diff --git a/components/esm/esmwriter.cpp b/components/esm/esmwriter.cpp
index 3ea6bd350a..a6aa82665a 100644
--- a/components/esm/esmwriter.cpp
+++ b/components/esm/esmwriter.cpp
@@ -2,185 +2,182 @@
 
 #include <cassert>
 #include <fstream>
-#include <iostream>
-
-bool count = true;
+#include <stdexcept>
 
 namespace ESM
 {
+    ESMWriter::ESMWriter() : mRecordCount (0), mCounting (false) {}
 
-int ESMWriter::getVersion()
-{
-    return mHeader.mData.version;
-}
-
-void ESMWriter::setVersion(int ver)
-{
-    mHeader.mData.version = ver;
-}
-
-void ESMWriter::setAuthor(const std::string& auth)
-{
-    mHeader.mData.author.assign (auth);
-}
-
-void ESMWriter::setDescription(const std::string& desc)
-{
-    mHeader.mData.desc.assign (desc);
-}
-
-void ESMWriter::setRecordCount (int count)
-{
-    mHeader.mData.records = count;
-}
-
-void ESMWriter::setFormat (int format)
-{
-    mHeader.mFormat = format;
-}
-
-void ESMWriter::addMaster(const std::string& name, uint64_t size)
-{
-    Header::MasterData d;
-    d.name = name;
-    d.size = size;
-    mHeader.mMaster.push_back(d);
-}
-
-void ESMWriter::save(const std::string& file)
-{
-    std::ofstream fs(file.c_str(), std::ios_base::out | std::ios_base::trunc);
-    save(fs);
-}
-
-void ESMWriter::save(std::ostream& file)
-{
-    m_recordCount = 0;
-    m_stream = &file;
-
-    startRecord("TES3", 0);
-
-    mHeader.save (*this);
-
-    endRecord("TES3");
-}
-
-void ESMWriter::close()
-{
-    m_stream->flush();
-
-    if (!m_records.empty())
-        throw "Unclosed record remaining";
-}
-
-void ESMWriter::startRecord(const std::string& name, uint32_t flags)
-{
-    m_recordCount++;
-
-    writeName(name);
-    RecordData rec;
-    rec.name = name;
-    rec.position = m_stream->tellp();
-    rec.size = 0;
-    writeT<int>(0); // Size goes here
-    writeT<int>(0); // Unused header?
-    writeT(flags);
-    m_records.push_back(rec);
-
-    assert(m_records.back().size == 0);
-}
-
-void ESMWriter::startSubRecord(const std::string& name)
-{
-    writeName(name);
-    RecordData rec;
-    rec.name = name;
-    rec.position = m_stream->tellp();
-    rec.size = 0;
-    writeT<int>(0); // Size goes here
-    m_records.push_back(rec);
-
-    assert(m_records.back().size == 0);
-}
-
-void ESMWriter::endRecord(const std::string& name)
-{
-    RecordData rec = m_records.back();
-    assert(rec.name == name);
-    m_records.pop_back();
-
-    m_stream->seekp(rec.position);
-
-    count = false;
-    write((char*)&rec.size, sizeof(int));
-    count = true;
-
-    m_stream->seekp(0, std::ios::end);
-
-}
-
-void ESMWriter::writeHNString(const std::string& name, const std::string& data)
-{
-    startSubRecord(name);
-    writeHString(data);
-    endRecord(name);
-}
-
-void ESMWriter::writeHNString(const std::string& name, const std::string& data, size_t size)
-{
-    assert(data.size() <= size);
-    startSubRecord(name);
-    writeHString(data);
-
-    if (data.size() < size)
+    unsigned int ESMWriter::getVersion() const
     {
-        for (size_t i = data.size(); i < size; ++i)
-            write("\0",1);
+        return mHeader.mData.version;
     }
 
-    endRecord(name);
-}
-
-void ESMWriter::writeHString(const std::string& data)
-{
-    if (data.size() == 0)
-        write("\0", 1);
-    else
+    void ESMWriter::setVersion(unsigned int ver)
     {
-        // Convert to UTF8 and return
-        std::string ascii = m_encoder->getLegacyEnc(data);
-
-        write(ascii.c_str(), ascii.size());
-    }
-}
-
-void ESMWriter::writeHCString(const std::string& data)
-{
-    writeHString(data);
-    if (data.size() > 0 && data[data.size()-1] != '\0')
-        write("\0", 1);
-}
-
-void ESMWriter::writeName(const std::string& name)
-{
-    assert((name.size() == 4 && name[3] != '\0'));
-    write(name.c_str(), name.size());
-}
-
-void ESMWriter::write(const char* data, size_t size)
-{
-    if (count && !m_records.empty())
-    {
-        for (std::list<RecordData>::iterator it = m_records.begin(); it != m_records.end(); ++it)
-            it->size += size;
+        mHeader.mData.version = ver;
     }
 
-    m_stream->write(data, size);
-}
+    void ESMWriter::setAuthor(const std::string& auth)
+    {
+        mHeader.mData.author.assign (auth);
+    }
 
-void ESMWriter::setEncoder(ToUTF8::Utf8Encoder* encoder)
-{
-    m_encoder = encoder;
-}
+    void ESMWriter::setDescription(const std::string& desc)
+    {
+        mHeader.mData.desc.assign (desc);
+    }
 
+    void ESMWriter::setRecordCount (int count)
+    {
+        mHeader.mData.records = count;
+    }
+
+    void ESMWriter::setFormat (int format)
+    {
+        mHeader.mFormat = format;
+    }
+
+    void ESMWriter::addMaster(const std::string& name, uint64_t size)
+    {
+        Header::MasterData d;
+        d.name = name;
+        d.size = size;
+        mHeader.mMaster.push_back(d);
+    }
+
+    void ESMWriter::save(const std::string& file)
+    {
+        std::ofstream fs(file.c_str(), std::ios_base::out | std::ios_base::trunc);
+        save(fs);
+    }
+
+    void ESMWriter::save(std::ostream& file)
+    {
+        mRecordCount = 0;
+        mRecords.clear();
+        mStream = &file;
+
+        startRecord("TES3", 0);
+
+        mHeader.save (*this);
+
+        endRecord("TES3");
+    }
+
+    void ESMWriter::close()
+    {
+        if (!mRecords.empty())
+            throw std::runtime_error ("Unclosed record remaining");
+    }
+
+    void ESMWriter::startRecord(const std::string& name, uint32_t flags)
+    {
+        mRecordCount++;
+
+        writeName(name);
+        RecordData rec;
+        rec.name = name;
+        rec.position = mStream->tellp();
+        rec.size = 0;
+        writeT<int>(0); // Size goes here
+        writeT<int>(0); // Unused header?
+        writeT(flags);
+        mRecords.push_back(rec);
+
+        assert(mRecords.back().size == 0);
+    }
+
+    void ESMWriter::startSubRecord(const std::string& name)
+    {
+        writeName(name);
+        RecordData rec;
+        rec.name = name;
+        rec.position = mStream->tellp();
+        rec.size = 0;
+        writeT<int>(0); // Size goes here
+        mRecords.push_back(rec);
+
+        assert(mRecords.back().size == 0);
+    }
+
+    void ESMWriter::endRecord(const std::string& name)
+    {
+        RecordData rec = mRecords.back();
+        assert(rec.name == name);
+        mRecords.pop_back();
+
+        mStream->seekp(rec.position);
+
+        mCounting = false;
+        write (reinterpret_cast<const char*> (&rec.size), sizeof(int));
+        mCounting = true;
+
+        mStream->seekp(0, std::ios::end);
+
+    }
+
+    void ESMWriter::writeHNString(const std::string& name, const std::string& data)
+    {
+        startSubRecord(name);
+        writeHString(data);
+        endRecord(name);
+    }
+
+    void ESMWriter::writeHNString(const std::string& name, const std::string& data, size_t size)
+    {
+        assert(data.size() <= size);
+        startSubRecord(name);
+        writeHString(data);
+
+        if (data.size() < size)
+        {
+            for (size_t i = data.size(); i < size; ++i)
+                write("\0",1);
+        }
+
+        endRecord(name);
+    }
+
+    void ESMWriter::writeHString(const std::string& data)
+    {
+        if (data.size() == 0)
+            write("\0", 1);
+        else
+        {
+            // Convert to UTF8 and return
+            std::string ascii = mEncoder->getLegacyEnc(data);
+
+            write(ascii.c_str(), ascii.size());
+        }
+    }
+
+    void ESMWriter::writeHCString(const std::string& data)
+    {
+        writeHString(data);
+        if (data.size() > 0 && data[data.size()-1] != '\0')
+            write("\0", 1);
+    }
+
+    void ESMWriter::writeName(const std::string& name)
+    {
+        assert((name.size() == 4 && name[3] != '\0'));
+        write(name.c_str(), name.size());
+    }
+
+    void ESMWriter::write(const char* data, size_t size)
+    {
+        if (mCounting && !mRecords.empty())
+        {
+            for (std::list<RecordData>::iterator it = mRecords.begin(); it != mRecords.end(); ++it)
+                it->size += size;
+        }
+
+        mStream->write(data, size);
+    }
+
+    void ESMWriter::setEncoder(ToUTF8::Utf8Encoder* encoder)
+    {
+        mEncoder = encoder;
+    }
 }
diff --git a/components/esm/esmwriter.hpp b/components/esm/esmwriter.hpp
index be3ae33abe..b0925463a0 100644
--- a/components/esm/esmwriter.hpp
+++ b/components/esm/esmwriter.hpp
@@ -13,92 +13,101 @@ namespace ESM {
 
 class ESMWriter
 {
-    struct RecordData
-    {
-        std::string name;
-        std::streampos position;
-        size_t size;
+        struct RecordData
+        {
+            std::string name;
+            std::streampos position;
+            size_t size;
+        };
+
+    public:
+
+        ESMWriter();
+
+        unsigned int getVersion() const;
+        void setVersion(unsigned int ver = 0x3fa66666);
+        void setEncoder(ToUTF8::Utf8Encoder *encoding);
+        void setAuthor(const std::string& author);
+        void setDescription(const std::string& desc);
+        void setRecordCount (int count);
+        void setFormat (int format);
+
+        void addMaster(const std::string& name, uint64_t size);
+
+        void save(const std::string& file);
+        ///< Start saving a file by writing the TES3 header.
+
+        void save(std::ostream& file);
+        ///< Start saving a file by writing the TES3 header.
+
+        void close();
+        ///< \note Does not close the stream.
+
+        void writeHNString(const std::string& name, const std::string& data);
+        void writeHNString(const std::string& name, const std::string& data, size_t size);
+        void writeHNCString(const std::string& name, const std::string& data)
+        {
+            startSubRecord(name);
+            writeHCString(data);
+            endRecord(name);
+        }
+        void writeHNOString(const std::string& name, const std::string& data)
+        {
+            if (!data.empty())
+                writeHNString(name, data);
+        }
+        void writeHNOCString(const std::string& name, const std::string& data)
+        {
+            if (!data.empty())
+                writeHNCString(name, data);
+        }
+
+        template<typename T>
+        void writeHNT(const std::string& name, const T& data)
+        {
+            startSubRecord(name);
+            writeT(data);
+            endRecord(name);
+        }
+
+        template<typename T>
+        void writeHNT(const std::string& name, const T& data, int size)
+        {
+            startSubRecord(name);
+            writeT(data, size);
+            endRecord(name);
+        }
+
+        template<typename T>
+        void writeT(const T& data)
+        {
+            write((char*)&data, sizeof(T));
+        }
+
+        template<typename T>
+        void writeT(const T& data, size_t size)
+        {
+            write((char*)&data, size);
+        }
+
+        void startRecord(const std::string& name, uint32_t flags);
+        void startSubRecord(const std::string& name);
+        void endRecord(const std::string& name);
+        void writeHString(const std::string& data);
+        void writeHCString(const std::string& data);
+        void writeName(const std::string& data);
+        void write(const char* data, size_t size);
+
+    private:
+        std::list<RecordData> mRecords;
+        std::ostream* mStream;
+        std::streampos mHeaderPos;
+        ToUTF8::Utf8Encoder* mEncoder;
+        int mRecordCount;
+        bool mCounting;
+
+        Header mHeader;
     };
-
-public:
-    int getVersion();
-    void setVersion(int ver);
-    void setEncoder(ToUTF8::Utf8Encoder *encoding); // Write strings as UTF-8?
-    void setAuthor(const std::string& author);
-    void setDescription(const std::string& desc);
-    void setRecordCount (int count);
-    void setFormat (int format);
-
-    void addMaster(const std::string& name, uint64_t size);
-
-    void save(const std::string& file);
-    void save(std::ostream& file);
-    void close();
-
-    void writeHNString(const std::string& name, const std::string& data);
-    void writeHNString(const std::string& name, const std::string& data, size_t size);
-    void writeHNCString(const std::string& name, const std::string& data)
-    {
-        startSubRecord(name);
-        writeHCString(data);
-        endRecord(name);
-    }
-    void writeHNOString(const std::string& name, const std::string& data)
-    {
-        if (!data.empty())
-            writeHNString(name, data);
-    }
-    void writeHNOCString(const std::string& name, const std::string& data)
-    {
-        if (!data.empty())
-            writeHNCString(name, data);
-    }
-
-    template<typename T>
-    void writeHNT(const std::string& name, const T& data)
-    {
-        startSubRecord(name);
-        writeT(data);
-        endRecord(name);
-    }
-
-    template<typename T>
-    void writeHNT(const std::string& name, const T& data, int size)
-    {
-        startSubRecord(name);
-        writeT(data, size);
-        endRecord(name);
-    }
-
-    template<typename T>
-    void writeT(const T& data)
-    {
-        write((char*)&data, sizeof(T));
-    }
-
-    template<typename T>
-    void writeT(const T& data, size_t size)
-    {
-        write((char*)&data, size);
-    }
-
-    void startRecord(const std::string& name, uint32_t flags);
-    void startSubRecord(const std::string& name);
-    void endRecord(const std::string& name);
-    void writeHString(const std::string& data);
-    void writeHCString(const std::string& data);
-    void writeName(const std::string& data);
-    void write(const char* data, size_t size);
-
-private:
-    std::list<RecordData> m_records;
-    std::ostream* m_stream;
-    std::streampos m_headerPos;
-    ToUTF8::Utf8Encoder* m_encoder;
-    int m_recordCount;
-
-    Header mHeader;
-};
-
 }
+
 #endif
diff --git a/components/esm/loadtes3.hpp b/components/esm/loadtes3.hpp
index b73a4c31e4..5614d295f6 100644
--- a/components/esm/loadtes3.hpp
+++ b/components/esm/loadtes3.hpp
@@ -24,7 +24,7 @@ namespace ESM
                 versions are 1.2 and 1.3. These correspond to:
                 1.2 = 0x3f99999a and 1.3 = 0x3fa66666
             */
-            int version;
+            unsigned int version;
             int type;           // 0=esp, 1=esm, 32=ess (unused)
             NAME32 author;      // Author's name
             NAME256 desc;       // File description