How to switch from one sided to two sided document?

Question

I have been writing a thesis that is currently in one sided layout, but I would like to switch everything except for contents, abstract, acknowledgement and dedication into two sided layout. Is it possible? Here is a simple document that uses my current preamble

 \documentclass[11pt,a4paper,oneside]{report} 
 \usepackage[pdftex]{graphicx}
 \usepackage[T1]{fontenc} 
 \usepackage{fouriernc}
 \usepackage{mathtools}
 \usepackage{amsfonts,amsmath,amssymb,amsthm} 
 \usepackage[a4paper, hmargin={3.5cm,3cm}, vmargin={2.5cm,2.5cm}]{geometry} 
 \usepackage{multicol}
 \usepackage{chngcntr} % reset footnote for each chapter
 \usepackage{fancyhdr} % headline
 \usepackage{enumerate}
 \usepackage{wasysym} % symbols
 \usepackage{faktor}%for factor rings 
 \usepackage{ marvosym }
 \usepackage{ragged2e}
 \usepackage{blindtext}
 %%-------------------footnotes-------------------------------------
 \counterwithout{footnote}{chapter}% reset footnote for each chapter
 \usepackage[hang]{footmisc} %align text of footnotes
 \setlength{\footnotesep}{0.4cm}
 %---------------------note--------------------------------------
 \newtheoremstyle{note}% hnamei 
    {3pt}% hSpace abovei 
    {3pt}% hSpace belowi note
    {}% hBody fonti 
    {}% hIndent amounti1
    {\itshape}% hTheorem head fonti 
    {\spacedlowsmallcaps}%
    {:}% hPunctuation after theorem headi 
    {.5em}% hSpace after theorem headi2
    {}%
  \theoremstyle{note}
 \newtheorem{note}{Definition}
 %------------------------theorem-------------------------------
 \theoremstyle{plain}
 \newtheorem{thm}{Theorem}[chapter] % reset theorem numbering for each    chapter
 \newtheorem{defn}[thm]{Definition} % definition numbers are dependent on    theorem numbers
 \newtheorem{exmp}[thm]{Example}
 \newtheorem{cor}[thm]{Corollary}
 \newtheorem{lem}[thm]{Lemma}
 \newtheorem{prop}[thm]{Proposition}
 \renewcommand\arraystretch{1.2}
 \DeclareMathOperator{\disc}{disc}
 \DeclareMathOperator{\order}{\mathcal{O}_{K}} 
 \DeclareMathOperator{\z}{\mathbf{Z}} 
 \DeclareMathOperator{\q}{\mathbf{Q}} 
 \DeclareMathOperator{\C}{\mathbf{C}}
 \DeclarePairedDelimiter{\Span}{\langle}{\rangle}
 \DeclarePairedDelimiter{\bs}{\lvert}{\rvert}
 \DeclareMathOperator{\discr}{disc}
 %--------------------proof-------------------------------------
 \newcommand\prosto{\rule{1ex}{2.6ex}}
 \renewcommand\qedsymbol{\prosto}
 \makeatletter % ''proof''from italic to bold
 \renewenvironment{proof}[1][\proofname]{\par
 \pushQED{\qed}%
 \normalfont \topsep6\p@\@plus6\p@\relax
 \trivlist
 \item[\hskip\labelsep
    \bfseries
 #1\@addpunct{.}]\ignorespaces
 }{%
 \popQED\endtrivlist\@endpefalse
 }
 \makeatother
 %-------------------headline-------------------------------
 \pagestyle{fancy}
 \lhead{\empty} %left headline
 \rhead{\normalfont \small \itshape \rightmark} 
 \cfoot{\empty} 
 \rfoot{\thepage}
 \renewcommand{\chaptermark}[1]{\markboth{#1}{}}
 \renewcommand{\sectionmark}[1]{\markright{\thesection\ #1}}
 \fancypagestyle{plain}{\fancyhead{}\renewcommand{\headrulewidth}{0pt}} 
 \def\headrulewidth{0pt} 
 \setlength{\headheight}{14pt} 
 %-------------------------------------------------------------
 \usepackage[pdftex]{hyperref}

 \begin{document}
 \chapter{1}
 \blindtext
 \blindtext
 \chapter{2}
 \blindtext
 \blindtext
 \section{1}
 \blindtext
 \blindtext
 \end{document} 

Answer 1

It can be done by switching off the boolean @twoside for the front matter. However, it is not to be recommended.

\documentclass[11pt,a4paper,twoside]{book} 
\usepackage[pdftex]{graphicx}
\usepackage[T1]{fontenc} 
\usepackage{fouriernc}
\usepackage{mathtools}
\usepackage{amsfonts,amsmath,amssymb,amsthm} 
\usepackage[a4paper, hmargin={3.5cm,3cm}, vmargin={2.5cm,2.5cm}]{geometry} 
\usepackage{multicol}
\usepackage{chngcntr} % reset footnote for each chapter
\usepackage{fancyhdr} % headline
\usepackage{enumerate}
\usepackage{wasysym} % symbols
\usepackage{faktor}%for factor rings 
\usepackage{ marvosym }
\usepackage{ragged2e}
\usepackage{blindtext}
%%-------------------footnotes-------------------------------------
\counterwithout{footnote}{chapter}% reset footnote for each chapter
\usepackage[hang]{footmisc} %align text of footnotes
\setlength{\footnotesep}{0.4cm}
%---------------------note--------------------------------------
\newtheoremstyle{note}% hnamei 
   {3pt}% hSpace abovei 
   {3pt}% hSpace belowi note
   {}% hBody fonti 
   {}% hIndent amounti1
   {\itshape}% hTheorem head fonti 
   {\spacedlowsmallcaps}%
   {:}% hPunctuation after theorem headi 
   {.5em}% hSpace after theorem headi2
   {}%
 \theoremstyle{note}
\newtheorem{note}{Definition}
%------------------------theorem-------------------------------
\theoremstyle{plain}
\newtheorem{thm}{Theorem}[chapter] % reset theorem numbering for each    chapter
\newtheorem{defn}[thm]{Definition} % definition numbers are dependent on    theorem numbers
\newtheorem{exmp}[thm]{Example}
\newtheorem{cor}[thm]{Corollary}
\newtheorem{lem}[thm]{Lemma}
\newtheorem{prop}[thm]{Proposition}
\renewcommand\arraystretch{1.2}
\DeclareMathOperator{\disc}{disc}
\DeclareMathOperator{\order}{\mathcal{O}_{K}} 
\DeclareMathOperator{\z}{\mathbf{Z}} 
\DeclareMathOperator{\q}{\mathbf{Q}} 
\DeclareMathOperator{\C}{\mathbf{C}}
\DeclarePairedDelimiter{\Span}{\langle}{\rangle}
\DeclarePairedDelimiter{\bs}{\lvert}{\rvert}
\DeclareMathOperator{\discr}{disc}
%--------------------proof-------------------------------------
\newcommand\prosto{\rule{1ex}{2.6ex}}
\renewcommand\qedsymbol{\prosto}
\makeatletter % ''proof''from italic to bold
\renewenvironment{proof}[1][\proofname]{\par
\pushQED{\qed}%
\normalfont \topsep6\p@\@plus6\p@\relax
\trivlist
\item[\hskip\labelsep
   \bfseries
#1\@addpunct{.}]\ignorespaces
}{%
\popQED\endtrivlist\@endpefalse
}
\makeatother
%-------------------headline-------------------------------
\pagestyle{fancy}
\lhead{\empty} %left headline
\rhead{\normalfont \small \itshape \rightmark} 
\cfoot{\empty} 
\rfoot{\thepage}
\renewcommand{\chaptermark}[1]{\markboth{#1}{}}
\renewcommand{\sectionmark}[1]{\markright{\thesection\ #1}}
\fancypagestyle{plain}{\fancyhead{}\renewcommand{\headrulewidth}{0pt}} 
\def\headrulewidth{0pt} 
\setlength{\headheight}{14pt} 
%-------------------------------------------------------------
\usepackage[pdftex]{hyperref}

\begin{document}
\frontmatter
\begingroup
\makeatletter
\@twosidefalse
\makeatother

\chapter*{Preface}
\blindtext

\tableofcontents

\endgroup

\mainmatter
\chapter{1}
\blindtext
\blindtext
\chapter{2}
\blindtext
\blindtext
\section{1}
\blindtext
\blindtext
\end{document} 

Here I have changed the class to book that has a two sided scheme, and introduced the subdivisions \frontmatter and \mainmatter (references etc. should be in \backmatter). The front matter material is put in a group where \@twosidefalse has been issued at the beginning.

Answer 2

The same problem for me was fixed by this workaround

\documentclass[11pt,a4paper,twoside]{book} % Start the document with two-sided option     
\usepackage{ifthen}

% Some code

\setboolean{@twoside}{false} % Temporarily move to one-sided mode

% One-sided matter
% ...

\setboolean{@twoside}{true} % Move back to two-sided mode

% General matter
% ...

Edit:

As mentioned in the comments it is not really advisable as (1) ifthen package is supposedly obsolete and (2) having both oneside and twoside alignments in the same file is generally not recommended as it gives a document that is inconsistent and not printer-friendly.

The only reason I had to do this is that this was a constraint imposed by my University to have both one-sided front-matter and two-sided main-matter in the same PDF book; which is exactly what the question specified.