset);
 }
 
 void CompilerContext::startFunction(Declaration const& _function)
@@ -170,7 +168,7 @@ unsigned CompilerContext::currentToBaseStackOffset(unsigned _offset) const
 	return m_asm.deposit() - _offset - 1;
 }
 
-u256 CompilerContext::getStorageLocationOfVariable(const Declaration& _declaration) const
+pair<u256, unsigned> CompilerContext::getStorageLocationOfVariable(const Declaration& _declaration) const
 {
 	auto it = m_stateVariables.find(&_declaration);
 	solAssert(it != m_stateVariables.end(), "Variable not found in storage.");
diff --git a/libsolidity/CompilerContext.h b/libsolidity/CompilerContext.h
index 76923a77a..87f90d4c4 100644
--- a/libsolidity/CompilerContext.h
+++ b/libsolidity/CompilerContext.h
@@ -24,6 +24,7 @@
 
 #include <ostream>
 #include <stack>
+#include <utility>
 #include <libevmcore/Instruction.h>
 #include <libevmcore/Assembly.h>
 #include <libsolidity/ASTForward.h>
@@ -42,7 +43,7 @@ class CompilerContext
 {
 public:
 	void addMagicGlobal(MagicVariableDeclaration const& _declaration);
-	void addStateVariable(VariableDeclaration const& _declaration);
+	void addStateVariable(VariableDeclaration const& _declaration, u256 const& _storageOffset, unsigned _byteOffset);
 	void addVariable(VariableDeclaration const& _declaration, unsigned _offsetToCurrent = 0);
 	void removeVariable(VariableDeclaration const& _declaration);
 	void addAndInitializeVariable(VariableDeclaration const& _declaration);
@@ -82,7 +83,7 @@ public:
 	/// Converts an offset relative to the current stack height to a value that can be used later
 	/// with baseToCurrentStackOffset to point to the same stack element.
 	unsigned currentToBaseStackOffset(unsigned _offset) const;
-	u256 getStorageLocationOfVariable(Declaration const& _declaration) const;
+	std::pair<u256, unsigned> getStorageLocationOfVariable(Declaration const& _declaration) const;
 
 	/// Appends a JUMPI instruction to a new tag and @returns the tag
 	eth::AssemblyItem appendConditionalJump() { return m_asm.appendJumpI().tag(); }
@@ -144,10 +145,8 @@ private:
 	std::set<Declaration const*> m_magicGlobals;
 	/// Other already compiled contracts to be used in contract creation calls.
 	std::map<ContractDefinition const*, bytes const*> m_compiledContracts;
-	/// Size of the state variables, offset of next variable to be added.
-	u256 m_stateVariablesSize = 0;
 	/// Storage offsets of state variables
-	std::map<Declaration const*, u256> m_stateVariables;
+	std::map<Declaration const*, std::pair<u256, unsigned>> m_stateVariables;
 	/// Offsets of local variables on the stack (relative to stack base).
 	std::map<Declaration const*, unsigned> m_localVariables;
 	/// Labels pointing to the entry points of functions.
diff --git a/libsolidity/CompilerUtils.cpp b/libsolidity/CompilerUtils.cpp
index 5fc8bd8f2..511254fa5 100644
--- a/libsolidity/CompilerUtils.cpp
+++ b/libsolidity/CompilerUtils.cpp
@@ -199,7 +199,6 @@ unsigned CompilerUtils::loadFromMemoryHelper(Type const& _type, bool _fromCallda
 	return numBytes;
 }
 
-
 unsigned CompilerUtils::prepareMemoryStore(Type const& _type, bool _padToWordBoundaries) const
 {
 	unsigned numBytes = _type.getCalldataEncodedSize(_padToWordBoundaries);
diff --git a/libsolidity/ExpressionCompiler.cpp b/libsolidity/ExpressionCompiler.cpp
index 6f5331294..a0a688bbd 100644
--- a/libsolidity/ExpressionCompiler.cpp
+++ b/libsolidity/ExpressionCompiler.cpp
@@ -67,9 +67,10 @@ void ExpressionCompiler::appendStateVariableAccessor(VariableDeclaration const&
 		length += CompilerUtils(m_context).storeInMemory(length, *paramType, true);
 
 	// retrieve the position of the variable
-	m_context << m_context.getStorageLocationOfVariable(_varDecl);
-	TypePointer returnType = _varDecl.getType();
+	auto const& location = m_context.getStorageLocationOfVariable(_varDecl);
+	m_context << location.first;
 
+	TypePointer returnType = _varDecl.getType();
 	for (TypePointer const& paramType: paramTypes)
 	{
 		// move offset to memory
@@ -81,7 +82,6 @@ void ExpressionCompiler::appendStateVariableAccessor(VariableDeclaration const&
 		returnType = dynamic_cast<MappingType const&>(*returnType).getValueType();
 	}
 
-	m_context << u256(0); // @todo
 	unsigned retSizeOnStack = 0;
 	solAssert(accessorType.getReturnParameterTypes().size() >= 1, "");
 	if (StructType const* structType = dynamic_cast<StructType const*>(returnType.get()))
@@ -93,21 +93,20 @@ void ExpressionCompiler::appendStateVariableAccessor(VariableDeclaration const&
 		{
 			if (types[i]->getCategory() == Type::Category::Mapping)
 				continue;
-			m_context
-				<< eth::Instruction::DUP2 << structType->getStorageOffsetOfMember(names[i])
-				<< eth::Instruction::ADD;
-			m_context << u256(0); //@todo
+			pair<u256, unsigned> const& offsets = structType->getStorageOffsetsOfMember(names[i]);
+			m_context << eth::Instruction::DUP1 << u256(offsets.first) << eth::Instruction::ADD << u256(offsets.second);
 			StorageItem(m_context, *types[i]).retrieveValue(SourceLocation(), true);
 			solAssert(types[i]->getSizeOnStack() == 1, "Returning struct elements with stack size != 1 not yet implemented.");
-			m_context << eth::Instruction::SWAP2 << eth::Instruction::SWAP1;
+			m_context << eth::Instruction::SWAP1;
 			retSizeOnStack += types[i]->getSizeOnStack();
 		}
-		m_context << eth::Instruction::POP << eth::Instruction::POP;
+		m_context << eth::Instruction::POP;
 	}
 	else
 	{
 		// simple value
 		solAssert(accessorType.getReturnParameterTypes().size() == 1, "");
+		m_context << u256(location.second);
 		StorageItem(m_context, *returnType).retrieveValue(SourceLocation(), true);
 		retSizeOnStack = returnType->getSizeOnStack();
 	}
@@ -666,10 +665,9 @@ void ExpressionCompiler::endVisit(MemberAccess const& _memberAccess)
 	case Type::Category::Struct:
 	{
 		StructType const& type = dynamic_cast<StructType const&>(*_memberAccess.getExpression().getType());
-		m_context << eth::Instruction::POP; //@todo
-		m_context << type.getStorageOffsetOfMember(member) << eth::Instruction::ADD;
-		//@todo
-		m_context << u256(0);
+		m_context << eth::Instruction::POP; // structs always align to new slot
+		pair<u256, unsigned> const& offsets = type.getStorageOffsetsOfMember(member);
+		m_context << offsets.first << eth::Instruction::ADD << u256(offsets.second);
 		setLValueToStorageItem(_memberAccess);
 		break;
 	}
diff --git a/libsolidity/LValue.cpp b/libsolidity/LValue.cpp
index 8e618e87f..234072bce 100644
--- a/libsolidity/LValue.cpp
+++ b/libsolidity/LValue.cpp
@@ -77,7 +77,8 @@ void StackVariable::setToZero(SourceLocation const& _location, bool) const
 StorageItem::StorageItem(CompilerContext& _compilerContext, Declaration const& _declaration):
 	StorageItem(_compilerContext, *_declaration.getType())
 {
-	m_context << m_context.getStorageLocationOfVariable(_declaration) << u256(0);
+	auto const& location = m_context.getStorageLocationOfVariable(_declaration);
+	m_context << location.first << u256(location.second);
 }
 
 StorageItem::StorageItem(CompilerContext& _compilerContext, Type const& _type):
@@ -86,7 +87,6 @@ StorageItem::StorageItem(CompilerContext& _compilerContext, Type const& _type):
 	if (m_dataType.isValueType())
 	{
 		solAssert(m_dataType.getStorageSize() == m_dataType.getSizeOnStack(), "");
-		//@todo the meaning of getStorageSize() probably changes
 		solAssert(m_dataType.getStorageSize() == 1, "Invalid storage size.");
 	}
 }
@@ -98,12 +98,18 @@ void StorageItem::retrieveValue(SourceLocation const&, bool _remove) const
 		return; // no distinction between value and reference for non-value types
 	if (!_remove)
 		CompilerUtils(m_context).copyToStackTop(sizeOnStack(), sizeOnStack());
-	m_context
-		<< eth::Instruction::SWAP1 << eth::Instruction::SLOAD << eth::Instruction::SWAP1
-		<< u256(2) << eth::Instruction::EXP << eth::Instruction::SWAP1 << eth::Instruction::DIV;
-	//@todo higher order bits might be dirty. Is this bad?
-	//@todo this does not work for types that are left-aligned on the stack.
-	// make those types right-aligned?
+	if (m_dataType.getStorageBytes() == 32)
+		m_context << eth::Instruction::POP << eth::Instruction::SLOAD;
+	else
+	{
+		m_context
+			<< eth::Instruction::SWAP1 << eth::Instruction::SLOAD << eth::Instruction::SWAP1
+			<< u256(0x100) << eth::Instruction::EXP << eth::Instruction::SWAP1 << eth::Instruction::DIV;
+		if (m_dataType.getCategory() == Type::Category::FixedBytes)
+			m_context << (u256(0x1) << (256 - 8 * m_dataType.getStorageBytes())) << eth::Instruction::MUL;
+		else
+			m_context << ((u256(0x1) << (8 * m_dataType.getStorageBytes())) - 1) << eth::Instruction::AND;
+	}
 }
 
 void StorageItem::storeValue(Type const& _sourceType, SourceLocation const& _location, bool _move) const
@@ -111,12 +117,43 @@ void StorageItem::storeValue(Type const& _sourceType, SourceLocation const& _loc
 	// stack: value storage_key storage_offset
 	if (m_dataType.isValueType())
 	{
-		//@todo OR the value into the storage like it is done for ByteArrayElement
-		m_context
-			<< u256(2) << eth::Instruction::EXP << eth::Instruction::DUP3 << eth::Instruction::MUL
-			<< eth::Instruction::SWAP1 << eth::Instruction::SSTORE;
-		if (_move)
+		solAssert(m_dataType.getStorageBytes() <= 32, "Invalid storage bytes size.");
+		solAssert(m_dataType.getStorageBytes() > 0, "Invalid storage bytes size.");
+		if (m_dataType.getStorageBytes() == 32)
+		{
+			// offset should be zero
 			m_context << eth::Instruction::POP;
+			if (!_move)
+				m_context << eth::Instruction::DUP2 << eth::Instruction::SWAP1;
+			m_context << eth::Instruction::SSTORE;
+		}
+		else
+		{
+			// OR the value into the other values in the storage slot
+			m_context << u256(0x100) << eth::Instruction::EXP;
+			// stack: value storage_ref multiplier
+			// fetch old value
+			m_context << eth::Instruction::DUP2 << eth::Instruction::SLOAD;
+			// stack: value storege_ref multiplier old_full_value
+			// clear bytes in old value
+			m_context
+				<< eth::Instruction::DUP2 << ((u256(1) << (8 * m_dataType.getStorageBytes())) - 1)
+				<< eth::Instruction::MUL;
+			m_context << eth::Instruction::NOT << eth::Instruction::AND;
+			// stack: value storage_ref multiplier cleared_value
+			m_context
+				<< eth::Instruction::SWAP1 << eth::Instruction::DUP4;
+			// stack: value storage_ref cleared_value multiplier value
+			if (m_dataType.getCategory() == Type::Category::FixedBytes)
+				m_context
+					<< (u256(0x1) << (256 - 8 * dynamic_cast<FixedBytesType const&>(m_dataType).getNumBytes()))
+					<< eth::Instruction::SWAP1 << eth::Instruction::DIV;
+			m_context  << eth::Instruction::MUL << eth::Instruction::OR;
+			// stack: value storage_ref updated_value
+			m_context << eth::Instruction::SWAP1 << eth::Instruction::SSTORE;
+			if (_move)
+				m_context << eth::Instruction::POP;
+		}
 	}
 	else
 	{
@@ -134,28 +171,31 @@ void StorageItem::storeValue(Type const& _sourceType, SourceLocation const& _loc
 		else if (m_dataType.getCategory() == Type::Category::Struct)
 		{
 			// stack layout: source_ref source_offset target_ref target_offset
+			// note that we have structs, so offsets should be zero and are ignored
 			auto const& structType = dynamic_cast<StructType const&>(m_dataType);
 			solAssert(structType == _sourceType, "Struct assignment with conversion.");
 			for (auto const& member: structType.getMembers())
 			{
-				//@todo actually use offsets
 				// assign each member that is not a mapping
 				TypePointer const& memberType = member.second;
 				if (memberType->getCategory() == Type::Category::Mapping)
 					continue;
-				m_context << structType.getStorageOffsetOfMember(member.first)
-					<< eth::Instruction::DUP5 << eth::Instruction::DUP2 << eth::Instruction::ADD;
-				m_context << u256(0); // zero offset
-				// stack: source_ref source_off target_ref target_off member_offset source_member_ref source_member_off
+				pair<u256, unsigned> const& offsets = structType.getStorageOffsetsOfMember(member.first);
+				m_context
+					<< offsets.first << u256(offsets.second)
+					<< eth::Instruction::DUP6 << eth::Instruction::DUP3
+					<< eth::Instruction::ADD << eth::Instruction::DUP2;
+				// stack: source_ref source_off target_ref target_off member_slot_offset member_byte_offset source_member_ref source_member_off
 				StorageItem(m_context, *memberType).retrieveValue(_location, true);
 				// stack: source_ref source_off target_ref target_off member_offset source_value...
-				solAssert(2 + memberType->getSizeOnStack() <= 16, "Stack too deep.");
-				m_context << eth::dupInstruction(3 + memberType->getSizeOnStack())
-					<< eth::dupInstruction(2 + memberType->getSizeOnStack()) << eth::Instruction::ADD;
-				// stack: source_ref source_off target_ref target_off member_offset source_value... target_member_ref
-				m_context << u256(0); // zero offset
+				solAssert(4 + memberType->getSizeOnStack() <= 16, "Stack too deep.");
+				m_context
+					<< eth::dupInstruction(4 + memberType->getSizeOnStack())
+					<< eth::dupInstruction(3 + memberType->getSizeOnStack()) << eth::Instruction::ADD
+					<< eth::dupInstruction(2 + memberType->getSizeOnStack());
+				// stack: source_ref source_off target_ref target_off member_slot_offset member_byte_offset source_value... target_member_ref target_member_byte_off
 				StorageItem(m_context, *memberType).storeValue(*memberType, _location, true);
-				m_context << eth::Instruction::POP;
+				m_context << eth::Instruction::POP << eth::Instruction::POP;
 			}
 			if (_move)
 				m_context
@@ -185,6 +225,7 @@ void StorageItem::setToZero(SourceLocation const&, bool _removeReference) const
 	else if (m_dataType.getCategory() == Type::Category::Struct)
 	{
 		// stack layout: storage_key storage_offset
+		// @todo this can be improved for packed types
 		auto const& structType = dynamic_cast<StructType const&>(m_dataType);
 		for (auto const& member: structType.getMembers())
 		{
@@ -192,11 +233,10 @@ void StorageItem::setToZero(SourceLocation const&, bool _removeReference) const
 			TypePointer const& memberType = member.second;
 			if (memberType->getCategory() == Type::Category::Mapping)
 				continue;
-			// @todo actually use offset
+			pair<u256, unsigned> const& offsets = structType.getStorageOffsetsOfMember(member.first);
 			m_context
-				<< structType.getStorageOffsetOfMember(member.first)
-				<< eth::Instruction::DUP3 << eth::Instruction::ADD;
-			m_context << u256(0);
+				<< offsets.first << eth::Instruction::DUP3 << eth::Instruction::ADD
+				<< u256(offsets.second);
 			StorageItem(m_context, *memberType).setToZero();
 		}
 		if (_removeReference)
@@ -208,7 +248,28 @@ void StorageItem::setToZero(SourceLocation const&, bool _removeReference) const
 		// @todo actually use offset
 		if (!_removeReference)
 			CompilerUtils(m_context).copyToStackTop(sizeOnStack(), sizeOnStack());
-		m_context << eth::Instruction::POP << u256(0) << eth::Instruction::SWAP1 << eth::Instruction::SSTORE;
+		if (m_dataType.getStorageBytes() == 32)
+		{
+			// offset should be zero
+			m_context
+				<< eth::Instruction::POP << u256(0)
+				<< eth::Instruction::SWAP1 << eth::Instruction::SSTORE;
+		}
+		else
+		{
+			m_context << u256(0x100) << eth::Instruction::EXP;
+			// stack: storage_ref multiplier
+			// fetch old value
+			m_context << eth::Instruction::DUP2 << eth::Instruction::SLOAD;
+			// stack: storege_ref multiplier old_full_value
+			// clear bytes in old value
+			m_context
+				<< eth::Instruction::SWAP1 << ((u256(1) << (8 * m_dataType.getStorageBytes())) - 1)
+				<< eth::Instruction::MUL;
+			m_context << eth::Instruction::NOT << eth::Instruction::AND;
+			// stack: storage_ref cleared_value
+			m_context << eth::Instruction::SWAP1 << eth::Instruction::SSTORE;
+		}
 	}
 }
 
diff --git a/libsolidity/Types.cpp b/libsolidity/Types.cpp
index 500ae9b05..147eff1ec 100644
--- a/libsolidity/Types.cpp
+++ b/libsolidity/Types.cpp
@@ -35,54 +35,72 @@ namespace dev
 namespace solidity
 {
 
-std::pair<u256, unsigned> const* MemberList::getMemberStorageOffset(string const& _name) const
+void StorageOffsets::computeOffsets(TypePointers const& _types)
 {
-	if (!m_storageOffsets)
+	bigint slotOffset = 0;
+	unsigned byteOffset = 0;
+	map<size_t, pair<u256, unsigned>> offsets;
+	for (size_t i = 0; i < _types.size(); ++i)
 	{
-		bigint slotOffset = 0;
-		unsigned byteOffset = 0;
-		map<string, pair<u256, unsigned>> offsets;
-		for (auto const& nameAndType: m_memberTypes)
+		TypePointer const& type = _types[i];
+		if (!type->canBeStored())
+			continue;
+		if (byteOffset + type->getStorageBytes() > 32)
 		{
-			TypePointer const& type = nameAndType.second;
-			if (!type->canBeStored())
-				continue;
-			if (byteOffset + type->getStorageBytes() > 32)
-			{
-				// would overflow, go to next slot
-				++slotOffset;
-				byteOffset = 0;
-			}
-			if (slotOffset >= bigint(1) << 256)
-				BOOST_THROW_EXCEPTION(TypeError() << errinfo_comment("Object too large for storage."));
-			offsets[nameAndType.first] = make_pair(u256(slotOffset), byteOffset);
-			solAssert(type->getStorageSize() >= 1, "Invalid storage size.");
-			if (type->getStorageSize() == 1 && byteOffset + type->getStorageBytes() <= 32)
-				byteOffset += type->getStorageBytes();
-			else
-			{
-				slotOffset += type->getStorageSize();
-				byteOffset = 0;
-			}
-		}
-		if (byteOffset > 0)
+			// would overflow, go to next slot
 			++slotOffset;
+			byteOffset = 0;
+		}
 		if (slotOffset >= bigint(1) << 256)
 			BOOST_THROW_EXCEPTION(TypeError() << errinfo_comment("Object too large for storage."));
-		m_storageSize = u256(slotOffset);
-		m_storageOffsets.reset(new decltype(offsets)(move(offsets)));
+		offsets[i] = make_pair(u256(slotOffset), byteOffset);
+		solAssert(type->getStorageSize() >= 1, "Invalid storage size.");
+		if (type->getStorageSize() == 1 && byteOffset + type->getStorageBytes() <= 32)
+			byteOffset += type->getStorageBytes();
+		else
+		{
+			slotOffset += type->getStorageSize();
+			byteOffset = 0;
+		}
 	}
-	if (m_storageOffsets->count(_name))
-		return &((*m_storageOffsets)[_name]);
+	if (byteOffset > 0)
+		++slotOffset;
+	if (slotOffset >= bigint(1) << 256)
+		BOOST_THROW_EXCEPTION(TypeError() << errinfo_comment("Object too large for storage."));
+	m_storageSize = u256(slotOffset);
+	swap(m_offsets, offsets);
+}
+
+pair<u256, unsigned> const* StorageOffsets::getOffset(size_t _index) const
+{
+	if (m_offsets.count(_index))
+		return &m_offsets.at(_index);
 	else
 		return nullptr;
 }
 
+std::pair<u256, unsigned> const* MemberList::getMemberStorageOffset(string const& _name) const
+{
+	if (!m_storageOffsets)
+	{
+		TypePointers memberTypes;
+		memberTypes.reserve(m_memberTypes.size());
+		for (auto const& nameAndType: m_memberTypes)
+			memberTypes.push_back(nameAndType.second);
+		m_storageOffsets.reset(new StorageOffsets());
+		m_storageOffsets->computeOffsets(memberTypes);
+	}
+	for (size_t index = 0; index < m_memberTypes.size(); ++index)
+		if (m_memberTypes[index].first == _name)
+			return m_storageOffsets->getOffset(index);
+	return nullptr;
+}
+
 u256 const& MemberList::getStorageSize() const
 {
 	// trigger lazy computation
 	getMemberStorageOffset("");
-	return m_storageSize;
+	return m_storageOffsets->getStorageSize();
 }
 
 TypePointer Type::fromElementaryTypeName(Token::Value _typeToken)
@@ -830,18 +848,11 @@ MemberList const& StructType::getMembers() const
 	return *m_members;
 }
 
-u256 StructType::getStorageOffsetOfMember(string const& _name) const
+pair<u256, unsigned> const& StructType::getStorageOffsetsOfMember(string const& _name) const
 {
-
-	//@todo cache member offset?
-	u256 offset;
-	for (ASTPointer<VariableDeclaration> const& variable: m_struct.getMembers())
-	{
-		if (variable->getName() == _name)
-			return offset;
-		offset += variable->getType()->getStorageSize();
-	}
-	BOOST_THROW_EXCEPTION(InternalCompilerError() << errinfo_comment("Storage offset of non-existing member requested."));
+	auto const* offsets = getMembers().getMemberStorageOffset(_name);
+	solAssert(offsets, "Storage offset of non-existing member requested.");
+	return *offsets;
 }
 
 TypePointer EnumType::unaryOperatorResult(Token::Value _operator) const
diff --git a/libsolidity/Types.h b/libsolidity/Types.h
index 5e4970780..cc7a0e243 100644
--- a/libsolidity/Types.h
+++ b/libsolidity/Types.h
@@ -43,6 +43,26 @@ using TypePointer = std::shared_ptr<Type const>;
 using FunctionTypePointer = std::shared_ptr<FunctionType const>;
 using TypePointers = std::vector<TypePointer>;
 
+
+/**
+ * Helper class to compute storage offsets of members of structs and contracts.
+ */
+class StorageOffsets
+{
+public:
+	/// Resets the StorageOffsets objects and determines the position in storage for each
+	/// of the elements of @a _types.
+	void computeOffsets(TypePointers const& _types);
+	/// @returns the offset of the given member, might be null if the member is not part of storage.
+	std::pair<u256, unsigned> const* getOffset(size_t _index) const;
+	/// @returns the total number of slots occupied by all members.
+	u256 const& getStorageSize() const { return m_storageSize; }
+
+private:
+	u256 m_storageSize;
+	std::map<size_t, std::pair<u256, unsigned>> m_offsets;
+};
+
 /**
  * List of members of a type.
  */
@@ -71,8 +91,7 @@ public:
 
 private:
 	MemberMap m_memberTypes;
-	mutable u256 m_storageSize = 0;
-	mutable std::unique_ptr<std::map<std::string, std::pair<u256, unsigned>>> m_storageOffsets;
+	mutable std::unique_ptr<StorageOffsets> m_storageOffsets;
 };
 
 /**
@@ -411,7 +430,7 @@ public:
 
 	virtual MemberList const& getMembers() const override;
 
-	u256 getStorageOffsetOfMember(std::string const& _name) const;
+	std::pair<u256, unsigned> const& getStorageOffsetsOfMember(std::string const& _name) const;
 
 private:
 	StructDefinition const& m_struct;
diff --git a/test/SolidityEndToEndTest.cpp b/test/SolidityEndToEndTest.cpp
index de6f43b77..a07b78872 100644
--- a/test/SolidityEndToEndTest.cpp
+++ b/test/SolidityEndToEndTest.cpp
@@ -991,18 +991,20 @@ BOOST_AUTO_TEST_CASE(multiple_elementary_accessors)
 
 BOOST_AUTO_TEST_CASE(complex_accessors)
 {
-	char const* sourceCode = "contract test {\n"
-							 "  mapping(uint256 => bytes4) public to_string_map;\n"
-							 "  mapping(uint256 => bool) public to_bool_map;\n"
-							 "  mapping(uint256 => uint256) public to_uint_map;\n"
-							 "  mapping(uint256 => mapping(uint256 => uint256)) public to_multiple_map;\n"
-							 "  function test() {\n"
-							 "    to_string_map[42] = \"24\";\n"
-							 "    to_bool_map[42] = false;\n"
-							 "    to_uint_map[42] = 12;\n"
-							 "    to_multiple_map[42][23] = 31;\n"
-							 "  }\n"
-							 "}\n";
+	char const* sourceCode = R"(
+		contract test {
+			mapping(uint256 => bytes4) public to_string_map;
+			mapping(uint256 => bool) public to_bool_map;
+			mapping(uint256 => uint256) public to_uint_map;
+			mapping(uint256 => mapping(uint256 => uint256)) public to_multiple_map;
+			function test() {
+				to_string_map[42] = "24";
+				to_bool_map[42] = false;
+				to_uint_map[42] = 12;
+				to_multiple_map[42][23] = 31;
+			}
+		}
+	)";
 	compileAndRun(sourceCode);
 	BOOST_CHECK(callContractFunction("to_string_map(uint256)", 42) == encodeArgs("24"));
 	BOOST_CHECK(callContractFunction("to_bool_map(uint256)", 42) == encodeArgs(false));
@@ -3269,6 +3271,130 @@ BOOST_AUTO_TEST_CASE(constant_variables)
 	})";
 	compileAndRun(sourceCode);
 }
+
+BOOST_AUTO_TEST_CASE(packed_storage_structs_uint)
+{
+	char const* sourceCode = R"(
+		contract C {
+			struct str { uint8 a; uint16 b; uint248 c; }
+			str data;
+			function test() returns (uint) {
+				data.a = 2;
+				if (data.a != 2) return 2;
+				data.b = 0xabcd;
+				if (data.b != 0xabcd) return 3;
+				data.c = 0x1234567890;
+				if (data.c != 0x1234567890) return 4;
+				if (data.a != 2) return 5;
+				data.a = 8;
+				if (data.a != 8) return 6;
+				if (data.b != 0xabcd) return 7;
+				data.b = 0xdcab;
+				if (data.b != 0xdcab) return 8;
+				if (data.c != 0x1234567890) return 9;
+				data.c = 0x9876543210;
+				if (data.c != 0x9876543210) return 10;
+				return 1;
+			}
+		}
+	)";
+	compileAndRun(sourceCode);
+	BOOST_CHECK(callContractFunction("test()") == encodeArgs(1));
+}
+
+BOOST_AUTO_TEST_CASE(packed_storage_structs_enum)
+{
+	char const* sourceCode = R"(
+		contract C {
+			enum small { A, B, C, D }
+			enum larger { A, B, C, D, E}
+			struct str { small a; small b; larger c; larger d; }
+			str data;
+			function test() returns (uint) {
+				data.a = small.B;
+				if (data.a != small.B) return 2;
+				data.b = small.C;
+				if (data.b != small.C) return 3;
+				data.c = larger.D;
+				if (data.c != larger.D) return 4;
+				if (data.a != small.B) return 5;
+				data.a = small.C;
+				if (data.a != small.C) return 6;
+				if (data.b != small.C) return 7;
+				data.b = small.D;
+				if (data.b != small.D) return 8;
+				if (data.c != larger.D) return 9;
+				data.c = larger.B;
+				if (data.c != larger.B) return 10;
+				return 1;
+			}
+		}
+	)";
+	compileAndRun(sourceCode);
+	BOOST_CHECK(callContractFunction("test()") == encodeArgs(1));
+}
+
+BOOST_AUTO_TEST_CASE(packed_storage_structs_bytes)
+{
+	char const* sourceCode = R"(
+		contract C {
+			struct s1 { byte a; byte b; bytes10 c; bytes9 d; bytes10 e; }
+			struct s2 { byte a; s1 inner; byte b; byte c; }
+			byte x;
+			s2 data;
+			byte y;
+			function test() returns (bool) {
+				x = 1;
+				data.a = 2;
+				data.inner.a = 3;
+				data.inner.b = 4;
+				data.inner.c = "1234567890";
+				data.inner.d = "123456789";
+				data.inner.e = "abcdefghij";
+				data.b = 5;
+				data.c = 6;
+				y = 7;
+				return x == 1 && data.a == 2 && data.inner.a == 3 && data.inner.b == 4 &&
+					data.inner.c == "1234567890" && data.inner.d == "123456789" &&
+					data.inner.e == "abcdefghij" && data.b == 5 && data.c == 6 && y == 7;
+			}
+		}
+	)";
+	compileAndRun(sourceCode);
+	BOOST_CHECK(callContractFunction("test()") == encodeArgs(true));
+}
+
+BOOST_AUTO_TEST_CASE(packed_storage_structs_delete)
+{
+	char const* sourceCode = R"(
+		contract C {
+			struct str { uint8 a; uint16 b; uint8 c; }
+			uint8 x;
+			uint16 y;
+			str data;
+			function test() returns (uint) {
+				x = 1;
+				y = 2;
+				data.a = 2;
+				data.b = 0xabcd;
+				data.c = 0xfa;
+				if (x != 1 || y != 2 || data.a != 2 || data.b != 0xabcd || data.c != 0xfa)
+					return 2;
+				delete y;
+				delete data.b;
+				if (x != 1 || y != 0 || data.a != 2 || data.b != 0 || data.c != 0xfa)
+					return 3;
+				delete x;
+				delete data;
+				return 1;
+			}
+		}
+	)";
+	compileAndRun(sourceCode);
+	BOOST_CHECK(callContractFunction("test()") == encodeArgs(1));
+	BOOST_CHECK(m_state.storage(m_contractAddress).empty());
+}
+
 BOOST_AUTO_TEST_SUITE_END()
 
 }
diff --git a/test/SolidityOptimizer.cpp b/test/SolidityOptimizer.cpp
index 161d1f898..85b77d210 100644
--- a/test/SolidityOptimizer.cpp
+++ b/test/SolidityOptimizer.cpp
@@ -120,7 +120,7 @@ BOOST_AUTO_TEST_CASE(unused_expressions)
 				data;
 			}
 		})";
-	compileBothVersions(29, sourceCode);
+	compileBothVersions(36, sourceCode);
 	compareVersions("f()");
 }